Ectopic third molars in the sigmoid notch: etiology, diagnostic imaging and treatment options

Abstract

BackgroundThe etiology of ectopic third molars located in the sigmoid notch of the mandible is unclear. Only a few cases have been reported. The aim of this article is to discuss the etiology as well as treatment options and diagnostic imaging techniques.MethodsA PubMed and Medline search of the literature from 1965 to 2015 to ectopic third molars in the mandibular notch was performed. Furthermore, a clinical case provided by the authors is reported.ResultsAmong the eight reviewed cases, two male and six female patients were affected that ranged from 25 to 62 years of age (mean 48.4). Pain and swelling in the preauricular region or trismus but also the absence of symptoms was reported. Only in two of the summarized articles an extra-oral access for the removal of the tooth was used. The etiology seems to be individually different, however dentigerous cysts and chronic inflammation seem to play an important role in their appearance. While previous diagnostic reports described two-dimensional diagnostic imaging, currently the three-dimensional imaging is common for preoperative surgical planning with respect to removing ectopic molars.ConclusionsEctopic third molars in the mandible are a rare condition. The etiology seems to be individually different. Nowadays, three-dimensional imaging is common for preoperative surgical planning.

Comprehensive analysis of ectopic mandibular third molar: a rare clinical entity revisited

“…The pressure resulted from these associated lesions displaces tooth buds in an abnormal direction which were further developed in the ectopic region [ 25 , 37 ]. Moreover, local inflammations support the progressive expansion of cysts and serves as an additional factor to force the migration of the tooth into an ectopic position [ 17 ]. However, some cases are not involved with any pathological lesions, thus other etiological factors in its pathogenesis can’t be ruled out [ 9 , 31 , 39 ].…”

Ectopic third molar associated with a cyst in the sigmoid notch

“…Ectopic third molars are quite rare. Third molars displaced in condylar region, coronoid process, sigmoid notch, ascending ramus, maxillary sinus, and infratemporal fossa have been reported 1 . In the present report, an ectopic mandibular third molar in the sigmoid notch associated with a cyst was presented.…”

“…Reviewing English literatures, including the current case, a total of eight cases of ectopic third molar in the sigmoid notch have been reported (five females, three males; mean age: 44.1 years; range: 37–60 years) 1 . Among these eight cases, five cases were associated with inflamed cystic lesion1, 2, 3, 4; one case with circum coronal radiolucency histopathologically diagnosed as chronic inflamed granulation tissue, 5 implicating that the pressure of cystic fluid and the expansion caused by chronic inflamed granulation tissues might play potential roles for producing a route of migration of the ectopic third molar. Noteworthy, as demonstrated in the present case as well as the report of Hanisch et al., 1 CBCT can provide accurate three-dimensional images and valuable information for preoperative evaluation and surgical treatment plan for ectopic third molars.…”

“…Teeth that are impacted or displaced in unusual locations are called ectopic teeth. The etiology of ectopic teeth is still unclear with theories that have been postulated including disturbances in tooth development, displacement due to pathologic conditions, trauma, or iatrogenic activities 1 . Ectopic third molars are quite rare.…”

“…Among these eight cases, five cases were associated with inflamed cystic lesion1, 2, 3, 4; one case with circum coronal radiolucency histopathologically diagnosed as chronic inflamed granulation tissue, 5 implicating that the pressure of cystic fluid and the expansion caused by chronic inflamed granulation tissues might play potential roles for producing a route of migration of the ectopic third molar. Noteworthy, as demonstrated in the present case as well as the report of Hanisch et al., 1 CBCT can provide accurate three-dimensional images and valuable information for preoperative evaluation and surgical treatment plan for ectopic third molars. Intraoral surgical approach has been employed for the extraction of the ectopic molars in seven cases 1 ; only one case used extra-oral surgical access 3…”