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Speedy surgical-orthodontic treatment with temporary anchorage devices as an alternative to orthognathic surgery
CLINICIAN’S CORNER
Speedy surgical-orthodontic treatment with temporary anchorage devices as an alternative to orthognathic surgery Kyu-Rhim Chung,a Seong-Hun Kim,b and Baek-Soo Leec Seoul and Uijongbu, Korea Introduction: We describe a new type of corticotomy-assisted orthodontic treatment called speedy orthodontics for treating severe anterior protrusion in adults. Once medullary bone is deformed after corticotomy, recovery to its original dimension is impossible if the greenstick fractured bone is ossified as it was deformed. Speedy orthodontics describes a protocol to allow movement of dental segments over a shorter time by using a corticotomy and an orthopedic force with temporary anchorage devices. Methods: After proper diagnosis and treatment planning, the maxillary first premolars are removed, and then a corticotomy is performed to outline a block of bone around the maxillary anterior teeth under local anesthesia. An interval of 2 weeks is optimal between the labial and lingual corticotomy for sufficient healing and less patient anxiety. The maxillary anterior teeth are fixated into a single unit with the specially designed lingual retractor. A retraction force of 500 to 900 g per side is applied to the lingual retractor and the C-palatal plate placed in the midpalatal area. After anterior bone segment retraction, finishing is performed with full fixed appliances. Results: Correct overbite and overjet, facial balance, and improvement of lip protrusion were obtained in adults with protrusion treated by speedy orthodontics. Conclusions: This new type of treatment mechanics can be an effective alternative to orthognathic surgery in adults with protrusion. (Am J Orthod Dentofacial Orthop 2009;135:787-98)
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urrently, the number of middle-aged patients with periodontal problems is increasing, as is the need for orthodontic treatment.1,2 In adults with bimaxillary protrusion, correction might involve removal of 4 premolars. The anterior teeth can be retracted with fixed appliances, with or without orthognathic surgery.1,3,4 However, during retraction, the characteristics of the anterior alveolar bone can resist the efforts to remodel bone. The anatomic limits set by the cortical plates of the alveolus at the level of the incisor apices act as barriers to incisor retraction (Fig 1).3 Also, orthodontic treatment requiring closure of extraction a
President, Korean Society of Speedy Orthodontics, Seoul, Korea. Assistant professor, Division of Orthodontics, Department of Dentistry, Uijongbu St Mary’s Hospital, Catholic University, Uijongbu, Korea. c Professor and chairman, Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyunghee University, Seoul, Korea. Partly supported by the Korean Society of Speedy Orthodontics and the alumni fund of the Department of Dentistry and Graduate School of Clinical Dental Science, Catholic University of Korea. The authors report no commercial, proprietary, or financial interest in the products or companies described in this article. Reprint requests to: Seong-Hun Kim, Department of Orthodontics, Catholic University of Korea, Uijongbu St. Mary’s Hospital, 65-1 Geumoh-dong, Uijeongbu, Gyeonggi-do, 480-717, South Korea; e-mail, bravortho@catholic. ac.kr. Submitted, February 2007; revised and accepted, March 2007. 0889-5406/$36.00 Copyright © 2009 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2007.03.036 b
spaces has a high risk of side effects such as bone loss and root-end resorption in adults with periodontal damage. Now, advances in cone-beam computed tomography (CBCT) make it possible to determine the side effects easily (Fig 2).5,6 Consequently, the clinician can minimize long treatment plans and avoid unnecessary or difficult tooth movements to reduce risk.7 One way to achieve this goal is to use segmental osteotomy.8-10 This procedure removes some limits to tooth movement and shortens treatment time. The down side is concern about side effects such as loss of tooth vitality, avascular necrosis in the bone segment, and the typical risks of general anesthesia and hospitalization. The proximity of the roots must be carefully evaluated during the surgical and retraction procedures. Köle11 introduced a corticotomy technique to enable movement of a bone segment that includes a tooth by sectioning the layer of compact bone. It is a surgical technique that allows the fairly rapid movement of a tooth or group of teeth without requiring the teeth to move a great distance through bone. A corticotomy is less risky than segmental osteotomy or orthognathic surgery.12-17 Corticotomy is a less expensive and less morbid solution, because osteotomies are performed only on the cortical layer. Various kinds of corticotomy 787
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Fig 1. A, Pretreatment and B, posttreatment lateral cephalograms of 22-year-old woman with severe anterior protrusion treated by orthodontic mini-implant after all first premolars were extracted. After 26 months of treatment, cortical bone remodeling at the root apex did not occur.
facilitating orthodontic treatment have been introduced for better results (Fig 3). Chung18,19 developed the new types of corticotomy-assisted orthodontic treatment called speedy orthodontics for treating anterior protrusion patients as an alternative orthodontic treatment strategy that can achieve a result equivalent to that of orthognathic osteotomy.20 SPEEDY SURGICAL ORTHODONTIC TREATMENT
Fig 2. CBCT views (V-Works, version 5.02, Cybermed, Seoul, Korea) of orthodontic treatment. A, 3-dimensional reconstruction image from a 38-year-old woman after 20 months of treatment. Marginal alveolar bone covering the entire dentition was observed. B, Sagittal image from a 24-year-old woman after treatment. Rootend resorption on the mandibular anterior teeth is shown. C, 3-dimensional reconstruction image (Invivodental, version 4.01, Anatomaging Inc, San Jose, Calif) from a 16-year-old girl after mini-implant placement. Root contact can be seen in CBCT view.
The medullary bone around anterior teeth can be easily bent by retraction force if the cortical layer between basal bone and alveolar bone is removed. Once bone is deformed after corticotomy, recovery to its original dimension is impossible if the greenstick fractured bone was ossified as it was deformed (Fig 4, A).19 Speedy orthodontics describes a protocol to allow movement of dental segments in a shorter time by using a corticotomy and an orthopedic force with intraosseous anchorage.18,19 We believe that this has advantages such as slow retraction of the anterior segment, no fixation surgical plate, and local anesthesia, and is less risky compared with a segmental osteotomy (Fig 4, B and C).18-20 The force applied after the corticotomy is heavier than the typical orthodontic force, since the goal is to move the block of bone that was circumscribed rather than moving teeth through the bone.21 Therefore, temporary anchorage devices for speedy orthodontics should bear not only orthodontic but also orthopedic forces. Most current miniscrews (polished surface screws) cannot bear the dynamic, heavy force required. To overcome the limitations of conventional skeletal anchorage and achieve optimal imme-
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Fig 3. Corticotomy can be used for accelerating orthodontic treatment: A, for Wilckodontics17 procedure; B, for reducing the skeletal resistance to arch expansion by surgical removal of the cortical layer at the lateral maxillary buttress.
Fig 4. A, Schematic illustration of speedy orthodontics and sequence of anterior retraction after corticotomy. The medullary bone around the anterior teeth can be easily bent by retraction force if the cortical layer between the basal bone and the alveolar bone is removed (used with permission from B. C. Decker; in: Bell WH, Guerrero CA, editors. Distraction osteogenesis of the facial bones). B, Pretreatment and C, posttreatment lateral cephalograms of speedy orthodontics. After 9 months of active treatment, bimaxillary protrusion was dramatically improved in this 27-year-old woman.
diate or early skeletal fixation, we usually use different types of temporary anchorage devices, called C-tube, C-palatal plate (C-plate), and C-implant.22-24 The C-tube that can accommodate an orthodontic archwire and the sand-blasted, large-grit, acidetched, surface-treated C-implant is usually used as labial orthopedic anchorage.22,23 The C-plate is used for more effective and reliable skeletal anchorage in the palatal area during lingual retraction of the maxillary anterior bone segment.24
Speedy orthodontics is effectively used in adults for bimaxillary protrusion, maxillary anterior protrusion, and Class II malocclusion with open bite. Treatment procedures
Before surgical orthodontic treatment, we usually use mounted models, full-mouth periapical radiographic views, lateral cephalograms, panoramic radiographs, and extraoral and intraoral photos for treatment planning. Plaster model surgery and cephalometric
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Fig 5. Surgical procedures of anterior peri-segmental corticotomy: A, palatal corticotomy; B, labial corticotomy; C, CBCT view (PSR-9000N, Asahi Roentgen, Kyoto, Japan) after peri-segmental corticotomy. Sagittal view shows depth of corticotomy.
Fig 6. Schematic illustration of en-masse retraction by using peri-segmental corticotomy: A, titanium C-palatal plate, drill-free screws, and C-lingual retractor; B, lateral cephalogram showing the retraction appliances and peri-segmental corticotomy. Intraoral photographs: C, before retraction and D, occlusal changes after 4 months of retraction.
simulation should be done to predict the path of planned movement. Risks during the corticotomy are increased if there is active periodontal inflammation or disease, or if excess heat is released during the proce-
dure. The treatment is preceded by periodontal care until the active disease is under control. The surgical procedure is optimal 2 weeks after the labial and lingual corticotomy because it allows for a
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sufficient healing period and lowers patient anxiety.19 In the maxilla, a mucoperiosteal incision is made along the palatal mucosa, and the bone is exposed, avoiding the incisal nerve and the artery. A vertical and horizontal bone cut is made at the first premolar sites, and the cortical bone is removed. Two weeks later, to allow reconnection of the palatal soft-tissue blood supply, a buccal corticotomy is executed in the same manner as was done on the palate (Fig 5). A C-plate is placed on the midpalatal bone area by using self-drilling miniscrews (diameter, 1.5 mm; length, 5-7 mm) (Gebrüder Martin GmbH & Co KG, Tuttlingen, Germany). The detailed surgical procedure was described in a previous article.19 After the surgery, the maxillary anterior teeth are fixated into a single unit with the specially designed lingual retractor.25,26 A retraction force of 500 to 900 g per side is applied to the lingual retractor and the C-plate (Fig 6). After retraction of the anterior corticotomized segment, the C-lingual retractor is removed, and anterior brackets are placed to level and align the full dentition. All maxillary appliances are debonded after active treatment. Fixed and removable retainers are recommended because of the periodontal status and the potential for elastic rebound in the surgical sites. The following case reports of adults show the treatment changes after speedy orthodontics. CASE REPORTS Case 1
A 28-year-old woman complained of lip protrusion and wanted a more esthetic smile (Figs 7 and 8). Skeletal and dental characteristics showed a severe overjet, a flat occlusal plane, and severely protruded incisors. She had a convex profile with an ANB angle of 2.5°, a low mandibular plane (FMA, 22°; SN-OP angle, 16.5°), and protrusive incisors (interincisal angle, 107°; maxillary incisor to NA angle, 35°; maxillary incisor to NA, 10 mm; mandibular incisor to NB angle, 35°; mandibular incisor to NB, 8.5 mm; IMPA, 109.5°). The overall treatment objective was to reduce the lip protrusion by conventional orthodontic treatment, after extraction of all first premolars. However, the pretreatment panoramic radiograph showed poor periodontal support, and the patient asked not to remove all the prosthesis on the mandibular dentition. The treatment objectives based on the results of cephalometric and study model analyses were to extract all first premolars, perform an anterior peri-segmental corcorticotomy, place a C-lingual retractor for rapid anterior retraction, and use a C-palatal plate for absolute anchorage and hooks for lingual retraction. An anterior segmental osteotomy (ASO) was performed in the mandible under
local anesthesia. Maxillary anterior retraction was completed in 5 months after the peri-segmental corticotomy; treatment took 12 months. The posttreatment cephalometric analysis showed marked retraction of the anterior teeth and decreased lip fullness; these contributed to a decrease in facial convexity. Retention was provided by maxillary and mandibular lingual bonded retainers and wraparound retainers. Case 2
A 30-year-old woman had the chief complaint of self-consciousness about her poor appearance caused by protruded front teeth (Figs 9 and 10). The diagnosis was a skeletal Class II malocclusion with bidentoalveolar protrusion and compromised periodontal status. The treatment strategy was to extract all first premolars to correct the convex profile, perform speedy orthodontics with a maxillary C-lingual retractor for anterior retraction, and use a C-palatal plate for anchorage reinforcement. However, because the maxillary left second premolar was endodontically treated, we decided to extract the compromised tooth, retract the maxillary left first premolar into the extraction space, and then perform the speedy orthodontic treatment. After 4 months of maxillary retraction and alignment, the designated 3 teeth were removed. A corticotomy was performed in the maxilla, and ASO was performed in the mandible under local anesthesia. Fixed orthodontic appliances were placed on the maxillary posterior teeth and mandibular teeth, followed by the mandibular ASO, which was fixated with plates and screws, and further stabilized with a 0.017 ⫻ 0.025-in stainless steel archwire. After a healing period of about 4 weeks, mandibular leveling and alignment began. After 5 months, maxillary anterior retraction was completed, and finishing continued for 6 months. The total treatment period was 15 months. Superimposition of the pretreatment and posttreatment cephalometric tracings shows that alveolar bone bending was achieved during anterior retraction (Fig 10). Case 3
A 40-year-old woman had a Class II molar and canine relationship with a skeletal Class II pattern and a deep labiomental sulcus, a prominent upper lip, an everted lower lip, and increased interlabial gap (Figs 11 and 12). Skeletal and dental characteristics showed a severe overjet, severely protruded maxillary incisors, and slightly procumbent mandibular incisors. After all first premolars were extracted, an anterior peri-segmental corticotomy was performed in the maxilla, and ASO was also performed in the mandible under local anesthesia.
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Fig 7. Intraoral photographs and lateral cephalograms of case 1, a 28-year-old woman: A and C, pretreatment; B and D, posttreatment.
Fig 8. Superimposition of lateral cephalograms from pretreatment (black line) to posttreatment (red line).
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Fig 9. Intraoral photographs and lateral cephalograms of case 2, a 30-year-old woman: A and C, pretreatment; B and D, posttreatment.
Fig 10. Superimposition of lateral cephalograms from pretreatment (black line) to posttreatment (red line).
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Fig 11. Intraoral photographs and lateral cephalogram of case 3, a 40-year-old woman: A and C, pretreatment; B and D, posttreatment.
Fig 12. Superimposition of lateral cephalograms from pretreatment (black line) to posttreatment (red line).
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The active retraction period was 4 months, and total treatment was 10 months. Case 4
A woman, age 50 years 10 months, had pronounced dental and labial protrusion and was diagnosed with a skeletal Class II malocclusion with bidentoalveolar protrusion and compromised periodontal status (Figs 13 and 14). All first premolars were removed, and then a corticotomy to outline a block of bone around the maxillary anterior teeth and retract the mandibular anterior teeth with an ASO was performed. After 4 months of active retraction and 5 months of conventional orthodontic treatment, proper occlusion and alignment were obtained. Good overjet, overbite, facial balance, and reduction of hypermentalis activity were also achieved, and the pretreatment Class I molar relationship was maintained. Cephalometric analysis showed slight increases of FMA (from 32.2° to 32.5°) and the occlusal plane (SN to OP angle, 15.1° to 19.3°). The maxillary incisors were significantly retracted with the rigid anchorage from the C-lingual retractor and the C-plate (FH-U1 angle, from 121° to 98.6°; maxillary incisor to NA, 11.5 to 7 mm; maxillary incisor to NA angle, 30.7° to 15.7°). The ANB angle increased slightly during treatment from 3.2° to 5.3°. The mandibular incisors were flared a little because of the intrusive mechanics and the alignment of the severe crowding (IMPA, 93.7° to 96.4°; FMIA, 54.1° to 51°; mandibular incisor to NB, 12.3 to 11.2 mm; mandibular incisor to NB angle, 31.7° to 27.7°). Marked retraction of lip posture was noted, especially of the lower lip (upper lip to E-plane, 5.7 to 2.5 mm; lower lip to E-plane, 8.2 to 0.9 mm). The interincisal angle increased significantly (114.4° to 132.4°) because of anterior bone-segment bending. There was no change in her periodontal status before and after treatment. Alignment and intrusion of the mandibular incisors was associated with mild root-end resorption. Fixed and removable retainers were prescribed due both to the periodontal status and the potential for elastic rebound in the surgical sites. The Table shows the cephalometric measurements of our patients. DISCUSSION
Surgical intervention, including orthognathic surgery and corticotomy, can expand the boundaries of conventional orthodontic treatment, shorten treatment time, and improve a patient’s appearance quickly.4,12,13,17-21 An adult with severe bimaxillary protrusion is considered unsuitable for typical orthodontic treatment with extractions and full fixed appliances because of the high risk of periodontal deterioration and root-end
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resorption. All patients in these case reports had an urgent esthetic goal to retract the lips and teeth. After considering the options, the patients agreed to maxillary peri-segmental corticotomy with maxillary fixed anchorage, a treatment protocol called speedy orthodontics. This protocol takes advantage of the concept of compression osteogenesis in the corticotomized segment during orthopedic traction.18,19 Compression osteogenesis is performed by compressing 2 cut bone surfaces together after the corticotomy. According to Kawakami et al,27 after corticotomies in animals, there are increases in the number of cells, the irregularity of functional arrangement of cells and fibers, the amount of bone resorption, and the apposition and width of the sutures. Changes were seen mostly in the cortical layer, whereas minimal changes were noticeable in spongy bone. The medullary bone around the anterior teeth can be easily bent by heavy retraction force if the cortical layer between the basal and alveolar bones is interrupted. Chung et al28 compared the treatment outcomes of conventional orthodontic treatment, ASO, and speedy orthodontics in adult anterior protrusion patients. In their study, the upper alveolar ridge angle, which described the alveolar bone bending effect, showed a significant decrease in the speedy orthodontics group. Speedy orthodontics is different from accelerated osteogenic orthodontics developed by Wilcko et al17 in that it requires removal of a section of cortical bone rather than punctures in the cortical plate, followed by orthopedic traction against the isolated block of bone and teeth.18-21 In the animal study of Kim,29 who evaluated the change by en-masse retraction of the maxillary anterior teeth with anterior block corticotomy, there were no histologic findings of root resorption or irregularities of the periodontal ligaments in the corticotomy group compared with the control group. If there is periodontal disease, it must be treated and stabilized and proper home care established before orthodontic treatment; this is especially important for a patient for whom speedy orthodontics is planned. This was made clear in an animal experiment by Ericsson et al.30 The orthodontic movement of plaque-infected teeth can alter the formation of the connective tissue attachment and cause an infrabony pocket. They noted that the plaque moved from the supragingival area subgingivally during tipping and intrusion movements. For an adult with a history of periodontal disease and bone loss, it is wise to avoid tipping movements. Bodily translation is healthier if force on the periodontal ligament is lessened.31 The maxillary palatal and buccal corticotomies
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Fig 13. Intraoral photographs and lateral cephalograms of case 4, a woman aged 50 years 10 months: A and C, pretreatment; B and D, posttreatment.
Fig 14. Superimposition of lateral cephalograms from pretreatment (black line) to posttreatment (red line).
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Table.
Cephalometric survey Case 1
Measurement SNA (°) SNB (°) ANB (°) PFH/AFH (%) SN-OP (°) FH-UI (°) FMA (°) IMPA (°) FMIA (°) UL-E plane (mm) LL-E plane (mm) Interincisal angle (°) Mx 1-NA (mm) Mx 1-NA (°) Mn 1-NB (mm) Mn 1-NB (°) SN-PP (°)
Case 2
Case 3
Case 4
Average*
Pre
Post
Pre
Post
Pre
Post
Pre
Post
81.6 79.2 2.4 66.8 17.9 116.0 24.3 95.9 59.8 ⫺0.9 0.6 123.8 7.3 25.3 7.9 28.4 10.2
78.5 76 2.5 70.8 16.5 125 22 109.5 50 2.5 5.5 107 10 35 8.5 35 9
77.5 74 3.5 71.1 18 109 21.5 98.5 59 ⫺1.5 0.5 131 5.5 23 6.5 22.5 9
82 75 7 60.4 18.5 121 33.5 101.5 46 1.5 5.5 105 10 30 15 39 11
81 72.5 8.5 59.1 24 95 35 97 48 0 0.5 133 ⫺1 5 12 34 10
75.5 70 5.5 61.5 19 125 27 107 46 2.5 6.0 101 11.5 38.5 13 35 16
75 69 6 61.5 24 104 27 112 41 ⫺3.5 ⫺2.5 116 2 19 10 39.5 16
82.5 79.3 3.2 63.4 18.7 121 32.2 93.7 54.1 5.7 8.2 114.4 11.5 30.7 12.3 31.7 5.2
81.4 76.1 5.3 63.1 19.0 98.6 32.5 96.4 51.1 2.5 0.9 132.4 7 15.7 11.2 27.7 3.4
Pre, Pretreatment; Post, posttreatment. *For Korean women, data from Korean Association of Orthodontists.36
were done at different times, 2 weeks apart.18,19 This minimizes the obstruction of blood circulation and lessens the burden to both the operator and the patient. However, segmental retraction after ASO seemed to have the advantage of minimal orthodontic intervention in the mandibular arch and allowed us to maintain a reasonable mandibular incisor proclination angle. The chosen treatment also allowed immediate intrusion of the mandibular anterior segment; this facilitated maxillary retraction. In the maxilla, the level of orthopedic force was taken from the theories of Suya,21 Kawakami et al,27 and Yoshikawa,32 in which a force of 500 to 900 g per side is applied to the C-plate and the C-tube. Some authors tried to retract the anterior dentition in patients with bone loss using skeletal anchorage.33 The result was disappointing due to excessive tipping and the relapse tendency. We avoided these effects by uniting the anterior teeth into a unit and bending back the premaxillary segment, taking advantage of compression osteogenesis to reduce the insult on the roots of the teeth both in pressure and time. No root-end resorption of the maxillary incisors was evident. In some protrusion patients, we apply force to the maxillary segment on both the lingual aspect of the C-lingual retractor and the C-plate, and on the labial aspect of the C-tube simultaneously. The purpose was to provide bodily retraction rather than simply tipping the segment back. We estimated the center of resistance to be more apical in a paient with reduced bone
support.34,35 In the Lee and Chung study, the center of resistance was found to be 44.32% apically to the cervical area vertically and 46.38% apically when corticotomy is performed 5 mm below the root apex of 6 anterior teeth and on the lingual and labial sides of the first premolars.34 CONCLUSIONS
These case reports show speedy surgical orthodontic treatment with peri-segmental corticotomy and skeletal anchorage to provide correction that can be used as an alternative to orthognathic surgery. We thank Gerald Nelson, Division of Orthodontics, University of California at San Francisco, for assisting with manuscript preparation. REFERENCES 1. Melsen B. Limitations in adult orthodontics. In: Melsen B, editor. Current controversies in orthodontics. Berlin: Quintessence Publishing Company; 1991. p. 147-80. 2. Miyajima K, Nagahara K, Lizuka T. Orthodontic treatment for a patient after menopause. Angle Orthod 1996;66:173-80. 3. Handelman CS. The anterior alveolus: its importance in limiting orthodontic treatment and its influence on the occurrence of iatrogenic sequelae. Angle Orthod 1996;66:95-109. 4. Proffit WR, White RP Jr. Who needs surgical-orthodontic treatment? Int J Adult Orthod Orthognath Surg 1990;5:81-9. 5. Hamada Y, Kondoh T, Noguchi K, Ino M, Isono H, Ishi H, et al. Application of limited cone beam computed tomography to clinical assessment of alveolar bone grafting: a preliminary report. Cleft Palate Craniofac J 2005;42:128-36.
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6. Huang J, Buman A, Mah J. The cutting edge: three-dimensional radiographic analysis in orthodontics. J Clin Orthod 2005;39: 421-8. 7. Newman WG. Possible etiologic factors in external root resorption. Am J Orthod 1975;67:522-37. 8. Bell WH, Jacobs JD, Legan HL. Treatment of Class II deep bite by orthodontic and surgical means. Am J Orthod 1984;85:1-20. 9. Bojrab DG, Dumas JE, Lahrman DE. JCO interviews Dr. David G. Bojrab, Dr. James E. Dumas, and Dr. Don E. Lahrman on surgical-orthodontics. J Clin Orthod 1977;11:330-42. 10. Laigan DT, Hey JH, West HA. Aseptic necrosis following maxillary osteotomies: report of 36 cases. J Oral Maxillofac Surg 1990;48:142-56. 11. Köle H. Surgical operations on the alveolar ridge to correct occlusal abnormalities. Oral Surg Oral Med Oral Pathol 1959; 12:515-29. 12. Bell WH. Surgical-orthodontic treatment of interincisal diastemas. Am J Orthod 1970;57:158-63. 13. Anholm M, Crites D, Hoff R, Rathbun E. Corticotomy-faciliated orthodontics. Calif Dent Assoc J 1986;7:8-11. 14. Düker J. Experimental animal research into segmental alveolar movement after corticotomy. J Maxillofac Surg 1975;3:81-4. 15. Gantes B, Rathbun E, Anholm M. Effects on the periodontium following corticotomy-facilitated orthodontics. J Periodontol 1990;61:234-8. 16. Bell WH, Levy BM. Revascularization and bone healing after maxillary corticotomies. J Oral Surg 1972;30:640-8. 17. Wilcko WM, Wilcko T, Bouquot TE, Ferguson DJ. Rapid orthodontics with alveolar reshaping: two case reports of decrowding. Int J Periodontics Restorative Dent 2001;21:9-19. 18. Chung KR. Speedy orthodontics. In: Chung KR, editor. Textbook of speedy orthodontics. Seoul: Jeesung; 2001. 19. Chung KR, Kim SH, Kook YA. Speedy surgical orthodontic treatment with skeletal anchorage in adults. In: Bell WH, Guerrero CA, editors. Distraction osteogenesis of the facial bones. Hamilton, Ontario, Canada: B. C. Decker; 2006. 20. Oh MY, Ko SJ. Corticotomy-assisted orthodontics. J Clin Orthod 2001;35:331-9. 21. Suya H. Corticotomy in orthodontics. In: Hosl E, Baldauf A, editors. Mechanical and biological basics in orthodontic therapy. Heidelberg, Germany: Hutig Buch Verlag; 1991. p. 207-26. 22. Chung KR, Nelson G, Kim SH, Kook YA. Severe bidentoalveolar protrusion treated with orthodontic microimplant-dependent en-masse retraction. Am J Orthod Dentofacial Orthop 2007;132: 105-15.
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23. Chung KR, Kim YS, Linton JL, Lee YJ. The miniplate with tube for skeletal anchorage. J Clin Orthod 2002;36:407-12. 24. Chung KR, Kook YA, Kim SH, Mo SS, Jung JA. Class II malocclusion treated by combining a lingual retractor and a palatal plate. Am J Orthod Dentofacial Orthop 2008;133:112-23. 25. Kim SH, Park YG, Chung KR. Severe anterior open bite malocclusion with multiple odontoma treated by C-lingual retractor and horseshoe mechanics. Angle Orthod 2003;73:206-12. 26. Kim SH, Park YG, Chung KR. Severe anterior deep bite malocclusion treated by C-lingual retractor mechanics. Angle Orthod 2004;74:280-5. 27. Kawakami T, Nishimoto M, Matsuda Y, Deguchi T, Eda S. Histologic suture changes following retraction of the maxillary anterior bone segment after corticotomy. Endod Dent Traumatol 1996;12:38-43. 28. Lee JK, Chung KR, Baek SH. Treatment outcomes of orthodontic treatment, corticotomy-assisted orthodontic treatment, and anterior segmental osteotomy for bimaxillary dentoalveolar protrusion. Plast Reconst Surg 2007;120:1027-36. 29. Kim HS. Histologic changes following en masse retraction of the maxillary anterior teeth after anterior block corticotomy in beagle dogs [thesis]. Seoul, Korea: Kyung-Hee University; 2005. 30. Ericsson I, Thilander B, Lindhe J, Okamoto H. The effect of orthodontic tilting movements on the periodontal tissues of infected and non-infected dentitions in dogs. J Clin Periodontol 1977;4:278-93. 31. Årtun J, Urbye KS. 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. 32. Yoshikawa Y. Effects of corticotomy on maxillary retraction induced by orthopedic force. J Matsumoto Dent Coll Soc 1987;13:292-320. 33. Fukunaga T, Kuroda S, Kurosaka H, Takano-Yamamoto T. Skeletal anchorage for orthodontic correction of maxillary protrusion with adult periodontitis. Angle Orthod 2006;76:148-55. 34. Lee HG, Chung KR. The vertical location of the center of resistance for maxillary six anterior teeth during retraction using three dimensional finite element analysis. Korea J Orthod 2001; 31:425-38. 35. Siatkowski RE. Lingual lever-arm technique for en masse translation in patients with generalized marginal bone loss. J Clin Orthod 1999;33:700-4. 36. Korean Association of Orthodontists. Cephalometric norm of Korean adults with normal occlusion. Korea: Ji-Sung Publishing Co., 1998. p. 589-95.
Speedy surgical-orthodontic treatment with temporary anchorage devices as an alternative to orthognathic surgery Kyu-Rhim Chung,a Seong-Hun Kim,b and Baek-Soo Leec Seoul and Uijongbu, Korea Introduction: We describe a new type of corticotomy-assisted orthodontic treatment called speedy orthodontics for treating severe anterior protrusion in adults. Once medullary bone is deformed after corticotomy, recovery to its original dimension is impossible if the greenstick fractured bone is ossified as it was deformed. Speedy orthodontics describes a protocol to allow movement of dental segments over a shorter time by using a corticotomy and an orthopedic force with temporary anchorage devices. Methods: After proper diagnosis and treatment planning, the maxillary first premolars are removed, and then a corticotomy is performed to outline a block of bone around the maxillary anterior teeth under local anesthesia. An interval of 2 weeks is optimal between the labial and lingual corticotomy for sufficient healing and less patient anxiety. The maxillary anterior teeth are fixated into a single unit with the specially designed lingual retractor. A retraction force of 500 to 900 g per side is applied to the lingual retractor and the C-palatal plate placed in the midpalatal area. After anterior bone segment retraction, finishing is performed with full fixed appliances. Results: Correct overbite and overjet, facial balance, and improvement of lip protrusion were obtained in adults with protrusion treated by speedy orthodontics. Conclusions: This new type of treatment mechanics can be an effective alternative to orthognathic surgery in adults with protrusion. (Am J Orthod Dentofacial Orthop 2009;135:787-98)
C
urrently, the number of middle-aged patients with periodontal problems is increasing, as is the need for orthodontic treatment.1,2 In adults with bimaxillary protrusion, correction might involve removal of 4 premolars. The anterior teeth can be retracted with fixed appliances, with or without orthognathic surgery.1,3,4 However, during retraction, the characteristics of the anterior alveolar bone can resist the efforts to remodel bone. The anatomic limits set by the cortical plates of the alveolus at the level of the incisor apices act as barriers to incisor retraction (Fig 1).3 Also, orthodontic treatment requiring closure of extraction a
President, Korean Society of Speedy Orthodontics, Seoul, Korea. Assistant professor, Division of Orthodontics, Department of Dentistry, Uijongbu St Mary’s Hospital, Catholic University, Uijongbu, Korea. c Professor and chairman, Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyunghee University, Seoul, Korea. Partly supported by the Korean Society of Speedy Orthodontics and the alumni fund of the Department of Dentistry and Graduate School of Clinical Dental Science, Catholic University of Korea. The authors report no commercial, proprietary, or financial interest in the products or companies described in this article. Reprint requests to: Seong-Hun Kim, Department of Orthodontics, Catholic University of Korea, Uijongbu St. Mary’s Hospital, 65-1 Geumoh-dong, Uijeongbu, Gyeonggi-do, 480-717, South Korea; e-mail, bravortho@catholic. ac.kr. Submitted, February 2007; revised and accepted, March 2007. 0889-5406/$36.00 Copyright © 2009 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2007.03.036 b
spaces has a high risk of side effects such as bone loss and root-end resorption in adults with periodontal damage. Now, advances in cone-beam computed tomography (CBCT) make it possible to determine the side effects easily (Fig 2).5,6 Consequently, the clinician can minimize long treatment plans and avoid unnecessary or difficult tooth movements to reduce risk.7 One way to achieve this goal is to use segmental osteotomy.8-10 This procedure removes some limits to tooth movement and shortens treatment time. The down side is concern about side effects such as loss of tooth vitality, avascular necrosis in the bone segment, and the typical risks of general anesthesia and hospitalization. The proximity of the roots must be carefully evaluated during the surgical and retraction procedures. Köle11 introduced a corticotomy technique to enable movement of a bone segment that includes a tooth by sectioning the layer of compact bone. It is a surgical technique that allows the fairly rapid movement of a tooth or group of teeth without requiring the teeth to move a great distance through bone. A corticotomy is less risky than segmental osteotomy or orthognathic surgery.12-17 Corticotomy is a less expensive and less morbid solution, because osteotomies are performed only on the cortical layer. Various kinds of corticotomy 787
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Fig 1. A, Pretreatment and B, posttreatment lateral cephalograms of 22-year-old woman with severe anterior protrusion treated by orthodontic mini-implant after all first premolars were extracted. After 26 months of treatment, cortical bone remodeling at the root apex did not occur.
facilitating orthodontic treatment have been introduced for better results (Fig 3). Chung18,19 developed the new types of corticotomy-assisted orthodontic treatment called speedy orthodontics for treating anterior protrusion patients as an alternative orthodontic treatment strategy that can achieve a result equivalent to that of orthognathic osteotomy.20 SPEEDY SURGICAL ORTHODONTIC TREATMENT
Fig 2. CBCT views (V-Works, version 5.02, Cybermed, Seoul, Korea) of orthodontic treatment. A, 3-dimensional reconstruction image from a 38-year-old woman after 20 months of treatment. Marginal alveolar bone covering the entire dentition was observed. B, Sagittal image from a 24-year-old woman after treatment. Rootend resorption on the mandibular anterior teeth is shown. C, 3-dimensional reconstruction image (Invivodental, version 4.01, Anatomaging Inc, San Jose, Calif) from a 16-year-old girl after mini-implant placement. Root contact can be seen in CBCT view.
The medullary bone around anterior teeth can be easily bent by retraction force if the cortical layer between basal bone and alveolar bone is removed. Once bone is deformed after corticotomy, recovery to its original dimension is impossible if the greenstick fractured bone was ossified as it was deformed (Fig 4, A).19 Speedy orthodontics describes a protocol to allow movement of dental segments in a shorter time by using a corticotomy and an orthopedic force with intraosseous anchorage.18,19 We believe that this has advantages such as slow retraction of the anterior segment, no fixation surgical plate, and local anesthesia, and is less risky compared with a segmental osteotomy (Fig 4, B and C).18-20 The force applied after the corticotomy is heavier than the typical orthodontic force, since the goal is to move the block of bone that was circumscribed rather than moving teeth through the bone.21 Therefore, temporary anchorage devices for speedy orthodontics should bear not only orthodontic but also orthopedic forces. Most current miniscrews (polished surface screws) cannot bear the dynamic, heavy force required. To overcome the limitations of conventional skeletal anchorage and achieve optimal imme-
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Fig 3. Corticotomy can be used for accelerating orthodontic treatment: A, for Wilckodontics17 procedure; B, for reducing the skeletal resistance to arch expansion by surgical removal of the cortical layer at the lateral maxillary buttress.
Fig 4. A, Schematic illustration of speedy orthodontics and sequence of anterior retraction after corticotomy. The medullary bone around the anterior teeth can be easily bent by retraction force if the cortical layer between the basal bone and the alveolar bone is removed (used with permission from B. C. Decker; in: Bell WH, Guerrero CA, editors. Distraction osteogenesis of the facial bones). B, Pretreatment and C, posttreatment lateral cephalograms of speedy orthodontics. After 9 months of active treatment, bimaxillary protrusion was dramatically improved in this 27-year-old woman.
diate or early skeletal fixation, we usually use different types of temporary anchorage devices, called C-tube, C-palatal plate (C-plate), and C-implant.22-24 The C-tube that can accommodate an orthodontic archwire and the sand-blasted, large-grit, acidetched, surface-treated C-implant is usually used as labial orthopedic anchorage.22,23 The C-plate is used for more effective and reliable skeletal anchorage in the palatal area during lingual retraction of the maxillary anterior bone segment.24
Speedy orthodontics is effectively used in adults for bimaxillary protrusion, maxillary anterior protrusion, and Class II malocclusion with open bite. Treatment procedures
Before surgical orthodontic treatment, we usually use mounted models, full-mouth periapical radiographic views, lateral cephalograms, panoramic radiographs, and extraoral and intraoral photos for treatment planning. Plaster model surgery and cephalometric
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Fig 5. Surgical procedures of anterior peri-segmental corticotomy: A, palatal corticotomy; B, labial corticotomy; C, CBCT view (PSR-9000N, Asahi Roentgen, Kyoto, Japan) after peri-segmental corticotomy. Sagittal view shows depth of corticotomy.
Fig 6. Schematic illustration of en-masse retraction by using peri-segmental corticotomy: A, titanium C-palatal plate, drill-free screws, and C-lingual retractor; B, lateral cephalogram showing the retraction appliances and peri-segmental corticotomy. Intraoral photographs: C, before retraction and D, occlusal changes after 4 months of retraction.
simulation should be done to predict the path of planned movement. Risks during the corticotomy are increased if there is active periodontal inflammation or disease, or if excess heat is released during the proce-
dure. The treatment is preceded by periodontal care until the active disease is under control. The surgical procedure is optimal 2 weeks after the labial and lingual corticotomy because it allows for a
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sufficient healing period and lowers patient anxiety.19 In the maxilla, a mucoperiosteal incision is made along the palatal mucosa, and the bone is exposed, avoiding the incisal nerve and the artery. A vertical and horizontal bone cut is made at the first premolar sites, and the cortical bone is removed. Two weeks later, to allow reconnection of the palatal soft-tissue blood supply, a buccal corticotomy is executed in the same manner as was done on the palate (Fig 5). A C-plate is placed on the midpalatal bone area by using self-drilling miniscrews (diameter, 1.5 mm; length, 5-7 mm) (Gebrüder Martin GmbH & Co KG, Tuttlingen, Germany). The detailed surgical procedure was described in a previous article.19 After the surgery, the maxillary anterior teeth are fixated into a single unit with the specially designed lingual retractor.25,26 A retraction force of 500 to 900 g per side is applied to the lingual retractor and the C-plate (Fig 6). After retraction of the anterior corticotomized segment, the C-lingual retractor is removed, and anterior brackets are placed to level and align the full dentition. All maxillary appliances are debonded after active treatment. Fixed and removable retainers are recommended because of the periodontal status and the potential for elastic rebound in the surgical sites. The following case reports of adults show the treatment changes after speedy orthodontics. CASE REPORTS Case 1
A 28-year-old woman complained of lip protrusion and wanted a more esthetic smile (Figs 7 and 8). Skeletal and dental characteristics showed a severe overjet, a flat occlusal plane, and severely protruded incisors. She had a convex profile with an ANB angle of 2.5°, a low mandibular plane (FMA, 22°; SN-OP angle, 16.5°), and protrusive incisors (interincisal angle, 107°; maxillary incisor to NA angle, 35°; maxillary incisor to NA, 10 mm; mandibular incisor to NB angle, 35°; mandibular incisor to NB, 8.5 mm; IMPA, 109.5°). The overall treatment objective was to reduce the lip protrusion by conventional orthodontic treatment, after extraction of all first premolars. However, the pretreatment panoramic radiograph showed poor periodontal support, and the patient asked not to remove all the prosthesis on the mandibular dentition. The treatment objectives based on the results of cephalometric and study model analyses were to extract all first premolars, perform an anterior peri-segmental corcorticotomy, place a C-lingual retractor for rapid anterior retraction, and use a C-palatal plate for absolute anchorage and hooks for lingual retraction. An anterior segmental osteotomy (ASO) was performed in the mandible under
local anesthesia. Maxillary anterior retraction was completed in 5 months after the peri-segmental corticotomy; treatment took 12 months. The posttreatment cephalometric analysis showed marked retraction of the anterior teeth and decreased lip fullness; these contributed to a decrease in facial convexity. Retention was provided by maxillary and mandibular lingual bonded retainers and wraparound retainers. Case 2
A 30-year-old woman had the chief complaint of self-consciousness about her poor appearance caused by protruded front teeth (Figs 9 and 10). The diagnosis was a skeletal Class II malocclusion with bidentoalveolar protrusion and compromised periodontal status. The treatment strategy was to extract all first premolars to correct the convex profile, perform speedy orthodontics with a maxillary C-lingual retractor for anterior retraction, and use a C-palatal plate for anchorage reinforcement. However, because the maxillary left second premolar was endodontically treated, we decided to extract the compromised tooth, retract the maxillary left first premolar into the extraction space, and then perform the speedy orthodontic treatment. After 4 months of maxillary retraction and alignment, the designated 3 teeth were removed. A corticotomy was performed in the maxilla, and ASO was performed in the mandible under local anesthesia. Fixed orthodontic appliances were placed on the maxillary posterior teeth and mandibular teeth, followed by the mandibular ASO, which was fixated with plates and screws, and further stabilized with a 0.017 ⫻ 0.025-in stainless steel archwire. After a healing period of about 4 weeks, mandibular leveling and alignment began. After 5 months, maxillary anterior retraction was completed, and finishing continued for 6 months. The total treatment period was 15 months. Superimposition of the pretreatment and posttreatment cephalometric tracings shows that alveolar bone bending was achieved during anterior retraction (Fig 10). Case 3
A 40-year-old woman had a Class II molar and canine relationship with a skeletal Class II pattern and a deep labiomental sulcus, a prominent upper lip, an everted lower lip, and increased interlabial gap (Figs 11 and 12). Skeletal and dental characteristics showed a severe overjet, severely protruded maxillary incisors, and slightly procumbent mandibular incisors. After all first premolars were extracted, an anterior peri-segmental corticotomy was performed in the maxilla, and ASO was also performed in the mandible under local anesthesia.
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Fig 7. Intraoral photographs and lateral cephalograms of case 1, a 28-year-old woman: A and C, pretreatment; B and D, posttreatment.
Fig 8. Superimposition of lateral cephalograms from pretreatment (black line) to posttreatment (red line).
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Fig 9. Intraoral photographs and lateral cephalograms of case 2, a 30-year-old woman: A and C, pretreatment; B and D, posttreatment.
Fig 10. Superimposition of lateral cephalograms from pretreatment (black line) to posttreatment (red line).
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Fig 11. Intraoral photographs and lateral cephalogram of case 3, a 40-year-old woman: A and C, pretreatment; B and D, posttreatment.
Fig 12. Superimposition of lateral cephalograms from pretreatment (black line) to posttreatment (red line).
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The active retraction period was 4 months, and total treatment was 10 months. Case 4
A woman, age 50 years 10 months, had pronounced dental and labial protrusion and was diagnosed with a skeletal Class II malocclusion with bidentoalveolar protrusion and compromised periodontal status (Figs 13 and 14). All first premolars were removed, and then a corticotomy to outline a block of bone around the maxillary anterior teeth and retract the mandibular anterior teeth with an ASO was performed. After 4 months of active retraction and 5 months of conventional orthodontic treatment, proper occlusion and alignment were obtained. Good overjet, overbite, facial balance, and reduction of hypermentalis activity were also achieved, and the pretreatment Class I molar relationship was maintained. Cephalometric analysis showed slight increases of FMA (from 32.2° to 32.5°) and the occlusal plane (SN to OP angle, 15.1° to 19.3°). The maxillary incisors were significantly retracted with the rigid anchorage from the C-lingual retractor and the C-plate (FH-U1 angle, from 121° to 98.6°; maxillary incisor to NA, 11.5 to 7 mm; maxillary incisor to NA angle, 30.7° to 15.7°). The ANB angle increased slightly during treatment from 3.2° to 5.3°. The mandibular incisors were flared a little because of the intrusive mechanics and the alignment of the severe crowding (IMPA, 93.7° to 96.4°; FMIA, 54.1° to 51°; mandibular incisor to NB, 12.3 to 11.2 mm; mandibular incisor to NB angle, 31.7° to 27.7°). Marked retraction of lip posture was noted, especially of the lower lip (upper lip to E-plane, 5.7 to 2.5 mm; lower lip to E-plane, 8.2 to 0.9 mm). The interincisal angle increased significantly (114.4° to 132.4°) because of anterior bone-segment bending. There was no change in her periodontal status before and after treatment. Alignment and intrusion of the mandibular incisors was associated with mild root-end resorption. Fixed and removable retainers were prescribed due both to the periodontal status and the potential for elastic rebound in the surgical sites. The Table shows the cephalometric measurements of our patients. DISCUSSION
Surgical intervention, including orthognathic surgery and corticotomy, can expand the boundaries of conventional orthodontic treatment, shorten treatment time, and improve a patient’s appearance quickly.4,12,13,17-21 An adult with severe bimaxillary protrusion is considered unsuitable for typical orthodontic treatment with extractions and full fixed appliances because of the high risk of periodontal deterioration and root-end
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resorption. All patients in these case reports had an urgent esthetic goal to retract the lips and teeth. After considering the options, the patients agreed to maxillary peri-segmental corticotomy with maxillary fixed anchorage, a treatment protocol called speedy orthodontics. This protocol takes advantage of the concept of compression osteogenesis in the corticotomized segment during orthopedic traction.18,19 Compression osteogenesis is performed by compressing 2 cut bone surfaces together after the corticotomy. According to Kawakami et al,27 after corticotomies in animals, there are increases in the number of cells, the irregularity of functional arrangement of cells and fibers, the amount of bone resorption, and the apposition and width of the sutures. Changes were seen mostly in the cortical layer, whereas minimal changes were noticeable in spongy bone. The medullary bone around the anterior teeth can be easily bent by heavy retraction force if the cortical layer between the basal and alveolar bones is interrupted. Chung et al28 compared the treatment outcomes of conventional orthodontic treatment, ASO, and speedy orthodontics in adult anterior protrusion patients. In their study, the upper alveolar ridge angle, which described the alveolar bone bending effect, showed a significant decrease in the speedy orthodontics group. Speedy orthodontics is different from accelerated osteogenic orthodontics developed by Wilcko et al17 in that it requires removal of a section of cortical bone rather than punctures in the cortical plate, followed by orthopedic traction against the isolated block of bone and teeth.18-21 In the animal study of Kim,29 who evaluated the change by en-masse retraction of the maxillary anterior teeth with anterior block corticotomy, there were no histologic findings of root resorption or irregularities of the periodontal ligaments in the corticotomy group compared with the control group. If there is periodontal disease, it must be treated and stabilized and proper home care established before orthodontic treatment; this is especially important for a patient for whom speedy orthodontics is planned. This was made clear in an animal experiment by Ericsson et al.30 The orthodontic movement of plaque-infected teeth can alter the formation of the connective tissue attachment and cause an infrabony pocket. They noted that the plaque moved from the supragingival area subgingivally during tipping and intrusion movements. For an adult with a history of periodontal disease and bone loss, it is wise to avoid tipping movements. Bodily translation is healthier if force on the periodontal ligament is lessened.31 The maxillary palatal and buccal corticotomies
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Fig 13. Intraoral photographs and lateral cephalograms of case 4, a woman aged 50 years 10 months: A and C, pretreatment; B and D, posttreatment.
Fig 14. Superimposition of lateral cephalograms from pretreatment (black line) to posttreatment (red line).
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Table.
Cephalometric survey Case 1
Measurement SNA (°) SNB (°) ANB (°) PFH/AFH (%) SN-OP (°) FH-UI (°) FMA (°) IMPA (°) FMIA (°) UL-E plane (mm) LL-E plane (mm) Interincisal angle (°) Mx 1-NA (mm) Mx 1-NA (°) Mn 1-NB (mm) Mn 1-NB (°) SN-PP (°)
Case 2
Case 3
Case 4
Average*
Pre
Post
Pre
Post
Pre
Post
Pre
Post
81.6 79.2 2.4 66.8 17.9 116.0 24.3 95.9 59.8 ⫺0.9 0.6 123.8 7.3 25.3 7.9 28.4 10.2
78.5 76 2.5 70.8 16.5 125 22 109.5 50 2.5 5.5 107 10 35 8.5 35 9
77.5 74 3.5 71.1 18 109 21.5 98.5 59 ⫺1.5 0.5 131 5.5 23 6.5 22.5 9
82 75 7 60.4 18.5 121 33.5 101.5 46 1.5 5.5 105 10 30 15 39 11
81 72.5 8.5 59.1 24 95 35 97 48 0 0.5 133 ⫺1 5 12 34 10
75.5 70 5.5 61.5 19 125 27 107 46 2.5 6.0 101 11.5 38.5 13 35 16
75 69 6 61.5 24 104 27 112 41 ⫺3.5 ⫺2.5 116 2 19 10 39.5 16
82.5 79.3 3.2 63.4 18.7 121 32.2 93.7 54.1 5.7 8.2 114.4 11.5 30.7 12.3 31.7 5.2
81.4 76.1 5.3 63.1 19.0 98.6 32.5 96.4 51.1 2.5 0.9 132.4 7 15.7 11.2 27.7 3.4
Pre, Pretreatment; Post, posttreatment. *For Korean women, data from Korean Association of Orthodontists.36
were done at different times, 2 weeks apart.18,19 This minimizes the obstruction of blood circulation and lessens the burden to both the operator and the patient. However, segmental retraction after ASO seemed to have the advantage of minimal orthodontic intervention in the mandibular arch and allowed us to maintain a reasonable mandibular incisor proclination angle. The chosen treatment also allowed immediate intrusion of the mandibular anterior segment; this facilitated maxillary retraction. In the maxilla, the level of orthopedic force was taken from the theories of Suya,21 Kawakami et al,27 and Yoshikawa,32 in which a force of 500 to 900 g per side is applied to the C-plate and the C-tube. Some authors tried to retract the anterior dentition in patients with bone loss using skeletal anchorage.33 The result was disappointing due to excessive tipping and the relapse tendency. We avoided these effects by uniting the anterior teeth into a unit and bending back the premaxillary segment, taking advantage of compression osteogenesis to reduce the insult on the roots of the teeth both in pressure and time. No root-end resorption of the maxillary incisors was evident. In some protrusion patients, we apply force to the maxillary segment on both the lingual aspect of the C-lingual retractor and the C-plate, and on the labial aspect of the C-tube simultaneously. The purpose was to provide bodily retraction rather than simply tipping the segment back. We estimated the center of resistance to be more apical in a paient with reduced bone
support.34,35 In the Lee and Chung study, the center of resistance was found to be 44.32% apically to the cervical area vertically and 46.38% apically when corticotomy is performed 5 mm below the root apex of 6 anterior teeth and on the lingual and labial sides of the first premolars.34 CONCLUSIONS
These case reports show speedy surgical orthodontic treatment with peri-segmental corticotomy and skeletal anchorage to provide correction that can be used as an alternative to orthognathic surgery. We thank Gerald Nelson, Division of Orthodontics, University of California at San Francisco, for assisting with manuscript preparation. REFERENCES 1. Melsen B. Limitations in adult orthodontics. In: Melsen B, editor. Current controversies in orthodontics. Berlin: Quintessence Publishing Company; 1991. p. 147-80. 2. Miyajima K, Nagahara K, Lizuka T. Orthodontic treatment for a patient after menopause. Angle Orthod 1996;66:173-80. 3. Handelman CS. The anterior alveolus: its importance in limiting orthodontic treatment and its influence on the occurrence of iatrogenic sequelae. Angle Orthod 1996;66:95-109. 4. Proffit WR, White RP Jr. Who needs surgical-orthodontic treatment? Int J Adult Orthod Orthognath Surg 1990;5:81-9. 5. Hamada Y, Kondoh T, Noguchi K, Ino M, Isono H, Ishi H, et al. Application of limited cone beam computed tomography to clinical assessment of alveolar bone grafting: a preliminary report. Cleft Palate Craniofac J 2005;42:128-36.
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6. Huang J, Buman A, Mah J. The cutting edge: three-dimensional radiographic analysis in orthodontics. J Clin Orthod 2005;39: 421-8. 7. Newman WG. Possible etiologic factors in external root resorption. Am J Orthod 1975;67:522-37. 8. Bell WH, Jacobs JD, Legan HL. Treatment of Class II deep bite by orthodontic and surgical means. Am J Orthod 1984;85:1-20. 9. Bojrab DG, Dumas JE, Lahrman DE. JCO interviews Dr. David G. Bojrab, Dr. James E. Dumas, and Dr. Don E. Lahrman on surgical-orthodontics. J Clin Orthod 1977;11:330-42. 10. Laigan DT, Hey JH, West HA. Aseptic necrosis following maxillary osteotomies: report of 36 cases. J Oral Maxillofac Surg 1990;48:142-56. 11. Köle H. Surgical operations on the alveolar ridge to correct occlusal abnormalities. Oral Surg Oral Med Oral Pathol 1959; 12:515-29. 12. Bell WH. Surgical-orthodontic treatment of interincisal diastemas. Am J Orthod 1970;57:158-63. 13. Anholm M, Crites D, Hoff R, Rathbun E. Corticotomy-faciliated orthodontics. Calif Dent Assoc J 1986;7:8-11. 14. Düker J. Experimental animal research into segmental alveolar movement after corticotomy. J Maxillofac Surg 1975;3:81-4. 15. Gantes B, Rathbun E, Anholm M. Effects on the periodontium following corticotomy-facilitated orthodontics. J Periodontol 1990;61:234-8. 16. Bell WH, Levy BM. Revascularization and bone healing after maxillary corticotomies. J Oral Surg 1972;30:640-8. 17. Wilcko WM, Wilcko T, Bouquot TE, Ferguson DJ. Rapid orthodontics with alveolar reshaping: two case reports of decrowding. Int J Periodontics Restorative Dent 2001;21:9-19. 18. Chung KR. Speedy orthodontics. In: Chung KR, editor. Textbook of speedy orthodontics. Seoul: Jeesung; 2001. 19. Chung KR, Kim SH, Kook YA. Speedy surgical orthodontic treatment with skeletal anchorage in adults. In: Bell WH, Guerrero CA, editors. Distraction osteogenesis of the facial bones. Hamilton, Ontario, Canada: B. C. Decker; 2006. 20. Oh MY, Ko SJ. Corticotomy-assisted orthodontics. J Clin Orthod 2001;35:331-9. 21. Suya H. Corticotomy in orthodontics. In: Hosl E, Baldauf A, editors. Mechanical and biological basics in orthodontic therapy. Heidelberg, Germany: Hutig Buch Verlag; 1991. p. 207-26. 22. Chung KR, Nelson G, Kim SH, Kook YA. Severe bidentoalveolar protrusion treated with orthodontic microimplant-dependent en-masse retraction. Am J Orthod Dentofacial Orthop 2007;132: 105-15.
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23. Chung KR, Kim YS, Linton JL, Lee YJ. The miniplate with tube for skeletal anchorage. J Clin Orthod 2002;36:407-12. 24. Chung KR, Kook YA, Kim SH, Mo SS, Jung JA. Class II malocclusion treated by combining a lingual retractor and a palatal plate. Am J Orthod Dentofacial Orthop 2008;133:112-23. 25. Kim SH, Park YG, Chung KR. Severe anterior open bite malocclusion with multiple odontoma treated by C-lingual retractor and horseshoe mechanics. Angle Orthod 2003;73:206-12. 26. Kim SH, Park YG, Chung KR. Severe anterior deep bite malocclusion treated by C-lingual retractor mechanics. Angle Orthod 2004;74:280-5. 27. Kawakami T, Nishimoto M, Matsuda Y, Deguchi T, Eda S. Histologic suture changes following retraction of the maxillary anterior bone segment after corticotomy. Endod Dent Traumatol 1996;12:38-43. 28. Lee JK, Chung KR, Baek SH. Treatment outcomes of orthodontic treatment, corticotomy-assisted orthodontic treatment, and anterior segmental osteotomy for bimaxillary dentoalveolar protrusion. Plast Reconst Surg 2007;120:1027-36. 29. Kim HS. Histologic changes following en masse retraction of the maxillary anterior teeth after anterior block corticotomy in beagle dogs [thesis]. Seoul, Korea: Kyung-Hee University; 2005. 30. Ericsson I, Thilander B, Lindhe J, Okamoto H. The effect of orthodontic tilting movements on the periodontal tissues of infected and non-infected dentitions in dogs. J Clin Periodontol 1977;4:278-93. 31. Årtun J, Urbye KS. 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. 32. Yoshikawa Y. Effects of corticotomy on maxillary retraction induced by orthopedic force. J Matsumoto Dent Coll Soc 1987;13:292-320. 33. Fukunaga T, Kuroda S, Kurosaka H, Takano-Yamamoto T. Skeletal anchorage for orthodontic correction of maxillary protrusion with adult periodontitis. Angle Orthod 2006;76:148-55. 34. Lee HG, Chung KR. The vertical location of the center of resistance for maxillary six anterior teeth during retraction using three dimensional finite element analysis. Korea J Orthod 2001; 31:425-38. 35. Siatkowski RE. Lingual lever-arm technique for en masse translation in patients with generalized marginal bone loss. J Clin Orthod 1999;33:700-4. 36. Korean Association of Orthodontists. Cephalometric norm of Korean adults with normal occlusion. Korea: Ji-Sung Publishing Co., 1998. p. 589-95.