Medida angular para aferi？？o do t？nus muscular na paralisia facial

background: the decrease of facial movements in peripheral facial paralysis and the resulting aesthetical sequels may have important emotional repercussions as a consequence to the functional deficit, and depending on the intensity of the clinical condition. orofacial rehabilitation has as a purpose to favor the recovery of orofacial movements and to adequate and/or adapt orofacial functions and facial mimic. however, quantifying therapeutic results in an attempt to measure the muscle tonus is a challenge. generally, the used forms of measurement are general and subjective. aim: to propose the labial commissure angle as an anthropometric marker and to evaluate its reliability as an objective tool to evaluate the modification of the facial muscle tonus after rehabilitation. method: participants of the study were 20 patients presenting peripheral facial paralysis - level iv. the study was conducted using images from the photographical documentation taken fifteen days to one year post-onset of facial paralysis. the angle was measured by tracings determined by pre-established anthropometric facial points, such as the line between the glabella and the gnation and the crossing with the left and right chelion points determining an angle manually measured with a protractor on the photography. results: the average labial commissure angle before treatment was of 101.70 and after rehabilitation of 93.80 (standard deviation, sd = 4.3). the statistical analysis indicated a significant difference (p < 0.001). conclusion: the results obtained suggest that the labial commissure angle allows the objective evaluation of facial muscle tonus modification.