title: Subcutaneous air emphysema--a rare condition (four case reports).
mesh_terms: D000328:Adult; D003737:Dental Cavity Preparation / Q000009:adverse effects; D003762:Dental Instruments / Q000009:adverse effects*; D004646:Emphysema / Q000209:etiology*; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011176:Post and Core Technique / Q000009:adverse effects; D012390:Root Canal Therapy / Q000009:adverse effects; D013352:Subcutaneous Emphysema / Q000209:etiology*; D014081:Tooth Extraction / Q000009:adverse effects