Extreme distal movement of the unerupted mandibular premolar below the coronoid process: Report of a case
1997 Volume 43 Issue 2 Pages 103-105
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1997 Volume 43 Issue 2 Pages 103-105
Occasionally an unerupted tooth moves to a location that is some distance from the site from which it arose. This is often caused by the force of a tumor or a cyst, but sometimes the mechanism of the movement cannot be identified. We report the case of a 15-yearold girl in whom an unerupted mandibular first premolar moved below the coronoid process because of no apparent cause. A dental radiograph taken at the age of 9 years showed that the tooth germ of 7 was located in normal position and it appeared to be erupting. However, a panoramic tomogram taken at the age of 12 years showed that F4 was located in a horizontal position below the second molar. The unerupted first premolar continued distal movement, and 3 years later it had migrated below the coronoid process. During the 6 years, it appeared to have slowly moved a distance of about 6cm. No symptoms related to the tooth have developed.
We speculate that the movement was caused by rupture of the gubernacular cord, early loss of deciduous teeth, hypodontia, microdontia, or other factors.
