Longitudinal occlusal changes from primary to permanent dentition in children with normal primary occlusion.

This purpose of this research was to examine the stability of normal occlusion during the transition from primary to permanent dentition. The sample consisted of 128 children (83 boys and 45 girls) 4.5 to 5.5 years old with normal occlusion in the primary dentition. The subjects were reexamined at 12.5 to 13.5 years. None had received orthodontic treatment. Although all the subjects had normal occlusion in the primary dentition, 72.7% (73.5% boys and 71.1% girls) had developed anomalies following eruption of the permanent teeth. These anomalies included crowding, Class II Division 1 or Class II Division 2 malocclusion, mesial occlusion complex, lateral crossbite, anterior crossbite, premature tooth loss, openbite or other anomalies.