ALIGNING THE GINGIVAL HEIGHTS OF INCISORS WITH PROSTHETIC RESTORATION DURING LINGUAL ORTHODONTIC TREATMENT

Yoav Mazor D.M.D.

Yossi Nisani D.M.D.

Silvia Geron D.M.D., M.Sc , Tel Aviv University, Israel  

www.lingualnews.com Vol 2 No 2 November 2004

One of the main objectives of adult orthodontic treatment is achieving dental and periodontal aesthetics. The main concern in adult lingual orthodontics is to achieve the same results, while preserving maximal aesthetics during the orthodontic treatment. Aligning gingival heights of incisors requires intrusion or extrusion of the incisors. This may create some aesthetic problems during the orthodontic treatment, especially if the incisors are restored with prostodontic crowns.
1. The intruded tooth will be shortened.
2. The extruded tooth will be elongated.
3. If the extruded tooth has a crown restoration, then the gingival margins of the crown can be exposed.
4. the aesthetics of the anterior restorations becomes more visible and critical to the lingual patient during the orthodontic treatment, since the anterior teeth have already been straightened. These problems can easily be treated by replacing the old unaesthetic crowns with nicer temporary crowns before the orthodontic treatment, and by replacing the crowns again during the course of orthodontic treatment, after achieving intrusions or extrusions. However this procedure is expensive and time consuming. it also requires debonding and rebonding of the brackets on the restored teeth. In lingual treatment this procedure is difficult and requires another laboratory stage for positioning the brackets on the new crown. The case presented here suggests a simple solution to avoid replacing the temporary crown and the lingual bracket during treatment.

Case presentation:
A 29 years old woman presented with the main complaint of crooked and protruded upper incisors. She insisted on an invisible orthodontic appliance, and required an immediate aesthetic improvement, since she had settled the date for her marriage in three months. She was diagnosed a Skeletal Class II cases and with anterior crowding. Clinical examination revealed an unaesthetic smile due to an old unaesthetic ceramic crown on tooth 21, asymmetric incisors and uneven gingival line. Tooth 21 had very low (incisal) gingival line. Tooth 11 was protruded with high gingival line, about 2 mm higher then the gingival line of the canines. (Figure 1)

Fig 1: Tooth 21 has low gingival line. Tooth 11 has high gingival line, about 2 mm higher then the gingival line of the canines.

Treatment plan included replacement of the ceramic crown , Extraction of the second premolars,, and an upper and lower lingual fixed appliance.

Treatment progress:
After replacement of the ceramic crown with a temporary acrilic crown (figure 2), lingual appliance was bonded to the upper and lower arches. Bracket positions of the incisors were modified to achieve intrusion of tooth 21 and extrusion of tooth 11 in order to level the upper gingival line.

Fig 2: Temporary crown on tooth 21 at the beginning of orthodontic treatment with lingual brackets

Alignment and leveling of the teeth and the gingival line  were achieved within three months. During this stage the incisal edge of tooth 11 which extruded was reshaped (figure 3)

Fig 3: Alignment and leveling of the teeth and  the gingival line. Gingival line is now correct but the incisal line is not.

Although the gingival line was and smile aesthetics was very much improved, the aesthetics of the anterior teeth was disrupted because of the uneven incisal line and the short crown of tooth 21. The patient was referred to her dentist who corrected the incisal line by restoration of the temporary crown with composite restoration, without taking of the crown or the bracket (Figure 4). The treatment could now be continued with acceptable anterior aesthetics, to the patients' satisfaction.

Fig 4: Composite restoration of the acrilic temporary crown, still in treatment.

www.lingualnews.com 
Adult and Lingual Orthodontics
EDITORS:
Dr. Silvia Geron D.M.D., M.Sc
Dr. Rafi Romano D.M.D., M.Sc
Dr. Pablo Echarri D.M.D., M.Sc