Palatal sutural response to buccal muscular displacement in the rat.

Buccal shields inserted in the mouths of 30-day-old Sprague-Dawley rats displaced the buccal musculature away from the maxillary molar teeth. Intermolar distances increased significantly (P less than 0.02) 15 days following insertion of the appliance, thereafter decreasing with time. Histologically, at the level of the first molars, ossification of the sutural cartilage occurred earlier than in control sutures. While different interpretations are given to explain this result, the adaptive nature of secondary cartilage in the intermaxillary suture of the rat was demonstrated. This adaptation may be limited by the nature of mechanical stress exerted upon, and/or the growth potential, of the suture.