Facial asymmetry of skeletal origin - correlation of some mandibular parameters

Introduction: Asymmetry of craniofacial region can be recognized as presence of size and shape difference in left and right side of the face and can be result of difference in shape and bad position of craniofacial bones. Degree of asymmetry is reduced and equality in left and right parts of the face is increased closer to the cranium. Skeletal asymmetry imply maxillar and mandibular alteration or both, as the alteration on other skeletal structures. Posteroanterior (frontal) cephalometry x-ray is the most helpful x-ray in face asymmetry analyssis, since distortion is minimum, so the comparation of left anad right side is the most accurate. Aim of the study: The purpose of the study is to see the correlation between the deviation degree of mandible to the left or to the right, the length of the corpus and ramus of mandible and the size of the gonial angle in patients with facial asymmetry. Material and method: The study has been conducted on 31 posteroanterior (frontal) X-rays (PA Xrays) of patients with facial asymmetry of skeletal origin. The following parameters were analyzed: the length of the corpus and ramus of mandible and the size of gonial angle on the left and the right side and the direction and the deviation degree of mandible (angle Me-ANS-SS). The acquired data have been statistically analyzed by Spearman test of correlation and regression analysis with several variables. Results: The results of the study show that the angle Me-ANS-SS statistically significantly positively correlates with the gonial angle on the right side (rho = 0.56, p<0.05) and that the length of the mandible corpus to the left and the gonial angle on the right side, statistically significantly affects the size of the Me-ANS-SS angle, that is for the deviation to the right (p<0.05). Statistically important higher values of the corpus length were found on the right side and the Me-ANS-SS angle in the group with the deviation to the left (p<0.01). Conclusion: The length of corpus and ramus of mandible, as well as the size of the gonial angle has a significant role in defining the facial asymmetry of skeletal origin. However, along with these, other parameters may have influence on the appearance, direction and degree of deviation of the lower jaw.