peri·odon·titis
noun/ˌperiədɒnˈtaɪtɪs/
/ˌperiədɑːnˈtaɪtɪs/
(British English also pyorrhoea)
(North American English also pyorrhea)
[uncountable] (medical)- a condition in which the area around the teeth becomes painful and swollen (= larger than normal), which may make the teeth fall out
牙周炎