Begg`s Technique. Still an Effective Tool

Abstract

Begg,s technique is suggested to be an effective technique for treating malocclusion. Its distinctive features are vertical slot brackets, auxillary springs and special wire (AJ Wilcock). As the wire used is a round wire in a round vertical slot the tooth movement which takes places is crown tipping (uncontrolled tipping). The root uprighting and torquing requires placement of auxillaries which is considered to be a tedious and technique sensitive approach.

The most common problem encountered with this technique is adequate torque expression post retraction. The current article discusses a case of a bimaxillary protrusion in which all 1st premolar extraction was done and post treatment adequate torque was achieved.

Kywords:

Auxillaries, Begg,s brackets, Bimaxillary protrusion.

INTRODUCTION

Begg,s technique was introduced by P R Begg.1 This technique is based on differential light wire technique .1 This technique uses special round wire (AJ Wilcock) which is engaged in the round vertical slot of the bracket using a lock pin.

The contact between the wire and the slot is a one point contact and as a result the tooth movement which takes places is a tipping movement of crown. An uncontrolled tipping takes places i.e. the crown moves on application of force and root moves in an opposite direction. As a result of this type of movement an additional stage i.e. Stage III is incorporated in this technique in which auxillaries are placed additional to base wire so that the root moves while crown remains stable. The anchorage requirement in this technique is also minimum as light forces are applied with round wire and Class I elastics.

The treatment procedure in Begg`s technique is broadly divided into three stages.

Stage I- the goals are:

1. To reduce overbite
2. To eliminate anterior crowding
3. Levelling and alignment of arches
4. Attainment of Class I molar and canine relationship.

Stage II

1. To maintain Stage I results
2. Closure of extraction spaces

Stage III

1. To maintain Stage I and II results
2. To achieve final axial angulations and inclinations of all teeth (root parallelism)

The current case describes about a female patient with Class I bimaxillary protrusion treated with Begg`s technique.

CASE REPORT

A 17-year-old female patient reported in the orthodontic clinic with a chief complaint of poor esthetics due to forwardly placed upper & lower front teeth.

Extra-oral examination, the patient had an apparently symmetric face with mesoprosopic face form and incompetent lips. On profile examination patient had a convex facial profile. The smile of the patient was symmetric and consonant with 100% maxillary incisor display on smiling.(Figure 1a-b)

Intra-oral examination revealed all teeth in upper & lower arch are present till 2nd molar.U shaped upper & lower arch. The gingival health was satisfactory. Class I molar & canine relationship bilaterally. (Figure 1a-b)

Functional examination, patient showed normal speech pattern, oronasal breathing and a typical swallowing pattern. The path of closure of mandible was normal.

Examination of study casts showed apparently symmetrical arches with a Class I molar & canine relationship. .There was 4mm overjet and 2mm overbite.

Cephalometric analysis revealed that patient was in CVMI stage VI (completion) and had Class I skeletal bases with average angle case and, proclined upper & lower incisors.(Figure 5)

The soft tissue analysis revealed a protrusive upper lip and lower lip with an acute nasolabial angle.

Diagnosis : Skeletal Class I malocclusion with average growth pattern. Angle`s Class I, Dewey`s type 2

Problem List

• Convex facial profile
• Incompetent lips
• Protrusive upper & lower lips
• Upper & lower proclination
• Increased overjet.

Treatment Objectives

• To improve facial profile
• To correction proclination of upper & lower arch.
• To achieve normal Overjet and Overbite

Treatment progress

Case was planned as 1st premolar extraction. Begg`s brackets were bonded in upper and lower arch and initial leveling and alignment of stage I was carried out using 0.014 in and 0.016 in AJ wilcock wire. The bite opening was carried out using light Class II elastics( 5/16 in 2oz yellow elastics) with 30° anchor bend in 0.016 in AJ wilcock wire. At the end of Stage I an edge to edge bite was achieved.(Figure 3)

Stage II was carried out with 0.018 in AJ wilcock wire. The retraction was carried out using Class I elastics ( 3/8 in 3 oz pink elastics) with maintanence of Stage I by incorporating 15° anchor bend in the base wire.(Figure 3)

Stage III was carried out at the end of space closure. The base wire used was 0.020 in AJ wilcock wire with an anchor bend of 5°. The torquing auxillaries used was four spur auxillary in upper arch and uprighting spring in all the canines and 2nd premolar using 0.012in AJ wilcock wire. Light Class II elastics were used with an additional gable bend of 5° distal to canine in the upper arch. A toe out bend in the lower arch was given to negate mesiolingual rotational tendency of molars due to Class II elastics.(Figure 4)

Results

At the end of Stage III both the arches were leveled and aligned , extraction space was closed, adequate torque was achieved with proper angulations. (Figure 2a-b)

The profile of the patient improved , competency of lips was achieved, upper and lower proclination got corrected and patient also attained a consonant smile.(Figure 6,7)

DISCUSSION

The current case is of a bimaxillary protrusion characterized by protrusion of anterior dentoalveolar segment. This bimaxillary protrusion results in excessively convex profile of the patient , incompetent lips with their increased procumbency. The prevelance is more in African-American and Asian population(begg`s technique.2-4 The patient normally wants to get it corrected keeping into account the protrusion of lips.

The etiology can be genetics as well as acquired. The acquired factors include habits such as mouth breathing, tongue thrust and macroglossia.5

Begg`s mechanotherapy was used in current case. The criteria for using Begg`s technique was relatively well aligned arches without any crowding which alleviated the used of multiloop arch wires used for resolving crowding in this technique. The bite opening mechanics was also easier and fast as the pre-existing bite was not deep. In such cases using Begg technique is always beneficial as it is a light wire technique which delivers optimum orthodontic forces and no additional anchorage reinforcement is needed.

The results of this study suggested that after retraction only the dental parameters changed and not the skeletal parameters i.e. the upper and lower incisor proclination got corrected, lip protrusion got corrected but maxilla and mandible skeletal remained same.(Table no.1) The result of this study is similar to study done by Kurz for correction of bimaxillary protrusion.6

The most common problem encountered while using Begg`s mechanics is loss of torque resulting in dished in facial appearance. In this case judicious use of mechanics by creating optimum balance between Class I active retraction force and bite opening bends resulted in good clinical result, proper achievement of torque, parallelism of roots, reduction in lip procumbency and a pleasant facial profile with no root prominence and a consonant smile.

CONCLUSION

1. Begg`s technique if used with judicious mechanics is an effective tool in achieving optimum results.
2. Light continuos forces delivered by this technique reduces the requirement of anchorage reinforcement in posterior segment.
3. Bimaxillary protrusion with excessive proclination and relatively well aligned arches are best suited cases for Begg`s technique.

Acknowledgement: I would like to acknowledgment Dr RH Kamble and Dr Narendra Sharma for their constant guidance.

REFERENCES