At the finish of orthodontic treatment, it is imperative that the outlined goals of orthodontic treatment be attained. These can be broadly categorised into five major groups:

• 1.

  Normal occlusion in centric relation

• 2.

  Normal functional movements

• 3.

  Optimum facial and dental aesthetics

• 4.

  Healthy temporomandibular joint (TMJ) in harmony with occlusion

• 5.

  Good periodontal health

Clinical examination of the face includes evaluation of the profile and smile at rest and in a dynamic state. Assessment of profile includes nasolabial angle, chin prominence, lip relations at rest and relation of lips to anterior teeth.

Clinical assessment of occlusion in functional movements of the mandible is performed to evaluate any interferences during the lateral and forward glide of the mandible. While the patient is made to feel relaxed and asked to perform gentle glide of the mandible forward with teeth in occlusion. A smooth glide with uniform contacts is expected with functional surfaces of upper and lower anterior teeth. The labial-incisal surfaces of the mandibular incisors should smoothly glide against the lingual surfaces of the maxillary incisors with uniform pressure (exhibiting no premature contacts) without any deflection. Any errors in occluso-gingival discrepancy in bracket placement or errors in tip causing premature contacts should be taken care at this stage either by repositioning the brackets or appropriate bends in the wires.

During lateral right and left movements of the mandible, a gentle lateral slide on canines is expected. During the lateral jaw movement, there should be complete disocclusion of the buccal teeth. The hanging lingual cusp of the maxillary molar is often an interference. The hanging lingual cusps and buccal interference are caused by a narrow upper arch or inadequate buccal root torque or a combination thereof. The interference in lateral movement, therefore, should be corrected with appropriate buccal root torque and coordination the upper and lower arch forms.

Following records are prepared and evaluated ( Fig. 56.1 ):

• 1.

  A set of upper and lower working/study models and a wax bite.

• 2.

  Lateral cephalogram and orthopantomogram (OPG).

• 3.

  Clinical photos of posed and spontaneous smile.

Pre-finish evaluation of a case related to achieving a finished occlusion.

Case: VS, 20/M (A) Pre-treatment photographs and occlusion show the patient prior to treatment with a standard edgewise fixed appliance following the extraction of all first premolars. (B) After space consolidation, clinical examination, including profile and intraoral photos, reveals that the maxillary anterior teeth are under-torqued. (C) After finishing and detailing, it is noted that sufficient torque has been achieved. This improvement has enhanced the relationship between the lips and the anterior teeth, as well as the overall facial profile. (D) Pre-treatment lateral cephalogram showed a U1-SN angle of 124.4 degrees and an inter-incisal angle of 110.9 degrees. (E) The lateral cephalogram taken after space consolidation revealed a decrease in the U1-SN angle to 94.4 degrees and an increase in the inter-incisal angle to 139.4 degrees, resulting in under-torqued maxillary anterior teeth. (F) The post-treatment lateral cephalogram indicated an increase in the U1-SN angle to 103.5 degrees and a decrease in the inter-incisal angle to 129 degrees, restoring the proper relationship between the lips and teeth. (G) Pretreatment (H) Prefinish and (I) Posttreatment OPGs (J) Pre-treatment occlusion. (K) Post-treatment occlusion. Note flexible spiral wire (FSW) retainer in upper and lower arches.

Upper and lower models are used to outline and record discrepancies from normal deviations so that suitable measures can be taken to achieve normal occlusion. Study models are registered with a wax bite and mounted on a semi-adjustable articulator. The mounted study models are the most useful reference for comparison with pre-treatment models to evaluate improvement in existing malocclusion, unwanted effects of orthodontic therapy. The pre-finish study models serve as a reference to outline the desired occlusion and plan the retention appliance. The arch forms, intermolar and intercanine widths and cuspal relations are best judged on articulated models. With current trends in 3D scanning, the dental casts have been substituted with digital models and analysis of occlusal pressure and contact points.

Lateral cephalogram is assessed for the thickness of cortical bone around maxillary/mandibular anterior teeth and position of roots, which should be placed centred in the alveolus process. The inclination of the long axis of maxillary central incisor to SN plane serves as a guide to labiolingual inclination and hence the torque. A low angle (<110 degrees) suggests a need for further palatal root torque to be incorporated ( Fig. 56.1 E). A pre-debond stage cephalogram is also useful for evaluation of remaining growth, which will affect further treatment strategies on finishing and suggest any alterations in the retention schedule. The soft tissue profile, skeletal profile, upper airway are also readily evaluated.

OPG is the most useful guide for evaluating the mesiodistal tip of the teeth and relationship of roots of teeth with those of neighbouring teeth. Based on the OPG evaluation, compensating bends are placed in the arch wire to ensure that the desired root and crown tip should be attained. OPG X-ray can also offer an overview of periodontal status to mark the teeth ( Fig. 56.1 G–I) for further intra-oral periapical (IOPA) X-rays for detailed periodontal examination. The pre-treatment and post-treatment occlusion of a case are exhibited in Fig. 56.1 J and K.

The pre-adjusted appliance system can place the teeth according to its predetermined prescription, while needs of an individual or the nature of malocclusion may substantially differ from its inbuilt prescription. The use of the pre-adjusted appliance is based on the premise of complete expression of the prescription, which can be attained only on insertion of full-size wires. In day-to-day orthodontic practice, full-size wires are rarely used; therefore, the total potential of a pre-adjusted appliance in achieving final tooth positions remains underutilised. The placement of full-size wires and expression of tip, torque and alignment of arches in achieving correct occlusion is predetermined by the accurate positioning of the brackets and tubes. It is practically impossible to place all the brackets free from error. These bracket positioning errors become apparent during finishing stage and reflect in a variety of forms of less than ideal occlusion. Hence, a selective bracket repositioning may be required, which should be undertaken before finishing wires are inserted. Case study given in Fig. 56.1 shows that following incisor retraction often there is a torque loss which can be quantified on a lateral cephalogram besides clinical evaluation. Loss of torque usually occurs during space closure and retraction of anterior teeth because of play between the the bracket slot and arch wire. After the full-size arch wire was placed with additional palatal root torque, cephalometric parameters showed improvement as did the incisor-lip relationship.

It is essential to recognize that full-size wires are required for torque to be effective ( Fig. 56.2 ). However, there may be a slight play of up to 2 degrees at the interface between the wire and the bracket. This is attributed to manufacturers often producing bracket slots that are slightly larger and wires that are slightly smaller than the specified dimensions. Consequently, this discrepancy leads to a torque loss that exceeds the calculated value derived from exact measurements ( Fig. 56.2 A,B). The actual loss of torque is, in fact, double the amount of play observed between the wire and the bracket slot.

There is a loss of torque during space closure and retraction of anterior teeth. Rectangular wires are manufactured by drawing round wires by rolling; therefore, the edges of the wires are round, which accounts for the interplay between the bracket slot and the best-fit wire. (A) The actual loss of torque is the play between the wire and the bracket slot. Manufacturers tend to make the bracket slot slightly larger and the wire slightly smaller than the recommended size, resulting in greater torque loss than the calculated value when exact dimensions are used. (B) The figure demonstrates torque loss with different sizes of wire in 0.022 × 0.028 in. slot.

Source: Based on the concept of Schwaninger B. Evaluation of the straight arch wire concept. Am J Orthod 1978;74(2):188–96 .

In a standard edgewise appliance system, Tweed suggested that a long V-bend should be incorporated at a mid-incisor point to prevent the mesial tipping of the roots during overjet reduction. Following final space closure, required torque is attained by incorporation of active root torque in the anterior portion. Integration of palatal root/buccal crown torque during retraction causes loss of tip; it is called the wagon wheel effect ( Figs 56.3 and 56.4 ). Finishing wires of 0.0215 × 0.0275 in. are fabricated with an artistic positioning bends between two maxillary central incisors and one each on both sides between central and lateral incisors. In the mandibular arch, similar bends of much less intensity are required ( Fig. 56.4 ). An illustration of the artistic bends, and the finishing bends used in standard edgewise wire, is shown in Figure 56.5.i .

The incorporation of torque. (A) When no torquing is desired, the wire should be parallel to bracket slot. (B) For palatal root torque, the wire torque is incorporated in a gingival direction. (C) For buccal torque, the wire torque is incorporated in the incisal direction. (D) In case of torquing single tooth, torque is incorporated in part of the arch wire.

Wagon wheel effect. (A) The anterior teeth and their roots in an arch are placed as shown. (B) When labial crown torque is incorporated in the wire, the roots of anterior teeth tend to converge towards the centre like spokes of a wheel. It has been often called a wagon wheel effect.

The artistic bends/finishing bends. Arch wire is usually full size.Marking for artistic bends. (A) Long V-bend placed between central incisors. (B) A second artistic bend is incorporated between central and lateral incisors with arrows depicting the direction of the bend. (C) A third artistic bend being placed between lateral incisor and canine. (D) Finished wire.

Figure 56.5.ii depicts the application of the artistic positioning bend in a clinical setting, demonstrating its use for relocating the contact point between the maxillary central incisors.

The artistic bends/finishing bends for relocating the contact point between maxillary central incisors. Arch wire is usually full size. (A) Note the contact point relation between two maxillary central incisors (contact at the middle third). To improve the aesthetics in the anterior region, it was decided to relocate the contact point at the incisal third. (B) An artistic bend between the two central incisors was created (the wire is not ligated in the anterior brackets). It is called a centred V-bend, as only opposite moments in the second order are required without any vertical forces. (C) Wire, when completely ligated in the arch, appears to be straightened out in the incisor region but will deliver equal and opposite moments desired to obtain root paralleling and relocation of contact point at incisal third. ( D–F ) After 4 months of treatment, note the relocation of the contact point at the incisal third of the maxillary central incisors. Photographs in A and E were made with slight open bite to appreciate proximal contact between centrals.

Using light round wires replacing rectangular wires was the original method for settling recommended by Tweed in the 1940s. According to him, these light wires must have ‘first and second order bends’ of intensity used in rectangular wires which are not a necessity with the pre-adjusted appliance system. These light arch wires would quickly settle the teeth into final occlusion and should remain in place for only a few weeks at most. The light wires have inherent disadvantage of loss of precise control of arch form. Therefore, a careful watch on occlusion is required. The patient is recommended to chew sugar-free gum, which helps to settle the occlusion in maximum inter-cuspation while the teeth try to occupy positions in the alveolar bone. Vertical elastics should be used in the buccal segment as and when needed.

Laced vertical elastics were in practice around Tweed’s era; however, later this technique was modified by removal of the posterior part of the rectangular arch wire while leaving a segment of the rectangular arch wire in a canine-to-canine or premolar-to-premolar region. Elastics for settling are placed around tubes and brackets. A typical arrangement is to use light 0.25 in. elastics with class II or class III pattern depending upon the type of correction desired. The rubber bands can also be used in a configuration of triangulation M or W or a fashion that will appear suitable to bring in maximum inter-cuspation ( Fig. 56.6 ). These elastics should not remain in place for more than 2 weeks. This technique is contraindicated in patients with major rotations or posterior cross-bites, for it does not offer good control on posterior teeth.

Triangular settling elastics on upper and lower lighter round arch wires can be used for short duration (1–2 weeks) to achieve good inter-cuspation during the final finishing stage.

Long class II elastics can be used to achieve class I canine and molar relationship as shown in Fig. 56.7 for a non-extraction case while short class II elastics to settle the occlusion in class I canine and molar relationship to achieve good inter-cuspation during the final finishing stage ( Fig. 56.8 ). Note rectangular arch wire in the mandibular arch and round arch wire in the maxillary arch. Mandibular arch act as a stabilising arch against which maxillary teeth are vertically erupted to achieve good inter-cuspation.

A non-extraction case with class II end on molar relationship.

Long class II elastics can be used to achieve class I canine and molar relationship

Short class II elastics to settle the occlusion in class I canine and molar relationship to achieve good intercuspation during the final finishing stage.

Note rectangular arch wire in the mandibular arch and round arch wire in the maxillary arch. Mandibular arch act as a stabilising arch against which maxillary teeth are vertically erupted to achieve good intercuspation.

A variant of short class II elastics to settle the occlusion in class I canine and molar relationship is shown in Fig 56.9 . The anterior teeth are engaged in sectional round arch wire while the buccal segment can be maintained in figure of 8 using soft ligature around brackets free from main arch wire. Short class II elastic for a very short duration can bring out good intercuspation of the posterior teeth.

A variant of short class II elastics to settle the occlusion in class I canine and molar relationship.

The anterior teeth are engaged in sectional round wire while the buccal segment can be maintained in figure of 8 fashion without any wire. Short class II elastics for a very short duration can bring out good inter-cuspation of the posterior teeth.

A passive utility arch fabricated in 0.016 × 0.016 in. stainless steel wire is tied in bracket slots of incisors. Passive arches help to maintain overbite and arch length, while premolars are kept free to settle in occlusion with inter-digitation.

An alternative to segmental elastics or light round arch wires for settling is a rubber or plastic tooth positioner. The tooth positioner is a custom-made resilient mouthpiece, which is a useful adjunct to quickly ‘sock in’ the unsettled occlusion. The resilient positioners are made from upper and lower impressions, and a wax bite is recorded in centric occlusion. A face bow record in centric relation is required. The models are transferred on an articulator in centric relation. The teeth on upper and lower models are selectively split into several segments to be seated in best occlusion. The positioners are made in this new ‘set-up’ occlusion.

On the day of debond appointment, the soft tooth positioner is issued with instructions of 24 h wear. In 2 weeks’ time, the occlusion is usually settled, showing improved occlusion and the patient is ready for new retainers, which are made from freshly made impressions. Tooth positioners have been found effective in improving the occlusal finish, but the effects are independent of an increase in occlusal contacts. Positioners primarily help to achieve first-order alignment by tipping teeth into an improved inter-cuspation.

The tooth-size discrepancy may be corrected either by reducing tooth mass in one arch with inter-proximal enamel reduction (usually lower incisors) or by an addition of tooth mass with a restorative material in the opposing arch. It is more common to find an excess tooth substance in the lower arch. If the Bolton’s analysis confirms excess, it is advisable to carry out inter-proximal recontouring in the lower anterior region in the initial stages of treatment. As the finishing stage is approached, the relative tooth mass in the upper anterior segment is evaluated, and inter-proximal reduction is carried out if necessary. The tooth size discrepancy may be overcome with suitable aesthetic restoration of microdontic maxillary lateral incisor(s). The maxillary tooth size smaller values are commonly contributed by the peg shaped or a microdontic lateral incisor. Such conditions require the space to be made available for the restorative work to be done by the dentist or a prosthodontist.

Standard errors in occlusion seen during or at a finish of anterior retraction are tabulated in Table 56.1 . Plausible reasons and solutions are classified side by side.

TABLE 56.1

Common errors in occlusion seen at final space closure and suggested solutions for finishing and detailing

S.no.	Problem	Aetiology	Possible solution(s)
1.	Upper lip in poor relationship with incisors	i. Excessive tipping of teeth during retraction: inadequate labial crown torque	Maxillary and mandibular coordinated rectangular arch wires with additional torque and bite opening mechanism are placed.
		ii. Poor vertical relation, that is, extrusion of maxillary incisors
		iii. Lack of distal tip on anterior teeth: upright incisors	Bracket positions would require fine adjustments or the same can be overcome by refining bends in the finishing arch wire.
		iv. Problems with occluso-gingival heights at occlusal plane	Finishing bends or redo faulty brackets positions
		v. Asymmetrical first-order relations	Use coordinated arch wires
2.	Asymmetrical overjet	i. Lack of coordination of upper and lower arches in anterior segment	Coordinated arch wires of higher dimensions
		ii. Localised first-order deficiency or excess thickness of composite bonding material on selective bracket base	First-order bends at selective bracket locations
		iii. Anatomical variation in tooth morphology	Modification of tooth anatomy
3.	Unilateral or bilateral buccal cross-bite appearing at finishing stage	i. Lack of coordination of arches	Full-size coordinated arches for transverse widths: care for inter canine and inter molar widths
		ii. Collapse of arch width with prolonged use of light arch wires
		iii. Premature contacts causing deflection of the mandible	Remove any premature contacts causing deviation of the mandible to cross-bite. Check for buccal root torque on maxillary molars and hanging palatal cusp should be attended to
		iv. Class III skeletal pattern may exhibit mandibular transverse growth	Institute appropriate maxillary dental expansion
4.	No overjet, yet spaces remain in the maxillary arch: common site distal to lateral incisors	i. Loss of distal tip of the roots during space closure: root crowding. Root crowding is clinically assessed by a careful examination of the long axis of the clinical crowns. Inadequate tip of the roots can be assessed on intraoral periapical X-rays.	Institute correct bracket positions and use full-size arch wires and make finishing arch wires by building artistic positioning bends. The desired torque should also be achieved at this stage.
		ii. Improper brackets positioning in relation to facial clinical crown axis (FCCA)
		iii. Correction of large overjet with undersize arch wires	Distalise maxillary dental arch if needed.
		iv. Excessive labial proclination of mandibular incisors	Labial root torque on lower incisors will contribute to their lingual crown movement, thereby allowing some overjet correction.
		v. Mandibular excess tooth material on Bolton’s analysis	Consider the proximal reduction of teeth in the lower arch.
		vi. Bolton discrepancy in the anterior segment	Check for deficiency in tooth material substance on maxillary teeth. Small lateral incisors may require aesthetic modification with composites.
5.	Overjet remaining while all spaces in the maxillary arch are consolidated.	i. Inadequate forward positioning of the mandible in class II malocclusion	Use class II elastics or fixed functional appliance to reposition mandible forward
		ii. Upright mandibular incisors	Procline lower incisors within permissible limits of the case
6.	Poor buccal cusp to fossa relations	i. Upper arch intra-arch discrepancy in bracket/tube heights on premolar and molar leading to a discrepancy in marginal ridge relations	Correction of vertical marginal ridge discrepancy by altering bracket positions or appropriate step-up/step-down bends
		ii. Excessive distobuccal rotation of the maxillary first molars during use of class I intra-arch force	Complete control of rotations of premolars would require couple force by bonding lingual attachments from initiation of orthodontic treatment
		iii. Mesial tip of the first molar	Maxillary first molars would need sufficient toe-in bends. Full size edgewise arch wire. Tie with full seating and tight ligatures. Check for anterior and buccal root torque or prescription of brackets.
		iv. Inadequate buccal root torque
		v. Hanging lingual cusps of molar(s)
		vi. Incomplete correction of rotations
		vii. Lower-arch intra-arch discrepancy in bracket/tube heights on premolar and molar leading to discrepancy in marginal ridge relations	Wires with sufficient buccal root torque are a must to position buccal segment in a good occlusal cusp to fossa relations.
		viii. Lingual tip of lower molar, lack of sufficient arch width and buccal root torque	Mandibular arch would require a full-size wire to prevent lingual dumping of the molars.
		ix. Excessive mesial tip of the first molar	Incorrect tube angulations and placement must be corrected or compensated with tip back and toe in bends.
		x. Incomplete correction of the rotations
7.	Midlines/centre lines not coinciding	i. Asymmetrical retraction and lack of tooth material on one side of the arch	Cross-elastics work well for minor problems of midline discrepancy. Gain lost space and maintain class I canine relations.
		ii. Loss of space unilaterally
8.	Lack of anterior guidance	i. Lack of anterior guidance is often caused by poor relations of upper and lower incisors	Good inter-incisal angle with little overbite and 2 mm overjet will give a smooth anterior guidance to occlusion.
		ii. Insufficient anterior root torque will lead to large inter-incisal angle resulting in poor anterior guidance and inadequate separation of occlusal teeth
9.	Immediate deflection on anterior or lateral movement	Lack of mutual protection	Develop canine relations with the required tip of teeth and overbite enough to cause smooth glide on canine with disocclusion of the rest of the teeth on both the sides of the arch. Any interference due to hanging cusp in buccal segments should be taken care with due torque and tip for that tooth. Develop smooth canine guidance through correct mesio-distal tip and proper cuspal heights. During smooth glide and lateral excursions, there should be no cuspal interference in buccal region. Coordinated wires focus on maintenance of inter-molar and inter-canine widths become imperative.
10.	Interferences in protrusive and lateral excursions	i. Lack of good relations between upper and lower canines is often the result of either premature contact due to excessive cusp height or buccal overbite in canine region or lack of complete overbite	Adequate torque and bite opening; bracket heights correction.
		ii. Deep bite and hanging cusps

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