Permalink : http://hdl.handle.net/2115/86846

KEYWORDS : 筋突起;埋伏智歯;含歯性嚢胞;coronoid process;impacted lower third molar;dentigerous cyst

埋伏智歯が本来の位置から遠く離れ，それが下顎枝最上方の筋突起に位置することは非常にまれである．今回われわれは筋突起に埋伏した含歯性嚢胞を伴う智歯の1 例を経験したので報告する． 患者は72歳，男性．2021年5 月に左側耳下腺咬筋部の腫脹と疼痛を自覚し，近在歯科を受診した．症状が悪化傾向であったため，当院を紹介受診した．初診時の口腔外所見では左側耳下腺咬筋部の腫脹，疼痛と重度の開口障害を認めた．口腔内所見では開口障害により視認は困難であったが，左側頬粘膜に浮腫性の腫脹を認めた．画像検査では筋突起内に逆性埋伏智歯とその周囲に嚢胞様透過像を認め，それら周囲の軟組織の肥厚を認めた．血液検査所見では炎症反応を認めた．埋伏智歯ならびに嚢胞様病変への感染と診断し，抗菌薬による消炎を行った．消炎後，全身麻酔下で埋伏智歯抜歯ならびに嚢胞摘出を施行した．病理組織学的診断は含歯性嚢胞が考えられた．現在，術後6 か月を経過しているが，問題なく経過している．
It is extremely rare that impacted third molar teeth move distantly from their original position and are　located in the coronoid process. In this case study, an impacted third molar tooth with a dentigerous cyst in the coronoid process is reported. The patient was a 72-year-old man. He noticed swelling and pain in the region of the left parotid-masseteric and visited his regular dentist. He was referred to our hospital because his symptoms gradually worsened. A clinical examination revealed severe swelling and pain in the region of the left parotid-masseteric, trismus, and edematous swelling in the buccal mucosa. A computed tomography scan showed a cyst-like transmission image surrounding the reverse impacted third molar tooth within the c oronoid process. A severe inflammatory response was revealed through a blood examination. An infection to the impacted third molar tooth and cyst-like lesion was diagnosed and treated with antibiotics. After the inflammation reduced, the impacted third molar tooth extraction and cyst enucleation was performed under general anesthesia. A histopathological examination showed a dentigerous cyst. Six months after the operation, the postoperative healing process was positive.