Assessment of bone healing and hypoesthesia in the upper lip after Le Fort I osteotomy with self-setting α-tricalcium phosphate and absorbable plates

Abstract

PurposeThe purpose of this study was to evaluate hypoesthesia of the upper lip and bone formation using self-setting α-tricalcium phosphate (Biopex®) between the segments following Le Fort I osteotomy with bent absorbable plate fixation. Subjects and methodsThe subjects were 47 patients (94 sides) who underwent Le Fort I osteotomy with and without mandibular osteotomy. They were divided into a Biopex® group (48 sides) and a control group (46 sides). The Biopex® was inserted into the anterior part of the gap between the segments in the Biopex® group. Trigeminal nerve hypoesthesia at the region of the upper lip was assessed bilaterally by the trigeminal somatosensory-evoked potential (TSEP) method. The area of the Biopex® at the anterior part in the maxilla was assessed immediately after surgery and 1 year postoperatively by computed tomography (CT). ResultsThe mean measurable period and standard deviation were 13.2 ± 18.5 weeks in the control group, 14.5 ± 17.9 weeks in the Biopex® group, and there was no significant difference in TSEP. The area of the Biopex® after 1 year was significantly smaller than that immediately after surgery (right side: P = 0.0024, left side: P = 0.0001) and bone defects between the segments could not be found in the Biopex® group. In the control group, although the areas of bone defect after 1 year were significantly smaller than that immediately after surgery on the right side (P = 0.0133) and left side (P = 0.0469) in the frontal view, complete healing of the bone defects could be seen in 12 of 46 sides after 1 year. ConclusionThis study suggested that inserting Biopex® in the gap between the maxillary segments was useful for new bone formation and it did not prevent the recovery of upper lip hypoesthesia after Le Fort I osteotomy with absorbable plate fixation.