The "sinking" root phenomenon.
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008963:Molar / Q000000981:diagnostic imaging*; D010482:Periapical Abscess / Q000000981:diagnostic imaging; D011859:Radiography; D014085:Tooth Migration / Q000000981:diagnostic imaging*; D014092:Tooth Root / Q000000981:diagnostic imaging*