Periodontics · patient case question
How is the bone loss on the mesial of #30 classified radiographically?
Patient case: Periodontal bone loss assessed on radiograph and at surgery
Patient: Female, 52 years old
Chief Complaint: “My gums have pulled back and my back teeth feel loose.”
Background: Irregular dental attendance. Former smoker. No relevant medical history.
Vital Signs: BP 126/78 mmHg · HR 74 bpm
Findings: Radiographs show angular loss of the crestal bone on the mesial of #30, the crest sloping apically away from the CEJ rather than running parallel to it. At #19, a periodontal probe calibrated in millimetres reads 4 mm in the sulcus, and the gingival margin sits 1 mm CORONAL to the CEJ. A surgical photograph after flap reflection shows an interproximal defect in which the bone is lost between two adjacent roots while the facial and lingual plates remain.
Show answer and explanation
Correct answer: A. Vertical (angular) bone loss
- A. CORRECT. VERTICAL or ANGULAR bone loss is present when the crest slopes APICALLY along the root surface, so that the base of the defect lies apical to the surrounding crest and an oblique angle forms between the root and the bone. Vertical defects are the ones that may be amenable to regeneration, which is why the distinction is worth making.
- B. Horizontal bone loss keeps the crest PARALLEL to a line joining the CEJs of adjacent teeth. The whole crest drops together and no angular defect forms. That is not what is described.
- C. Furcation involvement is bone loss into the interradicular space of a MULTIROOTED tooth, seen as a triangular radiolucency between the roots. The stem describes loss on the mesial surface, not between the roots.
- D. Physiologic crest sits 1–2 mm apical to the CEJ, runs parallel to it, and is corticated. Anything beyond that is disease.
Note: Radiographs systematically UNDERSTATE bone loss, because the buccal and lingual plates superimpose on the defect. The interproximal picture is the only part a two-dimensional film reads reliably.