1998 Volume 36 Issue 1 Pages 165-172
Delayed eruption or tooth impaction is caused by systemic or local etiologic factors such as cysts, odontogenic tumors, supernumerary teeth, delayed tooth development and gingival fibrosis. Usually impacted primary teeth involved the permanent dentition and are rare in the primary dentition.
We encountered two cases of delayed eruption of the mandibular left primary second molars which had exposed a small area of the occlusal surface and had stopped erupting. The patients were a 4year-0-month-old girl and a 6-year-8-month-old girl. There were no particular findings in their genera healthl condition or family history in either case. Radiographs did not reveal any abnormal findings such as cysts or odontomas around the teeth in either case.
In case one, the mandibular left primary second molar was located at the same height of the cervical line as the neighboring primary first molar. The shape of the tooth crown was normal and root development was almost completed. Under the primary second molar, the tooth germ of the permanent second premolar could not be defected. Treatment involved surgical exposure of the tooth crown. One year and five months later the left primary second molar erupted spontaneously. The tooth germ of the second premolar was simultaneously recognized using radiography.
In case two, the lower primary second molar was located under the mesially drifted permanent first molar which resulted in loss of eruption space. The root was short and irregularly formed while the tooth germ of the permanent second premolar was recognized.
Treatment was surgical exposure of the tooth crown, distalizing of the first permanent molar to regain eruption space and traction of the primary second molar. After 10 months, the primary second molar erupted and occluded with the elongated upper primary second molar.
In both cases, gingival tissues overlying the teeth demonstrated pericoronal myxofibrous hyperplasia histologically.
