Introduction: The aim of this study was to quantify the changes in sagittal condylar path inclination during maximum mandibular protrusion in relation to the stage of dental and physical development throughout the mixed dentition period.
Methods: A total of 161 children, 6.5 to 13 years of age, were divided by dental stage into 3 subgroups: early mixed dentition without anterior guidance, early mixed dentition with anterior guidance, and late mixed dentition. The control group consisted of 41 adults (mean age, 28 years). All subjects had normal temporomandibular joint function and neutral occlusion. Five maximum protrusion-retrusion movements were recorded by using an ultrasound jaw-tracking system supported with software that automatically calculated the condylar path inclination angle (CPIA).
Results: Significant differences were found between the 3 subgroups of children. In the late mixed dentition subgroup, girls had significantly steeper condylar paths on the left side than boys. In the early mixed dentition with anterior guidance subgroup, the right CPIA was significantly larger than the left CPIA. Linear regression analysis showed that condylar path inclination was positively correlated with both body height and weight, although the correlation was statistically weak.
Conclusions: These findings indicate that CPIA increases with the maturation of occlusion.