Histological and molecular temporomandibular joint analyses after mandibular advancement surgery: study in minipigs.
OBJECTIVE
The objective of this study was to elucidate the changes occurring in the temporomandibular joint (TMJ) after surgical mandibular advancement with different fixation techniques: bicortical screws (rigid fixation) and miniplates (semi-rigid fixation).


METHODS
Eighteen minipigs were equally and randomly divided into 3 groups: Group I (control), nonoperated animals; Group II, animals submitted to surgical advancement surgery and osteosynthesis by bicortical screws; and Group III, animals submitted to surgical advancement surgery and osteosynthesis by miniplates. Four months after the surgeries, the presence of interleukin (IL)-6 and IL-10 in synovial fluid samples was assessed in ELISA experiments. TMJs were histologically prepared.


RESULTS
Higher levels of IL-10 (P = .0436) were found for Group II. Descriptive histological analysis was compatible with the ELISA findings.


CONCLUSIONS
Rigid fixation evokes more pronounced signs of bone remodeling in the TMJ, whereas malleable fixation promotes a more intense inflammatory activity. Therefore, rigid fixation seems to transmit a higher impact of postoperative masticatory forces to the TMJ.
Department of Orthodontics, Bauru School of Dentistry, University of São Paulo, Brazil. r-navarro@hotmail.com
Ricardo
R
de Lima Navarro
Paula Vanessa Pedron
PV
Oltramari
Eduardo
E
Sant'Ana
José Fernando Castanha
JF
Henriques
Rumio
R
Taga
Tânia Mary
TM
Cestari
Paulo César Rodrigues
PC
Conti
Fernando Queiroz
FQ
Cunha
Carlos Ferreira
CF
Santos
D000704:Analysis of Variance; D000818:Animals; D001860:Bone Plates; D016723:Bone Remodeling; D001863:Bone Screws; D003799:Dental Stress Analysis; D004797:Enzyme-Linked Immunosorbent Assay; D018836:Inflammation Mediators / Q000032:analysis; D016753:Interleukin-10 / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D019248:Jaw Fixation Techniques / Q000295:instrumentation*; D008297:Male; D008334:Mandible / Q000601:surgery*; D019186:Mandibular Advancement / Q000379:methods*; D008335:Mandibular Condyle / Q000502:physiology; D011897:Random Allocation; D013552:Swine; D013556:Swine, Miniature; D013582:Synovial Fluid / Q000737:chemistry; D013704:Temporomandibular Joint / Q000503:physiopathology*
D018836:Inflammation Mediators; D015850:Interleukin-6; D016753:Interleukin-10