Prosthodontics & Occlusion · patient case question
What was the cause of the mobility and bone loss around #21?
Patient case: Denosumab, Kennedy Class I RPD with a precision attachment on #21
Scenario: Patient with OSTEOPOROSIS taking DENOSUMAB. Kennedy Class I with a PRECISION ATTACHMENT on tooth #21. The chief complaint involves MOBILITY TYPE 3; the COLD TEST WAS NEGATIVE but the tooth was SENSITIVE TO PERCUSSION. A periapical shows one crown carrying the attachment system, bone resorption to the MIDDLE THIRD of the root, and an inflamed (not infected) periodontal ligament.
Show answer and explanation
Correct answer: C. The distal torquing force generated by the attachment to the distal-extension RPD
- A. Caries would produce a restorative problem but does not explain a torquing pattern of bone loss with a rigid attachment on a distal-extension case.
- B. Denosumab REDUCES bone resorption — it is an antiresorptive. It cannot be the cause of localised bone loss around one abutment.
- C. Correct. In a Kennedy Class I (distal-extension) case the base is supported partly by resilient mucosa and partly by the rigid abutment. As the base settles into the tissue under load, the RIGID attachment transmits a distal TORQUING/tipping force to the terminal abutment. Repeated over time this produces the classic picture: increasing mobility and vertical bone loss on the abutment.
- D. The tooth's endodontic status is a consequence in this case, not the cause of the periodontal breakdown.
Note: This is why stress-breaking designs, mesial rests, physiologic (altered cast) impressions and regular relining exist in distal-extension partial denture design.
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