Improvement in jaw motion following treatment of unilateral crossbite in a child with primary dentition: A case report

This case report examines jaw motion during both habitual opening-closing and gum chewing in a young (3 years, 10 months) patient with unilateral crossbite at the primary dentition stage. Jaw motion was measured three times: 1. before treatment; 2. after active treatment; and 3. after retention. The abnormal habitual open-close pathway seen prior to treatment was improved after retention. Prior to treatment, movement of the affected-side condyle preceded movement of the non-affected-side condyle during opening. After retention, the movement of the condyles was better coordinated. The chopping type chewing pattern, with less lateral movement, before treatment changed to a more grinding type pattern on the affected side after activation. This study suggests that the prescribed treatment effectively improved both the patient's morphology and function. However, neither the open-close pathways nor the chewing patterns were completely normal after retention. The results in this case suggest that early treatment of functional unilateral crossbite can be effective.