ADA NBDE National Board Dental Part II

Answer: B - When a tooth continues to erupt after oral cavity emergence and then ceases, it is called ankylosis. The cause of the condition is trauma, abnormal tongue pressure, root resorption, and a small ligament gap. The disturbed tooth is usually below the occlusal plan of adjacent teeth and shows absence of periodontal ligament. Adjacent teeth may display an incline towards the affected tooth.