Which statement best describes horizontal bone loss?

• A. It shows angular defects along the root
• B. It shows a radiographic sign of furcation involvement
• C. It shows even apical migration of the alveolar crest around teeth
• D. It shows root resorption at apex

Answer: (C)

The concept being tested is how horizontal bone loss appears on radiographs. Horizontal bone loss presents as a uniform, even retreat of the alveolar crest around the teeth, so the crest migrates apically in a parallel fashion around each root. This yields a consistent distance from the CEJ to the crest across multiple surfaces, indicating generalized, uniform destruction.

This description fits horizontal bone loss because it contrasts with vertical (angular) defects, which are localized and show irregular, angled bone loss along a root. Furcation involvement refers to bone loss in the space between a multi-rooted tooth’s roots, not a uniform crest recession. Root resorption at the apex is a different process affecting the tooth root itself, not the crestal bone level around the teeth. So the statement about even apical migration of the alveolar crest around teeth best describes horizontal bone loss.