PURPOSE: This study was designed to investigate the effects of artificial mechanical separation of the circummaxillary sutures on craniofacial growth in growing rats. MATERIALS AND METHODS: Twenty 4-week-old Wistar strain male rats were divided equally into experimental and control groups. In the experimental group, 4 holes were made on the maxillary and temporary bones, and expansion appliances were placed into the holes for sutural separation bilaterally. The operated control group underwent sham surgery only. Lateral and dorsoventral cephalograms were taken of the animals every 2 weeks from age 4 to 12 weeks. Linear and angular measurements on the lateral cephalograms were analyzed and subjected to statistical treatment with Student's t-test. All animals were killed for histologic examination 8 weeks after the initiation of the experiment. RESULTS: Nasomaxillary growth and the forward displacement were significantly larger in the experimental group than in the controls (P <.01). New bone formation was clearly observed in the (mechanically separated) sutural space in association with normal healing of the sutural structures. CONCLUSIONS: These findings show that mechanical separation of the circummaxillary sutures, as a new orthopedic approach, accelerated nasomaxillary growth, in this experimental model. Copyright 2002 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 60:667-675, 2002
PURPOSE: This study was designed to investigate the effects of artificial mechanical separation of the circummaxillary sutures on craniofacial growth in growing rats. MATERIALS AND METHODS: Twenty 4-week-old Wistar strain male rats were divided equally into experimental and control groups. In the experimental group, 4 holes were made on the maxillary and temporary bones, and expansion appliances were placed into the holes for sutural separation bilaterally. The operated control group underwent sham surgery only. Lateral and dorsoventral cephalograms were taken of the animals every 2 weeks from age 4 to 12 weeks. Linear and angular measurements on the lateral cephalograms were analyzed and subjected to statistical treatment with Student's t-test. All animals were killed for histologic examination 8 weeks after the initiation of the experiment. RESULTS: Nasomaxillary growth and the forward displacement were significantly larger in the experimental group than in the controls (P <.01). New bone formation was clearly observed in the (mechanically separated) sutural space in association with normal healing of the sutural structures. CONCLUSIONS: These findings show that mechanical separation of the circummaxillary sutures, as a new orthopedic approach, accelerated nasomaxillary growth, in this experimental model. Copyright 2002 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 60:667-675, 2002