Which radiographic landmarks help assess bone height around posterior teeth?

• A. Lamina dura
• B. Cementoenamel junction
• C. Alveolar crest and interproximal bone height
• D. Pulp chamber

Answer: (C)

This question tests how radiographs show the amount of bone supporting posterior teeth. The two key landmarks are the alveolar crest and the interproximal bone height. The alveolar crest is the top edge of the bone between adjacent teeth; its position relative to the cementoenamel junction helps indicate how much height of bone remains and how much has been lost. The interproximal bone height refers to the bone between the roots of neighboring teeth, revealing patterns of bone loss in the area behind the dentition. Together, these landmarks give a clear picture of the vertical and horizontal bone support around posterior teeth, which is essential for assessing periodontal health and prognosis.

Lamina dura, while useful as a marker of the root socket and periodontal ligament space, does not by itself quantify bone height between teeth. The cementoenamel junction provides a fixed reference point for attachment loss but is not the primary measure of bone height. The pulp chamber is internal to the tooth and irrelevant to bone height assessment.