By Dr Hassem Geha
A 47 Year-old male was referred to a clinic for implant placement in the right maxilla. The patient was healthy with no contributory medical history.
The intraoral examination revealed extensive dental work. The status of the periodontal tissue was within normal limits with mild gingival recession and no deep pockets.
The panoramic radiograph showed multiple endodontically treated teeth. Tooth 12 appeared to have a previous endodontic surgery. Tooth had extruding endodontic material with a periapical radiolucency, Teeth 13 and 23 had also some extruding endodontic material but with no noticeable periapical radiolucencies. The maxillary sinuses presented with dome shaped thickening of the mucosa consistent with retention cyst of the maxillary sinus – an entity that requires no treatment.
Another incidental finding was an ectopic third molar that is impacted inferior to the left mandibular canal, at proximity of the mandibular angle and with its crown facing the left mandibular condyle. The mandibular canal appears to be in contact with the body of the root of the impacted third molar. The follicular sac is preserved and is not enlarges.
The decision was to do radiographic follow-up annually to evaluate for possible cystic/tumoral degeneration of the follicular sac.
The etiology of an ectopic tooth cannot always be determined. It may be associated with developmental disorders of jaws, pathological conditions or iatrogenic. Several theories have been put forward to explain ectopic locations of third molars, including the aberrant eruption, trauma, and ectopic formation of tooth germs. A third molar may be displaced a great distance from its habitual location because of an aborted eruption, a displacement due to lesions such as cysts or osseous tumors, or an alteration of the eruption due to a lesions such as odontogenic tumors. Ectopic third molars have been noted in ascending ramus, condylar region and coronoid process.
In this case, the ectopic tooth was not associated with any pathology. A surgical removal of this tooth was not planned the potential risks that might be related during the surgery such as severing the mandibular nerve and the lingual nerve or causing a pathological fracture of the mandible.
A free PDF version of this case study is accessible here: ectopicthirdmolar