S12-06 SESSION 12: FACIOCRANIOSYNOSTOSIS – PART II ERUPTION OF MAXILLARY POSTERIOR PERMANENT MOLARS FOLLOWING EARLY CONVENTIONAL LE FORT III: ADVANCEMENT AND EARLY AND LATE LE FORT III DISTRACTION

Abstract

Introduction: 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. Methods: This single-institution, 33-year (1973 to2006), retrospective study included patients with syndromic craniosynostosis treated with early conventional Le Fort III osteotomy/advancement and Le Fort III distraction. Inclusion criteria consisted of the following: (1) surgical intervention, Le Fort III or midface distraction osteogenesis, befor eage 8 years; (2) two panoramic radiographs, one before surgery and one in adolescence; (3) no apparent abnormalities in the position of permanent tooth buds before surgery; and (4) complete clinical and dental records. Panoramic radiographs taken presurgically (time 1) and at least 1 year post-surgically (time 2) were inspected by a craniofacial orthodontist at two different time points, 1 week apart, to ascertain intrarater reliability. Both the right and left molar tooth buds were classified as being present or displaced and further subdivided into location (tuberosity and sinus), impacted, ankylosed, extracted, or absent and recorded for each time point. 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 maxilla 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. Conclusion: 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.