Craniofacial Growth in Rabbits: Effects of Midfacial Surgical Trauma and Rigid Plate Fixation

Abstract

Objective: To examine the effects of soft-tissue manipulation, rigid microplate fixation, and multiple osteotomies on the growing midface in rabbits. Design: Randomized, controlled experiment. Subjects: Forty 6-week-old male New Zealand white rabbits. Interventions: Group 1, exposure of the left nasofrontal and midzygomatic arch regions with periosteal elevation; group 2, osteotomies at left nasofrontal suture and midzygomatic arch; group 3, rigid plate fixation of osteotomies; and group 4, rigid plate fixation alone. Animals were killed at age 20 weeks; growth was assessed by linear and spatial measurements of craniofacial regions. Results: Linear data disclosed shortening of the left nasal bone (P<.05) in groups 2 through 4. Groups 3 and 4 also had shortened left zygomatic arches and orbital diameters (P<.05). Euclidean distance matrix analysis showed significant restrictive shape alterations in groups 2 through 4 (P<.05). Significant contralateral shape alterations also were found in group 3. Conclusion: Rigid plate fixation does not cause more severe growth disturbance than bony trauma. Use of rigid plate fixation after bony trauma does not seem to increase the restrictive effects of trauma on growth. Furthermore, removal of rigid plate fixation may not prevent growth disturbances and may induce further harmful trauma to the growing midface. (Arch Otolaryngol Head Neck Surg. 1995;121:556-561)