The experimental evaluation of facial asymmetry of mandibular prognathism patients

Abstract

The relationship between subjective and objective evaluation of facial asymmetry of mandibular prognathism patients shown by photographs, was investigated. Seven parts of measuring distances and angles representing facial asymmetry were selected in the first experiment and six for the second experiment.
The parts of the face include: the distance from the median line of the face to point A, B, Ch and Al of right and left sides, angle ABC of right and left sides, angle OBC of right and left sides, and the right and left sides of the chin (Me) as shown in the diagram of a mandibular prognathism patient. The two results are as follow:
1) The evaluation by the oral surgeons in our department, using multiple regression analysis, showed that the more the asymmetry in the region of the mandibular angle was severe, the more the facial asymmetry was felt to be severe. On the other hand, the result obtained from a questionnaire, distributed at the same time to the same subjects showed the chin to be most important for realizing facial symmetry. Therefore oral surgeons are inclined to pay too much attention to asymmetry of the chin region.
2) Multiple regression analysis shows, for oral surgeons and the public, that the postoperative improvement of facial asymmetry is most closely related to the improvement of the symmetry of the mandibular angle region. However, 57.5% of oral surgeons, on the questionnaire, regarded the asymmetry of the chin region as most important in evaluating the asymmetry of the face. The percentage indicating the mandibular angle was only 20%. This was remarkably different from the 60% of the public. Together the multiple regression analysis and questionnaire results coincide, and they suggest that the mandibular angle is the most important part in judging the asymmetry of the face.