摘要

The objective of this study was to assess the association between an increase in the proportion of the superior head of the lateral pterygoid muscle (SHLP) inserted into the temporomandibular joint (TMJ) disc and the presence of anterior disc displacement diagnosed by using MRI. We analyzed 75 images of patients with anterior displacement and 75 controls with normal relationship between the mandibular head and the articular tubercle also diagnosed by MRI. Levels of insertion were measured. Descriptive and analytic statistics were calculated. Analyses of differences were made by Fischer%26apos;s exact test and also were calculated clinical significance (OR, CI = 95%). The average insertion of SHLP was 71.14% (SD 14.13) in controls and 67.80% (SD.16.23) in cases group. The only relationship that presented a significant association (OR 5.61) was found when comparing subjects with a percentage of inserting the disc into the SHLP at 50% with those who had higher levels of insertion (50%). Our results suggest that the highest percentage of insertion serves as a protective factor for anterior disc displacement, probably due to greater control of neuromuscular activity. El objetivo de este estudio fue evaluar la asociaci車n entre el aumento de la proporci車n de la cabeza superior del m迆sculo pterigoideo lateral (CSPT) insertado en la articulaci車n temporomandibular (ATM) y la presencia de desplazamiento discal anterior diagnosticado mediante resonancia magn谷tica. Se analizaron 75 im芍genes de pacientes con desplazamiento discal anterior y 75 controles con una relaci車n normal entre la cabeza de la mand赤bula y el tub谷rculo articular, tambi谷n diagnosticada por resonancia magn谷tica. Los niveles de inserci車n fueron medidos. La estad赤stica descriptiva y anal赤tica fueron calculadas. Los an芍lisis de las diferencias se hicieron por la prueba exacta de Fischer, y tambi谷n se calcul車 la significancia cl赤nica (OR, IC=95%). La inserci車n media de la CSPT fue 71,14% (DS 14,13) en los controles y 67,80% (SD 16,23) en los casos de grupo. La 迆nica relaci車n que present車 una asociaci車n significativa (OR 5,61) se encontr車 al comparar los sujetos con un porcentaje de inserci車n en la CSPT 50% con aquellos que ten赤an niveles m芍s altos de inserci車n (50%). Nuestros resultados sugieren que el mayor porcentaje de inserci車n sirve como un factor de protecci車n para el desplazamiento discal anterior, probablemente debido a un mayor control de la actividad neuromuscular.

  • 出版日期2010

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