LINGUAL ORTHODONTICS - THE TREATMENT OF CHOICE FOR COMPLEX PERIODONTAL AND RESTORATIVE PATIENTS

Silvia Geron, D.M.D., M.Sc
Jacob Horwitz, D.M.D

www.lingualnews.com Vol 4 No 2 September 2006

Introduction
Patients with complex restorative and periodontal problems may need orthodontic treatment as part of the rehabilitation treatment plan. These patients commonly seek orthodontic treatment in order to re-establish the aesthetics of their dentition and smile. In addition, they are often referred by colleagues, to improve periodontal defects, eliminate an existing traumatic occlusion, or to redistribute spaces and create a proper site for implant restoration, for improved prognosis of the dentition and restorations. 

These patients present a challenge to the orthodontists for many reasons. The missing teeth reduce the available anchorage, bonding the brackets to restorations with different restorative materials is more difficult, and periodontal disease history makes these patients more vulnerable to the risks of orthodontic treatment, like exacerbation of periodontal disease, additional alveolar bone loss, gingival recession and root resorption (1).
In addition to the orthodontic management of these patients, retention of the orthodontic result during unstable transitional periods of implant placement and healing periods requires special attention to the treatment planning and multidisciplinary coordination. Frequently, these patients have high aesthetic demands, asking for invisible orthodontic appliances. Lingual orthodontics might be the treatment of choice for this patients group.
The purpose of this article is to describe the different considerations and treatment options of a complex periodontal and restorative case treated with implant restorations combined with lingual orthodontics.

Case presentation
A 58 years of age male, diagnosed with severe chronic generalized periodontitis with a neglected dentition, bad oral hygiene, calculus and gingival inflammation, was referred by his periodontist for orthodontic preliminary evaluation .
Patient's main complaint was the severe mobility of his upper incisors, especially the upper left central incisor which was severely extruded and mobile, trapped behind the lower lip and jiggling in every movement of his lips.
Extraoral examination revealed a slight convex profile with reduced lower facial height and severe impairment of his dental and smile aesthetics (Fig 1).

Fig 1: Pre treatment facial photos:The patient had a slight convex profile with reduced lower facial height and severe impairment of his dental and smile aesthetics

Intra oral examination shows Class 2 occlusal relations, with an overjet of 10 mm, deep impinging overbite, with the lower incisors biting on the palatal gingival of the upper incisors, incisors' flaring, and a diastema of 8 mm between the maxillary central incisors. The patient also had severe crowding in the lower anterior region. He was missing the lower premolars and molars except for the third molars which were tipped mesially (Fig 2). Occlusal contacts existed only between the upper and lower third molars, except for the contacts between lower incisors and palatal gingiva.

Fig 2. Pre treatment Intra oral photos: very large overjet, deep impinging overbite, incisors' flaring, and a very large diastema , severe lower crowding , missing the lower premolars and molars with occlusal contacts existed only between the upper and lower third molar.

Severe tooth mobility was noted, due to the traumatic occlusion on the incisors, reduced periodontal attachment and loss of posterior support, as well as the parafunction of the lower lip. The patient had severe gingival recessions in many teeth, deep infra-bony pockets and reduced alveolar bone level (Fig 3), as revealed by the orthopantomogram and clinical examination. The upper left central incisor had no alveolar bone support and needed to be extracted.

Fig 3: Pre treatment panoramic x-ray

Treatment goals
Total rehabilitation was needed, the goals of which were:
1. to eliminate and treat dental and periodontal diseases with a reduced but healthy periodontium;
2. to achieve a normal relation between dental arches with normal overjet and overbite, eliminate the parafunction of the lower lip and excessive anterior occlusal forces on the incisors, and arrive at a stable result;
3. aesthetic goals included achieving a pleasing smile arc with normal incisal exposure at rest and smile.

Treatment options
Due to the severity and complexity of the case, the patient needed comprehensive oral rehabilitation. Periodontal, and prosthetic treatment combined with orthodontic therapy was suggested.

The inclusion of an orthodontic component targeted two purposes: The correction of the overjet and overbite, and closing the diastema of the upper incisors. Correcting the deep bite and the incisors' proclination would release the load applied on the incisors from the parafunction of the lip treating the secondary .occlusal traumatism. Reducing the size of the anterior diastema would provide better conditions for achieving esthetic results restoring the upper incisors, gaining appropriate interocclusal relation and enabling treatment of periodontal bone defects.

The disadvantage of this treatment approach can be summarized in increased treatment time and expenses. Such a complicated treatment using an orthodontic device exposes the patient to additional risks, such as exacerbation of periodontal disease due to difficulties in maintaining oral hygiene resulting in additional alveolar bone loss, gingival recession and possible root resorption.
However, proper periodontal treatment and regular maintenance therapy are essential for successful treatment. It was shown that teeth with advanced alveolar bone loss and migration may not experience additional loss of bone support or attachment with orthodontic treatment, if maintained correctly. (2-7)

The timing of the combined treatment requires special attention. In the present case orthodontic treatment should be coordinated with implant insertion enabling the surgeon the needed inter-dental space, preferably without the orthodontic appliance.
In some cases implants can be inserted prior to orthodontic treatment, to be used for anchorage. However, this treatment sequence requires delaying orthodontic treatment for several months, until the implants are integrated. This approach may complicate the treatment since the position and survival of the teeth are not final. As a result, the implants may be positioned in discordance with the prosthetic needs. Multi session surgical approach may be used in such cases. This further complicates the treatment and prolongs treatment time.

Treatment plan
Treatment commenced with periodonal initial preparation, including oral hygiene reinforcement, scaling and root planing. Lingual orthodontics treatment then followed. The final prosthetic treatment will be decided in the revaluation phase.
For this case Lingual orthodontics was selected, because of its mechanical advantage over the conventional orthodontics, the bite opening and intrusive effect (8).

Treatment progress
Upper Lingual brackets G7 (ORMCO Co, Orange, Calif.) were bonded indirectly, after preparation of the indirect bonding tray with the Lingual Bracket Jig (9). During the removal of the bonding tray the upper left central incisor was accidentally extracted, and had to be bonded as a pontic the neighbour lateral incisor (Fig 4)

Fig 4. During the removal of the bonding tray the upper left central incisor was accidentally extracted, and had to be bonded the neighbour lateral incisor

The case required maximum anchorage, complicated by the large overjet and the lower incisors occluding distal to the maxillary incisor brackets.
After bonding the upper lingual brackets, the lower incisors occluded on the bite planes of the maxillary brackets, and the third molars were dis-occluded. With this condition the occlusal contacts on the incisors, directed anterior to the centre of resistance (Fig 5), may aggravate the proclinaion of the incisors (8,10). To avoid this complication, posterior bite blocks made of composite material were bonded to the third molars at the bonding appointment. (Fig 6)

Fig 5. the occlusal contacts on the incisors, directed anterior to the centre of resistance may aggravate the proclinaion of the incisors

Fig 6. posterior bite blocks were bonded to the third molars at the bonding appointment.

The bite blocks allowed occlusion on the third molars, releasing the excessive occlusal forces from the incisors. The incisors' proclination and space closure could now be corrected using very light orthodontic forces, which would not endanger to periodontally compromised dentition. The lower crowding was resolved with a lingual appliance and extraction of the lower left central incisor.  

Fig 7. At the end of orthodontic treatment the spaces were closed, overjet and overbite were within normal limits and good posterior occlusion was achieved

At the end of orthodontic treatment the spaces were closed, overjet and overbite were within normal limits and good posterior occlusion was achieved (fig 7). Radiographic examination shows root parallelism and improvement in vertical bone defects (Fig 8). Treatment objectives were fully achieved in a comparatively short treatment time (8 months).  The patient was referred for temporary restoration of the upper arch, and for implants in the lower arch. Prior to the final restoration in the lower arch the patient needed another short orthodontic phase to improve the inclination of the right lower third molar.

Fig 8: Post treatment periapical x-rays shows root parallelism and improvement in vertical bone defects

Facial photos at the end of treatment show a significant improvement in the facial appearance due to improved lip support and labio-mental fold. Smile analysis show a nice smile line, parallel to the lower lip, with exposure of 70% of the incisors. (Fig 9).

Fig 9. Facial photos at the end of treatment show a significant improvement in the lip support, smile line and facial appearance of the patient

Fig 10. Intraoral photos show good posterior occlusion, normal overjet and overbite, and normal incisors inclination.

Intraoral photos show good posterior occlusion, normal overjet and overbite, and normal incisors inclination (fig 10). However the gingival line was not harmonious, since the patient had long upper lip and did not expose his gingival line at smile, and correction of gingival line was not included in the treatment goals.

Conclusions
The case presented here demonstrates that multidisciplinary treatment which includes Lingual orthodontics treatment enables improved conditions for implant and prosthetic restoration in a very difficult initial restorative situation and periodontally compromised patient..
Lingual orthodontics is an effective tool for adult treatment due to mechanical advantage. .

References
1. Bone modeling: biomechanics, molecular mechanisms and clinical perspectives W. Eugene Roberts et al 2004 Semin Orthod 10:2; 123-161

2. Artun J, Urbye K. The effect of orthodontic treatment on periodontal bone support in patients with advanced loss of marginal periodontium. Am J Orthod Dentofacial Orthop 1988;93:143-8

3. Thilander B. Infrabony pockets and reduced alveolar bone height in relation to orthodontic therapy. Semin Orthod 1996;2:55-61

4. Polson A, Caton J, Polson AP, Nyman S, Novak J, Reed B. Periodontal response after tooth movement into infrabony defects. J Periodontol
1984;55:197-202.

5. Horwitz J., Lingual Orthodontics and Periodontal Treatment. www.lingualnews.com Vol 1 No 2 March 2003

6. Melsen B, Agerbaek N, Eriksen J, Terp S. New attachment through periodontal treatment and orthodontic intrusion. Am J Orthod Dentofacial Orthop 1988;94:104-16

7. Diedrich PR : Orthodontic procedures improving periodontal prognosis.
Dental Clinics of North America I Vol 40 No 4 )875-887 October 1996

8. Geron S. Managing the orthodontic treatment of patients with Advanced Periosontal Diaease : The Lingual Appliance World J Orthod 2004;5:324-331.

9. Geron S. The lingual bracket jig. J Clin Orthod 1999;32:457-62.

10. Geron S., Romano R., Brosh T., Vertical Force in Labial and Lingual Orthodontics Applied on Maxillary Incisors - Theoretical Approach, Angle Ortho. 2004, 74;195-201

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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