[A case of horizontal impaction of mandibular left and right deciduous central incisors]

This paper reports on a rare case of horizontal impaction of the mandibular left and right deciduous central incisors. The patient was a 4 year and 7-month-old-girl at the time of first visit to our clinic. She had no previous history, and there was no family history or anomaly in her general physical condition. All the deciduous teeth except the mandibular left and right deciduous central incisors had already erupted. The right deciduous central incisor was impacted completely and the left one erupted with its incisal edge about 2 mm at the lingual gingiva. In the X-ray examination, the horizontal impaction of the mandibular left and right deciduous incisors were noted. There were no cysts, odontoma or tumors. Both of them were extracted to prevent loss of space for the permanent central incisors. Each root of both teeth was curved 90 degrees in the lingual direction at half of length of the root. There was no anomaly of figure and color in their crowns. In the histopathologic examination, there was no anomaly except for the small root resorption at the labial and lingual sides. 3 years and 3 months after extraction of the deciduous central incisors, approximately two thirds of the crowns of the left and right mandibular permanent central incisors have erupted. Both of them incline to the lingual direction and rotate and there is a space of about 5 mm between them. This case is still under observation.