Stability of the Le Fort I osteotomy for maxillary advancement using rigid fixation and porous block hydroxyapatite grafting

PURPOSE: The purpose of this study was to evaluate the stability of maxillary advancement using bone plates for skeletal stabilization and porous block hydroxyapatite (PBHA) as a bone graft substitute for interpositional grafting. PATIENTS AND METHODS: The records of 78 patients (55 female, 23 male) with a diagnosis of anteroposterior maxillary hypoplasia were retrospectively evaluated. All patients underwent greater than 5 mm Le Fort I maxillary advancement with rigid fixation and PBHA interpositional grafting. The study sample was divided into 3 groups on the basis of the concurrent superior or inferior positioning of the maxillary incisors. Presurgery (T1), immediately postsurgery (T2), and longest follow-up (T3) lateral cephalometric tracings were superimposed to analyze for horizontal and vertical changes at the following landmarks: (1) point A, (2) incisal edge of the maxillary incisor, and (3) mesial cusp tip of maxillary first molar. RESULTS: The maxilla was inferiorly repositioned in 27 patients, superiorly repositioned in 21 patients, and advanced horizontally without a significant vertical change in 30 patients. All groups showed 0.5 mm or less horizontal and vertical relapse. There was no statistically significant difference between the 3 groups. CONCLUSIONS: Maxillary advancement with Le Fort 1 osteotomies by using rigid fixation and interpositional PBHA grafting is a stable and predictable procedure regardless of the direction of vertical maxillary movement.