MULTIDISCIPLINARY APPROACH TO REHABILITATE MISSING TEETH
A 31 year old female patient visited the Department of Dental Specialties, Mayo Clinic, Rochester, Minnesota, for the replacing of tooth numbers 7 and 10 which were congenitally missing. On extra oral examination, the lips were competent, maxillary anteriors had short clinical crowns and the patient displayed approximately 4 to 6 mm of gingiva upon smiling. No gross facial asymmetries were present. The nasolabial angle was normal to slightly obtuse. On intra oral examination, the patient had an end-on molar relationship with neither crowding nor spacing in either arch, the overbite of approximately 6 mm. The overjet was 1 to 2 mm. Midlines were nearly coincident. Teeth no. 8 and 9 had veneers and presented with teeth 7 and 10 as actually canine teeth that had been moved mesially for abutment bridge support (Fig 1) The patient had been treated and had the existing restorations for approximately 19 years.
It was determined that the patient would benefit from pre-prosthetic orthodontic treatment of distalization of canines and implant reconstruction of teeth 7 and 10. The roots of the teeth adjacent to the edentulous area would be required to be parallel or slightly divergent to create sufficient bone for implant placement. The existing combination bridge work in the 6 and 11 areas was removed as were the veneers placed on teeth 8 and 9 and replaced with provisional restorations. Orthodontic treatment was initiated. Intrusion of the maxillary anterior teeth and flaring the mandibular anterior teeth to some degree was also initiated. (Figure 2). This later allowed for appropriate gingival positioning of the dentogingival complex. Separation of units on teeth no. 7 and 10 allowed them to be distalized. After a few adjoining months of continued orthodontic therapy, adequate space was obtained in area of teeth 7 and 10. (Figure 3) Two implants 3.5*11.5 (Nobel Biocare Replace select, Yorba Linda, CA, USA) were inserted in areas of teeth 7 and 10. These were fitted with direct to fixture abutments zirconia with a titanium base. These were affixed with abutments screws that were torqued to 35 Ncm. (Figure 4) Teeth were prepared for full coverage restorations in sites Nos. 5, 6, 8, 9, 11, and 12 and were all provisionalized. One week postoperatively, the gingiva continued to develop around restorations. The patient was accepting as to the aesthetics and bright/uniform appearance of her dentition. (Fig 6 and 7)
The restorative dentist is challenged with decision-making revolving around missing teeth and defective restorations in everyday clinical situations. The decision to retain or extract a tooth, replace defective restorations, replace periodontally compromised abutment teeth to restore a dentition to form and function is an integral part of treatment planning. The clinician’s knowledge and clinical experience strongly influences the modality of treatment selected for the patient. Implants are considered as a indispensable part of comprehensive oral rehabilitation and have become a primary treatment option for the replacement of congenitally missing teeth.  The literature states that the presence of adjacent teeth is important to maintain the position of unopposed tooth in bucco-lingual and mesio-distal directions. Adequate space, quality and quantity of bone are to be assessed before the implant placement. The implant should be at a minimum distance of 1.5 mm from adjacent teeth and 3 mm away from adjacent implant. Sufficient space should be available for fabrication of esthetically harmonious restorations. A quantifiable width to length ratio between maxillary anterior teeth can be established objectively after taking various factors like dynesthetic and dentogenic concepts in consideration [3,4]. The pink esthetic score and the white esthetic score are tools, which can be used objectively to evaluate the single-tooth implant restorations in the esthetic zone .[4,5]Few of the studies stated that the direction of tooth movement was associated with the side of maximum bone density reduction and that CBCT is a useful approach for evaluating bone density changes around teeth induced by orthodontic tooth movement.
Dental implants have become the most common form of treatment employed for congenitally missing lateral incisors. The interdisciplinary treatment planning of pre-prosthetic orthodontic treatment coupled with periodontal maintenance visits yielded a satisfactory outcome for the patient. This case report highlights the integration of multidisciplinary approach in future esthetic functionally oriented dentistry for oral rehabilitation.
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