Introduction: Patients with micrognathia undergoing mandibular distraction osteogenesis (MDO) for functional and aesthetic improvement are at significant risk for dental complications. This study investigates association of two osteotomy patterns-oblique and inverted-L-with risk to developing dentition.
Methods: Our senior orthodontist performed a retrospective review of dental radiographs of patients undergoing MDO with confirmed oblique or inverted-L osteotomies between 2012 and 2022. Images were assessed for evidence of missing, damaged, or displaced teeth, and proportion of affected hemimandibles by injury type and median number of affected teeth per hemimandible were compared between groups using appropriate statistical methodology.
Results: Analysis included 44 patients (23 oblique, 21 inverted-L) and 85 hemimandibles (45 and 40). Mean age at surgery was 3.1±4.6 years, and mean time to imaging was 4.9±4.1 years; there was no difference between groups (p=0.23, p=0.34, respectively). Oblique osteotomy was associated with greater odds of missing teeth (OR 13.3, p<0.001), damaged teeth (OR 3.2, p=0.02), and any dental injury (OR 39.9, p<0.001) compared to inverted-L, as well as greater number of missing teeth (β=0.6, p<0.01), damaged teeth (β=0.3, p=0.02), and total number of affected teeth (β=0.9, p<0.001). There was no difference in incidence (p=0.5) or number (p=0.4) of displaced teeth between groups.
Conclusion: Inverted-L osteotomies were associated with fewer dental complications as compared to oblique osteotomy at all ages studied. While longer-term follow up and prospective data are needed prior to making definitive recommendations, this data is helpful to surgeons as they plan MDO.
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