The purpose of this study was to examine the effects of forced mouth opening on murine mandibular condylar head remodeling. We hypothesized that forced mouth opening would cause an anabolic response in the mandibular condylar cartilage. Six-week-old female C57BL/6 mice were divided into 3 groups: (1) control, (2) 0.25 N, and (3) 0.50 N of forced mouth opening. Gene expression, micro-CT, and proliferation were analyzed. 0.5 N of forced mouth opening caused a significant increase in mRNA expression of Pthrp, Sox9, and Collagen2a1, a significant increase in proliferation, and a significant increase in trabecular spacing in the subchondral bone, whereas 0.25 N of forced mouth opening did not cause any significant changes in any of the parameters examined. Forced mouth opening causes an increase in the expression of chondrocyte maturation markers and an increase in subchondral trabecular spacing.
BenjaminMRalphsJR (2004). Biology of fibrocartilage cells. Int Rev Cytol233:1-45.
2.
CancelMGrimardGThuillard-CrisinelDMoldovanFVillemureI (2009). Effects of in vivo static compressive loading on aggrecan and type II and X collagens in the rat growth plate extracellular matrix. Bone44:306-315.
3.
ChenJGuptaTBaraszJAKalajzicZYehWCDrissiH. (2009a). Analysis of microarchitectural changes in a mouse temporomandibular joint osteoarthritis model. Arch Oral Biol54:1091-1098.
4.
ChenJSorensenKPGuptaTKiltsTYoungMWadhwaS (2009b). Altered functional loading causes differential effects in the subchondral bone and condylar cartilage in the temporomandibular joint from young mice. Osteoarthritis Cartilage17:354-361.
5.
ForwoodMRTurnerCH (1995). Skeletal adaptations to mechanical usage: results from tibial loading studies in rats. Bone17(4 Suppl):197S-205S.
6.
FujisawaTKubokiTKasaiTSonoyamaWKojimaSUeharaJ. (2003). A repetitive, steady mouth opening induced an osteoarthritis-like lesion in the rabbit temporomandibular joint. J Dent Res82:731-735.
7.
GuptaAKohliVSHazareyPVKharbandaOPGunjalA (2009). Stress distribution in the temporomandibular joint after mandibular protraction: a 3-dimensional finite element method study. Part 1. Am J Orthod Dentofacial Orthop135:737-748.
8.
KawaiNTanakaELangenbachGEvan WesselTSanoRvan EijdenTM. (2008). Jaw-muscle activity changes after the induction of osteoarthrosis in the temporomandibular joint by mechanical loading. J Orofac Pain22:153-162.
9.
KubokiTTakenamiYMaekawaKShinodaMYamashitaAClarkGT (2000). Bio-mechanical calculation of human TM joint loading with jaw opening. J Oral Rehabil27:940-951.
10.
LaiAChowDHSiuSWLeungSSLauEFTangFH. (2008). Effects of static compression with different loading magnitudes and durations on the intervertebral disc: an in vivo rat-tail study. Spine (Phila PA 1976)33:2721-2727.
11.
LuderHULeblondCPvon der MarkK (1988). Cellular stages in cartilage formation as revealed by morphometry, radioautography and type II collagen immunostaining of the mandibular condyle from weanling rats. Am J Anat182:197-214.
12.
MilamSB (2005). Pathogenesis of degenerative temporomandibular joint arthritides. Odontology93:7-15.
13.
NgAFYangYOWongRWHäggEURabieAB (2006). Factors regulating condylar cartilage growth under repeated load application. Front Biosci11:949-954.
14.
OhnoSSchmidTTanneYKamiyaTHondaKOhno-NakaharaM. (2006). Expression of superficial zone protein in mandibular condyle cartilage. Osteoarthritis Cartilage14:807-813.
15.
PanigrahiPVineethV (2009). Biomechanical effects of fixed functional appliance on craniofacial structures. Angle Orthod79:668-675.
RaffertyKLSunZEgbertMBakkoDWHerringSW (2007). Changes in growth and morphology of the condyle following mandibular distraction in minipigs: overloading or underloading?Arch Oral Biol52:967-976.
19.
RoblingAGDuijvelaarKMGeeversJVOhashiNTurnerCH (2001). Modulation of appositional and longitudinal bone growth in the rat ulna by applied static and dynamic force. Bone29:105-113.
20.
ShenGDarendelilerMA (2005). The adaptive remodeling of condylar cartilage—a transition from chondrogenesis to osteogenesis. J Dent Res84:691-699.
21.
ShenGRabieABZhaoZHKaluarachchiK (2006). Forward deviation of the mandibular condyle enhances endochondral ossification of condylar cartilage indicated by increased expression of type X collagen. Arch Oral Biol51:315-324.
22.
ShibukawaYYoungBWuCYamadaSLongFPacificiM. (2007). Temporomandibular joint formation and condyle growth require Indian hedgehog signaling. Dev Dyn236:426-434.
23.
SugiyamaTPriceJSLanyonLE (2010). Functional adaptation to mechanical loading in both cortical and cancellous bone is controlled locally and is confined to the loaded bones. Bone46:314-321.
24.
TanakaEAoyamaJMiyauchiMTakataTHanaokaKIwabeT. (2005). Vascular endothelial growth factor plays an important autocrine/paracrine role in the progression of osteoarthritis. Histochem Cell Biol123:275-281.
25.
TanakaEDetamoreMSMercuriLG (2008). Degenerative disorders of the temporomandibular joint: etiology, diagnosis, and treatment. J Dent Res87:296-307.
26.
TangGHRabieABHäggU (2004). Indian hedgehog: a mechanotransduction mediator in condylar cartilage. J Dent Res83:434-438.
27.
WadhwaSKapilaS (2008). TMJ disorders: future innovations in diagnostics and therapeutics. J Dent Educ72:930-947.
28.
WangDLJiangSDDaiLY (2007). Biologic response of the intervertebral disc to static and dynamic compression in vitro. Spine (Phila PA 1976)32:2521-2528.
