ESTHETIC EXAMINATION

• Face: shape/morphology/profi le/symmetry
• Smile line
• Midline
• Maxillary central incisors’ edge position
• Maxillary occlusal plane
• Intradental proportion
• Maxillary gingival level
• Interdental proportion
• Mandibular occlusal plane
• Tooth shade/gingival shade

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Face

Facial evaluation is a fundamental step in any esthetic treatment to identify significant asymmetries or disharmonies that may interfere with treatment planning¹ and analyze the shape of the face to plan a pleasant smile.

To evaluate the frontal and lateral angles, the dentist should assume a position that is at the same height as the patient and in front of their face, in an upright position. If the dentist and the patient are of significantly different heights, both can sit on stools with adjustable heights. The patient should be oriented to look forward toward the horizon, as with the natural head position during daily activities². It is recommended to use frontal [Figure 2-04A–C] and lateral [Figure 2-05A,B] view photographs as well as videos to record the esthetic aspects that can help the diagnosis and treatment planning, to significantly improve communication with the patient, and to help them to understand the identified problems [Figure 2-04A–C].

[Figure 2-04A–C] The dentofacial esthetic analysis is performed with the patient upright, looking at the horizon. Ideally, the faces of the patient and the dentist should be on the same level. As essential facial photographs for esthetic analysis, we suggest three frontal view photographs – one with the lips at rest, one with a posed smile, and one with a wide smile.

[Figure 2-05A,B] Lateral view photographs with the lips at rest and a posed smile are suggested to complement the dentofacial esthetic analysis.

During the esthetic analysis of the patient’s face and smile, horizontal and vertical lines should be drawn on the photographs to be used as reference planes for an objective evaluation. In the frontal view, it is suggested to draw horizontal lines through the trichion (hairline), glabella, subnasale point, and menton^1,3–5. The interpupillary line and the intercommisural line will also be determined with a dashed line to enable the horizontal alignment of the photograph [Figures 2-06 and 2-07].

[Figure 2-06] Horizontal lines are determined on the frontal view photograph of the patient’s face for facial analysis to verify the harmony between the facial thirds and to identify dentofacial anomalies.

[Figure 2-07] A critical esthetic parameter to be observed during clinical and photographic evaluation is the parallelism of the interpupillary line with the occlusal plane. When this does not occur, a complete analysis should be carried out to verify whether the discrepancy is the interpupillary line, the occlusal plane, or both. If misalignment exists between these lines, a combination of horizontal reference lines, such as the ophriac, interalar, and intercommissural lines, should be used as a parameter. A mock-up or temporary restoration is recommended to confirm the harmony of the planned smile.

After determining the horizontal lines, the face will be divided into three sections, as follows:

Upper third: distance from trichion to the glabella.

Middle third: distance from the glabella to the subnasale point.

Lower third: distance from the subnasale point to the menton.

The lower third can be subdivided into upper and lower portions. The upper portion extends from the subnasale point to the oral commissure, and the lower portion from the oral commissure to the menton. There is usually a 1:2 ratio between these portions [Figure 2-08A–D].

[Figure 2-08A–D] Clinical cases in which there is a lack of parallelism between the interpupillary line, intercommissural line, and occlusal plane. Resolution via restorative treatment [A,B]. Resolution via orthodontic treatment and orthognathic surgery [C,D]. (Case courtesy of Dr. Marcos Pitta.)

This facial “sectioning” enables the detection of facial asymmetries. Abnormalities identified in the upper third of the face are often related to craniofacial syndromes. The symmetry of the eyes, nose, cheeks, and ears is generally observed in the middle third of the face. The lower third is the most relevant for the dentist, as it is where changes can be made through orthodontic, orthognathic, restorative, and orofacial harmonization treatments. Vertical or horizontal discrepancies in skeletal development or a reduction in the vertical dimension of occlusion (VDO) can be observed.

After drawing the horizontal lines, the midline of the face is drawn using the glabella, the philtrum, and the menton as references [Figure 2-09]. The facial midline analysis allows the assessment of horizontal symmetry between the right and left sides of the patient’s face. Horizontal asymmetries were found in 52.4% of individuals¹. Significantly asymmetrical faces may be associated with growth anomalies, developmental anomalies, or pathologies. Such cases should be evaluated with special attention and additional diagnostic tests, if necessary. As a biometric parameter, the facial midline is perpendicular to the interpupillary line in approximately 70% of cases^6,7.

[Figure 2-09] Position of the facial midline: the center of the glabella, the philtrum, and the menton are the references.

It is recommended to evaluate the patient’s facial morphology⁸ as it can influence treatment planning. Patients can be brachyfacial, dolichofacial, or mesiofacial^9–12. Brachyfacial individuals generally have a short lower third of the face, a long mandibular ramus, pronounced masseters, and wide dental arches. They may present a deep overbite. In the sagittal view, they present a reduced distance from the nasal base to the menton. Additionally, the base of the mandible is almost parallel to the ground due to a smaller gonial angle¹³ [Figure 2-10A,B].

[Figure 2-10A,B] Patient with brachyfacial morphology: lower third of the face with a short appearance, long mandibular ramus, and pronounced masseters are common features in these individuals.

On the other hand, dolichofacial individuals present an elongated lower third of the face, with a short mandibular ramus, masseters that are not very pronounced, and narrow dental arches. They may present an anterior open bite and inadequate functional guidance [Figure 2-11A,B]. In the sagittal view, the base of the mandible is inclined due to an obtuse gonial angle. Such patients may require a reduction of the VDO by occlusal adjustment, orthodontics, or orthognathic surgery. Mesiofacial individuals represent an intermediate and balanced pattern of the above characteristics. Radiographic or cephalometric tests can be requested to properly diagnose the facial morphology.

[Figure 2-11A,B] Patient with dolichofacial morphology: an elongated lower third of the face, short mandibular ramus, and masseters that are not very pronounced are observed in these individuals.

Determining the magnitude, frequency, duration, distribution, and direction of the occlusal forces to which the teeth or restorations will be submitted is fundamental to defining the treatment risks. Clinical studies have shown a correlation between facial morphology and the patient’s bite force^14–17. Brachyfacial individuals can present intense bite forces, three to four times higher than dolichofacial individuals¹⁴. The long mandibular ramus and acute gonial angle in brachyfacial individuals suggest a mechanical advantage for the mandibular elevator muscles^14–16,18, amplifying the forces that act on the stomatognathic system.

Facial evaluation in the sagittal view is also recommended to analyze the anteroposterior relationship between the maxilla and mandible. In addition, it allows the definition of the patient’s profile from the facial contour angle resulting from the intersection of two straight lines: the first from the glabella to the subnasale point, and the second from the subnasale point to the chin (soft tissue pogonion)^19,20.

A typical angle between these lines is from 165 to 175 degrees [Figure 2-12A]. Angles less than 165 degrees denote convex facial profiles [Figure 2-12B], and those greater than 180 degrees denote concave profiles [Figure 2-12C]. These anteroposterior discrepancies should be confirmed by complementary facial analysis, combined with a thorough cephalometric study and evaluation with an orthodontist or oral surgeon to verify the dental or skeletal factors that need to be addressed.

[Figure 2-12A–C] Patient profile type determined according to the angle of the facial contour formed by the intersection of two straight lines: the first from the glabella to the subnasale point, and the second from the subnasale point to the chin: normal [A]; convex [B]; concave [C]. A typical angle between these lines is from 165 to 175 degrees. Angles less than 165 degrees denote convex facial profiles, and those greater than 180 degrees denote concave facial profiles [A–C].

For example, a patient with significant overjet of the anterior teeth but with facial proportions and a facial contour angle within the normal range should generally not require orthognathic surgery. On the other hand, angles less than 165 degrees suggest maxillary protrusion or mandibular retrusion, characteristic of Angle Class II patients. This information and the dental issues mentioned may suggest a need for orthognathic surgery [Figure 2-13A–D]. Angles greater than 180 degrees suggest maxillary retrusion or mandibular protrusion, characteristic of Angle Class III patients. These patients may require orthognathic surgery to correct the position of the maxilla, mandible, or both, depending on the treatment plan suggested by the interdisciplinary team [Figure 2-14A–D].

[Figure 2-13A–D] Patient with a convex profile: the case solution involved orthodontic treatment combined with orthognathic surgery.

[Figure 2-14A–D] Patient with a concave profile: the case solution involved orthodontic treatment combined with orthognathic surgery.

The dentist needs to be aware that the profile facial analysis is part of the complete clinical examination, and the information obtained should be considered along with the patient’s wishes and needs as well as the treatment goals. Some changes between the cited reference values will still be compatible with acceptable esthetics and function.

[Figure 2-15A–C] The facial shape can be classified in a simplified way as rectangular [A], oval [B], or triangular [C].

Smile line

The position of the lips during smile determines the amount of tooth and gingival exposure. The height of the smile line and its curvature may vary depending on the patient’s age and facial anatomy²¹. Lips elongate during craniofacial growth and the aging process. As a general rule, they lower by about 1 centimeter (cm) per decade of life after the age of 40 due to reduced muscle tone and loss of tissue collagen.

According to Tjan et al²², three levels of smile line can be identified: low – when patients do not show more than 75% of the height of the anterior teeth, present in 20.5% of the cases; average – when patients show 75% to 100% of the anterior teeth and interdental papillae, present in 69% of the cases; high – when patients show the full extent of the anterior teeth and a variable range of gingival tissue, present in 10.5% of the cases [Figure 2-16A–C]. According to these authors, a high smile line is twice as common in females compared with males.

[Figure 2-16A–C] The smile line can be classified as low [A], average [B], or high [C]. The smile line is an important parameter to consider during treatment planning and clinical execution, as minimal imperfections in the restorations or gingival architecture will be visible in cases of average, and – particularly – high smile lines, which may compromise expectations regarding the esthetic outcomes.

Knowledge of the amount of tooth and gums that is exposed during the smile is critical in determining the extent and complexity of treatment. Patients with a high smile line and high esthetic expectations will demand extra attention from the interdisciplinary team, since minimal imperfections in the restorations or the gingival architecture will be visible and may compromise the esthetic results. Dentists should be aware that excessive gingival display in high smile lines can have multiple etiologies aside from lip hypermobility; for example, vertical maxillary excess, short upper lip, supraeruption of the maxillary anterior teeth, and wear due to attrition followed by compensatory dentoalveolar eruption and altered passive eruption. Such diagnostic possibilities should be discussed with the patient, along with the consideration of the biologic costs of additional surgical or esthetic procedures to correct them²³ [Figures 2-17 to 2-23].

[Figure 2-17A–F] Low smile line: milled metal-ceramic crowns with attachments and a removable partial denture were used.

[Figure 2-18A–C] Average smile line: crown lengthening surgery was performed, followed by minimally invasive ceramic restorations.

[Figure 2-19A,B] Average smile line: replacement of a fixed metal-ceramic prosthesis with a fixed dentogingival metal-ceramic prosthesis.

[Figure 2-20A,B] Average smile line: a combination of orthodontic treatment, orthognathic surgery, and ceramic restorations.

[Figure 2-21A,B] High smile line: connective tissue graft (CTG) surgery to conceal the grayish appearance of teeth 11 and 21, followed by composite resin restorations on teeth 12 and 22, and ceramic crowns on teeth 11 and 21.

[Figure 2-22A,B] High smile line: replacement of ceramic crowns and the manufacture of a fixed dentogingival prosthesis for teeth 24 to 26.

[Figure 2-23A–D] High smile line: the case solution involved the combination of orthodontic treatment with orthognathic surgery.

When taking photographs or videos to record the extent of the smile, one should try to keep the patient relaxed, as a spontaneous smile produces a higher smile line and exposure of approximately 30% more of the teeth and gums in the premolar region compared with a posed smile^24,25 [Figure 2-24A,B].

[Figure 2-24A,B] A professional taking photographs and videos of the patient with a smartphone in an uncomplicated manner.

The shape and thickness of the lips warrant some consideration. The curvature of the upper lip in line with the maxillary gingival levels grants harmony to the smile, in the same way as does the curvature of the lower lip in relation to the maxillary incisal plane. For this reason, a flat lower lip tends not to harmonize with a curved incisal plane in the case of dominant central incisors²⁶. Regarding the thickness of the lips, thick lips tend to harmonize with dominant anterior teeth and thin ones with less dominant anterior teeth⁵.

It is recommended to pay attention to the symmetry of the lip morphology. Since the lips are the frame of the smile²⁷, when they are asymmetric, there is an uneven tooth and gingival exposure, resulting in a “crooked” smile aspect. This aspect should be recorded through photographs and clarified with the patient before any procedure is performed to avoid patient dissatisfaction, since about 22% of individuals have asymmetric lips²⁸ [Figure 2-25A,B].

[Figure 2-25A,B] The shape of the patient’s lip pre- and posttreatment. Asymmetric lip morphology can generate a feeling of an uneven smile and patient dissatisfaction at the end of treatment. This should be clarified with the patient before any procedure because many patients have asymmetric lips.

The measurement of the length of the lips can be helpful in the differential diagnosis of gingival smiles^29,30. As a reference, the average lip length at 30 years of age is 20 to 22 millimeters (mm) in females and 22 to 24 mm in males³¹.

Midline

Whether the position of the dental midline is acceptable with the facial midline or whether it is displaced laterally should be evaluated. A more precise analysis of this displacement will be carried out during the analysis and treatment planning of the case, and its meaning and relevance should be discussed with the patient at the appropriate moment [Figure 2-26A,B].

[Figure 2-26A,B] The alignment between the facial midline and the dental midline is one of the critical factors of a harmonious smile. This aspect should be discussed with the patient due to its implications for the type and extent of treatment.

In addition to the position of the dental midline, the inclination of this line in relation to the facial midline should be carefully evaluated for its esthetic impact. In order to discuss the feasibility and indication of different treatment approaches, this inclination should be communicated to the interdisciplinary team and the dental laboratory technician (DLT) through photographs, videos, and models (plaster or virtual) mounted on an articulator using a facebow [Figure 2-27A,B].

[Figure 2-27A,B] The inclination of the dental midline in relation to the face is considered an unpleasing factor for the harmony of the smile. This information should be included in the diagnosis and its correction should be considered in the treatment options.

MAXILLARY CENTRAL INCISORS’ EDGE POSITION

The three-dimensional (3D) maxillary central incisors’ edge position is the “keystone” or starting point for the esthetic evaluation and restorative treatment plan^7,32,33, being closely associated with the facial midline. Its determination is directly linked not only to esthetic aspects but also to functional and phonetic ones, as will be shown later in this chapter and in other chapters.

The maxillary central incisors’ edge position is planned by analyzing the exposure of the teeth and lips at rest and during smile, statically through photographs and dynamically through videos. During the examination and recording of the images, the patient is asked to keep the lips slightly apart without the teeth making contact. In order to help the patient in this task, ask them to pronounce the letter “M” and to keep their lips still after pronouncing it. Another way would be to ask them to lightly touch their lips and then open them enough to breathe through their mouth [Figure 2-28].

[Figure 2-28] The maxillary central incisors’ edge position is the “keystone” for determining esthetics and integration with masticatory and phonetic function.

As a general rule, the anterior teeth need to be elongated in the incisal direction in cases of insufficient tooth exposure caused by severe tooth wear or maxillary deficiency. Alternatively, they need to be shortened in cases of excessive tooth exposure due to changes in growth or development, anterior supraeruption in Angle Class II patients, or in the case of periodontal problems. Lengthening and shortening of the incisal edges should always consider the patient’s occlusal parameters, as discussed in Chapter 3 [Figure 2-29A–D].

[Figure 2-29A–D] Clinical cases with changes in the position of the incisal edges of the maxillary anterior teeth.

Regarding the sagittal view, the horizontal position of the buccal surface of the maxillary central incisors and the relationship of the incisal edges to the limit between the dry and wet lower lip vermilion should be recorded during the pronunciation of the labiodental sounds “F” and “V”^34–36 [Figure 2-30A,B]. This record should be taken in the sagittal view and complemented by an additional “12 o’clock” view [Figure 2-31]. Both views will assist in identifying long or proclined incisal edges, which interfere with the lip closure but are limited in terms of identifying short incisal edges.

[Figure 2-30A,B] Determination of the position of the incisal edges with the aid of phonetic tests, with the patient pronouncing the “F” and “V” sounds.

[Figure 2-31] A photograph from the “12 o’clock” view helps to plan the dental contour. The position of the maxillary anterior teeth should not interfere with the trajectory of lip closure.

When evaluating the dentofacial profile, the dentist should determine how a buccal contour change could affect esthetics. Anterior teeth with a buccal inclination should generally not be significantly increased in contour due to the risk of impairing esthetics and interfering with the lower lip closure trajectory. On the other hand, teeth with a lingual inclination may have their buccal contour increased in most clinical situations.

Maxillary occlusal plane

The orientation of the maxillary occlusal plane has a critical connection to esthetics and function. Its inadequate assessment is one of the most common errors in complex cases, capable of generating significant esthetic and functional disharmonies. Using a correctly positioned facebow for mounting the models on the articulator is imperative in patients with facial asymmetry patterns or an irregular occlusal plane [Figure 2-32A,B]. According to Margossian et al¹, the interpupillary line was the primary horizontal reference in 88.4% of the situations, followed by the intercommissural line. When the interpupillary line is asymmetric (11.6% of the cases), a combination of horizontal facial reference lines, such as the ophriac (eyebrow line), interpupillary, interalar, and intercommissural lines, is critical to minimizing errors [Figure 2-33].

[Figure 2-32A,B] Cases of facial asymmetries can result in treatment planning and execution failures if not diagnosed by the specialist team and the DLT. The assembly of the facebow aligned with a combination of horizontal facial reference lines, such as the ophriac (eyebrow line), interpupillary, interalar, and intercommissural lines, is critical to minimizing errors.

[Figure 2-33] Auxiliary horizontal reference lines for facebow assembly.

In the frontal view, the occlusal plane should be correctly oriented with the horizontal reference lines and be perpendicular to the facial midline, following the curvature of the lower lip^{3,4,34,36–42}. In the sagittal plane, the occlusal plane should be oriented in relation to the reference plane used, as detailed in Chapter 8.

The esthetic appearance of the maxillary occlusal plane is related to its horizontal dimensions and how much the teeth fill the buccal corridor; that is, the space between the buccal surfaces of the posterior teeth and the lip commissures³⁸ [Figure 2-34A–C]. The buccal corridor allows the visualization of the smile’s natural alignment by contrasting the buccal surfaces of the teeth with the dark area resulting from the shadows of the cheek^43,44.

[Figure 2-34A–C] The buccal corridor allows the visualization of the natural alignment of the smile by contrasting the buccal surfaces of the teeth with the dark area resulting from the shadows of the cheek: wide [A], moderate [B], and minimal [C] buccal corridor.

The presence, dimensions, and esthetic influence of the buccal corridor should be observed during the clinical examination and in photographs of the patient’s spontaneous smile. Its restorative, orthodontic, or orthodontic–orthognathic treatment should be discussed with the patient due to its biologic complexity. Therefore, a wide buccal corridor should not be the reason for treatment unless the patient’s complaints are relevant to this aspect⁴³.

Intradental Proportion

The dental proportion of the maxillary central incisors, defined as the width/height ratio, is a valuable parameter for analysis and esthetic treatment planning⁴⁵. Although ratios for the dental proportion have been shown to be 74% to 89% in the literature⁴⁶, those between 75% to 80% are considered more harmonious^5,45,47–49. Dental proportions with a ratio below 70% result in an elongated morphologic appearance, and those above 85% in a wide appearance [Figure 2-35A–E].

[Figure 2-35A–E] An example of dental proportions is the width/height ratio. In general, values between 75% and 80% are considered more harmonious.

The average crown dimension of a maxillary central incisor ranges from 8.3 to 9.3 mm in width and 10.4 to 11.2 mm in height. Incisal wear associated with age, function, or bruxism are factors that can modify this dimension^46,50. The maxillary lateral incisors are 2 to 3 mm narrower than the central incisors. The maxillary canines are 1 to 1.5 mm narrower than the central incisors; the maxillary central incisors and canines have similar crown heights, with variations of about 0.5 mm, being 1 to 1.5 mm longer than the lateral incisors⁴⁵.

Another reference is that the maxillary central incisors and canines are, on average, 20% longer than the lateral incisors; the maxillary lateral incisors are 25% narrower than the central incisors, and the maxillary canines are 10% narrower than the central incisors⁵⁰. Several authors have tried to establish relationships between the zygomatic distance, the interpupillary distance, or other facial measurements as a reference to determine the width of the central incisors, but without conclusive results⁵ [Table 2-01].

[Table 2-01] Anatomical references to aid smile planning.

Maxillary gingival level

For geometric harmony of the maxillary gingival margins, they should be parallel to the curvature of the upper lip. Any lack of continuity or asymmetry in this parallelism will disturb the sense of balance of this composition²⁷ [Figure 2-36].

[Figure 2-36] The optimal position of the gingival zenith.

The gingival zenith is the highest point of the gingival margin. Ideally, the central incisors should be symmetric in contour and at gingival zenith height^3,4. The central incisors and canines generally have gingival margins that are 0.5 to 1 mm more apical than those of the lateral incisors^3,4,41,52,53. The connection of the gingival zeniths of the three teeth in a quadrant forms the gingival triangle, which ideally should be symmetric with the opposite side [Figure 2-37].

[Figure 2-37] Harmony of marginal contour and gingival zenith position.

The frequency and magnitude of distal zenith displacement are tooth-dependent, generally more significant in the maxillary central incisor than in the lateral incisor, which is more significant than in the canine. In their study, Mattos and Santana⁵⁴ found that the gingival zenith was distally positioned from 0.06 to 0.96 mm in 96% of the maxillary central incisors, 70% of the lateral incisors, and 12% of the canines. These authors concluded that the gingival zenith is not universally displaced distally, as is commonly stated.

The exposure of the interdental papillae should be evaluated, as it is one of the essential esthetic characteristics of the smile. It impacts the treatment plan when the papillae are short or asymmetric. The interdental papillae of the maxillary teeth are visible during the smile in 91% of individuals. Even patients with low gingival margins can present papillae exposure in 87% of cases⁵⁵. According to Hochman et al⁵⁵, the absence of the interdental papillae during smile often represents the difference between a visually pleasing result and an unattractive artificial smile, in which it was deemed necessary to extend the interproximal contact.

As a reference, the ratio between the length of the papilla and the tooth should be around 40% of the dental crown height, measured from the gingival zenith to the incisal edge, or from 4.5 to 5.5 mm, from the gingival zenith to the lowest portion of the papilla^56,57 [Figure 2-38].

[Figure 2-38] The proportion of the dental papillae with the height of the dental crown.

Interdental proportion

For a very long time there has been a search for mathematic formulas to help in smile composition. Some theories proposed in esthetic treatment planning include the golden ratio^39,58, the golden percentage⁵⁹, Preston’s proportion⁶⁰, and the recurring esthetic dental (RED) proportion^61–63. The golden ratio is a classic concept that is used in several areas of knowledge. In dentistry, it determines that the width of the lateral incisor, in the frontal view, must be 62% of the width of the central incisor, and that the canine, in its mesial aspect, must present 62% of the width of the lateral incisor. Preston⁶⁰ concluded that the golden ratio occurred in only 17% of the cases and generated very dominant central incisors, producing a narrowing of the dental arch. In his work, he suggested a ratio of 66% of lateral incisors to central incisors, and 85% of canines to lateral incisors.

Snow⁵⁹ suggested that a “golden percentage” to establish harmony between the anterior teeth would be more appropriate. Thus, the central incisor of a quadrant would occupy 25% of the smile width on that side, the lateral incisor 15%, and the canine 10%. Ward^61,63 stated that a ratio of 70% between the central and lateral incisors and between the lateral incisors and canines would be more harmonious than the golden ratio.

Rosenstiel et al⁶² stated that this interdental proportion should also consider the tooth height, with 70% being favorable for teeth with average height (defined as 78% of the width/height ratio), 62% for long teeth, and 80% for short teeth. According to Ahmad⁵³, the most crucial factor in creating a harmonious esthetic result would be a reproducible and constant proportion inherent to the patient, instead of trying to adapt a predefined proportion [Figure 2-39A–D].

[Figure 2-39A–D] Comparison between the different theories to quantify the interdental proportion: golden ratio [A]; golden percentage [B]; Preston’s proportion [C]; recurring esthetic dental (RED) proportion [D].

Interdental proportions are dependent on ethnicity, gender, and personal preference, and their perception is also influenced by color, reflective angles, and interincisal angles^41,64. These proportions should not be considered absolute geometric laws, since there is significant individual variation as well as different proportions even in the various quadrants of the same individual. This author only uses the RED proportion as an initial parameter for determining the interdental proportions for treatment planning⁶⁶.

Mandibular occlusal planE

Clinical evaluation of the mandibular occlusal plane should be subdivided into the anterior and posterior teeth. The mandibular anterior teeth should be evaluated for their exposure and position. Limited information is available in the literature regarding these teeth, perhaps because it is wrongly assumed that they have little influence on esthetics. Nassif⁶⁷ demonstrated that individuals expose the mandibular anterior teeth more clearly than the maxillary anterior teeth during phonation. In their study, these authors showed that while 29% of subjects exhibited only the mandibular anterior teeth, 43% exhibited more mandibular anterior teeth than maxillary anterior teeth while speaking.

It is also necessary to assess whether the mandibular anterior teeth are leveled and aligned with the maxillary occlusal plane. As discussed in Chapter 3, this position will influence esthetics, function, and phonetics.

The dental proportion for the mandibular anterior teeth is 60% to 70% of the width/height ratio⁶⁸. Gingival margins and interdental papillae should be evaluated for alignment and symmetry, even though they are less relevant from an esthetic point of view when compared with the maxillary teeth [Figure 2-40].

[Figure 2-40] Morphologic characteristics of the maxillary anterior teeth.

Tooth/gingival SHADE

The initial chromatic appearance of the teeth to be treated and adjacent or antagonist teeth that can serve as a reference should be recorded through photographs with adequate lighting and white balance. Determining the four closest shades from the shade guide and placing their aligned incisal edges with the incisal edges of the natural teeth is an effective form of documentation, according to this author’s experience [Figure 2-41A–C]. The use of polarizing filters provides additional visual information that is very useful to the dentist and DLT for layering restorative materials [Figure 2-42A–F] to optimize esthetic results [Figure 2-43A–D].

[Figure 2-41A–C] The shade match should be performed in the first appointment through the use of photographs. The “raw” photo [A] can be manipulated into black and white in order to measure the value [B] or have its brightness reduced and contrast increased in order to observe the chromatic details of the tooth structure [C].

[Figure 2-42A–F] Polarizing filters have the potential to add useful visual information to assist the dentist and DLT in layering restorations.

[Figure 2-43A–D] A clinical case involving single-unit restorations and a fixed dentogingival prosthesis on dental implants with ceramic gingiva complemented by composite resin.

Suppose there is a need for a prosthetic restoration, such as complete dentures, removable dentures, or fixed dentogingival dentures, that involves reproducing the shade and texture of the gingival tissue. In that case, this shade should also be photographed with the appropriate gingival shade guide [Figure 2-44A–D].

[Figure 2-44A–D] Clinical case of a fixed dentogingival prosthesis over dental implants with ceramic gingiva.

Functional examination

A comprehensive examination is the starting point for an accurate diagnosis and a proper treatment plan.

The objective of the functional examination is to clinically determine the health status and stability of the components of the stomatognathic system such as the TMJs, the neuromuscular system, and the teeth. It is an integral part of the clinical examination and should be linked to the symptoms reported by the patient, considering the patient’s age and general health status.

During the anamnesis, the dentist should obtain critical information regarding the evolution of the reported functional problem(s), speed of progression, nature of continuity, and influence of external factors such as stress. The dentist should also seek to assess the degree of awareness of the patient concerning existing problems, since many patients do not have complaints and others may not understand the relationship between frequent pain or discomfort and occlusal function.

The functional examination described in this book requires approximately 10 minutes (min) for most patients and is not intended to be an extensive examination aimed at patients with temporomandibular disorders (TMDs). It should be carried out with attention and intention, and according to a particular method, in order to identify patients with a stomatognathic system in a pathologic state and who need to have their occlusal problems treated, including those problems that present potential risks to treatment.

It must be emphasized that the functional examination is not a static examination of occlusal morphology, comparing the patient’s current situation with an ideal preestablished model; rather, it is an individual and dynamic analysis that considers adaptive responses to the present occlusal morphology. Although such responses to stimulus variations have been a reality throughout the evolutionary history of living beings, they should be identified, monitored, or intercepted when there are clear signs that the current stimuli are exceeding the adaptive capacity of the system or causing it to deteriorate.

Many dentists find it difficult to perform this examination because joint disorders and muscle dysfunction often occur together⁶⁹. Understanding the meaning of functional clinical findings and their implications for the treatment plan is essential, especially in complex cases where a reorganizing approach should be adopted.

Clinical report – critical questions about the patient’s function

Using a clinical report with critical questions and clinical data organized in the form of checklists is essential to diagnose occlusal problems. Each question aims to explain important data from the history and evolution of the problems reported and follows an order so that it considers all parts of the stomatognathic system. Positive responses should be carefully explored in terms of history and functional examinations. They may also require examining models mounted on the articulator and complementary imaging tests for an accurate diagnosis [Figure 2-45].

[Figure 2-45] Clinical report with the functional examination.

• Mandibular dynamics
• TMJ evaluation
• TMJ sounds
• Muscular evaluation
• Bruxism/parafunctional activity
• Interarch relationship
• Centric relation (CR)/adapted centric position (ACP)/ maximal intercuspal position (MIP)
• Interferences
• Functional guidance
• VDO alteration

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Stages of the functional examination

The functional examination must initially follow a preestablished routine that should be individualized according to the patient’s responses. Relevant knowledge about the masticatory function, bruxism, and parafunctional activities are described in this book (more details in Chapter 7) and are the fundamental basis for the dentist to recognize signs of pathologies in the stomatognathic system⁷⁰, since the etiologic factors that led to the breakdown of the tooth can destroy the restorations to be performed.

As with the esthetic examination, the functional examination is performed from the outside to the inside, methodically and gradually. It is recommended to explain the objectives of each examination stage to the patient so that they feel cared for and protected. For example, brief palpation in the region of the TMJs and the main masticatory muscles serves to investigate the health status of these structures and whether they can influence the sequence or even the stability of the treatment.

The patient is instructed to report any sensitivity that may occur and to classify the possible resulting pain into four levels of intensity (0 = no pain; 1 = mild pain; 2 = moderate pain; 3 = severe pain), differentiating the right and left sides. All these data should be recorded for review during treatment to assess the effectiveness of the therapeutic decisions.

The suggested functional examination sequence is not intended to provide a definitive diagnosis of the patient’s stomatognathic system, but to investigate a relationship between the reported symptoms and the presence of clinical signs. It aims to identify possible overloads that may influence treatment prognosis.

Mandibular dynamics

The dentist is positioned in front of the patient. Ask the patient to open the mouth as much as possible and then to slowly close it three consecutive times. Evaluate the degree of opening and the occurrence of mandibular deviations or deflections during these movements. Openings of 35 to 50 mm and lateral and protrusive movements of 8 to 11 mm are considered normal^69,71–73. The data should be added to the clinical record. It is recommended to make a video of this part of the examination [Figure 2-46A–C].

[Figure 2-46A–C] Examination of mandibular dynamics: opening [A]; right lateral excursion [B]; left lateral excursion [C]. Openings of 35 to 50 mm and lateral and protrusive movements of 8 to 11 mm are considered normal.

Nonlinear openings or restricted movements may be related to intraarticular problems or masticatory muscle dysfunction. For diagnostic purposes, it is essential to differentiate deviations from mandibular deflections. Deviations are changes in the path of the mandible that occur during mouth opening but are reduced with the increase in the movement amplitude. They occur when a condyle has its translational movement restricted, causing the opening shift. When this restriction is overcome, as in the displacement of the lateral pole of the disc with reduction, the midline of the mandible becomes more centralized [Figure 2-47].

[Figure 2-47] Mandibular deviation during mouth opening movement. This occurs when the condyle has restricted translational movement, causing a shift of the opening trajectory. When this restriction is overcome, as in the displacement of the lateral pole of the disc with reduction, the midline of the mandible becomes more centralized.

Deflections are changes in the path of the mandibular midline that are accentuated with the opening of the mouth. They occur when the condyle encounters an obstacle in its path and is not able to perform an adequate translation movement, causing the mandibular midline to deviate to the affected side, as in cases of anterior displacement of the lateral pole of the disc without reduction or presence of intraarticular adhesions [Figure 2-48]. Deflections can also occur in cases of relevant muscle hyperactivity or in cases of fractures, hyperplasia, or neoplasms, which will require additional imaging tests. The palpation of the TMJ, the masticatory muscle, vertical load, and immobilization tests will help in the understanding of the present alterations^69,72.

[Figure 2-48] Mandibular deflection during mouth opening movement. Mandibular deflection is common in cases of anterior displacement of the lateral pole of the disc without reduction or intraarticular adhesions; it can also occur in relevant muscle hyperactivity, fractures, hyperplasia, or neoplasms.

TMJ evaluation

This part of the examination aims to clinically assess the health status of the TMJs, as they constitute the starting point of any restorative or orthodontic treatment^72,74. The TMJs should be in a healthy or physiologically adapted condition, even when structurally compromised, without any symptoms or signs of active pathology^75–77. In case of pain or discomfort in the TMJs during the examination, no irreversible treatment should be initiated.

It is suggested to observe all the patient’s responses, from the most subtle ones, maintaining eye contact during the functional examinations. This author considers palpation of the TMJs and masticatory muscles from behind the patient to be more ergonomic, although this can also be performed from the front.

1. External palpation of the TMJ capsule area: Using the index or middle fingers, the outer part of the TMJ capsule, located approximately 1 cm anterior of the tragus, should be palpated on both sides simultaneously. The palpation process should be initiated gently, gradually increasing the pressure according to the patient’s responses, up to a maximum of 1 kilogram (kg).

The patient is asked to open and close the mouth and report any pain or discomfort during palpation. The results should be recorded in the clinical record, detailing whether the two sides present similar symptoms or whether a specific side or region is predominant. This palpation detects the presence of TMJ inflammation, which should be treated at the beginning of treatment [Figure 2-49A–D].

[Figure 2-49A–D] Frontal and lateral views of the palpation of the TMJ capsule area performed with gradual pressure.

2. Palpation of the retrodiscal zone: As it is an unusual procedure, the dentist should lead the patient through this examination by introducing their little finger into the external auditory meatus on both sides to identify any pain or discomfort during jaw opening and closing. Then, the dentist should ask the patient to open the mouth to the maximal position possible while simultaneously moving the jaw forward. With experience, it is possible to feel signs of anterior displacement of the lateral pole of the disc, such as clicking, and to identify any inflammation of the retrodiscal zone [Figure 2-50A–D].

[Figure 2-50A–D] Frontal and lateral views of the palpation of the retrodiscal zone through the careful introduction of the little finger into the external auditory meatus with slight anterior pressure.

3. Auscultation: This should be performed during mandibular rotation by quick and short (around 2 cm) opening and closing movements, and should be translational. Although not essential, this part of the examination can be improved using a stethoscope or a Doppler device to define the moment and type of sound⁶⁹.

During mandibular rotation and lateral excursion, with the help of the patient, it is possible to assess for crepitation, that is, a sound similar to “grains of sand” between the joint surfaces. Crepitation can occur in cases of anterior displacement of the anterior and lateral poles of the disc when the condyle is positioned on the fibrous and irregular surface of the posterior part of the disc. It can also occur in disc perforation and degenerative processes of the TMJ such as osteoarthritis or rheumatoid arthritis⁷⁸.

Clicking is generally related to an anterior disc displacement, usually at its lateral pole, in translational movements of the condyle⁷². During the opening, when condylar translation occurs, the condyle “jumps” over the fibrous posterior edge of the disc, generating a sound that is usually audible. The greater the opening of the mouth necessary for disc reduction, the more the condylar trajectory will occur on the retrodiscal tissue, increasing the possibility of symptomatology. During the closure, the same logic applies. The earlier the disc moves forward, the more the condylar movement will occur without its presence.

Unfortunately, in many clinical situations, it is impossible to detect audible sounds or even significant movements of the mandibular trajectory due to the morphologic changes in the disc. Usually, 30% to 39% of asymptomatic patients present with disc disorders without significant clinical signs or symptoms, preventing the continuance of restorative treatment⁷⁹. TMJ sounds demonstrate that morphologic changes have occurred, but they have a limited impact on treatment prognosis if they are stable, adapted, and able to withstand functional forces, as is discussed later in this chapter.

Muscular evaluation

This examination assesses discomfort, pain, or muscle tension in the main masticatory muscles. When pain is detected, the cause of the problem should be investigated. As with TMJ problems, no restorative treatment of an irreversible nature should be started in the presence of muscle dysfunction, apart from emergencies.

Muscle palpation makes it possible to verify hypertrophy, hyperactivity, and muscle sensitivity. The results of this palpation should be interpreted together with the anamnesis and the rest of the functional examination. It has a subjective character concerning the patient’s responses, which will be more evident in cases of TMD. Due to the difficulty of palpating some muscles, particularly the medial pterygoid and inferior and superior lateral pterygoid muscles, functional tests are suggested to complement the examination.

1. Palpation: This should be performed bilaterally and symmetrically, with light to moderate pressure, accompanied by small circular movements. The patient should be instructed to compare and report the tenderness to palpation on both sides.

1a. Masseter: Start palpating the superficial head of the masseter using the index and middle fingers from the origin in the zygomatic arch, sliding the fingers with slight pressure to the insertion in the angle and ramus of the mandible. Try to identify sensitive areas with the mandible at rest. Then ask the patient to occlude the posterior teeth forcefully and, after observing the most prominent area of the contracted muscle, compress the fingers with a pressure of approximately 1 kg and assess the patient’s response. As the masseter is generally involved in muscle dysfunctions, and is overloaded in the case of bruxism or parafunctional activities, it can present some painful symptoms. The deep head of the masseter can be felt in the posterior part of the zygomatic arch, close to the tragus, after the patient opens the mouth as wide as possible [Figure 2-51A–D].

[Figure 2-51A–D] Frontal and lateral views of the palpation of the masseter area.

1b. Temporalis: Palpate the anterior, middle, and posterior bundles of this muscle with the index, middle, and ring fingers. Palpation should be performed with the patient at rest, and repeated after asking the patient to significantly occlude the posterior teeth. The anterior bundle of the temporal muscle is located over the zygomatic arch and anterior to the TMJ, the middle bundle over the TMJ, and the posterior bundle over the TMJ and behind the ear [Figure 2-52A–C].

[Figure 2-52A–C] Frontal and lateral views of the palpation of the temporal area.

The temporalis tendon can be palpated intraorally by placing the index finger on the anterior border of the mandibular ramus. This finger should be moved over the anterior border of the ramus until the coronoid process and tendon are palpated [Figure 2-53].

[Figure 2-53] Intraoral palpation of the temporalis muscle tendon.

1c. Medial pterygoid: Palpation can be performed extraorally at the internal angle of the mandible or intraorally with the tip of the index finger positioned below the retromolar area, almost on the lateral side of the pharyngeal wall. This intraoral palpation can be uncomfortable for the patient and may provoke a gag reflex [Figure 2-54].

[Figure 2-54] Intraoral palpation of the medial pterygoid muscle.

1d. Inferior lateral pterygoid: This muscle is usually involved in muscle dysfunction and TMD, but the validity of its intraoral palpation has been questioned in the literature due to its deep location and proximity to the origin of the medial pterygoid muscle^78,80,81. Recently, Stelzenmueller et al⁸² concluded that the essential requirement for palpating the inferior lateral pterygoid muscle is knowledge of its topography and intraoral access path. To effectively palpate this muscle, ask the patient to shift the mandible laterally toward the side to be evaluated. The examiner’s little finger, or index finger, should go along the oral vestibule, parallel to the upper part of the maxillary alveolar process, going beyond the maxillary tuberosity, reaching the lateral plate of the pterygoid process. At this time, a craniomedial finger movement should be performed to assess this muscle⁸² [Figure 2-55].

[Figure 2-55] Intraoral palpation of the inferior lateral pterygoid muscle.

1e. Sternocleidomastoid: This muscle can be a source of painful symptoms in cases of TMD⁶⁹. Its palpation is performed with the index finger and thumb, from its insertion in the mastoid process, following in a downward direction until its origin in the clavicle [Figure 2-56A,B].

[Figure 2-56A,B] Palpation of the sternocleidomastoid muscle from its origin to its insertion.

1f. Trapezius: The trapezius can also be a source of painful symptoms in cases of TMD. Its palpation is initiated from its origin in the occipital region, moving downward [Figure 2-57A,B].

[Figure 2-57A,B] Frontal and lateral views of the palpation of the trapezius muscle.

2. Load testing: The vertical load test is performed to jointly verify the health status of the TMJs and the degree of hyperactivity of the inferior lateral pterygoid muscles^72,77,78,83. Any sign of tension, pain, or discomfort during the test indicates that the TMJ on that side is compromised by some inflammatory process, which is either accompanied by structural changes or not. It can also indicate a hyperactive inferior lateral pterygoid muscle.

Load testing is essential to determine the feasibility of establishing a reference position for the treatment at that moment, as this requires healthy or adapted TMJs and inferior lateral pterygoid muscles that do not restrict condylar seating. Positive responses to the load test should be correlated with the patient history and other parts of the functional examination.

There are different ways to perform load testing. Dawson^72,77 recommended bilateral manipulation of the mandible, with smooth and short movements of mandible opening and closing to position the condyles in the articular fossa [Figure 2-58A,B]. In this technique, with the index, middle, ring, and little fingers carefully positioned at the angle of the mandible, gradual forces are applied in a superior (not posterior) direction over the angle of the mandible. This pressure should gradually intensify if there is no positive response. Pain under gentle pressure (about 0.5 to 1 kg) is usually the result of intraarticular issues. Responses provoked from moderate to high forces of 2 kg as well as tensions or manipulation difficulties suggest hyperactivity of the inferior lateral pterygoid muscle. According to Dawson⁷⁷, when the centric relation (CR) or adapted centric position (ACP) position cannot be certified by the vertical load test, treatment should not be started.

[Figure 2-58A,B] Bilateral Dawson manipulation performed during the examination to detect the presence of premature contact in CR. Apply upward pressure on the condyles to assess the health status of the TMJs and inferior lateral pterygoid muscles.

Load testing can also be performed with the aid of older devices such as a leaf gauge⁸⁴ or Lucia jig⁸⁵. Both devices help to differentiate between intraarticular and muscular problems, as the absence of posterior occlusal contacts produces different responses of the TMJs and the inferior lateral pterygoid muscles. Due to the lack of posterior occlusal support when using both devices, more muscle forces will be directed to the TMJs^86,87 [Figure 2-59]. The patient should report discomfort or pain if the retrodiscal tissue is inflamed, if the lateral and medial pole of the disc was previously displaced, or if there are degenerative changes. The use of these devices results in an improvement in the signs and symptoms present in cases of inferior lateral pterygoid muscle hyperactivity.

[Figure 2-59] Load testing can be carried out with a jig or leaf gauge. It should follow the same principles of bilateral Dawson manipulation but with muscle force applied by the patient.

An isometric contraction functional test can be performed when there are significant centric and noncentric patterned wear facets (more details later in this chapter) in relation to the patient’s age. For this, when observing signs of wear with a centric pattern compatible with bruxism clenching behavior, ask the patient to maintain an isometric muscle contraction for 30 to 60 seconds (s), with cotton rolls interposed in the premolar regions [Figure 2-60A,B].

[Figure 2-60A–F] The functional test of isometric contraction can be performed with the interposition of cotton rolls in the region of the premolars [A,B] or by asking the patient to “match” the wear facets and apply an isometric contraction for 30 to 60 s [C–F]. The TMJs or the masticatory muscles, especially the jaw elevator muscles or inferior lateral pterygoid muscle, may present symptoms, contributing to the diagnosis of the functional health status.

On the other hand, when noncentric wear facets are observed, ask the patient to move the jaw until the facets in the anterior teeth engage and, keeping this area of contact, apply an isometric contraction for the same length of time suggested above [Figure 2-60C–F]. These tests adequately diagnose and potentially reveal dysfunctional, parafunctional, and bruxism behavior. They check the health status of the TMJs and masticatory muscles, and are helpful for the patient to understand the implications of the problems identified.

3. Immobilization test: The degree of hyperactivity of the inferior lateral pterygoid muscle can be assessed by functional tests, called immobilization or provocation tests⁸⁸. The dentist stands in front of the patient and asks them to occlude firmly in the maximal intercuspal position (MIP) for 30 s and then try to perform a protrusive movement of the mandible against the resistance offered by the dentist’s index finger and thumb, situated on the chin. This same test can be performed with the dentist positioned behind the patient and with their hands wrapped around the patient’s jaw [Figure 2-61A,B]. Suppose there is pain or discomfort with the attempt to protrude the mandible. In that case, it will likely come from an hyperactive inferior lateral pterygoid muscle or, less commonly, from the displacement of the medial pole of the articular disc. The immobilization test should be completed laterally. From the MIP, the patient is asked to move the mandible to the right side while the dentist tries to block this movement with their left hand.

[Figure 2-61A,B] The immobilization test can be performed with the dentist in front of or behind the patient. The main objective is for the dentist to stabilize the mandible while the patient tries to protrude it.

The test is repeated for the left side in the same way. The inferior lateral pterygoid muscle on the opposite side of the mandibular trajectory is generally symptomatic when compromised⁸² [Figure 2-62A,B].

[Figure 2-62A,B] The lateral immobilization test is performed to evaluate the health status of the inferior lateral pterygoid muscle on the side opposite to the direction of movement.

Bruxism/parafunctional activity

Bruxism is a relevant risk factor capable of significantly affecting the predictability of restorative treatments.

According to the latest international consensus on the evaluation of bruxism⁸⁹, there are two different definitions:

Sleep bruxism: is the activity of the masticatory muscles during sleep, characterized as rhythmic (phasic) or non-rhythmic (tonic), not constituting a movement disorder or a sleep disorder in healthy individuals.

Awake bruxism: is the activity of the masticatory muscles when awake, characterized by repetitive or prolonged tooth contact or forced mandibular contraction, and not considered a disorder in healthy individuals.

A broad conceptual discussion about the etiology or the different means of diagnosing bruxism is beyond the scope of this book. It will be essential for the dentist to correlate the magnitude and patterns of dental attrition with grinding (rhythmic or phasic activity), common in sleep bruxism, and clenching (non-rhythmic or tonic activity), common in awake bruxism.

To date, objectively, there is no way to classify the patient’s degree of bruxism activity. The analysis of tooth wear patterns considering the patient’s age and any symptomatology at the TMJs or masticatory muscles is suggested for diagnosis and treatment planning. Thus, marked wear patterns relative to the expected structural condition for an individual of the same age should be considered during treatment planning in terms of the most appropriate restorative treatment and the long-term control and maintenance program [Figure 2-63A–J].

[Figure 2-63A–J] Different treatment approaches according to the patient’s degree of attrition and age. A 25-year-old patient with early signs of attrition was referred for a stabilizing interocclusal splint and to start a maintenance program. It is possible to observe the pronounced wear that occurred on this splint after 3 years, which corroborates its beneficial effect in protecting the tooth structure [A–D]. A 70-year-old patient with a degree of wear compatible with his age but with a wish to improve the esthetics of his smile by replacing old restorations with new minimally invasive ones [E–J].

Parafunctional activities are actions performed involuntarily and unconsciously, often frequently. They have the potential to damage the structures of the stomatognathic system from the moment they exceed the individual’s physiologic tolerance. Common examples include biting the nails; removing the cuticle with the teeth; chewing bubble gum; chewing one-sidedly; sucking the fingers; biting the lips, cheeks, or assorted objects such as safety pins, paper clips, and pen caps.

Interarch relationship

The observation of the interarch relationship should start in the functional examination and be complemented by examining the models mounted on an articulator.

In this part of the examination, the interarch relationship, overjet, and overbite should be evaluated.

According to the Angle classification, the static interarch relationship aids diagnostics and communication. Such static relationships and crossbites are essential to define restorative, orthodontic, or orthognathic surgery treatment strategies. VDO increases may be preferred in Angle Class III patients but may be contraindicated in Angle Class II patients [Figure 2-64A–C].

[Figure 2-64A–C] Angle classification: Class I [A]; Class II [B]; Class III [C].

Discrepancy between central relationship positions and maximal intercuspal position

The clinical objectives of this examination are to assess whether there is a discrepancy between the CR and MIP, in addition to the level of hyperactivity of the inferior lateral pterygoid muscles during mandibular manipulation, which can prevent the correct analysis of these positions. In order to verify the presence of premature contacts, it is recommended that the clinician manipulate the mandible according to their preferred technique^71,72,90 and “feel” whether it can perform the opening and closing movements without tension or restrictions until reaching a registrable CR position. It is recommended to mark the tooth with premature contact with an articulating tape and investigate whether it shows signs of occlusal trauma such as hypersensitivity, hypermobility, or wear facets⁹¹.

The particular situation of wear facets evidenced on the lingual surface of the maxillary anterior teeth is often present in patients with a history of orthodontic or prosthetic treatment, or even in those with a deep overbite [Figure 2-65A–F]. In these individuals, the anterior teeth may contain premature contacts in CR, contraindicating mandibular manipulation to access CR⁴ (more details in Chapter 9).

[Figure 2-65A–F] Wear facets on the lingual surface of the maxillary anterior teeth may be present in individuals with a history of orthodontic or prosthetic treatment. Due to the possibility of premature contact, an auxiliary device for intermaxillary registration, such as a jig or fronto-plateau, is recommended.

In cases like this or where it is a challenge to manipulate the mandible, there is a need for a jig, leaf gauge, or fronto-plateau to record a reproducible and consistent CR. It is necessary to schedule a subsequent appointment to assemble the models on the articulator.

There are no reports in the literature of any disadvantage when the patient has a coincidence of MIP and CR positions. However, restorative or orthodontic treatment should not be indicated only to achieve this goal⁹². Discrepancies between CR and MIP occur in approximately 90% of patients^93,94. The magnitude as well as the anterior, lateral, and vertical directions of these discrepancies should be documented in the clinical record and checked on the articulator.

Although a direct relationship between premature contacts and any specific symptom has not been scientifically established⁹⁵, discrepancies between CR and MIP greater than 1.5 mm, combined or not with lateral discrepancies, should be considered in treatment planning. According to this author’s experience, they are directly related to treatment stability. Patients with significant discrepancies may have an unstable maxillomandibular relationship if any of the stabilizing ridges of the MIP are removed during tooth preparation, restoration replacement, or occlusal adjustments. In these situations, it is recommended to mount the models on an articulator and carry out the adjustment test before starting the treatment. The patient needs to be aware of such findings and how they may influence the long-term stability of the treatment, participating in the decision-making process regarding their treatment or maintenance [Figure 2-66A–C].

[Figure 2-66A–C] To estimate the predictability of restorative treatment, it is recommended to mount the models on an articulator and perform trial adjustments before starting the treatment in patients with wide discrepancies between the CR and MIP positions.

The discrepancy between CR and MIP should be identified for diagnostic reasons. However, if no signs or symptoms exist, this will not influence the treatment. Nevertheless, in complex treatments, where a reorganizing approach is adopted (more details in Chapter 7), this discrepancy should be considered and corrected accordingly.

Examination of Functional Guidance and Posterior Interferences

Ask the patient to perform right and left lateral excursion and protrusion, observing the disclusion of the posterior teeth provided by the present guidance to examine functional guidance. This initial assessment should be complemented by using a 60 to 100 micrometer (μm) articulating tape between the anterior and posterior teeth during the same movements, observing the extension and position of the functional guidance and documenting any posterior occlusal contact [Figure 2-67A–C].

[Figure 2-67A–C] Examination of functional guidance in the right [A] and left [B] excursion movements and protrusion [C]. This guidance must effectively prevent occlusal interference with the posterior teeth during mandibular movements. The evaluation should be performed clinically and with the models mounted on the articulator.

VDO alteration

The magnitude of wear on the anterior and posterior teeth and any existing prostheses should be observed, and it should be noted on the clinical record whether the patient would benefit from changes to the VDO to improve facial harmony, improve occlusal relationships, or create space for the restorative material. This analysis should be supplemented during treatment planning with the models mounted on the articulator (more details in Chapter 11).

Complementary imaging examinations for a functional diagnosis

The request for additional imaging examinations for TMJs should be based on the severity of the clinical symptoms¹⁰⁴, especially in cases where the anamnesis and clinical examination were insufficient to establish an accurate diagnosis. These imaging tests can potentially influence the diagnosis and treatment plan¹⁰⁵, but cannot define treatment outcomes¹⁰⁶, and should always correlate with clinical data¹⁰⁷.

Panoramic radiograph: This is the most common and cost-effective type of radiographic examination. It is helpful for an initial general analysis, identifying pathologic processes and significant structural changes, and for the selection of a more specific imaging examination, if necessary¹⁰⁸. The panoramic radiograph allows the observation of size and shape asymmetries, degenerative changes, fractures, ankylosis, and neoplasms^70,109,110. Its interpretation is distorted by the oblique view of the condyle and the superimposition of images of the oropharynx, skull base, and zygomatic arch¹¹¹ [Figure 2-68].

[Figure 2-68] The panoramic radiograph is a valuable examination to provide an overview of the teeth and craniofacial structures. It usually has to be complemented by more specific examinations.

Cone beam computed tomography (CBCT): This is the examination of choice to assess the TMJs¹⁰⁹. Its main advantage is the detailed and 3D depiction of bone structures in the sagittal, coronal, and axial planes¹¹¹. The main indications for CBCT include structural assessment of the bony components of the TMJ for degenerative changes, remodeling, hyperplasia, fractures, ankylosis, and neoplasms [Figure 2-69].

[Figure 2-69] Cone beam computed tomography (CBCT) can provide detailed and 3D information about the critical aspects related to the bone structures of the TMJs.

Magnetic resonance imaging (MRI): This is the examination of choice to evaluate the soft tissue of the TMJs such as the condition and position of the disc, ligaments, and retrodiscal tissue¹⁰⁹. Due to the cost and discomfort of performing this test, the real benefits should be considered¹¹². CBCT and MRI often complement each other for diagnosing pathologies or evaluating the evolution of some treatments [Figure 2-70A–D].

[Figure 2-70A–D] Magnetic resonance imaging (MRI) is indicated to evaluate the soft tissue of the TMJs such as the condition and position of the disc, ligaments, and retrodiscal tissue.

Structural examination

This text aims to provide an overview of the most significant structural aspects of the intraoral clinical examination. The structural examination and the other constituent parts of the clinical examination should follow the preestablished sequence of the Clinical Examination Form.

• Carious lesion
• Questionable restoration
• Defective restoration
• Fragile remaining tooth structure
• Abrasion
• Attrition
• Biocorrosion
• Noncarious cervical lesion (NCCL)
• Intraradicular retainer
• Dental implant

Intraoral clinical examination – structural part

The use of magnification with loupes or a microscope is recommended for a meticulous intraoral clinical examination [Figure 2-71A,B]. A magnified vision combined with effective and targeted lighting allows the visual detection of minimal alterations and incipient problems of the hard and soft tissue, allowing more effective actions to prevent and control disease development. It is recommended that the structural examination be performed quadrant by quadrant, with clean, dry teeth isolated with cotton rolls.

[Figure 2-71A,B] It is recommended to perform the intraoral clinical examination with loupes or a microscope to better visualize the structures.

Intraoral photographs are recommended to complement the intraoral examination. They are of great use during the diagnosis and treatment planning phases, allowing accurate communication between members of the interdisciplinary team and facilitating patient communication. The use of an intraoral scanner has similar advantages to that of photographs. In addition, intraoral scanners allow the possibility of analyzing the occlusal aspects and planning and monitoring the progression of some lesions [Figure 2-72A–G].

[Figure 2-72A–G] Intraoral photographs allow the interdisciplinary team to have a direct view of the degree of involvement of the dental structures to assist in the diagnosis and treatment planning of the case. An intraoral scanner provides advantages similar to that of photographs, in addition to the possibility of analyzing occlusal aspects as well as planning and monitoring the progression of some lesions.

Carious lesion

Caries is the most prevalent chronic disease in the world¹¹³, resulting from an imbalance in the relationship of fluids from the bacterial biofilm with the mineral structure of the tooth. Excessive and frequent ingestion of fermentable carbohydrates causes changes in the organization and ecology of the biofilm on the tooth surface, making it more aciduric and acidogenic. These pH fluctuations cause demineralization and remineralization processes over months or years, which can lead to mineral loss from the tooth structure, clinically observed as a carious lesion^114,115.

Despite the existing technologies for detecting carious lesions, the visual–tactile examination still offers the most consistent clinical results¹¹⁶. Initially, with clean, dry, isolated, and adequately illuminated tooth surfaces, minimal visual changes in translucency, shade, or structural integrity of the hard tissue should be carefully examined. A tactile examination should follow the visual one, gently using the explorer with a rounded tip to evaluate the continuity and texture of the tooth structure. Vigorous probing or probing with a fine tip explorer should be avoided as it could cause weakened enamel to collapse, resulting in cavitation and the progression of a lesion that could be treated conservatively¹¹⁷ [Figure 2-73].

[Figure 2-73] Tactile examination with an explorer should be performed gently to assess the tooth structure’s continuity and texture.

Classification of carious lesions¹¹⁸

Carious lesions of fossa and fissure surfaces: These lesions are detected visually, aided by careful use of an explorer. Bitewing or periapical radiographs can assist in determining the extent of the lesion and invasiveness of the intervention^119,120 [Figure 2-74A,B].

[Figure 2-74A–F] Types of carious lesions: fossa and fissure carious lesions [A,B]; proximal carious lesions [C]; carious lesions of smooth surfaces [D,E]; root caries [F]. (Clinical cases kindly provided by Prof. Leandro Hilgert.)

Proximal carious lesions: These lesions are usually detected by careful visual and tactile inspection. Due to access and visualization difficulties, a combination of features should be used for diagnostic accuracy. Bitewing radiographs aid in the detection of lesions and treatment planning, but they cannot define lesion activity or confirm the existence of cavitation. Fiber-optic transillumination is helpful to aid in the identification of minimal structural changes, although with a low diagnostic sensitivity. Flossing can also aid in detecting interproximal demineralized areas if the floss frays or breaks as it passes through the teeth [Figure 2-74C].

Carious lesions of smooth surfaces: These usually occur on the buccal or lingual surfaces in patients with high caries activity. They are closely associated with poor hygiene, a diet high in carbohydrates, and xerostomia [Figure 2-74D,E].

Root caries: The prevalence of root caries is quite significant in patients over 65. The increased number of elderly people who still have their natural teeth, associated with the difficulty of controlling local and systemic factors, makes root caries a significant problem to be investigated and treated¹²¹ [Figure 2-74F].

In most of these patients, gingival recession causes the exposure of irregular and poorly mineralized tooth tissue that is susceptible to the demineralization process resulting from inadequate oral hygiene and a diet high in carbohydrates. Systemic diseases or medications (see Anamnesis) can alter the amount and quality of saliva, significantly increasing the risk of developing root caries^120,122,123.

Root caries can present rapid progression due to the configuration of the dentinal tubules and its critical pH for demineralization (6.7), significantly higher than that for enamel (5.2). At the same time, proteolytic degradation of the dentin may occur¹²⁴. Subgingival root caries or those inside periodontal pockets are rare because the pH of the gingival exudate is higher than 7.0¹¹⁵.

Some authors suggest the differentiation of root caries into the categories of active or inactive by their color and texture, although this is not entirely accurate. Active lesions would be yellowish or light brown and soft, with a leathery consistency when inspected with a blunt explorer, and inactive lesions would be darker, brighter, and hard¹¹⁵.

The dentist must understand that the carious lesion pattern warrants individual interpretation in the general context of susceptibility to establish adequate care, in order to modify the future pattern of the disease for that patient. The patient’s medical history, age, medications used, dental history, number of restorations, quality of oral hygiene, and diet are among the main risk factors to be evaluated. These risk factors should be considered during treatment planning, as they will influence not only the treatment but also the education, motivation, and maintenance of these patients in the long term.

Bacterial biofilm control is the most suitable treatment to contain the development and progression of carious lesions. Thus, the most effective long-term measure is adequate toothbrushing and interdental devices to biomechanically remove the biofilm associated with fluoride-containing toothpastes¹²⁵. The consumption of carbohydrates should be reduced, especially concerning frequency¹²⁶.

Radiographic examination

Radiographic examination is essential to complement the diagnosis of carious lesions, especially bitewing and periapical radiographs.

The diagnosis of carious lesions through radiographs should be made with caution due to the lack of clarity and objectivity in interpreting a two-dimensional representation of a 3D structure^127,128. False positives or negatives can also occur, and incipient lesions, limited to the enamel, only become apparent after 30% to 40% of demineralization has occurred¹²⁹.

Another aspect to consider is that radiographs can provide an image of the extent of the carious lesion but do not assess its activity. In this author’s opinion, in case of doubts about the diagnosis, the dentist should adopt a conservative approach and watch these lesions instead of opting for an invasive intervention [Figure 2-75A–D].

[Figure 2-75A–D] Radiographic examinations aid in detecting carious lesions. Panoramic radiographs do not allow accurate visualization of small carious lesions. Periapical and especially bitewing radiographs are recommended.

QUESTIONABLE RESTORATION

Direct or indirect restorations should be evaluated clinically and radiographically for the presence of secondary carious lesions. The experienced dentist must carefully differentiate a stain at the tooth–restoration interface from a carious lesion. When present, carious lesions cause softening of mineralized tissue or cavitation on the edges of the restoration. It is not always possible to assess the extent of these lesions under the restorations¹³⁰.

When in doubt about the restoration status, the patient should participate in the treatment decision. As the clinical examination cannot detect the fatigue state of the materials, it is necessary to advise the patient that small cracks present in the restoration can propagate, possibly causing the restoration or the tooth structure to fracture. Strategically important teeth, which potentially impair future treatment outcomes, should be considered with additional caution [Figure 2-76A–O].

[Figure 2-76A–O] Clinical cases showing questionable restorations, defective restorations, and structurally compromised teeth. The patient should be aware of all these findings to make an informed decision regarding the most appropriate treatment. In these cases, all questionable and defective restorations were replaced, with the aim of establishing the best possible structural and biologic condition.

QR code linking to the Clinical Evolution Form and Informed Consent Form templates that can be customized.

Such decisions should be thoroughly documented on the Clinical Evolution Form as a reference for reassessments and decisions. It is recommended that the patient sign an Informed Consent Form when deemed necessary.

Defective restoration

Existing defective direct or indirect restorations usually require intervention. Failures may be due to several factors such as poor marginal adaptation, secondary carious lesions, fracture of the restorative material, superficial degradation, overcontouring, chronic periodontal inflammation due to violation of the biologic width, absence of interproximal contact, inadequate occlusal contacts, or poor esthetics [Figure 2-76A–O].

The treatment plan should take into consideration the real meaning of these failures. The extent and location of these defects will determine whether the restoration should be repaired or replaced. Once again, such decisions should be taken together with the patient.

The interproximal contacts should be tested using dental floss/tape, as food impaction can harm the periodontium. The patient should be instructed on the importance of good interproximal contacts for occlusal stability, the health of the gingival tissue, and comfort during mastication.

Fragile remaining tooth structure

Structural assessment concerning tooth restorability is one of the most critical aspects of a restorative treatment. Often, this analysis can only be performed accurately after removing the present restorations and possible carious tissue under them. The remaining tooth structure relates directly to tooth strength and the prognosis; therefore, teeth with a compromised structure are at increased risk of failure [Figure 2-76A–O].

The relationship between the width of cavity preparation and the loss of marginal ridge integrity on tooth resistance has been studied by numerous authors. Vale¹³¹ found a decrease in tooth resistance when the occlusal isthmus of mesial-occlusal-distal (MOD) cavities increased from 1/4 to 1/3 of the intercuspal distance. Mondelli¹³² demonstrated that tooth resistance was significantly influenced by cavity design (occlusal [O]; mesial-occlusal [MO]; mesial-occlusal-distal [MOD]) and by cavity width, with a reduction of resistance of more than 50% for MODs with 1/2 of the intercuspal distance width. This reduction was more significant in a subsequent study in preparations for indirect restorations¹³³. The loss of tooth resistance caused by the loss of marginal ridges accentuates the concentration of forces on the remaining walls and plays a relevant role in reducing the strength of these teeth^{132,134–138}.

Fracture of endodontically treated teeth is among the most common causes of failure. According to Reeh et al¹³⁶, the higher incidence of problems concerning vital teeth is not associated with histologic alterations in the dentin but with structural losses resulting from carious lesions and the non-conservative access to the root canals. These authors reported a reduction in tooth resistance of 6% for the endodontic approach, 20% for the occlusal cavity, 46% for the MO cavity, and 63% for the MOD cavity. The reduction of proprioceptive response due to the loss of pulpar receptors may contribute to a higher rate of fractures in these teeth¹³⁹.

It is also essential to evaluate wall thickness in endodontically treated teeth. Scotti et al^140,141 concluded that teeth with walls thicker than 2 mm should receive adhesive intracoronary composite resin restorations, whereas those with walls thinner than 2 mm should receive restorations with cuspal coverage. Interproximal contacts should be considered a stabilizing factor¹⁴².

Cavity depth seems directly related to cusp deflection and may be a more relevant factor than wall width in terms of tooth strength^143,144. According to Forster et al¹³⁵, cavities with a depth of up to 3 mm can be restored with direct composite restorations, regardless of wall width, and cavities deeper than 5 mm require cuspal coverage. Torbjörner and Fransson¹⁴⁵ concluded in their work that a narrow and deep isthmus weakened the tooth more than a broad and shallow isthmus.

The presence of enamel is a determining factor for maintaining tooth strength, serving as an excellent substrate for adhesive procedures^{132,134–137}. On the other hand, the dentinoenamel junction and the dentin itself are essential for the dissipation of forces¹⁴⁶. Adhesive restorations transmit and distribute forces at the adhesive interface, decreasing cusp deflection¹⁴⁷ and potentially reinforcing tooth structure¹⁴¹.

According to Dietschi and Spreafico¹⁴⁸, replacing a direct restoration with an indirect one causes significant structural loss due to the path of insertion. However, cusp coverage compensates for this structural loss and is directly related to tooth longevity^148–150. Aquilino and Caplan¹⁴² performed a retrospective study of 400 endodontically treated teeth and concluded that teeth that received cusp coverage had six times higher survival rates than those with intracoronary restorations. However, despite the benefits of cusp coverage in restorations of endodontically treated teeth^142,149, Scurria et al¹⁵¹ stated that only 50% of posterior teeth had been restored with this approach.

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