Which set of findings is characteristic of chronic bruxism?

Correct answer: A. Occlusal wear facets, masseteric HYPERTROPHY, narrowed periodontal ligament spaces and thickened lamina dura

• A. CORRECT. This is the full cluster. The muscles HYPERTROPHY under repeated heavy loading, and bilateral MASSETERIC (and temporalis) hypertrophy is frequently the first change the patient or their family notices, producing the squared lower face described here — it is also the feature patients most often present about, since it is what they can see. In the bone, sustained functional loading produces a NARROWED periodontal ligament space and a THICKENED, more sclerotic lamina dura, along with buttressing bone and exostoses — the periodontium ADAPTING to load rather than being destroyed by it. Add interdigitating wear facets, scalloped tongue and linea alba and the diagnosis is complete.
• B. Abfraction lesions are a plausible accompaniment of parafunction, but they are one finding rather than the picture, and the muscular change is what this question turns on.
• C. Muscle ATROPHY is the opposite of what sustained repetitive loading produces. Atrophy points to disuse, denervation or a primary myopathy — not to parafunction.
• D. A widened PDL space with a thinned lamina dura and mobility describes occlusal TRAUMA acting on a REDUCED or inflamed periodontium, or an inflammatory or neoplastic process. In a periodontally healthy bruxist the ligament space narrows, not widens.

Note: ⚠️ The recall author selected ‘masticatory muscle atrophy’ and it is the wrong direction — bruxism causes HYPERTROPHY of the masseter and temporalis. Management: a hard, full-coverage occlusal splint (never a partial-coverage appliance, which permits over-eruption), review of stress and sleep, and — given the snoring and BMI here — evaluation for OBSTRUCTIVE SLEEP APNEA, which is strongly associated with sleep bruxism.