Morphological examination of impacted tooth in maxillary lateral incisor region using computed tomography for consideration of treatment modalities

A 10Y2M-old girl was referred to our clinic by a general practitioner for consultation regarding an impacted supernumerary tooth identified in the maxillary left incisor region. Our intraoral examination revealed a maxillary left lateral incisor with a tubercle morphology, with slight swelling identified in the labial gingival area between the lateral incisor and primary canine. The dental age of the patient was calculated to be 1 year behind her chronological age based on root formation observed in orthopantomographs. X-ray photographic examinations revealed an impacted tooth on the labial side, with the root apex presumably directed into the palatal side. Computed tomography (CT) was used to produce three-dimensional reconstruction images in order to obtain morphological information for the impacted tooth, which had a tuberculate shape and an appearance that differed from that of the tooth on the opposite side, which showed a typical morphology of a lateral incisor. Periodical examinations were performed thereafter, which confirmed the developmental progress of the root formation of the impacted tooth. At 11Y8M, the tooth had emerged into the oral cavity and was extracted under local anesthesia. Based on this case, we concluded that effective use of CT is beneficial for consideration of treatment modalities in patients with an impacted tooth.