title: Faculty-supervised measurements of the face and of mandibular movements on young adults.
abstract: OBJECTIVE
  The purpose of this study was to determine the average facial proportions and mandibular movement capacity of 316 first-year dental students who carefully recorded them on each other.
  
  
  METHODS
  This early exacting clinical experience was closely supervised by the authors in Columbus, Ohio during 1969-70. Five vertical and six horizontal distances were measured on each subject's face. An ala-tragus line and an occlusal line were drawn on the left side of the face to determine if these two lines were parallel. Measurements of mandibular movements involved maximum normal and hinge opening at the incisors and maximum amounts of right, left lateral and protrusive excursions of the mandible.
  
  
  RESULTS
  The ala width and distance between the tips of upper right and left canine cusps averaged (35.2 mm and 34.8 mm) but with very large individual variations. The distance between ala to occlusal plane lines was 29.9 mm at the tragus and 31.3 mm near the ala. The angle between orbitale and ala-tragus averaged 13.6 degrees.
  
  
  CONCLUSIONS
  The upper lip length was the most variable and the distance between the pupils was the most stable of the eleven facial measurements. The ala-tragus line and the occlusal plane lines were for all practical purposes parallel. Maximum jaw opening averaged 51.2 mm which was 3.0 times larger than maximal hinge opening of 17.2 mm. The maximum right plus left side jaw excursions (9.2 and 9.4 mm) totaled 18.6 mm, 2.3 times more than the 8.0 mm mean maximum forward protrusion.
authors.affiliation: Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio, USA.
authors.forename: Julian B
authors.initials: JB
authors.lastname: Woelfel
authors.affiliation: Department of Fixed Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Igarashi
authors.affiliation: Department of Prosthodontics, Wonkwang University College of Dentistry, Iksan, Korea.
authors.forename: Jin-Keun
authors.initials: JK
authors.lastname: Dong
keywords: Ala-tragus line; Anthropometry; Maximum and normal mandibular openings and excursions; Measurements of the face; Occlusal plane