Eruption of Maxillary Posterior Permanent Molars following Early Conventional Le Fort III Advancement and Early Le Fort III Distraction Procedures Compared to Late Surgical Intervention

Background: Le Fort III advancement and/or distraction involve osteotomies and dysjunction in the region of the maxillary tuberosity in proximity to the maxillary posterior tooth buds. The purpose of this study was to determine the effect of early conventional Le Fort III advancement and/or distraction on development and eruption of the maxillary posterior permanent molars. Methods: A retrospective review of patients diagnosed with syndromic craniosynostosis, who underwent early Le Fort III or early midface distraction and late surgical intervention, was analyzed. Results: In the early conventional Le Fort III surgery group, 93 percent of maxillary second molars and 28 percent of maxillary first molars experienced a disturbance in eruption. In the early distraction group, 82 percent of maxillary second molars and 20 percent of maxillary first molars experienced a disturbance in eruption. In the control group, the late conventional Le Fort III and the late distraction groups, only 26 percent of maxillary second molars and none of maxillary first molars experienced a disturbance in eruption. Conclusions: A common disruption seen postoperatively in the early Le Fort III and distraction groups was displacement of the second molars. The majority of the displaced tooth buds were located in the maxillary sinus. Overall, the early Le Fort III surgery groups experienced more frequent disturbances for both first and second molars, with the common sequela of displacement in the maxillary sinus, leading to the question of whether presurgical planning in cases of early intervention to address midface retrusion should include extraction/enucleation of the second molar tooth buds. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.