Comparison of maximum mouth-opening capacity and condylar path length in adults and children during the growth period.

A group of 80 children ranging in age from 6 to 10 years (subdivided into groups 1-5 according to chronological age) has been compared with an adult group on the basis of condylar path length and maximum mouth-opening capacity. The condylar path length and the mouth-opening capacity were measured using the ultrasonic JMA-System for registration. In the development of the temporomandibular joint (TMJ), condylar path length and mouth-opening capacity were found to increase with age in the juvenile group. In the oldest juvenile subgroup (subgroup 5; average age: 10.3 years) the condylar path length reached 17.6mm on the left and 17.3mm on the right. This is equivalent to 90.3% (left) and 91.1% (right) of the size in the adult group. The mean maximum mouth-opening capacity of the oldest juvenile subgroup was 56.3mm and reached 98.9% of the size in the adult group.