Procedures in Aesthetic Dentistry

Procedures in Aesthetic Dentistry

Subir Banerji and Shamir Mehta

Introduction

There can be considerable variation between individuals in the ideal appearance of the anterior aesthetic zone, which comprises the hard and soft tissues visible when the patient makes a broad smile. There are, however, universal concepts in dental aesthetics that are generally ‘acceptable’ to dental professionals, patients and the public alike. These include:

  • The elimination of oral disease.
  • The need for appropriate dental symmetry, proportion and harmony.
  • An appreciation of tooth position, form and morphology.
  • An understanding of the variations that exist in tooth colour and shade.

When a patient attends a dental practitioner seeking alteration to their anterior aesthetic zone, often with the aim of enhancing their dental and, in turn, facial attractiveness, it is essential that the practitioner:

  • Carefully listens to the patient’s concerns.
  • Adopts a systematic and meticulous approach towards all relevant clinical assessments and evaluations.
  • Has a clear understanding of the universal concepts of dental aesthetics and beauty.
  • Appreciates the varying protocols and materials that are available to affect any planned changes (often tooth colour/shade, size/shape/proportion and position), inclusive of the limitations inherent in the possible treatment option.
  • Underpinned treatment by the principles of ‘beneficence’, i.e. doing good and acting in the patient’s best interest and ‘non‐maleficence’, i.e. doing no harm.

Valid informed consent must be obtained when planning elective dental treatment. Considerations of the possible treatment options should be systematic, professional and conducted in a suitable environment, adopting a clear, accurate, balanced, logical, comprehensive and, where possible, evidence‐based approach to give the patient an as complete and comprehensive understanding as possible of all the risks and benefits of the proposed options, especially the option the patient selects.

This chapter outlines the key stages and principles for the evaluation of the anterior aesthetic zone and provides an overview of the techniques commonly applied to plan the effective and predictable implementation of proposed changes to dental appearance, avoiding the ambiguity often associated with subjective concepts in dental aesthetics and beauty.

This chapter also includes a summary of some of the techniques and treatments frequently applied in aesthetic dentistry. Such treatments should aim to meet the anticipated, realistic expectations agreed with the patient, and provide long‐term aesthetic and functional stability. Wherever possible, minimal intervention approaches and techniques should be applied.

Many conventional views on smile evaluation and the planning of aesthetic rehabilitation tend to be erroneously based on traditional concepts applied in the provision of complete dentures, rather than a thorough knowledge and understanding of the features of the natural dentition.

Smile Assessment

Equipment

  • Dental mirror.
  • Dental probe.
  • Periodontal probe(s).
  • Willis gauge.
  • Fox’s bite plane.
  • Wooden spatulas.
  • Camera/video camera.

Procedure Rationale
Patient history
Clear, complete, contemporaneous and accurate records should be made and kept for all patient history findings.
Medical history
The use of a confidential medical history template (completed prior to the initial appointment) may prove beneficial when screening for common conditions.
The patient’s medical history may:

  • Prevent them from attending for frequent and lengthy treatment sessions.
  • Require an alteration of the treatment protocol to take account of the condition itself and or the drugs used to treat it.
  • Contraindicate a certain form of treatment due to an allergy to a dental material or product that may be required to execute the treatment in an effective manner.
  • Contribute to the aesthetic concern itself, such as drug‐induced gingival hyperplasia.

In relation to those patients seeking elective treatments aimed at enhancement of the aesthetic zone, it is also relevant to screen for a possible diagnosis of body dysmorphic disorder. This is a psychiatric illness that is characterised by the preoccupation with an imagined defect in appearance.

Presenting complaint Concerns with the appearance of the aesthetic zone, often include concerns about tooth:

  • Colour.
  • Position.
  • Shape.

The use of a preconsultation aesthetic evaluation form may help to elicit salient information, especially relating to perceptions of self‐appearance. As far as possible, this should be noted using the patient’s own words.

Dental and sociobehavioural history To note:

  • The patient’s last dental visit and overall frequency of attendance.
  • Home care/oral hygiene practice.
  • Attitudes towards dentistry, past experiences and their expectations/treatment goals.
  • Occupation.
  • Relevant habits.
  • Dietary preferences.
Extraoral examination
Clear, complete, contemporaneous and accurate records, inclusive of any negative findings, should be made and kept on all aspects of the extraoral examination
To include assessments of the:

  • Temporomandibular joints, the associated musculature, the cervical lymph nodes and salivary glands.
  • Facial features: vertical facial proportions, facial symmetry, facial profile, facial shape and width.
  • Lip morphology and mobility.
  • The facial skin.
Temporomandibular joints (TMJs) and masticatory muscles TMJs to be examined bilaterally for the presence of:

  • Any tenderness or pain upon palpation of the area anterior to the auricular tragi or intra‐auricularly.
  • Signs of asynchronous movement and mandibular deviation on opening or closure.
  • Clicking sounds, and the stage – early, middle or late on opening and or closure.
  • Grating sounds, crepitation and/or joint locking.

The use of a stethoscope may prove helpful.
Muscles (generally the temporalis and the superficial and deep elements of the masseter muscles) should be examined, including palpation, for signs of tenderness, discomfort and hypertrophy.
Normal jaw opening should provide a minimum interincisal distance of 35 mm, and 12 mm of movement during lateral jaw movements.

Facial features: facial proportions – frontal view In general, when viewed from in front, with the patient adopting a natural pose, the face can be divided into three zones:

  • Upper third – hairline or forehead to the orphic (brow) line.
  • Middle third – orphic line to the interalar line (base of the nose).
  • Lower third – between the base of the nose and the tip of the chin (Figure 22.1).

In a ‘well‐proportioned face’ the three zones should be of similar vertical dimension.
The lower third is thought to have the greatest influence on facial appearance and may be ‘altered’ by dental intervention.

Facial features: facial symmetry – frontal view The facial midline (vertical plane) and interpupillary line (horizontal plane) are often used as reference lines/planes to determine the level and extent of asymmetry present (Figure 22.2).
Aesthetic harmony is said to exist when the vertical and horizontal reference planes are perpendicular to each other and the facial plane is coincident (within 2.0 mm) of the dental midline. A set of wooden spatulas or a Fox’s bite plane can serve as useful tools for assessing such features.
The interpupillary line may also help to determine and describe the position/orientation of the incisal, gingival and occlusal planes against an established horizontal axis.
Facial features: profile – lateral views Assessed laterally, with a natural head pose, using the Frankfort plane to verify head orientation, three types of profile are typically apparent:

  • Normal.
  • Convex.
  • Concave.

The ‘E‐line’ (an imaginary line that connects the tip of the nose to the tip of the chin) may be used to determine the profile. A ‘normal profile’ is thought to exist when the upper and lower lips are 4 mm and 2 mm posterior to the E‐line (Figure 22.3).
The concept of the ‘normal profile’ may, however, display marked variations between patients of different ethnicity.

Facial features: facial shape and width Four facial shapes have been described:

  • Ovoid.
  • Square.
  • Tapering.
  • Square‐tapering.

Four typological categories have also been defined by Ahmad (2005) in an attempt to correlate personality with facial shape:

  • Lymphatic – rounded full features associated with a timid personality.
  • Sanguine – prominent thick, well‐defined features linked with intransigence and spontaneity.
  • Nervous – large forehead, thin delicate features.
  • Bilious – rectangular and muscular features associated with a dominant personality.

It has been postulated that the morphology of the teeth and any restorations should conform to these facial types.
The facial width may be assessed as the width of ‘five eyes’.

Lips/labial features – morphology and mobility Morphological descriptions can include reference to the level of fullness (thick, medium or thin), width and symmetry. As a rule:

  • Wide lips are associated with a wide smile; a smile that is at least half the width of the face is said to be aesthetically pleasing.
  • Full lips are associated with the dominance of the maxillary central incisors in the smile zone.

Lip mobility – refers to the amount of lip movement on smiling. The rest position of the upper lip can be used to determine the level of incisal display at rest. This may typically range from:

  • 3.0–3.5 mm for a 30‐year‐old.
  • 1.0–1.5 mm for a 50‐year‐old.
  • 0.0–0.5 mm for a 70‐year‐old.

Phonetic tests, with the enunciation of ‘F’ and ‘V’ sounds can help establish and determine the desired spatial relationship between the maxillary incisal edges and the lower lip; ideally the maxillary incisal plane should follow the curvature of the lower lip as an accepted universal concept. A video image taken perpendicular to the facial midline with the patient talking and smiling can be a valuable record of the relationship of the lip in motion and the amount of the teeth and gums visible during function.

Facial skin Facial skin may be classed according to:

  • The level of pigmentation.
  • Tendency to burn.
  • The likelihood of a reaction to treatment.

The Fitzpatrick skin phototype classification may prove helpful when planning facial aesthetic treatments.

Intraoral examination To include a systematic assessment of the:

  • Soft tissues.
  • Periodontal tissues.
  • Dental hard tissues.
  • Occlusion and arch form.
  • The aesthetic zone.
  • Any edentulous spaces.
Soft tissue examination The soft tissues of the mouth and oropharynx should be meticulously assessed for any abnormality.
The presence of a tongue thrust or high frenal attachment should also be identified and recorded accordingly.
Periodontal tissues As part of essential practice, the patient’s overall standard of oral hygiene should be ascertained, noting the presence of any plaque and calculus deposits, anomalies in the colour and form of the gingivae, sensitivity, bleeding on probing and suppuration, tooth mobility and the presence of any furcation defects.
Periodontal probing should also be undertaken and recorded. The Basic Periodontal Examination provides an excellent starting point.
Where complex restorative care is planned or instability is suspected, it may be prudent to determine the levels of clinical attachment loss at six points per tooth, as well as undertaking and recording periodic plaque and bleeding scores to assess any developments following the provision of preventative advice and periodontal treatment.
Dental hard tissues A dental hard tissue chart should be completed, noting:

  • Teeth present/ absent.
  • Presence, location and extent of any carious lesions.
  • Any sound and defective restorations (noting signs of failure – such as leakage, marginal adaptation, lack of appropriate interproximal contact, restoration form, function and appearance).
  • Tooth fractures and or cracks.
  • Signs and location of pathological tooth wear.
  • Tooth malformations.
Occlusion and arch form Static occlusal features to assess and record include any signs of:

  • Tilting, rotation, drifting, supraeruption crowding, spacing, presence of diastema.
  • The overjet, overbite.
  • The arch form.
  • Interarch relationships: incisor, canine and molar segment relationships.
  • The occlusal vertical dimension/resting vertical dimension.

Dynamic occlusal assessment to note:

  • The intercuspal position (ICP).
  • Signs of occlusal instability.
  • The ease at which centric relation (CR) can be located, the first point of tooth contact in CR (CRCP – centric relation contact point) and the presence and extent of any slides between ICP and CRCP.
  • Tooth relationships during the undertaking of protrusive mandibular movement – the anterior guidance.
  • Tooth relationships during lateral excursive mandibular movements – canine guidance/ group function.
  • The presence of any working side/non‐working side occlusal interferences.
The aesthetic zone/smile zone The examination should include (Mehta, Aulakh and Banerji (2015):

  • Smile‐zone shape.
  • Dentolabial relationships.
  • Dental midlines.
  • Tooth colour, texture and form.
  • Tooth size, shape, proportion, symmetry and axial inclination.
  • Contact areas and embrasures.
  • Gingival aesthetics.
Smile zone shape Six shapes have been described:

  • Straight.
  • Curved.
  • Elliptical.
  • Bow‐shaped.
  • Rectangular.
  • Inverted.
Dentolabial relationships ‘Lipline’ is a term that describes the relationship between the inferior border of the upper lip and the maxillary teeth/gums on smiling/enunciating the sound ‘E’ (E‐test).
Three categories are recognised:

  • Low smile line – maxillary anterior teeth exposed by no more than 75%; no gingival display.
  • Medium smile line – 75–100% of clinical crown display as well as the interdental papillae,
  • High smile line – line extends beyond the gingival margin – the ‘gummy smile’ (Figure 22.4).
‘Smile width’ – the display of 10 maxillary teeth is the most common pattern seen (extending to the first molar teeth); the presence of any spaces between the buccal surfaces of the posterior teeth and the labial commissure – the buccal corridor, can give rise to a less than ideal appearance.
‘Smile arc’ (Figure 22.5) – refers to the relationship between the curvature of the lower lip and curvature of the incisal edges of the maxillary incisor teeth; ideally these planes should be symmetrical, with the superior lip border positioned slightly below the upper incisal plane, yielding a ‘convex incisal curve’.
In the case of a worn dentition, this may take the form of a ‘flat’ or ‘reverse smile’, thought to be less aesthetically pleasing as often associated with an ‘aged‐appearance’.
The dental midlines Ideally, the dental midline should be coincident with the facial midline; a 2 mm discrepancy is less noticeable (Figure 22.6). However, when more than 4 mm, orthodontic intervention may be indicated.
The upper and lower dental midlines show coincidence in 25% of the population only; a small discrepancy is likely to have limited impact.
Tooth colour, texture and form A colour assessment should consider:

  • Hue – base colour.
  • Chroma – saturation of base colour.
  • Value – brightness.
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Jan 22, 2018 | Posted by in General Dentistry | Comments Off on Procedures in Aesthetic Dentistry
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