Effect of maxillary osteotomy on subsequent craniofacial growth in adolescent monkeys.

LeFort I osteotomy was performed on seven adolescent Macaca fascicularis monkeys to study its effect on the subsequent dentocraniofacial growth. Eight adolescent monkeys were used as controls. Tantalum implants were inserted at predetermined areas in certain craniofacial bones of all monkeys. For stereometric cephalometry, implants were placed in both the left and right sides of the facial bones. Lateral cephalometric radiographs of all monkeys were taken prior to and immediately after metallic implant placement, immediately after maxillary osteotomy, and thereafter every 4 weeks during the postsurgical period. At least two cephalograms were taken on each occasion, one with the teeth in occlusion and the other with mouth wide open. The latter was used to view the mandibular condyle adequately. These findings suggest that the maxillary osteotomy did disturb the vertical growth of the maxilla at the PNS and retarded the horizontal growth at the premaxilla. The anterior growth of the maxilla and mandible and the vertical growth of the face were substantially reduced. The most interesting finding was also a reduction of the mandibular growth in all of its dimensions. The rate and the amount of reduced anterior mandibular growth were found to be coordinated with the anterior maxillary growth which resulted in all animals showing a normal overjet, overbite, and occlusion throughout the postsurgical observation period.