Orthopedic jaw movement observations. Part I: Determination and analysis of the length of protrusion.

An analysis and quantitation of protrusive and retrusive mandibular movement is provided. This report is one study along with four other parts analyzing the mandibular opening movement, the transversal shift during protrusion and retrusion, the mediotrusive movement and mastication. Protrusive movements of 225 individuals (180 patients, 45 volunteers) were analyzed using computerized axiography. Investigating both asymptomatic volunteers and patients with abnormal joint mobility helps to improve evaluation of these abnormalities. With the aid of diagnostic computer software, the length of the pathways was measured and the characteristics of the curves were analyzed. An average group was defined based on the values found in asymptomatic individuals, comprising 50% of our volunteers. The interquartile range for the male volunteers was 8.79-12.27 mm for the right joint and 9.43-12.93 mm for the left joint; for female volunteers it was 8.32-10.64 mm and 9.2-11.26 mm, respectively.