內文：
Introduction
Dilated odontoma 是極稀有的 developmental anomaly 具有相對應的 as a dilatation of the crown and root as a consequence of a deep, enamel-lined invagination and is considered a severe variant of dens invaginatus
An oval shape of the tooth lacking morphological characteristics of a crown or root implies that the invagination happened in the initial stages of morphodifferentiation Spontaneous eruption of an odontoma is a rare occurrence and the occurrence of a dilated odontoma in a supernumerary tooth is even rarer with only a few case reports documented in the English literature
We present an extremely rare case of erupted dilated odontoma occurring in the supernumerary tooth in anterior maxillary region in an 18-year-old male, which, to the best of our knowledge, is the first ever case reported in English literature
Case Report
Chief complaint : malformed tooth in his upper front region No history of medical or family problem
No previous history of trauma to the teeth or jaws 年齡：18 y/o male p’t
Intraoral clinical examination:
An anomalous tooth present in area of left maxillary central incisor mild pain which was intermittent(間斷地)
No swelling or mobility was observed Tender on percussion
EPT: (-)
A supernumerary tooth was observed palatally in relation to permanent maxillary lateral incisor region
Revealed the presence of impacted permanent maxillary left central incisor X-Ray findings:
The supernumerary tooth showed an oval radiolucent interior delineated by a well-defined radiopaque border
咬合片：The presence of impacted maxillary central incisor and supernumerary teeth in anterior maxillary region
Cone beam computerized tomography
Diagnose:
1. With dilated invaginated odontoma in supernumerary tooth in anterior maxillary region associated with periapical pathology
2. Supernumerary tooth in palatal region
3. Impacted permanent maxillary central incisor Treatment:
(1) The supernumerary tooth was subsequently extracted under local anaesthesia (2) Impacted central incisor was surgically exposed using a full thickness
mucoperiosteal flap
(3) An attachment was bonded along with looped ligature wire on the labial surface of tooth
(4) Flap was repositioned and a closed eruption was induced by orthodontic traction with a mild force of 60 gm, using elastomeric module
(5) maxillary and mandibular arches were bonded using fixed appliance with 0.022×
0.028 slot
(6) Leveling of both arches was continued with sequential arch wires and space was maintained for the central incisor
七個月後，阻生齒拉到main arch的高度，並在唇側黏上bracket，並且alignment with 0.012 NiTi as piggyback on 0.018 SS base arch wire.Keep follow up
Discussion
Morphological variations in dental structures involving either the crown or root 通常在常規性的X光片檢查才會發現
Dens invaginatus represents a rare form of developmental anomaly with a prevalence of 0.04% with a greater female predilection
The most frequently affected tooth is the maxillary lateral incisors, followed by maxillary
central incisors, premolars, canines, and molars
The most common site of compound odontoma is the anterior maxilla, characteristically over or between the roots of the erupted teeth. Though odontomas are seen frequently and constitute(構成) 22% of all odontogenic tumors, erupted odontomas are rare
In the present case, the differential diagnosis of compound odontomas was excluded as they typically present with multiple rudimentary(基本) tooth-like structures.
A dilated odontoma has been described as extremely rare type of dens invaginatus
The shape is usually irregular,but the dilated varieties are often well-defined, corticated,
round, or oval masses with radiolucent centres
In our case,the patient presented with a deformed(變形) crown with an oval shaped radiolucency suggestive of dilated odontoma
Coronal dens invaginatus has been categorized in 3 groups by Oehlers
anomalies should be further investigated for a genetic analysis as it might represent a chromosomal trait(染色體)
作者認為the first case report of an erupted dilated odontoma in a supernumerary tooth
早期發現，早期治療
題號 題目
1 下列何種顎骨良性腫瘤於 X 光片上較不常見牙根吸收？
A. 造釉細胞瘤（ameloblastoma）
B. 牙瘤（odontoma）
C. 骨性纖維瘤（ossifying fibroma）
D. 中央巨細胞肉芽腫（central giant cell granuloma）
答案(B ) 出處：103-2 國考題目
題號 題目
2 .那一種齒源性病變，比較可能於增生一段時間之後，便維持一定的
體積而不再變大？
A.Cementoblastoma B. Odontoma
C.Fibrous dysplasia D.Ameloblastoma 答案(B) 出處：99-2 國考題目
