A comparative study of unilateral dislocated mandibular condyle fractures in the rabbit.
OBJECTIVE
The purpose of this study was to clarify the influence of patients age and the degree of dislocation on the healing of mandibular condyle fractures.


METHODS
Sixty-two Japanese white rabbits (30 adolescent and 30 adult ones) were used. They underwent unilateral condylar neck osteotomy. The proximal fragments were positioned differently. In group I animals, the fragments were reduced into the original position, in group II animals the small fragment was dislocated 55-90 degrees to the ramus. In group III animals the proximal fragment was dislocated 135 degrees to the ramus. Gross and microscopic assessment was performed 4, 6, 8, 12 and 24 weeks postoperatively.


RESULTS
In adolescent animals, complete healing of the fracture was observed, irrespective of the degree of dislocation. In the adult animals, there was complete healing of the fractures in groups I and II. In group III animals, there was a decrease of ramus height accompanied by some fibro-cartilaginous changes.


CONCLUSIONS
Even in rabbits condylar deformation has been found following heavily dislocated artificial condylar fractures in adult animals. This result will help to decide for or against surgical treatment of condylar fractures in humans.
Takatsuka
Shigeyuki
S
Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, Kanazawa, Japan. takataka@oral.m.kanazawa-u.ac.jp
Terai
Kohichi
K
Yoshida
Kan
K
Narinobou
Masayoshi
M
Ueki
Koichiro
K
Nakagawa
Kiyomasa
K
Yamamoto
Etsuhide
E
D000367:Age Factors; D000818:Animals; D017102:Fracture Healing; D008297:Male; D008335:Mandibular Condyle / Q000293:injuries* / Q000473:pathology / Q000601:surgery; D008337:Mandibular Fractures / Q000473:pathology* / Q000601:surgery; D010027:Osteotomy / Q000379:methods*; D011817:Rabbits