Effects on the rat mandible of a chincup-type appliance and of partial or complete immobilization.
Sixty 20-day-old male rats were divided into 4 groups: controls (group 1), partly immobilized mandible with a chincup-type appliance (group 2) and completely immobilized mandible without (group 3) or with (group 4) a chincup-type appliance. After 4 weeks the rats were killed and 3 parameters were measured: number of 3H-thymidine labelled cells in the condylar cartilage. "Stutzmann's angle" and length of the mandible. The growth rate of the condylar cartilage and the lengthening of the mandible were both smaller than in the controls. The chincup treatment was much more efficient when the mandible was completely immobilized than when it was only partly immobilized.
Petrovic
A
A
INSERM, Unite 213, Faculté de Médecine, Strasbourg, France.
Stutzmann
J
J
D000818:Animals; D001345:Autoradiography; D002358:Cartilage, Articular / Q000254:growth & development / Q000473:pathology; D002508:Cephalometry; D005115:Extraoral Traction Appliances; D007103:Immobilization; D008297:Male; D008334:Mandible / Q000254:growth & development* / Q000473:pathology; D008335:Mandibular Condyle / Q000254:growth & development / Q000473:pathology; D008410:Masticatory Muscles / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains