Monobloc Osteotomy for Ankylosed Permanent Teeth with Immediate Orthodontic Traction: An Alternative Paradigm for Vertical Repositioning of Alveolar Bone for Implant Rehabilitation

Ankylosis describes the cessation of dental eruption secondary to fusion of the cementum to the alveolar bone.  Associated with various acquired or congenital factors, this pathosis typically defines a situation in which a tooth in infraocclusion remains refractory to orthodontic manipulation.  Repositioning segmental osteotomy with orthodontic guidance for a tooth-borne alveolar unit was developed more than 40 years ago and has enjoyed a long track record of success since then.  Clinicians across the globe have detailed the management of ankylosed permanent dentition with this technique, underscoring the physiologic soundness and predictability of this method.  It is conceptually akin to distraction osteogenesis:  advancement of the tooth-alveolar bone segment occurs before calcification of the resultant callus in the surgically created regenerate chamber.  Yet, a fraction of cases will fail despite even the most heroic efforts, prompting surgeons to ask, "What can be done now to restore this site?"  In the event that the transported ankylosed tooth becomes compromised and extraction is performed, the treatment will not be in vain, as this surgery serves a secondary function:  alignment of the interdental alveolar bone height and attached gingiva in preparation for implant restoration, if needed.  Indeed, among the contemporary techniques for the complex task of vertical ridge augmentation in the esthetic zone—onlay block grafting, interposition grafting, iliac corticocancellous grafting—osteotomy of the segment housing the ankylosed tooth with subsequent orthodontic refinement represents an efficient solution without the demerits that plague the classic approaches.  Two patients with histories of avulsion presented to our institution each with one ankylosed permanent maxillary central incisor.  One incisor measured seven millimeters apical to the occlusal plane, while the other measured two millimeters.  Both exhibited misaligned interdental alveolar crest and gingiva.  Multiple treatment modalities were discussed, including extraction and grafting, prosthetic build-up, distraction osteogenesis, and interdental osteotomy with immediate orthodontic traction, of which the last option was deemed the most viable.  Surgery proceeded with a vestibular incision and development of a full-thickness mucoperiosteal flap, bicortical osteotomies using the piezoelectric saw and completed with osteotomes, followed by bracket bonding to the tooth and attachment to the arch wire in a more coronal position.  The patients returned routinely for subjective assessment of soft tissue perfusion, as well as clinical evaluation of stability, alignment of interdental gingiva, alveolar bone, and the ankylosed teeth.  The patients underwent uneventful recovery with successful repositioning of the dentoalveolar complex.  At the postoperative day seven follow-up appointments, the patients experienced minimal discomfort with no evidence of necrosis of the osteotomized components or loss of pulpal vitality of the ankylosed teeth.  Furthermore, after three weeks, they presented with stable, vital teeth in the occlusal plane as well as optimal gingival and hard tissue leveling.  Current literature is replete with similar observations reported by surgeons worldwide.  As evidenced by the patients treated at our department, as well as the literature available today, movement of the dento-osseous element with orthodontic traction immediately after monobloc osteotomy offers predictability and safety for treating ankylosed permanent teeth.  Paramount to the success of the surgery is meticulous planning regarding the amount of movement, the number of teeth involved, and the growth potential of the patient.  In case of postoperative tooth devitalization which necessitates extraction, this modality yields favorable interdental alveolar orientation and gingival projection, priming the site for implant restoration.

Isaacson RJ, Strauss RA, Bridges-Poquis A, Peluso AR, Lindauer SJ.  Moving an Ankylosed Central Incisor Using Orthodontics, Surgery and Distraction Osteogenesis.  Angle Orthod 2001; 71:  411-418. 

Jensen OT, Kuhlke L, Bedard JF, White D.  Alveolar Segmental Sandwich Osteotomy for Anterior Maxillary Vertical Augmentation Prior to Implant Placement.  J Oral Maxillofac Surg 2006; 64:  290-296.