RESUMO
Analysis of previous data suggested the hypothesis that temporomandibular joint (TMJ) eminence shapes develop ideally to minimize joint loads. Hence, we tested this hypothesis in nine females and eight males in each of two groups, with and without TMJ disc displacement. Participants provided anatomical data used in a joint load minimization numerical model to predict, and jaw-tracking data used to measure, eminence shapes. Coordinate data (x,y) of shapes were fit to third-order polynomials for two sessions, sides, and methods (predicted, measured) for each participant. Inter-session data were reliable and averaged. Those with, compared with those without, disc displacement had higher measured shape range (5:1) and left-right asymmetry prevalence (4:1). In 29 symmetrical individuals, ANCOVA and Bonferroni tests compared vertical dimensions (y) at 11 postero-anterior points (x), 0.5 mm apart. Model-predicted and measured shapes were significantly different (P < or = 0.01) near the eminence crest, but joint load minimization was consistent with eminence shape for x < 3.0 mm.
Assuntos
Luxações Articulares/patologia , Côndilo Mandibular/patologia , Disco da Articulação Temporomandibular/patologia , Transtornos da Articulação Temporomandibular/patologia , Suporte de Carga/fisiologia , Adulto , Fenômenos Biomecânicos , Estudos Transversais , Oclusão Dentária , Assimetria Facial/patologia , Assimetria Facial/fisiopatologia , Feminino , Humanos , Luxações Articulares/fisiopatologia , Masculino , Côndilo Mandibular/fisiopatologia , Músculos da Mastigação/patologia , Músculos da Mastigação/fisiopatologia , Pessoa de Meia-Idade , Modelos Biológicos , Amplitude de Movimento Articular/fisiologia , Estresse Mecânico , Articulação Temporomandibular/patologia , Articulação Temporomandibular/fisiopatologia , Disco da Articulação Temporomandibular/fisiopatologia , Transtornos da Articulação Temporomandibular/fisiopatologia , Dimensão Vertical , Adulto JovemRESUMO
The role of retinoids in hairless mouse photocarcinogenesis has been studied extensively but remains controversial. By contrast, the role of corticosteroids has hardly been investigated. Many findings indicate an antagonism between the action of these two drugs. To examine these issues, we irradiated hairless mice thrice weekly for 10 weeks with 1.5 minimal erythema doses of solar simulating radiation (UVB + UVA). In the post-UV period, groups of mice were treated topically for 30 weeks with tretinoin, corticosteroid or emollient vehicle alone or with a sequential combination of corticosteroid and tretinoin. A control group remained topically untreated. All three agents, when used alone, significantly inhibited tumorigenesis. The sequential combination produced the greatest inhibition.