Time course of expression of bcl-2 and bax in rabbit condylar chondrocytes following forward mandibular positioning.
OBJECTIVE
To clarify the expression of Bcl-2 and Bax following forward mandibular positioning (FMP) in the condylar chondrocytes of rabbits.


METHODS
Sixty rabbits at 8 weeks of age were randomly allocated to the experimental group (n = 36) and control group (n = 24). Rabbits in the experimental group were induced to FMP by a functional appliance. Six rabbits from the experimental group and four from the control group were sacrificed after 3 days and 1, 2, 4, 8, and 12 weeks, respectively. All the right temporomandibular joints (TMJs) were collected and the expression of Bcl-2 and Bax was evaluated by immunohistochemical staining.


RESULTS
The results showed the expression pattern of Bcl-2 and Bax during 12 weeks after FMP. The expression of Bcl-2 reached the highest level at 1 week, whereas Bax reached its maximal expression after 4 weeks. Subsequently, the expression of Bcl-2 and Bax gradually decreased. The ratio of Bcl-2/Bax began to decrease 3 days after FMP and continued to decline until 12 weeks.


CONCLUSIONS
FMP with functional appliances could change the expression of Bcl-2 and Bax, which is related to apoptosis in condylar chondrocytes.
Wu
Meng-Jie
MJ
Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, Zhejiang University, Hangzhou, China.
Zhan
Jing
J
Gu
Zhi-Yuan
ZY
D000818:Animals; D002113:Calcification, Physiologic / Q000502:physiology; D049109:Cell Proliferation; D019902:Chondrocytes / Q000473:pathology*; D005260:Female; D005786:Gene Expression Regulation; D006984:Hypertrophy; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D019186:Mandibular Advancement / Q000295:instrumentation / Q000379:methods*; D008335:Mandibular Condyle / Q000473:pathology*; D018715:Microscopy, Video; D017289:Orthodontic Appliances, Functional; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D011817:Rabbits; D011897:Random Allocation; D013704:Temporomandibular Joint / Q000473:pathology; D013997:Time Factors; D051028:bcl-2-Associated X Protein / Q000032:analysis*
D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein