Bilateral mandibular distraction osteogenesis using an intraoral tooth-borne device
El Bialy TH, Razdolsky Y, Kravitz ND, Dessner S, Elgazzar RF. Long-term results of bilateral mandibular distraction osteogenesis using an intraoral tooth-borne device in adult Class II patients. Int J Oral Maxillofac Surgery 2013;42:1446-53
Correction of an Angle Class II relationship in a nongrowing patient can be a difficult task. Camouflage or orthognathic surgery is the standard choice available to practitioners. Both options have benefits and risks. Mandibular distraction osteogenesis offers orthodontists an alternative treatment for these patients. Distraction devices are broadly categorized as external or internal. The external devices are less favored because of their extraoral placement and the potential for scarring. Internal devices can be divided into bone borne, tooth borne, and hybrid. The aim of this study was to evaluate the short-term and long-term results of correcting a Class II relationship in adults with a tooth-borne distracter called the ROD1. Ten consecutive adults with Class II malocclusion were treated with the distracter and fixed orthodontic therapy and then followed for 8 years. Distraction was done between the second premolar and the first molar, or between the first and second molars, with a rate of 1 mm per day by activating the distractor’s screw 0.33 mm 3 times a day. The patients were asked to wear a chincup for 3 to 4 months after the distraction to balance the action of the suprahyoid muscles on the anterior segment. Favorable results included long-term (8 years) increases in mandibular corpus length (4.5 mm) and the SNB angle (2.3°). Unfavorable long-term outcomes included an increased mandibular plane angle (4.3°) and, in the short term, immediately after distraction, mandibular incisor proclination (7.5°), which was subsequently corrected during treatment. The study did not have a control group, but the results of the treatment seem to show that distraction could be a viable alternative in nongrowing Class II patients.
Reviewed by Spencer Dixon and Kyle Wilson
Importance of root development in autotransplantations
Denys D, Shahbazian M, Jacobs R, Laenen A, Wyatt J, Vinckier F, et al. Importance of root development in autotransplantations: a retrospective study of 137 teeth with a follow-up period varying from 1 week to 14 years. Eur J Orthod 2013;35:680-8
The use of autotransplantation in conjunction with orthodontic treatment is a surgical option that can offer patients with missing teeth an esthetic solution. Autotransplanted teeth, in contrast to osseointegrated implants, have the capacity for functional adaptation, ridge preservation, and continued alveolar bone induction in growing patients. The purpose of this study was to evaluate the effect of donor tooth development, donor tooth type, and orthodontic treatment on the long-term success of autotransplantations. The outcomes were evaluated for 137 autotransplanted teeth at a mean follow-up time of 4 years 11 months. Tooth type, reason for autotransplantation, eruption status, and root length at transplantation were noted. At follow-up, the teeth were evaluated clinically for mobility, palpation, percussion, probing depth, gingivitis index, vitality, and occlusal contacts. Radiologic evaluations included root resorption, lamina dura formation, ankylosis, apical closure, pulp chamber changes, and root development. Autotransplanted teeth with half to three quarters of total root length had less probability of later root resorption, greater probabilities of lamina dura formation and tooth vitality, and an overall increased probability of success. A decreased risk for ankylosis was found in combination with orthodontic treatment. Of 130 evaluated teeth, 90 showed partial or full obliteration of the pulp chamber, and 18 showed root canal fillings. The survival and success rates for the total number of transplanted teeth in the sample were 86.8% and 65.4%, and a 5-year survival of 93.1% and a 10-year survival of 72.2% were obtained. With well-established protocol and detailed case selection, autotransplanted teeth can yield favorable long-term prognoses for growing patients. Future research with longer follow-up periods is needed to determine the possibility of autotransplanted teeth as a lifelong treatment modality in young patients.
Reviewed by Andrea Dopp