- Email: [email protected]
Creating labial bone for immediate implant placement: A minimally invasive approach by using orthodontic therapy in the esthetic zone
Creating labial bone for immediate implant placement: A minimally invasive approach by using orthodontic therapy in the esthetic zone Takashi Watanabe, DDS, DDSc,a Baldwin W. Marchack, DDS, MBA,b and Henry H. Takei, DDS, MSc Meikai University School of Dentistry, Sakado, Saitama, Japan; Ostrow School of Dentistry of the University of Southern California, Los Angeles, Calif Orthodontic extrusion of nonrestorable teeth has been used for almost 20 years as an alternative to bone grafting in preparation for implant placement. Although this technique predictably creates bone and soft tissue, and improves the socket diameter and depth, most of the bone apposition occurs in the marginal alveolar and periapical areas of the extruded tooth. To create more labial bone, the standard orthodontic extrusion technique was modified to apply pressure on the hopeless tooth both coronally and palatally, which allowed bone at the site to develop apically and labially. Gingival thickness on the labial aspect was also increased, and the tissue biotype was improved. A clinical treatment is presented that illustrates the use of this technique. (J Prosthet Dent 2013;110:435-441)
Although Brånemark originally recommended a posthealing period of up to 12 months before placement of dental implants,1 problems with this approach were soon identified. When a tooth is extracted, the bundle bone at the extraction site is resorbed both horizontally and vertically because of the lack of function on the bone.2,3 If the subsequent bony defects are severe, then implant placement may be precluded or, if attempted, a poor esthetic result will be inevitable. In response to this problem, various approaches to postextraction alveolar ridge preservation and regeneration have been developed. Excellent results have been documented for some immediate implant placements into extraction sites,4,5 but, if the periodontal problems around the hopeless tooth are severe, then the soft- and hard-tissue defects at the site may require further therapy. Placement of autogenous bone blocks at the time of
extraction, either before or simultaneous with implant placement, has been advocated.6,7 However, such bone grafting procedures may be associated with significant donor-site morbidity.7 As an alternative, Salama and Salama,8 in 1993, suggested using orthodontic extrusion to create vertical bone and soft tissue at hopeless tooth sites before extraction and implant placement without the use of surgery. This approach was based on fundamental orthodontic principles. When orthodontic force is applied to a tooth, the periodontal ligament on the side to which the pressure is applied undergoes a process of hyaline degeneration and becomes necrotic. The necrotic cells are removed by foreign body giant cells and macrophages. Osteoclastic activities ensue, which promote bone resorption. On the opposite side of the tooth, tension is created, which stretches the periodontal ligaments and causes fibroblasts to differentiate. This
is followed by osteoblastic activities and the creation of new bone. The tooth moves because of the osteoclastic activities and bone resorption that occur on the pressure side. Bone apposition occurs because of the osteoblastic activity on the tension side.9,10 Molar uprighting and forced eruption11-13 expanded these insights. Early studies documented that bone apposition results at both the apex and the alveolar crest of extruded teeth, which maintains a normal (1-2 mm) relationship between the periodontium and cement-enamel junction.14-16 Unlike standard orthodontic tooth movement, orthodontic extrusion creates tension throughout the entire socket wall. It stretches the gingival fiber apparatus, which places tension on the alveolar bone and stimulates crestal bone deposition.17-19 Extrusion has been classified as the easiest type of movement to achieve in orthodontics.20 Researchers who have
Presented at the American Academy of Esthetic Dentistry 36th Annual Meeting, San Juan, Puerto Rico, August 2011. a
Clinical Professor, Meikai University School of Dentistry. Member, Board of Councilors, Ostrow School of Dentistry of the University of Southern California. c Professor, University of California at Los Angeles School of Dentistry. b
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Volume 110 Issue 6
1 Hopeless maxillary right central incisor before treatment.
2 Orthodontic wire was designed to move hopeless incisor palatally and coronally. sought to determine the optimal force of extrusion when the goal is remodeling alveolar bone have found a range of
between 15 and 80 g/mL.21-24 Heavy force is detrimental; instead, the force of extrusion applied must be minimal,
controlled, and continuous. Conventional orthodontic wire, which can generate a continuous light force over an extended period of time, is preferred. Over the past 2 decades, orthodontic extrusion of hopeless teeth has become a well-documented alternative to bone grafting in preparation for eventual implant placement.25-28 Such treatment has several objectives. In addition to remodeling the alveolar bone, it increases the zone of attached, keratinized gingiva as the gingival margin moves coronally away from the mucogingival junction.29,30 Extrusion also favorably affects the socket diameter and depth. As the root is extruded, the socket diameter and depth decrease. This creates a better environment for immediate implant placement by minimizing the gap between the implant and the surrounding tissue. For all of the benefits offered by this approach, it has a significant limitation. The greatest amount of bone apposition as a result of orthodontic extrusion occurs in the marginal alveolar and periapical areas of the extruded tooth.31,32 Some labial bone is also created, and orthodontic extrusion may succeed in changing the implant-placement site from a class 2 to a class 1, according to the Tinti classification of socket defects.33 However, the newly created labial bone is typically
3 A-C, Design of orthodontic wire and position of bracket shows combine procedure of extrusion and palatal tooth movement.
The Journal of Prosthetic Dentistry
Watanabe et al
December 2013 thin and prone to resorption after the implant is placed.34 As Tarnow et al35 demonstrated, bone resorption around implants occurs not only in a vertical direction but also horizontally, in the range of 1.3 to 1.4 mm. Furthermore, Spray et al36 showed that, as labial bone thickness approaches 1.8 to 2 mm, bone loss decreases significantly. For that reason, when implants are placed in the esthetic zone, the labial bone thickness should be at least 2 mm to avoid the loss of the labial bone plate and the consequent risk of soft-tissue recession.37 A modification of the orthodontic extrusion technique to develop alveolar bone not only apically and at the alveolar margins but also labially has been suggested. Cognizant that bone apposition occurs because of the osteoblastic activity on the tension side of orthodontic intervention, this technique requires the application of orthodontic pressure on the hopeless tooth both coronally and simultaneously in a palatal direction. When gentle pressure is applied in this manner over a period of 4 to 5 months, the result has been the development of the bone at the site, both vertically and labially. In addition,
437
4 Facial view of hopeless incisor after 5 months of vertical and palatal movement.
5 Incisal view after 5 months of therapy. Note palatal positioning of tooth.
6 A, Initial position of maxillary right central incisor root. B, Root has moved substantially after 5 months of extrusion.
Watanabe et al
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Volume 110 Issue 6 an increase in labial gingival thickness and an improvement of the gingival biotype occurs. The following clinical report illustrates the application of a 3-dimensional orthodontic extrusion in preparation for implant placement.
CLINICAL REPORT A 41-year-old man presented with pain and swelling at his right central maxillary incisor. Results of a clinical evaluation were severe labial gingival recession (Fig. 1), with a lack of attached gingiva and a mesial pocket depth of 6 mm. Radiographic examination revealed an extensive osseous defect. A treatment plan was developed to orthodontically extrude the hopeless incisor for 5 months to increase the amount of vertical and labial bone at the site while improving both the quantity and quality of the soft tissue. Before the extrusion, the patient underwent scaling and root planing to minimize the presence of active periodontal involvement. The extrusion was initiated by bonding brackets (Micro-arch APPLIANCES Formula-R, Roth Type; Tomy Intl Inc) to the maxillary premolars and incisors. Cobalt chromium orthodontic wire (0.016 0.016) was secured to the brackets with ligature wire (Fig. 2). To create pressure palatally as well as vertically, the bending of the wire included several key design elements: an L-loop and step-down design for coronal movement, an inset component for palatal movement, and a clockwise rotation of the orientation of the wire to avoid tipping and to achieve bodily movement. When the specially designed wire was placed in the strategically positioned bracket, torque was created in the correct direction to achieve the desired movement (Fig. 3). The patient was recalled at 3 different appointments at 4-week intervals to adjust the tension in the wire. At each appointment, the incisal edge and the palatal portion of the right central incisor were reduced to accommodate the new position
The Journal of Prosthetic Dentistry
7 Maxillary right central incisor after removal of orthodontic appliance and fabrication of interim restoration.
8 Postextraction site. Note additional concavity that resulted from extrusion.
9 A, Indicates original tooth position. B, Indicates postorthodontic position.
Watanabe et al
December 2013 of the tooth. When sufficient palatal movement was achieved to bring the maxillary and mandibular incisors edge to edge, the incisal edge was subsequently reduced. The patient returned 2 weeks after the fourth activation, approximately 3 months after the extrusion was initiated. The cobalt chromium orthodontic wire was replaced with 0.0175 0.0175 b-titanium alloy wire (TMA; Ormco Corp) and activated for the fifth time. The elasticity of the b-titanium alloy wire was estimated to be 20 times greater than that of stainless steel and provided good performance in the final stages of orthodontic treatment. The patient again returned every 2 weeks for 3 additional adjustments to the tension on the wire. Five months after the extrusion was initiated, the root of the right central incisor and the gingival margin had moved coronally by approximately 6 or 7 mm (Figs. 4-6). The orthodontic appliance was removed, and an interim crown was made and splinted to the adjacent interim restoration (Fig. 7). Two and a half months after the extrusion was completed, the maxillary right central incisor was atraumatically extracted, and the presence of newly formed bone was noted (Fig. 8). Two osseous concavities, labial and palatal, occurred at the extraction site (Fig. 9) because of the extrusion and palatal tooth movement. A 3.75-mm-diameter, 15-mm-long implant (Nobel Mk III; Nobel Biocare) was placed in the palatal concavity. To increase the thickness of the labial plate, bone grafting of the labial concavity was accomplished by using guided bone regeneration techniques (Fig. 10). An interim restoration was immediately delivered. A custom titanium abutment (Nobel Procera; Nobel Biocare) was designed and placed 6 months after the extraction and immediate implant placement (Fig. 11). The definitive restoration was delivered 6 months later (Fig. 12). After 4 years of follow-up, cone beam computerized tomographic images of
Watanabe et al
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10 A, Implant was placed in palatal concavity. B, Labial concavity was accomplished by using GBR techniques.
11 Custom titanium abutment was inserted 6 months after implant placement.
12 Definitive restoration, with labial gingival symmetry restored. the central incisor sites demonstrated the continuing presence of adequate labial bone at the site that was orthodontically enhanced, which indicated
an excellent long-term prognosis for the restoration (Fig. 13). Similarly successful results have been obtained for a total of 7 patients to date.
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13 Cone beam computed tomography images made 4 years after insertion of definitive restorations. A, Implant placed in extruded and palatally positioned maxillary right central incisor site. B, Implant placed in existing edentulous site of missing maxillary left central incisor.
SUMMARY Orthodontic extrusion and palatal tooth movement are effective procedures for site development for immediate implant placement and offer the following clinical advantages: 1. The volume and height of labial bone is increased. 2. The volume and height of the labial gingiva is increased. 3. The gingival biotype is improved. 4. The osseous concavity created from the remnants of the initial socket improves the predictability of new bone formation with a guided bone regeneration technique.
REFERENCES 1. Ohrnell LO, Hirsch JM, Ericsson I, Brånemark P-I. Single tooth rehabilitation using osseointegration. A modified surgical and prosthetic approach. Quintessence Int 1988;19:871-6. 2. Araújo MG, Lindhe J. Dimensional ridge alterations following tooth extraction. An experimental study in the dog. J Clin Periodontol 2005;32:212-8. 3. Van der Weijden F, Dell’Aqua F, Slot DE. Alveolar bone dimensional changes of post-extraction sockets in humans: a systematic review. J Clin Periodontol 2009;36:1048-58. 4. Lazzara RJ. Immediate implant placement into extraction sties: surgical and restorative advantages. Int J Periodontics Restorative Dent 1989;9:333-43. 5. Garber DA, Salama MA, Salama H. Immediate total tooth replacement. Compend Contin Educ Dent 2001;22:210-6.
6. Adell R, Lekholm U, Grondahl K, Brånemark P-I, Lindstrom J, Jacobsson M. Reconstruction of severely resorbed edentulous maxillae using osseointegrated fixtures in immediately autogenous bone grafts. Int J Oral Maxillofac Implants 1990;5:223-46. 7. Pikos M. Atrophic posterior mandibular reconstruction utilizing mandibular block autografts: Risk management. Int J Oral Maxillofac Implants 2003;18:765-6. 8. Salama H, Salama M. The role of orthodontic extrusive remodeling in the enhancement of soft and hard tissue profiles prior to implant placement: a systematic approach to the management of extraction site defects. Int J Periodontics Restorative Dent 1993;13: 313-33. 9. Graber TM, Swain BF. Tissue reactions in orthodontics. In: Orthodontics, current principles and techniques. St Louis: Mosby; 2012. p. 253-62. 10. Proffit WR. The biologic basis of orthodontic therapy. In: Contemporary orthodontics. St Louis: Mosby; 2013. p. 278-89. 11. Brown IS. The effect of orthodontic therapy on certain types of periodontal defects. J Periodontol 1973;44:742-56. 12. Ingber JS. Forced eruption. Part 1. J Periodontol 1974;45:199-206. 13. Ingber JS. Forced eruption. Part 2. J Periodontol 1976;47:203-16. 14. Oppenheim A. Artificial elongation of teeth. Am J Orthod Oral Surg 1940;26:931-42. 15. Ritchey B, Orban B. The crests of interdental alveolar septa. J Periodontol 1953;24:75-87. 16. Reitan K. Clinical and histologic observations on tooth movement during and after orthodontic movement. Am J Orthodont 1967;53: 721-45. 17. Reitan K. Effects of force magnitude and direction of tooth movement on different alveolar bone types. Angle Orthod 1964;34: 244-55. 18. Simon JH, Lythgoe JB, Torabinejad M. Clinical and histologic evaluation of extruded endodontically treated teeth in dogs. Oral Surg Oral Med Oral Pathol 1980;50:361-71.
The Journal of Prosthetic Dentistry
19. Pontoriero R, Celenza F Jr, Ricci G, Carnevale G. Rapid extrusion with fiber resection: a combined orthodonticperiodontic treatment modality. Int J Periodontics Restorative Dent 1987;7: 31-43. 20. Stoner MM. The edgewise appliance today: wire clinical consideration. In: Graber TM, Swain BF, editors. Current orthodontic concepts and techniques, Vol. 2. Philadelphia: WB Saunders; 1969. p. 414-82. 21. Oppenheim A. Human tissue response to orthodontic intervention of long and short duration. Am J Orthod Oral Surg 1942;28: 263-301. 22. Schwartz AM. Tissue changes incidental to tooth movement. Int J Orthod 1932;18: 331-52. 23. Noda K, Yoshii T, Nakamura Y, Kuwahara Y. The assessment of optimal orthodontic force in various tooth movements. Comparisons of tooth movement, root resorption, and degenerating tissue in tipping movement. Orthod Waves 2000;59:329-41. 24. Kondo K. A study of blood circulation in the periodontal membrane by electrical impedance plethysmography. Kokubyo Gakkai Zasshi 1969;36:20-42. 25. Zuccati G, Bocchieri A. Implant site development by orthodontic extrusion of teeth with poor prognosis. J Clin Orthod 2003;37: 307-11. 26. Korayem M, Flores-Mir C, Nassar U, Olfert K. Implant site development by orthodontic extrusion. A systematic review. Angle Orthod 2008;78:752-60. 27. Rasner SL. Orthodontic extrusion: an adjunct to implant treatment. Dent Today 2011;33: 104-9. 28. Makhmalbaf A, Chee W. Soft- and hardtissue augmentation by orthodontic treatment in the esthetic zone. Compend Contin Educ Dent 2012;33:302-6. 29. Batenhorst KF, Bowers GM, Williams JE. Tissue changes resulting from facial tipping and extrusion of incisors in monkeys. J Periodontol 1974;45:660-8.
Watanabe et al
December 2013 30. Ainamo J, Talari A. The increase with age of the width of attached gingiva. J Periodont Res 1976;11:182-8. 31. Graber TM, Swain BF. Orthodontics, current principles and techniques. St Louis: Mosby; 2012. p. 267. 32. Reitam K. Some factors determining the evaluation of forces in orthodontics. Am J Orthod 1957;43:32. 33. Tinti C, Parma-Benfenati S. Clinical classification of bone defects concerning the placement of dental implants. Int J Periodontics Restorative Dent 2003;23: 147-55.
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441 34. Araujo MG, Sukekava F, Wennstorm JL, Lindhe J. Ridge alterations following implant placement in fresh extraction sockets: an experimental study in the dog. J Clin Periodontal 2005;32:645-52. 35. Tarnow DP, Cho SC, Wallace SS. The effect of inter-implant distance on the height of inter-implant bone crest. J Periodontol 2000;71:546-9. 36. Spray JR, Black CG, Morris HF, Ochi S. The influence of bone thickness on facial marginal bone response: stage 1 placement through stage 2 uncovering. Ann Periodontol 2000;5:119-28.
37. Grunder U, Gracis S. Capelli M Influence of the 3-D bone-to-implant relationship on esthetics. Int J Periodontics Restorative Dent 2005;25:113-9. Corresponding author: Dr Takashi Watanabe 6-2, Kotakicho Ohara, Onahama Iwaki-City, Fukushima JAPAN E-mail: [email protected] Copyright ª 2013 by the Editorial Council for The Journal of Prosthetic Dentistry.
Although Brånemark originally recommended a posthealing period of up to 12 months before placement of dental implants,1 problems with this approach were soon identified. When a tooth is extracted, the bundle bone at the extraction site is resorbed both horizontally and vertically because of the lack of function on the bone.2,3 If the subsequent bony defects are severe, then implant placement may be precluded or, if attempted, a poor esthetic result will be inevitable. In response to this problem, various approaches to postextraction alveolar ridge preservation and regeneration have been developed. Excellent results have been documented for some immediate implant placements into extraction sites,4,5 but, if the periodontal problems around the hopeless tooth are severe, then the soft- and hard-tissue defects at the site may require further therapy. Placement of autogenous bone blocks at the time of
extraction, either before or simultaneous with implant placement, has been advocated.6,7 However, such bone grafting procedures may be associated with significant donor-site morbidity.7 As an alternative, Salama and Salama,8 in 1993, suggested using orthodontic extrusion to create vertical bone and soft tissue at hopeless tooth sites before extraction and implant placement without the use of surgery. This approach was based on fundamental orthodontic principles. When orthodontic force is applied to a tooth, the periodontal ligament on the side to which the pressure is applied undergoes a process of hyaline degeneration and becomes necrotic. The necrotic cells are removed by foreign body giant cells and macrophages. Osteoclastic activities ensue, which promote bone resorption. On the opposite side of the tooth, tension is created, which stretches the periodontal ligaments and causes fibroblasts to differentiate. This
is followed by osteoblastic activities and the creation of new bone. The tooth moves because of the osteoclastic activities and bone resorption that occur on the pressure side. Bone apposition occurs because of the osteoblastic activity on the tension side.9,10 Molar uprighting and forced eruption11-13 expanded these insights. Early studies documented that bone apposition results at both the apex and the alveolar crest of extruded teeth, which maintains a normal (1-2 mm) relationship between the periodontium and cement-enamel junction.14-16 Unlike standard orthodontic tooth movement, orthodontic extrusion creates tension throughout the entire socket wall. It stretches the gingival fiber apparatus, which places tension on the alveolar bone and stimulates crestal bone deposition.17-19 Extrusion has been classified as the easiest type of movement to achieve in orthodontics.20 Researchers who have
Presented at the American Academy of Esthetic Dentistry 36th Annual Meeting, San Juan, Puerto Rico, August 2011. a
Clinical Professor, Meikai University School of Dentistry. Member, Board of Councilors, Ostrow School of Dentistry of the University of Southern California. c Professor, University of California at Los Angeles School of Dentistry. b
Watanabe et al
436
Volume 110 Issue 6
1 Hopeless maxillary right central incisor before treatment.
2 Orthodontic wire was designed to move hopeless incisor palatally and coronally. sought to determine the optimal force of extrusion when the goal is remodeling alveolar bone have found a range of
between 15 and 80 g/mL.21-24 Heavy force is detrimental; instead, the force of extrusion applied must be minimal,
controlled, and continuous. Conventional orthodontic wire, which can generate a continuous light force over an extended period of time, is preferred. Over the past 2 decades, orthodontic extrusion of hopeless teeth has become a well-documented alternative to bone grafting in preparation for eventual implant placement.25-28 Such treatment has several objectives. In addition to remodeling the alveolar bone, it increases the zone of attached, keratinized gingiva as the gingival margin moves coronally away from the mucogingival junction.29,30 Extrusion also favorably affects the socket diameter and depth. As the root is extruded, the socket diameter and depth decrease. This creates a better environment for immediate implant placement by minimizing the gap between the implant and the surrounding tissue. For all of the benefits offered by this approach, it has a significant limitation. The greatest amount of bone apposition as a result of orthodontic extrusion occurs in the marginal alveolar and periapical areas of the extruded tooth.31,32 Some labial bone is also created, and orthodontic extrusion may succeed in changing the implant-placement site from a class 2 to a class 1, according to the Tinti classification of socket defects.33 However, the newly created labial bone is typically
3 A-C, Design of orthodontic wire and position of bracket shows combine procedure of extrusion and palatal tooth movement.
The Journal of Prosthetic Dentistry
Watanabe et al
December 2013 thin and prone to resorption after the implant is placed.34 As Tarnow et al35 demonstrated, bone resorption around implants occurs not only in a vertical direction but also horizontally, in the range of 1.3 to 1.4 mm. Furthermore, Spray et al36 showed that, as labial bone thickness approaches 1.8 to 2 mm, bone loss decreases significantly. For that reason, when implants are placed in the esthetic zone, the labial bone thickness should be at least 2 mm to avoid the loss of the labial bone plate and the consequent risk of soft-tissue recession.37 A modification of the orthodontic extrusion technique to develop alveolar bone not only apically and at the alveolar margins but also labially has been suggested. Cognizant that bone apposition occurs because of the osteoblastic activity on the tension side of orthodontic intervention, this technique requires the application of orthodontic pressure on the hopeless tooth both coronally and simultaneously in a palatal direction. When gentle pressure is applied in this manner over a period of 4 to 5 months, the result has been the development of the bone at the site, both vertically and labially. In addition,
437
4 Facial view of hopeless incisor after 5 months of vertical and palatal movement.
5 Incisal view after 5 months of therapy. Note palatal positioning of tooth.
6 A, Initial position of maxillary right central incisor root. B, Root has moved substantially after 5 months of extrusion.
Watanabe et al
438
Volume 110 Issue 6 an increase in labial gingival thickness and an improvement of the gingival biotype occurs. The following clinical report illustrates the application of a 3-dimensional orthodontic extrusion in preparation for implant placement.
CLINICAL REPORT A 41-year-old man presented with pain and swelling at his right central maxillary incisor. Results of a clinical evaluation were severe labial gingival recession (Fig. 1), with a lack of attached gingiva and a mesial pocket depth of 6 mm. Radiographic examination revealed an extensive osseous defect. A treatment plan was developed to orthodontically extrude the hopeless incisor for 5 months to increase the amount of vertical and labial bone at the site while improving both the quantity and quality of the soft tissue. Before the extrusion, the patient underwent scaling and root planing to minimize the presence of active periodontal involvement. The extrusion was initiated by bonding brackets (Micro-arch APPLIANCES Formula-R, Roth Type; Tomy Intl Inc) to the maxillary premolars and incisors. Cobalt chromium orthodontic wire (0.016 0.016) was secured to the brackets with ligature wire (Fig. 2). To create pressure palatally as well as vertically, the bending of the wire included several key design elements: an L-loop and step-down design for coronal movement, an inset component for palatal movement, and a clockwise rotation of the orientation of the wire to avoid tipping and to achieve bodily movement. When the specially designed wire was placed in the strategically positioned bracket, torque was created in the correct direction to achieve the desired movement (Fig. 3). The patient was recalled at 3 different appointments at 4-week intervals to adjust the tension in the wire. At each appointment, the incisal edge and the palatal portion of the right central incisor were reduced to accommodate the new position
The Journal of Prosthetic Dentistry
7 Maxillary right central incisor after removal of orthodontic appliance and fabrication of interim restoration.
8 Postextraction site. Note additional concavity that resulted from extrusion.
9 A, Indicates original tooth position. B, Indicates postorthodontic position.
Watanabe et al
December 2013 of the tooth. When sufficient palatal movement was achieved to bring the maxillary and mandibular incisors edge to edge, the incisal edge was subsequently reduced. The patient returned 2 weeks after the fourth activation, approximately 3 months after the extrusion was initiated. The cobalt chromium orthodontic wire was replaced with 0.0175 0.0175 b-titanium alloy wire (TMA; Ormco Corp) and activated for the fifth time. The elasticity of the b-titanium alloy wire was estimated to be 20 times greater than that of stainless steel and provided good performance in the final stages of orthodontic treatment. The patient again returned every 2 weeks for 3 additional adjustments to the tension on the wire. Five months after the extrusion was initiated, the root of the right central incisor and the gingival margin had moved coronally by approximately 6 or 7 mm (Figs. 4-6). The orthodontic appliance was removed, and an interim crown was made and splinted to the adjacent interim restoration (Fig. 7). Two and a half months after the extrusion was completed, the maxillary right central incisor was atraumatically extracted, and the presence of newly formed bone was noted (Fig. 8). Two osseous concavities, labial and palatal, occurred at the extraction site (Fig. 9) because of the extrusion and palatal tooth movement. A 3.75-mm-diameter, 15-mm-long implant (Nobel Mk III; Nobel Biocare) was placed in the palatal concavity. To increase the thickness of the labial plate, bone grafting of the labial concavity was accomplished by using guided bone regeneration techniques (Fig. 10). An interim restoration was immediately delivered. A custom titanium abutment (Nobel Procera; Nobel Biocare) was designed and placed 6 months after the extraction and immediate implant placement (Fig. 11). The definitive restoration was delivered 6 months later (Fig. 12). After 4 years of follow-up, cone beam computerized tomographic images of
Watanabe et al
439
10 A, Implant was placed in palatal concavity. B, Labial concavity was accomplished by using GBR techniques.
11 Custom titanium abutment was inserted 6 months after implant placement.
12 Definitive restoration, with labial gingival symmetry restored. the central incisor sites demonstrated the continuing presence of adequate labial bone at the site that was orthodontically enhanced, which indicated
an excellent long-term prognosis for the restoration (Fig. 13). Similarly successful results have been obtained for a total of 7 patients to date.
440
Volume 110 Issue 6
13 Cone beam computed tomography images made 4 years after insertion of definitive restorations. A, Implant placed in extruded and palatally positioned maxillary right central incisor site. B, Implant placed in existing edentulous site of missing maxillary left central incisor.
SUMMARY Orthodontic extrusion and palatal tooth movement are effective procedures for site development for immediate implant placement and offer the following clinical advantages: 1. The volume and height of labial bone is increased. 2. The volume and height of the labial gingiva is increased. 3. The gingival biotype is improved. 4. The osseous concavity created from the remnants of the initial socket improves the predictability of new bone formation with a guided bone regeneration technique.
REFERENCES 1. Ohrnell LO, Hirsch JM, Ericsson I, Brånemark P-I. Single tooth rehabilitation using osseointegration. A modified surgical and prosthetic approach. Quintessence Int 1988;19:871-6. 2. Araújo MG, Lindhe J. Dimensional ridge alterations following tooth extraction. An experimental study in the dog. J Clin Periodontol 2005;32:212-8. 3. Van der Weijden F, Dell’Aqua F, Slot DE. Alveolar bone dimensional changes of post-extraction sockets in humans: a systematic review. J Clin Periodontol 2009;36:1048-58. 4. Lazzara RJ. Immediate implant placement into extraction sties: surgical and restorative advantages. Int J Periodontics Restorative Dent 1989;9:333-43. 5. Garber DA, Salama MA, Salama H. Immediate total tooth replacement. Compend Contin Educ Dent 2001;22:210-6.
6. Adell R, Lekholm U, Grondahl K, Brånemark P-I, Lindstrom J, Jacobsson M. Reconstruction of severely resorbed edentulous maxillae using osseointegrated fixtures in immediately autogenous bone grafts. Int J Oral Maxillofac Implants 1990;5:223-46. 7. Pikos M. Atrophic posterior mandibular reconstruction utilizing mandibular block autografts: Risk management. Int J Oral Maxillofac Implants 2003;18:765-6. 8. Salama H, Salama M. The role of orthodontic extrusive remodeling in the enhancement of soft and hard tissue profiles prior to implant placement: a systematic approach to the management of extraction site defects. Int J Periodontics Restorative Dent 1993;13: 313-33. 9. Graber TM, Swain BF. Tissue reactions in orthodontics. In: Orthodontics, current principles and techniques. St Louis: Mosby; 2012. p. 253-62. 10. Proffit WR. The biologic basis of orthodontic therapy. In: Contemporary orthodontics. St Louis: Mosby; 2013. p. 278-89. 11. Brown IS. The effect of orthodontic therapy on certain types of periodontal defects. J Periodontol 1973;44:742-56. 12. Ingber JS. Forced eruption. Part 1. J Periodontol 1974;45:199-206. 13. Ingber JS. Forced eruption. Part 2. J Periodontol 1976;47:203-16. 14. Oppenheim A. Artificial elongation of teeth. Am J Orthod Oral Surg 1940;26:931-42. 15. Ritchey B, Orban B. The crests of interdental alveolar septa. J Periodontol 1953;24:75-87. 16. Reitan K. Clinical and histologic observations on tooth movement during and after orthodontic movement. Am J Orthodont 1967;53: 721-45. 17. Reitan K. Effects of force magnitude and direction of tooth movement on different alveolar bone types. Angle Orthod 1964;34: 244-55. 18. Simon JH, Lythgoe JB, Torabinejad M. Clinical and histologic evaluation of extruded endodontically treated teeth in dogs. Oral Surg Oral Med Oral Pathol 1980;50:361-71.
The Journal of Prosthetic Dentistry
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37. Grunder U, Gracis S. Capelli M Influence of the 3-D bone-to-implant relationship on esthetics. Int J Periodontics Restorative Dent 2005;25:113-9. Corresponding author: Dr Takashi Watanabe 6-2, Kotakicho Ohara, Onahama Iwaki-City, Fukushima JAPAN E-mail: [email protected] Copyright ª 2013 by the Editorial Council for The Journal of Prosthetic Dentistry.