下顎外側皮質骨を用いた顎裂部骨移植術の考案

Abstract

A monocortical mandibular bone grafting procedure for reconstruction of alveolar cleft was developed and assessed prospectively. The procedure was performed by harvesting lateral cortical bone plates from the symphysis and/or mandibular body and then placing these plates on the labial and palatal openings of the alveolar process defect. No particulate bone grafts were packed into the bony cavity. Based on CT findings at 6 months postoperatively, 58 of 70 clefts (82.9 %), including immature bony bridge cases, showed sufficient bone formation at the cleft site in the labio-palatal direction to facilitate migration of the permanent canines and/or lateral incisors. From periapical radiographic findings at the time of last follow-up, 54 of 62 clefts (87.1 %), except nonclassified 8 clefts in which cleft-related teeth were erupting showed ≥ 75 ％ of the root surface of cleft-adjacent teeth was covered with spanning bone. In addition, canines had erupted spontaneously through grafted bone in occlusion for 27 of 29 clefts (93.1 %) in which the cleft-adjacent canine was uncovered with bone during follow-up. Packing of particulate bone grafts in a secondary bone grafting procedure is clearly not a prerequisite for sufficient bone bridge formation and facilitation of teeth eruption, and placement of walls of cortical bone to enclose the defect is adequate for successful secondary alveolar bone grafting in the mixed dentition. Our procedure has advantages in reducing the quantity of bone required per unit volume of cleft defect, and thus could be applicable to larger cleft defects.