CASE 4418 Published on 31.03.2006

Ectopic third molar tooth with left maxillary dentigerous cyst


Head & neck imaging

Case Type

Clinical Cases


DR.SUNITHA LINGA REDDY DNB ELBIT MEDICAL DIAGNOSTICS LTD. Padmaja Palace , Flat No.401, Plot No.14, Hyderabad . DR.SANDEEP J MD ELBIT MEDICAL DIAGNOSTICS LTD. 1-2-593/40 Gagan Mahal Colony Hyderabad . DR.C.JOGA RAO MD,DMRD,DNB. ELBIT MEDICAL DIAGNOSTICS LTD. Naimisam Apartments, Flat No.401, Plot No.22, Hyderabad .


19 years, male

Clinical History
Left maxillary swelling of 4 months duration in a 19 year old male
Imaging Findings
19-year-old-male patient presented with left maxillary swelling of about 4 months duration. An OPG study revealed a well defined radiolucency around the crown of an ectopic upper third molar tooth.Caldwell view taken subsequently showed a soft tissue density mass with the ectopic tooth.Axial and coronal CT sections demonstrated a soft tissue density mass (30 HU) with thin rim of calcification and embedded upper 3rd molar tooth.
Cysts of the jaws are basically of two types1 ,developmental and inflammatory.Developmental cysts can be odontogenic and non odontogenic.Dentigerous cyst is a type of odontogenic cyst which is nearly twice as common in men as in women. In Shear`s series2 they were the most frequent type of odontogenic cyst in the first decade, but the majority of cases were seen in the second to fourth decades. These cysts are frequently symptomless and discovered initially during routine radiography. They develop most commonly around the crown of third mandibular molar tooth3. In our case the unerupted 3rd upper molar was in an ectopic location probably secondary to the cyst formation which has displaced the tooth superiorly, a rather rare entity especially taking into consideration the age and location. The occurrence of ectopic teeth at sites other than the immediate dental environment is rare. A few reports of tooth displacement into the maxillary sinus, nasal cavity, orbit, chin and mandibular ramus, condyle and coronoid process have been published4,5,6,7. Etiology of ectopic teeth can be due to developmental abnormalities, over crowding, trauma and sepsis4,6. Impaction of tooth in the maxillary sinus can be asymptomatic7. Such teeth are often discovered serendipitously on inspection of X-Rays of skull or teeth. In other cases symptoms such as nasal obstruction, facial fullness, head ache, hyposmia, anosmia, epistaxis, fever, rhinorrhea, deviation of naso maxillary anatomy can be observed4,6,7,8.It is seen as a well-demarcated unilocular radiolucency around the crown of an unerupted tooth relatively small (less than 2.0 cm in diameter).They can become large and multilocular which suggests their transformation into more serious lesions.Following enucleation of the cyst and extraction of the unerupted tooth, the prognosis is excellent. Recurrence is seldom observed after complete removal.Rare complications include transformation to an ameloblastoma, squamous cell carcinoma and intraosseous mucoepidermoid carcinomas1.
Differential Diagnosis List
Ectopic third molar tooth with left maxillary dentigerous cyst
Final Diagnosis
Ectopic third molar tooth with left maxillary dentigerous cyst
Case information
DOI: 10.1594/EURORAD/CASE.4418
ISSN: 1563-4086