Ideal treatment of the impaired

Transcription

1 RESEARCH IMPLANTS AS ANCHORAGE IN ORTHODONTICS: ACLINICAL CASE REPORT Dale B. Herrero, DDS KEY WORDS External anchorage Pneumatized Often, in dental reconstruction, orthodontics is required for either functional or aesthetic reasons. Frequently, the critical anchorage necessary to move the teeth may be lacking. This article documents how critically located implants can be used as anchorage during orthodontic treatment and can become definitive support for the final reconstruction. Osseointegrated implants in this manner achieved a more ideal and acceptable result for this patient. Dale B. Herrero, DDS, is located at 1331 Grand Avenue, Piedmont, CA INTRODUCTION Ideal treatment of the impaired dentition frequently requires orthodontic repositioning of key teeth. Orthodontic tooth movement requires a stable anchorage point either within or outside of the mouth. 1 In adult treatment, external anchorage is usually not an option. Research reports documenting the use of implants as intraoral anchorage date back to Earlier attempts were unsuccessful due to the lack of osseointegration. The use of osseointegrated titanium implants proved more predictable. 3 In 1993, Stean 1 documented how crowded teeth adjacent to an edentulous molar area could be repositioned orthodontically utilizing dental implants as anchorage. Evaluating anchorage in an animal model, Roberts et al 4 reported 100% rigidity and maintenance of integration of mandibular implants while resisting 3 N of continuous force for 13 weeks. Implants have also been placed in the palate for orthodontic anchorage. Wehrbein et al 5 in 1996 used 3.3-mmdiameter 4- and 6-mm-long titanium screw implants for the retraction of maxillary anterior teeth. The implants were used to close extraction sites when extraoral anchorage was unacceptable to the patient. Following orthodontic treatment, if the implants are to be used as support for a definitive prosthesis, it is imperative that idealized placement be achieved. Smalley 6 has described a technique for determining the ideal implant location relative to completion of implant therapy. CLINICAL REPORT A 64-year-old female presented for treatment complaining of a bad bite, joint noise, and poor aesthetics. Bone support in the maxillary right quadrant was very poor. Her periodontist recommended extraction of teeth 3 and 4. Tooth 2 was already missing. The patient requested restoration with a fixed prosthesis. Inadequate abutments and long bridge span negated this possibility without additional support. Throughout the mouth, multiple teeth required restoration due to caries or failing restorations. She also was not happy with the aesthetics of many existing posterior crowns, the Journal of Oral Implantology 5

2 IMPLANT ANCHORAGE FIGURE 1. Preoperative occlusal view. FIGURE 2. Preoperative diagnostic casts. tooth rotations in the maxilla, and the horizontal overbite (Figs 1, 2). She was interested in orthodontically correcting the horizontal overbite and restoring the missing teeth with implants. After consultation with the periodontist and orthodontist, a treatment plan 6 Journal of Oral Implantology was formulated to replace teeth 2 and 3 with implants and retract the maxillary anteriors. The primary challenge was to obtain anchorage to retract the anterior teeth. The remaining molar, tooth 1, had severely compromised bone support and was unacceptable as anchorage. The maxillary sinus was pneumatized with inadequate alveolar bone for implant placement (Fig 3). A maxillary sinus augmentation with a six-month maturation period and subsequent implant placement was prescribed. Sequential treatment in-

3 Dale B. Herrero FIGURE 3. Preoperative panoramic x-ray. FIGURE 4. Implant abutments in place. volved caries control, sinus augmentation, implant placement, and lower arch restoration followed by orthodontic treatment. The mandibular arch was restored to an ideal occlusal relationship to coordinate with maxillary movement. Following restoration of teeth 20 and 21, the maxillary right bridge was sectioned and teeth 3 and 4 were extracted. Healing was uneventful and a sinus augmentation was performed using a combination of demineralized freeze-dried bone (DFDB), osteogen (Impladent Ltd, Holliswood, NY), and osteomen. Ridge augmentation was also completed labial to tooth 5 to correct an undercut. Following healing, diagnostic study casts were obtained. The maxillary anterior teeth were repositioned in the idealized position. The Journal of Oral Implantology 7

4 IMPLANT ANCHORAGE FIGURE 5. Splinted, temporary, nonprecious metal crowns with orthodontic bracket. FIGURE 6. Final orthodontic result utilizing both implants as anchorage. diagnostic wax-up was completed and a vacuum-formed splint was made as a surgical guide. Five months elapsed before implants were placed. Two Seri-Oss threaded, hydroxyapatitecoated screws (Steri-Oss, Inc, Yorba Linda, CA) were placed in teeth 2 and 8 Journal of Oral Implantology 3 areas utilizing the surgical template. Five and one-half months later, the implants were uncovered and healing abutments placed. Six weeks later, 9- mm straight abutments were placed (Fig 4). A vinyl polysiloxane impression was made, and two nonprecious crowns were fabricated. The patient did not object to the all-metal posterior crowns when she was informed that orthodontic brackets could be soldered securely directly to the crowns and would facilitate treatment. The crowns were splinted and sent to the

5 Dale B. Herrero FIGURE 7. Final orthodontic and restorative result. FIGURE 8. Postrestorative panoramic x-ray; note the sinus augmentation and healthy bone around the implants. orthodontist for orthodontic bracket positioning. The crowns were then returned and cemented with a mixture of Temp-Bond cement (Kerr Manufacturing Co, Romulus, MI) and bacitracin (Fig 5). The orthodontist bracketed the rest of the maxillary arch. In 18 months, orthodontics was completed with the maxillary teeth retracted into the idealized position (Fig 6). The nonprecious crowns were removed and replaced with two splinted porcelain fused to metal (PFM) crowns. The remaining prosthetic treatment was then completed (Figs 7, 8). CONCLUSION This article demonstrates how collaboration between the orthodontist and the restorative dentist can accomplish Journal of Oral Implantology 9

6 IMPLANT ANCHORAGE optimal results in a highly motivated dental patient. ACKNOWLEDGMENT Orthodontic therapy was performed by Dr Straty Righellis of Oakland, Calif. REFERENCES 1. Stean H. Clinical case report: an improved technique for using dental implants as orthodontic anchorage. J Oral Implantol. 1993;19: Gainsworth BL, Higley LB. A study of orthodontic anchorage possibilities in basal bone. Am J Clin Orthod Oral Surg. 1945;31: Schwartz AM. Tissue changes incidental to orthodontic tooth movement. Orthod Oral Surg Radiogr Int. 1932;18: Roberts WE, Helm FR, Marshall KJ, Gongloff RK. Rigid endosseous implants for orthodontic and orthopedic anchorage. Angle Orthod. 1989;59: Wehrbein H, Glatzmaier J, Mundwiller U, Diedrich P. The orthosystem a new implant system for orthodontic anchorage in the palate. 1996;57: Smalley WM. Implants for tooth movement: determining implant location and orientation. 1995;7: Journal of Oral Implantology