DENTOALVEOLAR SURGERY

Relocation of Infrapositioned Ankylosed Teeth: Description of Orthodontic Bone Stretching and Case Series Philippe Bousquet, DDS, PhD,* Christele Artz, DDS, MSc, Matthieu Renaud, DDS, MSc, and Pierre Canal, DDS, PhDy z x Different treatments have been proposed to manage the consequences of ankylosed teeth. This clinical report, which includes several different clinical conditions, describes an orthodontic bone-stretching pro- cedure that can be used to relocate ankylosed teeth. The orthodontic bone-stretching technique involves only partial osteotomies, without the mobilization or repositioning of the alveolar segment, combined with orthodontic forces. The applied force facilitates tooth movement to the occlusal plane and can modify the axis of the ankylosed tooth. This relocation is possible because of a bone-stretching phenom- enon in the surgical area. In all of the cases, relocation of the ankylosed teeth was successfully performed and the gingival margins were corrected to improve the esthetic results. Ó 2016 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg -:1.e1-1.e12, 2016

Severe injuries of the periodontal ligament, frequently Bensheim, Germany) is an instrument for the quantifi- the permanent maxillary incisors in children, may lead cation of tooth mobility and can be used to confirm to the ankylosis phenomenon, resulting in fusion be- ankylosis. An electronic tapping head percusses the tween the mineralized root surface and the alveolar teeth. Ankylosed teeth have a shorter contact time, bone.1,2 Such ankylosis disturbs dentoalveolar resulting in lower Periotest values than those for intact development during growth. In fact, an ankylosed or mobile teeth.3 Ankylosis also can be discovered or tooth in a growing child does not erupt, resulting in confirmed during orthodontic treatment by tooth a vertical insufficiency of osseous growth, which can immobility under an applied orthodontic force. More- lead to infraclusion, an unesthetic smile, and over, ankylosis can be confirmed by radiographic eval- occlusal disharmony. Therefore, a patient with an uation, showing a lack of ligament space. ankylosed tooth might require treatment for Several alternatives exist to treat the consequences infraclusion and alveolar bone deficiency. of ankylosed teeth. The first solution is extraction of Ankylosis is clinically diagnosed by acute sound per- the ankylosed tooth. Rehabilitation can be conducted cussion (tooth resounding like crystal) and lack of with a bridge, but periodontal surgery (gingival graft) mobility in comparison with dull sound percussion might be necessary to improve the mucosal volume and physiological mobility of the adjacent unaffected of the ridge.4 Treatment using a dental implant also teeth (the periodontal ligament absorbs sound and can be used after extraction. However, bone regenera- allows mobility). A Periotest device (Siemens AG, tion with grafting may be necessary for vertical and

Received from Universite de Montpellier, Montpellier, France. Received March 17 2015 *Professor, Department of Periodontology, School of Dentistry; Accepted June 2 2016 Laboratoire Biologie Sante et Nanoscience EA42503. Ó 2016 American Association of Oral and Maxillofacial Surgeons Professor, Department of Orthodontics. y 0278-2391/16/30245-2 Doctor, Laboratoire Biologie, Sante et Nanoscience EA42503. z http://dx.doi.org/10.1016/j.joms.2016.06.002 Professor, Department of Orthodontics. x Address correspondence and reprint requests to Dr Bousquet: 40 rue des Dunes, 34500 Beziers, France; e-mail: dr.philippebousquet@ free.fr

1.e1 1.e2 ANKYLOSED TEETH AND ORTHODONTIC BONE STRETCHING lateral bone augmentation before implant place- The surgical procedure is performed using a Satelec ment.5,6 This surgical treatment represents the best Piezotome 2 with BS1 or BS5 slim tips (Acteon Group, management for ankylosed teeth with severe root Merignac, France). One buccal vertical interdental resorption, root fracture, or infection, usually leading osteotomy cut is performed on either side of the anky- to a poor prognosis. losed tooth in the same axis of the root maintaining a A second treatment option involves the conserva- safe distance from the adjacent teeth. Next, the 2 tion of ankylosed teeth on the arch. However, reloca- vertical cuts are connected through a third cut that tion to a correct position needs a surgical option is positioned in a subapical manner to the root apex because orthodontic treatment alone cannot correct of the ankylosed tooth. the position of the ankylosed tooth. Surgical luxation,7 The osteotomy involves the buccal cortex and segmental osteotomy with distraction,8-10 and cancellous bone preserving the palatal cortex intact. segmental osteotomy with repositioning11 are Therefore, no mobility of the sectioned dento- possible alternative treatments. However, de Souza osseous complex is observed (Fig 1). For occlusal et al12 reported the lack of a high level of evidence movement, ultrasonic cuts are generated on the for treatment options and the management of anky- buccal side. In contrast, for palatal movement, the losed anterior teeth. cuts are generated on the palatal side. The mucoper- Recently, a new orthodontic technique using bony iosteal flap is repositioned and sutured (Vicryl No. block movement was presented for the treatment of 4-0 and 5-0; Ethicon, Issy-Les-Moulineaux, France). ankylosed teeth with promising results.13 The aim of Immediately after the surgical procedure, heavy this clinical report is to describe an alternative surgical orthodontic traction on the ankylosed tooth is per- technique of orthodontic bone stretching (OBS) for formed. It is important to know the precise direction the management of ankylosed teeth in different clin- of the movement executed on the dento-osseous com- ical situations. plex, which must be in the same axis of the corticoto- The described cases were treated at Montpellier mies. The force must not exceed the anchorage value University Hospital. The procedure was approved by of the adjacent teeth. the local ethical committee (South of France Commit- The patient is prescribed amoxicillin (1 g 2 times a tee, Nice, France), and all of the participants provided day for 6 days), prednisolone (60 mg for 3 days), acet- written informed consent. aminophen (1 g 3 times a day for 3 days), and a 0.12% chlorhexidine solution (rinsing twice a daily starting 24 hours after surgery for 10 days). The sutures are Presurgical Preparation removed after 10 days. Continuous force must be First, orthodontic treatment was conducted for dys- applied to the ankylosed tooth, and the patient morphosis correction, excluding ankylosed teeth. Sec- undergoes traction reactivation every 2 weeks until ond, a specific orthodontic preparation was performed tooth repositioning is achieved. Movement of the before the surgical treatment (anchorage control, gen- dento-osseous complex is observed after 1 to 4 weeks. eration of an open space around the ankylosed tooth, When the ankylosed tooth reaches the occlusal plane, and alignment of the anterior gingival margins). an arch wire retainer is inserted for a period of Before surgery, dental computed tomography must 6 months to monitor the evolution. After removal of be performed to evaluate the position of the roots in the appliance, a wire is bonded to the incisors and 3 dimensions for surgical planning. The distance of canines, including the ankylosed teeth. the ankylosed tooth from the adjacent teeth, the axis of the ankylosed tooth, and the bone volume are impor- tant factors for positioning the corticotomy. Bone den- sity and cortical thickness also are evaluated to secure the osteotomy, which extends through the cortical bone, penetrating into the cancellous bone. Before sur- gery, an orthodontic attachment is bonded to the labial or palatal crown surface of the ankylosed tooth.

Surgical Procedure With the patient under local anesthesia, a buccal sulcular incision and 1 or 2 vertical releasing incisions FIGURE 1. Schema showing partial buccal cuts: frontal view and lateral view. The corticotomies run deep, but the palatal cortical are made on the distal side of the teeth adjacent to the bone is preserved. ankylosed tooth. A full-thickness mucoperiosteal flap Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. is reflected to expose the alveolar bone. J Oral Maxillofac Surg 2016. BOUSQUET ET AL 1.e3

Plaque control was not ideal, but there was no peri- odontal disease, except for gingivitis located in the maxilla (Fig 2). After clinical diagnosis, cone-beam computed tomography (CBCT) radiographs confirmed the ankylosis (Fig 3). After orthodontic preparation, with exclusion of the ankylosed tooth (Fig 4), a dysmorphosis correction led to the infraclusion of the ankylosed central incisor. A rate of 3 mm with an index of infraposition of 2 (moderate) according to the Malmgren and Malmgren classification14 was diagnosed. The treatment plan included ankylosed tooth repositioning with OBS after FIGURE 2. Intraoral photograph before orthodontic treatment in case 1. orthodontic preparation (anchorage and generation of an open space to facilitate tooth repositioning without Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. obstruction). CBCT was used to diagnose the anky- losis, resorption area, and apical fenestration under the nasal spine, as well as to determine the ideal space CASE 1 to relocate the ankylosed tooth. The tooth axis indi- A healthy 15-year-old boy was referred for ankylosed cated vertical and low palatal traction. upper left central incisor repositioning. He had intru- Before surgery, orthodontic brackets were bonded sion of the tooth at the age of 12 years followed by onto the labial and palatal crown surfaces to facilitate immediate repositioning and splinting for a few weeks immediate tooth traction. OBS was performed as and subsequent endodontic treatment. At age 14 years, described previously: One vertical osteotomy on the tooth was diagnosed as ankylosed to the maxilla each side of the roots was performed, and a horizontal during subsequent orthodontic treatment. osteotomy was made apically connecting the 2 vertical

FIGURE 3. Cone-beam computed tomography of left central incisor in case 1. Ankylosis was confirmed. A, anterior; P, posterior. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. 1.e4 ANKYLOSED TEETH AND ORTHODONTIC BONE STRETCHING

axis. Palatal and vestibular strengths were used alter- nately or in combination (Fig 6). No complications were encountered during or after surgery or during the orthodontic traction period. After 2 months of reactivation, the ankylosed tooth was correctly reposi- tioned and orthodontic retention was performed (Figs 7A, B). Importantly, vertical bone augmentation was achieved with simultaneous soft tissue augmenta- tion with optimal gingival margin alignment. Plaque control was improved to produce healthy periodontal tissues (Fig 7C).

CASE 2 FIGURE 4. Orthodontic preparation in case 1, excluding the ankylosed tooth, led to the correction of dysmorphosis. The A 17-year-old boy was treated for an anterior open ankylosed tooth appeared in infraposition. bite with atypical swallowing and a mouth-breathing Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. habit. When orthodontic treatment began, the right J Oral Maxillofac Surg 2016. maxillary incisors were immobile despite the applica- tion of orthodontic forces, leading to maxillary arcade osteotomies (Fig 5). The depth of the corticotomies intrusion (Fig 8). The dental history included trauma was increased to decrease the strength of the block to the right maxillary incisors from a bicycle fall at and to facilitate movement. Immediately after surgery, the age of 14 years. CBCT imaging showed root resorp- orthodontic traction was introduced with a correct tion and lack of the periodontal ligament to the right maxillary incisors, confirming ankylosis of the teeth (Fig 9). The diagnosis was ankylosis of the right maxil- lary incisors with apical and internal resorption of the central incisor. The results of vitality tests were posi- tive. After an endodontic consultation, it was decided to monitor the evolution of the resorption and to relo- cate the teeth. In a first step, the treatment objectives included correction of the posterior crossbite, Class II malocclu- sion, and tongue thrust, as well as obtaining a normal incisor relationship. A leveling process and an align- ment phase were completed, with exclusion of the 2 ankylosed teeth (Fig 10). The index of infraposition was 4 (extreme). The second step included reposition- ing of the ankylosed incisors with OBS. Immediately before surgery, a stainless steel arch wire was placed on the maxilla and on the mandible. Moreover, a nickel-titanium arch wire (round, 0.016 0.016 inch) was placed on both of the maxillary ankylosed teeth and was superimposed on the main arch. This arch wire applied a continuous orthodontic force to the ankylosed teeth. With the patient under local anesthesia, the mucoperiosteal flap was reflected, and the same surgical procedure (OBS) was conducted. The mucoperiosteal flap was reposi- tioned and sutured (Fig 11). The appliance was acti- vated immediately and every 2 weeks. When the ankylosed teeth reached the occlusal plane and when the orthodontic treatment was concluded, a final 0.021 0.025–inch stainless steel arch wire was inserted and retained for a period of 6 months FIGURE 5. Surgical treatment in case 1: vertical and apical partial osteotomies. (Fig 12). Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. The total treatment time to relocate the teeth to the J Oral Maxillofac Surg 2016. occlusal plane was 4 months, followed by 6 months of BOUSQUET ET AL 1.e5

FIGURE 6. Continuous force applied to ankylosed tooth in case 1. A, Arch wire on palatal side. B, Elastic wire on buccal side. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. retention. After removal of the appliance, the anterior bite improved the midline coincidence, and Class I maxillary teeth were stabilized with a lingual bonded molar and canine relationships were obtained. The retainer. The maxillary anterior gingival margins post-treatment panoramic radiograph showed that were improved, and alignment and leveling were the roots of the teeth were relatively parallel with sta- completed in both arches. A normal overjet and over- ble root resorption, except for the upper right canine,

FIGURE 7. Intraoral photographs after removal of appliance in case 1. A, Frontal view 6 months after surgery. B, Occlusal view 6 months after surgery. C, Frontal view of maxillary incisors 18 months after surgery. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. 1.e6 ANKYLOSED TEETH AND ORTHODONTIC BONE STRETCHING

At the 24-month post-treatment visit, the treatment result was stable with some gingival recession (<0.5 mm) on the right central incisor. The peri- odontal status did not show pathology, but the lack of plaque control aggravated the existing enamel defects. Cosmetic treatment of the anterior maxillary teeth was performed (Fig 14). A 2 years’ follow-up, CBCT comparison showed interdental alveolar bone movement to the occlusal plane and stable root morphology with internal resorption (Fig 15).

CASE 3 FIGURE 8. Intrusion of anterior section and right side in case 2. A 12-year-old girl presented with immobility of the Ankylosis was confirmed. maxillary central incisors despite active orthodontic Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. treatment (Fig 16A). The OBS procedure was per- J Oral Maxillofac Surg 2016. formed after flap elevation (Fig 16B). In this case, the intended movement was in the labial and distal which presented moderate external apical root resorp- direction. The bone cuts separating the 2 teeth tion. The superimposition of the pretreatment and were thin for the interdental corticotomy (BS1 and post-treatment lateral cephalometric tracings showed RD2 tips; Acteon Group), and the bone cuts were an overall vertical increase of the alveolar segment, broader for the distal and apical corticotomies to and point A could not be considered because it was improve movement (SL1 tip; Acteon Group). Immedi- supported by the corticotomy (Fig 13). In addition, ately after surgery, a spring was placed between the the right maxillary incisors were retroclined and central incisors. After 1 month of application of extruded because of the alveolar segment movement. orthodontic forces, the space between the 2 incisors

FIGURE 9. Cone-beam computed tomography in case 2 showing apical resorption of right incisors, as well as internal resorption of right cen- tral incisor. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. BOUSQUET ET AL 1.e7

FIGURE 10. Treatment result before surgery in case 2. A, Frontal view: infraclusion of right incisors (index of 4). B, Occlusal view. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. was increased and the incisors were correctly reposi- occurrence of gingivitis. A temporary esthetic treat- tioned (Figs 16C, D). ment of the crowns was performed with composite Despite the teaching of oral hygiene technique, pla- restoration. The gingival defect was corrected with que control remained very poor, with the consequent papilla regeneration (Fig 17). Comparison of the

FIGURE 11. Surgical treatment in case 2. A, Corticotomy using Satelec Piezotome 2 with BS1. B, Two vertical cuts connected by third sub- apical cut. C, Suture of flap. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. 1.e8 ANKYLOSED TEETH AND ORTHODONTIC BONE STRETCHING

by tissue regeneration or bone grafting is often neces- sary. These techniques have not shown reproducible or optimal results. Given the low number of patient treatments reported in the literature, the use of such vertical bone augmentation is limited.15 Conserving the tooth on the arch and moving it to the occlusal plane could be a better treatment option. For the relocation of ankylosed teeth, a segmental osteotomy is performed, as shown in case reports.12 The immediate mobilization and repositioning of the alveolar segment,16 associated with or without bone grafts,17 comprise a different technique with good FIGURE 12. Intraoral photograph in case 2: frontal view. The results. For this procedure, maintenance of the soft tis- ankylosed teeth were moved to the occlusal plane. sue attachment to the bone is an important limiting Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. factor for vascularization and immediate movement of the dento-osseous complex.17 To enable a gradual and slower soft tissue stretching, an osteotomy associ- ated with a distraction device has been proposed to panoramic images showed interdental alveolar bone 18 stretching and movement of the teeth (Fig 18). treat ankylosed teeth. Although adequate results have been reported, these techniques use a specific device that is sometimes complex and constraining. Discussion Furthermore, distractors have a unidirectional impact with heavy strengths (distraction rate of 0.5 to Extraction of ankylosed teeth does not compensate 1 mm/d); these techniques poorly predict movement for the alveolar hypo-development resulting from lack in the sagittal direction and can lead to incorrect of growth and can lead to a complex bony ridge defect. distraction vectors.19,20 For esthetic rehabilitation, vertical bone augmentation In OBS the osteotomy is limited to the buccal side of the alveolar bone. Vascularization is ensured by the presence of the palatal bone and the attached soft tis- sues. The surgical area is completely immovable because the osteotomy is not complete. This less trau- matic technique facilitates the movement of ankylosed teeth toward the occlusal plane, reflecting several phe- nomena. The cortical section decreases the resistance of the dental bone block. Before surgery, the orthodon- tic force does not move the ankylosed teeth and can lead to the intrusion of adjacent teeth. The anchorage of the arch is too low, and the resistance of the anky- losed tooth is too high. The partial buccal osteotomies facilitate the effect of orthodontic forces on the palatal cortical bone. In accordance with the Frost principle of the healing response,21 the relocation of the anky- losed tooth without ligament movement is permitted by bone movement. The OBS technique appears to be a bone-stretching phenomenon using ankylosed teeth as anchorage points. This result is different from bone distraction. Indeed, in OBS it is important not to wait for the for- mation of bone callus in the area of the partial os- teotomies. The applied forces are immediate and continuous, preventing healing in the area of the bone cuts and stretching the residual palatal bone. The use of a system to stabilize the block is not FIGURE 13. Superimposition of initial and final cephalometric tracings in case 2. necessary, and the attached orthodontic device Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. only induces and directs the movement into the J Oral Maxillofac Surg 2016. desired axis. BOUSQUET ET AL 1.e9

FIGURE 14. A, B, Intraoral photographs at 24 months after treatment in case 2: frontal view (A) and occlusal view (B). C, Photograph after esthetic treatment of enamel defects. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016.

Animal studies showed that a corticotomy increased compared with conventional instrumentation (bur or the turnover of alveolar bone. Sebaoun et al22 reported saw blade), leading to considerably higher bone activ- that catabolic and anabolic activities were 3 times ity and mineral density.22 This phenomenon is biolog- greater in the area adjacent to the cut. The osteoclast ical, but the clinical effect was not demonstrated and count and quantity of bone apposition were higher clinical studies are needed to confirm differences. An in this area. Bone fill increased using the Piezotome increase in the expression of the genes involved in

FIGURE 15. Cone beam radiographs after surgery and at 2 years after treatment in case 2. The interdental alveolar bone around the right incisors was moved using the orthodontic bone-stretching technique. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. 1.e10 ANKYLOSED TEETH AND ORTHODONTIC BONE STRETCHING

FIGURE 16. Case 3. A, Lack of movement of central incisors. B, Adaptation of cuts to desired movement. C, Displacement resulting from 15 days of spring forces. D, After 1 month of spring forces, the patient presented with poor plaque control. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. bone healing also was reported.23 This modification of osteotomies and can accelerate the bone-stretching activity is important for rapid orthodontic movements. movement in the area of the cuts, near the preserved Wilcko et al24 used these techniques and proposed cortical bone. The result of this strict bone move- that during the healing process, rapid tooth movement ment is repositioning of the tooth in the arch results from bone remodeling and pressure on the through orthodontic traction. In the block of 2 anky- periodontal ligament and its hyalinization, facilitating losed teeth (case 2), the right interincisor crestal tooth movement in bone. level moves with the block, and this phenomenon For the relocation of ankylosed teeth by the OBS was confirmed after comparison of the CBCT radio- technique, with the lack of the periodontal ligament, graphs. The slow bone movement (approximately only the biological bone phenomena associated with 2 mm per month) allows for the adaptation of the ultrasonic corticotomy may be present near partial soft tissue.

FIGURE 17. Intraoral photographs after relocation of maxillary central incisors, as well as temporary esthetic treatment for crown reconstruc- tion, in case 3. A, Frontal view. B, Occlusal view. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. BOUSQUET ET AL 1.e11

FIGURE 18. Panoramic radiographs in case 3. A, Before surgery. B, Two months after teeth relocation by orthodontic bone-stretching tech- nique. Bousquet et al. Ankylosed Teeth and Orthodontic Bone Stretching. J Oral Maxillofac Surg 2016. 1.e12 ANKYLOSED TEETH AND ORTHODONTIC BONE STRETCHING

Orthodontic preparation is essential and is associ- 6. Jensen SS, Terheyden H: Bone augmentation procedures in local- ated with the adequate management of the tissue ized defects in the alveolar ridge: Clinical results with different bone grafts and bone-substitute materials. Int J Oral Maxillofac around the ankylosed tooth. On the basis of our expe- Implants 24:218, 2009 rience, we think that more than 2 mm between the 7. Takahashi T, Takagi T, Moriyama K: Orthodontic treatment of a roots of adjacent teeth should be sufficient to allow traumatically intruded tooth with ankylosis by traction after surgical luxation. Am J Orthod Dentofacial Orthop 127:233, for thin partial osteotomies, while leaving enough 2005 bone on each side to prevent vascularization of the 8. Kinzinger GS, Janicke S, Riediger D, Diedrich PR: Orthodontic septum. The use of an ultrasonic saw with a slim pro- fine adjustment after vertical callus distraction of an ankylosed incisor using the floating bone concept. Am J Orthod Dentofa- file is preferred for precise surgery. cial Orthop 124:582, 2003 As the maxilla grows in the vertical direction, the 9. Isaacson RJ, Strauss RA, Bridges-Poquis A, et al: Moving an anky- ankylosed tooth and alveolar segment remain in infra- losed central incisor using orthodontics, surgery and distraction osteogenesis. Angle Orthod 71:411, 2001 clusion in most cases because there is no additional 10. Jensen OT, Cockrell R, Kuhlke L, Reed C: Anterior maxillary alve- alveolar growth at the ankylosed tooth site. After or- olar distraction osteogenesis: A prospective 5-year clinical study. thodontic treatment of an ankylosed tooth, the func- Int J Oral Maxillofac Implants 17:52, 2002 11. Medeiros PJ, Bezerra AR: Treatment of an ankylosed central tional and esthetic results may not remain stable incisor by single-tooth dento-osseous osteotomy. Am J Orthod over time if the jaw continues to grow. The continuous Dentofacial Orthop 112:496, 1997 growth of a patient must be considered when plan- 12. de Souza RF,Travess H, Newton T, Marchesan MA: Interventions for treating traumatised ankylosed permanent front teeth. ning the treatment. The degree of such infraclusion de- Cochrane Database Syst Rev CD007820, 2010 pends on individual growth, age, and gender.25 Slight 13. Bousquet P,Artz C, Canal P: Traitement des dents ankylosees par overtreatment could be a solution to compensate for corticotomie partielle l’orthodontic bone stretching. Etude preliminaire. Orthod Fr 84:333, 2013 this phenomenon. 14. Malmgren B, Malmgren O: Rate of infraposition of reimplanted The OBS technique is a viable procedure for the ankylosed incisors related to age and growth in children and treatment of ankylosed teeth. This surgical procedure adolescents. Dent Traumatol 18:28, 2002 15. 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