Craniofacial growth in rabbits. Effects of midfacial surgical trauma and rigid plate fixation.
OBJECTIVE
To examine the effects of soft-tissue manipulation, rigid microplate fixation, and multiple osteotomies on the growing midface in rabbits.


METHODS
Randomized, controlled experiment.


METHODS
Forty 6-week-old male New Zealand white rabbits.


METHODS
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.


CONCLUSIONS
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.
Laurenzo
J F
JF
Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, USA.
Canady
J W
JW
Zimmerman
M B
MB
Smith
R J
RJ
D000818:Animals; D001860:Bone Plates; D001863:Bone Screws; D002508:Cephalometry; D005145:Face / Q000601:surgery*; D005147:Facial Bones / Q000293:injuries / Q000601:surgery*; D008297:Male; D008445:Maxillofacial Development; D010027:Osteotomy; D011817:Rabbits; D011897:Random Allocation; D012886:Skull / Q000254:growth & development*