Relationship between mouth-opening force and facial skeletal dimensions in human females.

Maximum (MOF) and average (AOF) isometric mouth-opening forces were measured with an extra-oral gnathodynamometer in 34 females. Mean MOF and AOF with the teeth in centric relation were respectively 99.6 +/- 22.2 and 89.0 +/- 19.4 N with significant relationships between both MOF and AOF and body mass. Analysis of cephalometric measurements from 22 of the subjects revealed significant relationships between opening force (OF) and certain facial dimensions. In particular, larger OF were associated with features characteristic of an angular facial profile, viz long mandibular base, short mandibular body, large gonial angle and large angle NS-ML.