finishing and detailing in orthodontics

FINISHING AND DETAILING IN ORTHODONTICS

BY:DR JASMINE ARNEJA

CONTENTS

Introduction Evolution Dougherty’s factors in finishing Factors affecting the finishing phase Esthetic procedures in finishing Periodontal procedures in finishing Finishing to ABO requirements Positioners for finishing Conclusion

Introduction

Man has always tried to attain perfection in all his endeavours. In recent times, great deal of emphasis is placed on achieving perfect finishing of the orthodontic treatment so that the results are pleasing to the eye and hopefully are more stable and conducive to an improved function and health.

  Although, the earlier authors like Tweed did mention finishing of a

case, the impetus to this concept was given by Andrews, who expressed his dissatisfaction with the hundreds of completed cases that he saw at various meetings and which he felt were lacking in perfect occlusion. His own study of 120 non-orthodontic models led him to formulate the "six keys to normal occlusion ".

  Finishing is considered to be very difficult and time consuming in

Conventional Begg therapy. But the same has become very easy with the PEA systems. If the tip, torque and in-out compensation built into the appliance is accurately suited to the patients dentition, and if the brackets are properly positioned, then only minimal wire bending should be required to complete the treatment.

Finishing : It is the last step, before active treatment is discontinued, of ensuring that the teeth and related structures are positioned in such a way as will lead to a better stability of results, enhancement of esthetics, optimised functions of the stomato-gnathic system and an improvement of the health of the periodontium.

Detailing : It is the achievement of the ideal positions of every tooth in the vertical and horizontal planes with particular reference to the individual in-out, rotation, tip and torque adjustments.

Evolution of the concept of finishing

The concept of finishing has changed from that of the earlier authors who primarily relied on nature to achieve final finishing in each individual case. According to Angle, "the best the orthodontist can do is to secure

normal relations of the teeth and correct the general forms of the arch, leaving the finer adjustment to individual type form to be worked out by nature, which must, in any event, finally triumph".

Tweed relied primarily on placement of the lower incisors over basal bone. He also stressed the importance of artistic (second order) bends in the archwire.

Begg's philosophy on finishing emphasized the routine over movement and overcorrection of all aspects of the malocclusion (e.g. Deep-bites were finished in edge to edge or slight open bite, class II cases were finished in super class I, class III). So that teeth would settle into proper positions after tissue rebound.

Merrifield belief of finishing also plans stress on overcorrecting major problems so that changes seen during denture recovery would move occlusion towards ideal.

According to Bench et al “The natural forces of eruption and natural forces of occlusion combine with those of physiology and growth to settle teeth functionally into the best position for each individual's characteristics.”

  Andrew's in 1972 went against this belief and published

six keys to normal occlusion. This study established normal values for in out, tip and torque for each individual tooth which were then built into the edge wise brackets for the straight wire appliance.

DOUGHERTY’S FACTORS IN FINISHING

In 1976, Dougherty described 17 factors that should be con sidered in the finishing and detailing stage of orthodontic treatment.

1)Correction and overcorrection of A.P. jaw relation ship

  Proffit and Rickett’s recommends over treatment of Class II

and Class III malocclusion to overcome rebound of 1-2 mm. Zachrisson overcorrects rotations and labiolingual

displacements of individual teeth to 1/10th overmovement. McLaughlin and Bennett contend that Class II case with

deep bites benefit from over correction to an end-to-end position, and maintenance of that position with night time Class II elastics for six to eight weeks, which is followed by settling into an ideal Class I relationship.

2) Establishing correct tip of upper and lower anterior teeth.

AlOuabandi et al reposrted 6-7degree of lower incisor flaring when simply leveling the curve of spee

Raleigh Williams states that lower incisor apices should be spread distally to the crowns and the apices of the lower lateral incisor must be spread more than those of the centrall incisor. The apex of the lower cuspid should be positioned distal to the crown.

According to MBT (40’ upper anterior, 6’ lower anterior) the 34 degree of additional tip helps in overjet maintenance and better fit

3) Establishing correct torque of upper and lower anterior teeth

Torque is frequently lost during the retraction phase of treatment, especially in class II div 1 cases. Thus anterior teeth must be torqued to maintain the correct overjet and overbite and to establish stability

4) Coordinating arch widths and archform

  Arch form coordination prevents development of a cross

bite.

  McLaughlin and Bennett prefer widening the archform in the

bicuspid area, so that mesial of lower bicuspid contacts distal of upper cuspids and therefore the lower eight most anterior teeth make contact with upper six most anterior teeth during protru sive movements.

Cross-elastics in cuspid

areas used to compensate for asymmetrical upper archform (symmetrical arch indicated by dashed line).

Modified upper archform (dotted line): archwire canted in direction opposite to asymmetry.

5) Establishing correct posterior crown torque and crown tip

Mclaughlin and Bennett state that correct posterior crown torque is essential to prevent posterior interfer ences from developing and to allow seating of centric cusps.

In normal situation, the lingual cusp of the mandibular posterior teeth should be at the same level or a milimeter of the buccal cusp. This relationship makes the occlusal table of posteriors relatively flat tereby promoting a better contact between the maxillary lingual cusp with maxillary fossae.

“Rolling in” is a common phenomena seen in mandibular posterior teeth. In the maxillary arch, the palatal cusps of 1st molar and second premolar tend to be longer than the buccal cusp, thus disturbing proper interdigitation

Therefore flattening the CURVE OF WILSON results in improvement in interdigitation of maxillary and mandibular teeth.

6) Establishing marginal ridge relationship and contact points

  Marginal ridges are a key to achieve relative vertical

positioning of posterior teeth. This will position the cusp and fossae of adjascent teeth at the same level. Thereby the CEJ will also be at the same level, producing equal and suffient bone support and healthier periodontium

Contact point: Contact surfaces of teeth are generally located in the occlusal 1/3

of the proximal walls, slightly buccal to the central fossa in the molar and premolar area with the exception of maxillary 1st and 2nd molars.

The contact point between max incisors is located between the most incisal 1/3 having the perception of a vertical line

From CI To Canines, contact points gradually move from incisal to gingival

Contact points must be taken into good consideration to provide adequate post treatment stability and healthy periodontium.

7) Correction of midline discrepancies

It is important to establish the origin of the discrepancy in order to correct it

Upto 3 mm of mildline discrepancy can be corrected in this phase

Usually elastics are enough for midline correction but at times asymmetric stripping may be required

8) Establishing the interdigitation of teeth

  Different authors use different configuration of elastics

for final seating of occlusion. The elastics are worn after rectangular arches are changed to light round wires so that teeth can settle more comfortably.

  Alexander also recommends chewing sugarless gum to

get good interdigitation of teeth. Proffit describes 3 ways to settle the occlusion:

◦ Replacing rectangular wires by round light wires with some freedom of movement and using light vertical elastics

◦ Using laced posterior vertical elastics after removing the posterior wire segments

◦ Tooth positioner

Laced vertical elastics

Variations:◦ Cuspids labially displ. – extend sectional wire in upper

ant. seg to hold them in postn.◦ Diastemas – areas tied lightly with elastic thread or

ligature wires.◦ Teeth extracted. – figure of 8 ties –across extraction.

sites.◦ Palatal expansion cases -a small removable palatal plate

– maintain expansion during settling phase◦ Moderate to severe Cl II/I, full upper arch wire is used

with wire bend back distally- controls OJ

Serpentine wires:- 1 week before appliance removal U&L arch wires are removed ,ligated together in a serpentine fashion from PM to PM with ligature wire--- occlusion to settle without any interdental spacing– (in minimal discrepancies of tooth position)

Vertical spaghetti elastics:- 1 week before appliance removal U&L arch wires are removed .

0.16” ss wire secured in L arch with light steel ligatures and no arch wire in upper arch.

Series of triangular elastics placed btwn two arches. 3 arms of elastic include distal br. wing of one max tooth ,mesial br. wing of the postr tooth and the entire br. of mand tooth closest to it. In CI region two elastics placed in midline.

Wear full time – rapid settling of occlusionContraindicated in cases originally characterized by deep bite

(Class II div 2) :- serpentine wires used

Settling elastics with class II pull:- 2oz elastic started over L2M &U1Molar twisted and engaged over next 2 teeth and repeated to the UCi on X side

Settling elastics with class III pull:-starts from U2&L 1 M and extends to the Ci. on X side

Box elastics

w/m elastics

9) Checking cephalometric objectives

  McLaughlin and Bennett recommend that progress

headfilms should be taken about halfway through treat ment to allow time for reassessment of anchorage and possible changes in division of treatment time. They prefer to take final cephalogram three or four months before debonding

Important factors to evaluate with progress and final cephalometric x-rays include

◦ AP posn. of the incisors◦ incisor angulations, ◦ changes in the occlusal plane,◦ the degree to which vertical dev.iation occurred or

restricted, &◦ the success of the correction of horizontal and skeletal

components of the case.

10) Checking the parallelism of roots

  A panoramic X-ray should be taken before

debonding to evaluate root parallelism.

Parallel roots provide adequate bone support around each tooth thereby preventing tooth tipping to any side 

A v bend can be created in the midline to avoid root tipping while retraction.

In earlier treatment prescriptions, root uprighting was a definite stage in the treatment. With the advent of sliding mechanics and PEA, nedd for root uprighting has diminished.

Fuller wires (0.021 x 0.025 for 0.022” slots and 0.017 x 0.025 for 0.018” slots) are preferred. In case evident root tiping needs to be done, beta ti vires are recommended)

11) Maintaining the closure of all spaces

  McLaughlin and Bennett prefer passive tiebacks in

finishing stage especially in extraction cases to maintain space closure. Also lacebacks are routinely used.

12) Evaluating facial and profile esthetics  Roth suggests that the tip of upper incisors should be 2-

2.5mm below the lip embrasure of the upper and lower lips and 1mm of attached gingiva should be showing on full smile.

Artis tic positioning of the upper anterior teeth has been recommended by Tweed, Mollenhauer and recently by Sheridan.

13) Checking for TMJ dysfunctions such as clicking & locking

14) Checking functional movements

Coincidence of centric relation with centric occlusion is a goal for various authors

CHECK BITE! lower eight most anterior teeth make contact with the

upper six most anterior teeth during protrusive movements. Teeth should not prevent mandible from entering into or

leaving any excursion. In lateral excursion, the canines should provide a glide path

with no interference on the balancing side

15) Determining if all habits have been corrected :

Habits such as tongue thrusting will usually correct before finishing stage,

16) Correction of rotations and overcorrections where needed:

Rubber rotation wedges under rectangular wire. Steiner rotation wedges. Lingual elastics.

17) Establishing a relatively flat plane of occlusion

ESTHETIC PROCEDURES FOR FINISHING

GOLDEN PROPORTION MISSING LATERALS

◦ Fixed prosthodontics is treatment of choice

◦ In case of implants. 6.5 mm of space is required between adjascent roots to place a standard 3 mm wide implant

GINGIVAL ARCHITECTURE◦ Gingival zenith lies distal to long

axis of crown of CI and Canine and coincides with long axis of LI

ADJUNCT PERIODONTAL PROCEDURE

SUPRACRESTAL FIBROTOMY

POSITIONERS FOR SETTLING

ABO- CRE GUIDELINES

ABO MEASURING SCALE

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The buccolingual inclination of the maxillary and mandibular posterior teeth shall be assessed by using a flat surface that is extended between the occlusal surfaces of the right and left posterior teeth. When positioned in this manner, the straight edge should contact the buccal cusps of contralateral mandibular molars and premolars. The lingual cusps should be within 1 mm of the surface of the straight edge (fig. 9). In the maxillary arch, the straight edge should contact the lingual cusps of the maxillary molars and premolars. The buccal cusps should be within 1 mm of the surface of the straight edge00

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