Which reference landmark is used to quantify alveolar bone loss on radiographs?

Which reference landmark is used to quantify alveolar bone loss on radiographs?

• A. Occlusal plane
• B. Tissue color
• C. Cemento-enamel junction
• D. Tooth crown apex

Answer: (C)

Alveolar bone loss on radiographs is quantified by measuring the distance from the cementoenamel junction to the alveolar crest. The cementoenamel junction is used because it is a fixed, reproducible landmark on the tooth that remains relatively constant over time, unlike soft tissue levels. In health, the crest sits about 1–2 mm apical to the CEJ; as bone is lost, the crest moves farther from the CEJ, increasing that measurement. The occlusal plane isn’t a reference for bone height, tissue color reflects soft tissue status rather than bone height on X‑rays, and the tooth crown apex isn’t a reliable baseline for assessing alveolar bone support.

Alveolar bone loss on radiographs is quantified by measuring the distance from the cementoenamel junction to the alveolar crest. The cementoenamel junction is used because it is a fixed, reproducible landmark on the tooth that remains relatively constant over time, unlike soft tissue levels. In health, the crest sits about 1–2 mm apical to the CEJ; as bone is lost, the crest moves farther from the CEJ, increasing that measurement. The occlusal plane isn’t a reference for bone height, tissue color reflects soft tissue status rather than bone height on X‑rays, and the tooth crown apex isn’t a reliable baseline for assessing alveolar bone support.