A comparison of gradual distraction techniques for modification of the midface in growing sheep

The authors carried out experiments to advance the midface in growing sheep using a distraction farce across the zygomatico-maxillary sutures. They wi shed to assess the possibility of performing distraction osteogenesis acros s intact sutures as well as distraction after Le Fort osteotomies. Their re sults demonstrate that the technique of gradual distraction after osteotomy is successful in the growing animal. Bilateral distraction across intact s utures did not advance the midface or change the dental relationship. Unila teral distraction was successful in angulating the midface away from the di stracting force in the intact growing animal. Alternating unilateral distra ction or "waltzing" was surprisingly effective in advancing the midface in one of the animals studied and may become applicable in some craniofacial d eformities. In all intact animals there was some expansion of the zygomatic omaxillary suture as well as a substantial migration of the distraction dev ices through the bone.