J Oral Maxillofac Surg 60:389-394, 2002
Dentoalveolar Distraction Osteogenesis for Rapid Orthodontic Canine Retraction Reha ¸S. Kı˙¸snı˙¸scı˙, DDS, PhD,* Haluk ˙I¸serı˙, DDS, PhD,† Hakan H. Tu ¨ z, DDS, PhD,‡ and Ays¸e T. Altug, DDS§ Purpose:
We present a technique to reduce the overall orthodontic treatment time by means of dentoalveolar distraction osteogenesis. Patients and Methods: Eleven patients who were planned to undergo orthodontic treatment with bilateral first premolar extractions and subsequent bilateral canine tooth distalization underwent osteotomy around the canine tooth. The first premolar was extracted, and the buccal bone was carefully removed. After wound closure, a special orthopedic device was mounted and cemented to the first molar and canine teeth. Distraction was started the same day at the rate of 0.4 mm twice a day and continued until adequate movement of the canine teeth was achieved. The device was then removed, and orthodontic therapy was continued with fixed appliances. Results: The distraction rate and the device were well tolerated by all of patients. No anchorage loss in the second premolar and first molar teeth, root resorption, dental ankylosis, discoloration, or loss of vitality was detected. Conclusion: The concept of distraction osteogenesis for rapid orthodontic tooth movement is promising and feasible for clinical practice. © 2002 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 60:389-394, 2002 Distraction osteogenesis is a gradual bone-lengthening technique that was first introduced by Codivilla1 in 1905 and was popularized in the 1970s by the extensive work of Ilizarov2 in orthopedics. In 1992 McCarthy et al3 reported the first clinical application of distraction osteogenesis for mandibular lengthening to correct a facial deformity. Various indications in the oral and maxillofacial region were subsequently described.3-6 External devices were initially used for distraction osteogenesis. The devices for intraoral applications were introduced shortly afterward, and newer applications have been fostered.7-9 Intraoral distraction osteogenesis has been used for lengthening, widening, and augmentation to correct several skeletal problems.10-14
Conventional orthodontic treatments with either fixed or functional appliances rely on biological tooth movements.15 However, using conventional techniques, biological tooth movement can be achieved at a limited rate.16 This feature is thought to be a shortcoming, especially when major tooth relocation is necessary. The time required for tooth movement within the alveolar bone may lengthen the overall orthodontic treatment time. In this clinical report, we describe a surgical technique for rapid tooth movement. The principles of distraction osteogenesis by means of transportation of a bone disc are used to move a dentoalveolar segment. The aim of this clinical study was to establish an approach to reduce the overall orthodontic treatment time by means of dentoalveolar distraction osteogenesis.
Received from Ankara University, Dental School, Ankara, Turkey. *Professor, Department of Oral and Maxillofacial Surgery. †Professor, Department of Orthodontics. ‡Chief Resident, Department of Oral and Maxillofacial Surgery. §Research Assistant, Department of Orthodontics. Address correspondence and reprint requests to Dr Kis¸nis¸ci: Ankara Universitesi, Dis¸ Hekimlig˘i Faku ¨ ltesi, Bes¸evler, Konya Yolu ¨ zeri, 06500, Ankara, Turkey; e-mail:
[email protected] U
Patients and Methods Eleven patients (13 to 18 years old, 7 females and 4 males) scheduled for orthodontic treatment with bilateral bicuspid extractions and subsequent bilateral canine tooth distalization underwent the procedure that we describe. Patients and their parents were informed about the proposed treatment plan involving the surgical phase as well as the conventional alternative option, and their consent was obtained. The surgery was carried out in the maxilla (8 patients)
© 2002 American Association of Oral and Maxillofacial Surgeons
0278-2391/02/6004-0007$35.00/0 doi:10.1053/joms.2002.31226
389
390
DENTOALVEOLAR DISTRACTION OSTEOGENESIS
or the mandible (2 patients), and 1 patient underwent the procedure in both jaws. TECHNIQUE
An intraoral device for dentoalveolar distraction osteogenesis was custom designed to enable canine tooth distalization. When a unidirectionally moving shaft on the device is activated a full turn, it closes 0.4 mm, moving the canine tooth posteriorly toward the second premolar. The device was soldered to the canine and first molar bands on a plaster model and checked for fit and tolerance in the clinical setting. All patients underwent surgery on an outpatient basis with the use of local anesthesia, sometimes supplemented with sedation. A horizontal mucosal incision 2 to 2.5 cm long was made parallel to the gingival margin of the canine and bicuspid teeth well beyond the depth of the vestibule. Subperiosteal elevation was carried out to expose the canine root and the first premolar region. A vertical osteotomy was made on the anterior aspect of the canine tooth to be distracted posteriorly using multiple cortical holes made on the alveolar bone with a small, round, carbide bur under copious irrigation (Fig 1). The depth and location of the cortical holes were dictated by the proximity of the neighboring tooth. The osteotomy was continued and curved apically, passing 3 to 5 mm from the apex, which could readily be identified in the alveolar bone. A vertical osteotomy was made in a similar manner along the posterior aspect of the ca-
FIGURE 1. Vertically aligned multiple cortical holes on the medial and lateral aspects of the upper right canine root in the level corresponding to the mid portion of the canine root, continuing and curving apically and passing 3 to 5 mm from the apex.
FIGURE 2. Root of the upper right canine tooth is outlined medially and distally at the apical region after the use of a thin and tapered fissure bur to connect the holes.
nine tooth. A thin, tapered fissure bur was then used to connect the holes around the canine root (Fig 2). The root of the canine tooth thus was outlined anteriorly and posteriorly with a cone shape at the apical region. Fine osteotomes were then introduced and advanced in the coronal direction. The first premolar was extracted at this stage, and the buccal bone was carefully removed through the extraction socket using large, round burs between the bone cut at the distal canine region anteriorly and the second premolar posteriorly. The bone apical to the extraction socket and possible bony interferences at the buccal aspect that may be encountered during the distraction process were eliminated and/or smoothed between the canine and the second premolar teeth with preservation of palatal or lingual cortical shelves (Fig 3). The cortical bone at the apical region was also relieved for maximal bodily movement during distraction. In cases in which the apex was closely situated at or above the antrum floor, the bone between and in front of the moving axis of the root was removed or thinned out using round burs, with the maxillary sinus lining exposed to facilitate posterior movement of the dentoalveolar segment. Osteotomes in appropriate sizes were then used along the anterior aspect of the dentoalveolar segment that includes the canine tooth to split the surrounding spongy bone around its root off of the lingual or palatal cortex and neighboring teeth. The transport dentoalveolar segment in-
391
KIS¸NIS¸CI ET AL
cludes the buccal cortex and the underlying spongy bone that envelops the canine root, leaving an intact apical, lingual, or palatal cortical plate. Minimal force was necessary for full mobilization of the transport bone disc. The wound was irrigated with saline and closed in a single mucosal layer with an absorbable suture. The distraction device was fitted and cemented to the first molar and canine teeth at the end of the surgical procedure. The patients were prescribed an antibiotic and a nonsteroidal anti-inflammatory drug for 5 days. Dentoalveolar distraction was started on the day of the surgery and continued at a rate of 0.4 mm twice a day. It was discontinued when the canine tooth moved posteriorly into the desired position (Figs 4, 5). The device was then removed, and orthodontic therapy was continued with fixed appliances.
Results
FIGURE 3. Intraoperative view of the extraction socket of first premolar and upper right canine teeth carrying the dentoalveolar segment to be used as a transport disc. The cortical bone, especially at the level of the apical region, should also be eliminated for maximal bodily movement during distraction.
The follow-up period ranged from 4 to 11 months. The canine teeth were moved posteriorly or posteroinferiorly and made contact with the second premolars in 8 to 12 days. The distraction rate of 0.8 mm per day and the device were well tolerated. Clinically, the
FIGURE 4. Dentoalveolar distraction of the right lower canine tooth. A, Initial view before treatment. B, Day 3 of the distraction. C, Day 8 of the distraction.
392
DENTOALVEOLAR DISTRACTION OSTEOGENESIS
FIGURE 5. Dentoalveolar distraction of the right upper canine tooth. A, Initial view before treatment. B, Day 2 of the distraction. C, Day 9 of the distraction.
tooth-borne distraction devices did not cause any movement of the lateral incisors or second premolars. Root resorption and dental ankylosis were not detected in any of the patients (Figs 6, 7). No discoloration or radiographic evidence suggestive of loss of tooth vitality was noted. Vitality testing after the removal of orthodontic fixed appliances proved to be in normal ranges. In cases in which the bone had to be
FIGURE 6. Radiographic appearance of the upper right canine tooth (A) before dentoalveolar distraction, and (B) during fixed orthodontic treatment phase at a later stage, delineating new bone regenerated mesially.
FIGURE 7. Panoramic radiograph of a patient with bilateral upper canine teeth. A, Before dentoalveolar distraction. B, Immediately after dismounting of the distraction device; also shows parallel posterior movement.
393
KIS¸NIS¸CI ET AL
removed down to the antral lining, none of the patients complained about sinus symptoms.
Discussion The clinical applications of distraction osteogenesis in maxillofacial surgery are becoming broader, and several innovative techniques have been introduced to change the classic approaches or to optimize the correction of several deformities. In this clinical report, the reduced overall treatment time with this technique may be considered an advantage. Conventional orthodontic tooth movement is the result of biological cascades of resorption and apposition secondary to mechanical forces.17 Individual factors, such as the optimum force, turn over in the periodontal ligament, and bone metabolism plays a role in determination of the rate of tooth movement.18 However, the maximum rate of biological tooth movement has been found to be similar even with different magnitudes of forces.18 Classically, canine tooth distalization occurs at a rate of about 1 mm per month. Therefore, in cases in which premolar extractions are deemed necessary as part of the orthodontic treatment plan, the canine tooth distalization period takes approximately 6 to 8 months. To shorten the amount of time necessary for orthodontic tooth movement, various attempts have been made. In 1998 Liou and Huang19 presented a rapid canine retraction technique after extraction of the first premolars through weakening of the interseptal bone. The described canine tooth retraction technique was actually achieved through stretching of the periodontal ligament. Hyalinization as a result of pressure results in permanent damage and plays a major role as a ratelimiting factor in the orthodontic movement of teeth.20 Tissue and fibrous elements may become compromised during orthodontic treatment; this seems to be related to local injury of the periodontal ligament.21 It has been shown experimentally that decreased vascular supply occurs when the magnitude of tension forces is exceeded, resulting in cell death within the vicinity of the stretched fibers. Resorption of Sharpey’s fibers, vascular invasion of cells into the periodontal membrane, resorption of alveolar bone, and reduction in alveolar bone thickness and height were also inevitable in regions of tension.17,20 With our surgical technique, the dentoalveolus is designed as a bone transport segment for posterior movement. Vertical corticotomies were performed around the root of canine teeth, followed by splitting of the spongy bone around it. Therefore, the design of the surgical technique does not rely on periodontal
stretching, which obviates overloading and stress accumulation in these tissues. Patient compliance for social and professional reasons, especially in adults, may be a shortcoming because of the prolonged treatment time for orthodontic tooth movements. There also are some contraindications for tooth movement using orthodontic treatment, including short roots, inability to retain individual teeth after movement, and risk of periodontal attachment loss. These may limit the therapeutic goals and cause abandonment of treatment before ideal results are obtained.22,23 The technique that we describe here may have applicability for those who seek rapid orthodontic therapy or for patients who are good candidates to receive conventional treatment. The concept of distraction osteogenesis for rapid orthodontic tooth movement is thought to be promising and feasible for clinical practice.
References 1. Codivilla A: On the means of lengthening in the lower limbs the muscles and tissues which are shortened through deformity. Am J Orthop Surg 2:353, 1905 2. Ilizarov GA: The principles of the Ilizarov method. Bull Hosp Joint Dis Orthop Ins 48:1, 1988 3. McCarthy JG, Schreiber J, Karp N, et al: Lengthening the human mandible by gradual distraction. Plast Reconstr Surg 89:1, 1992 4. Cohen SR, Rutrick RE, Burstein FD: Distraction osteogenesis of the human craniofacial skeleton: Initial experience with a new distraction system. J Craniofac Surg 6:368, 1995 5. Polley JW, Figueroa AA, Charbel FB, et al: Monobloc craniomaxillofacial distraction osteogenesis in a newborn with severe craniofacial synostosis: A preliminary report. J Craniofac Surg 6:421, 1995 6. Molina F, Ortiz-Monasterio F: Mandibular elongation and remodeling by distraction: A farewell to major osteotomies. Plast Reconstr Surg 98: 825, 1996 7. McCarthy JG, Staffenberg DA, Wood RJ, et al: Introduction of an intraoral bone-lengthening device. Plast Reconstr Surg 96: 978, 1995 8. Diner PA, Kollar EM, Martinez H, et al: Intraoral distraction for mandibular lengthening: A technical innovation. J Craniomaxillofac Surg 24:92, 1996 9. Block MS, Cervini D, Chang A, et al: Anterior maxillary advancement using tooth-supported distraction osteogenesis. J Oral Maxillofac Surg 53:561, 1995 10. Bell WH, Gonzales M, Samchukov ML, et al: Intraoral widening and lengthening of the mandible in baboons by distraction osteogenesis. J Oral Maxillofac Surg 57:548, 1999 11. Block MS, Chang A, Crawford C: Mandibular alveolar ridge augmentation in the dog using distraction osteogenesis. J Oral Maxillofac Surg 54:309, 1996 12. Kisnisci RS, Fowel ST, Epker BN: Distraction osteogenesis in Silver-Russell syndrome to expand the mandible. Am J Orthod Dentofacial Orthop 116:25, 1999 13. Chin M, Toth BA: Distraction osteogenesis in maxillofacial surgery using internal devices: Review of five cases. J Oral Maxillofac Surg 54:45, 1996 14. Mommaerts MY: Transpalatal distraction as a method of maxillary expansion. Br J Oral Maxillofac Surg 37:268, 1999 15. Proffit WR, Fields HW: Fixed and removable appliances, in Proffit WR, Fields HW (eds): Contemporary Orthodontics (ed 2). St Louis, MO, Mosby-Year Book, 1993, pp 317-373
394 16. Reitan K: Biomechanical principles and reactions, in Graber TM, Swain BF (eds): Orthodontics: Current Principles and Techniques. St Louis, MO, CV Mosby, 1985, pp 101-192 17. Burstone CJ: The biophysics of bone remodeling during orthodontics: Optimal force considerations, in Norton LA, Burstone CJ (eds): The Biology of Tooth Movement. Boca Raton, FL, CRC Press, 1989, pp 321-332 18. Pilon JJGM, Kuijpers-Jagtman AM, Maltha JC: Magnitude of orthodontic forces and rate of bodily tooth movement: An experimental study. Am J Orthod Dentofacial Orthop 110:16, 1996 19. Liou EJ, Huang CS: Rapid canine retraction through distraction of the periodontal ligament. Am J Orthod Dentofacial Orthop 114:372, 1998
DENTOALVEOLAR DISTRACTION OSTEOGENESIS 20. Rygh P: The periodontal ligament under stress, in Norton LA, Burstone CJ (eds): The Biology of Tooth Movement. Boca Raton, FL, CRC Press, 1989, pp 9-12 21. Rygh P: Orthodontic root resorption studied by electron microscopy. Angle Orthod 47:1, 1977 22. Vanarsdall RL Jr: Tooth movement as an adjunct to periodontal therapy, in Genco RJ, Goldman HM, Cohen DW (eds): Contemporary Periodontics. St Louis, MO, CV Mosby, 1990, pp 505-519 23. Carranza FA Jr, Murphy NC: Orthodontic considerations in periodontal therapy, in Carranza FA Jr (ed): Glickman’s Clinical Periodontology (ed 7). Philadelphia, PA, Saunders, 1990, pp 750-758
