title: [Masseter thickness measured by ultrasonography of 50 young healthy adults in relation to facial morphology].
abstract: OBJECTIVE
  To quantify the normal range of the ultrasonically measured thickness of the masseter which is related to the variation of the facial morphology in different young individuals.
  
  
  METHODS
  The masseter thickness of 50 young healthy adults (25 men and 25 women) was measured bilaterally under relaxed conditions and with maximal clenching by a real-time ultrasound imaging technique. The relation between masseter thickness and facial morphology was also observed.
  
  
  RESULTS
  Under relaxed conditions, the mean thickness of the muscle in men was(11.83 +/- 1.19) mm, and under contracted conditions, (15.51 +/- 1.40) mm. In women, the respective measurements were(9.84 +/- 1.03) mm and (13.02 +/- 1.10) mm. In men the thickness of masseter had a negative linear correlation to the indices of FH/FWa (the ratio of the anterior facial height to the intergonial width) and FWz/FWa (the ratio of the bizygomatic facial width to the intergonial width).
  
  
  CONCLUSIONS
  The mean thickness of the masseter in men was larger than that in women, and the thickness of the muscle was related to the male facial morphology.
authors.affiliation: Department of Stomatology, PUMC Hospital, CAMS, PUMC, Beijing 100730, China. jizhi@yeah.net
authors.forename: J Z
authors.initials: JZ
authors.lastname: Zhao
authors.forename: Q
authors.initials: Q
authors.lastname: Dai
authors.forename: Q S
authors.initials: QS
authors.lastname: Lai
mesh_terms: D000328:Adult; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D009119:Muscle Contraction; D009126:Muscle Relaxation; D012737:Sex Factors; D014463:Ultrasonography