Abstract
We clinically investigated 40 teeth in 31 patients (mean age 7 years 6 months) requiring tooth extraction and performed cone beam computed tomography (CBCT) to obtain a definitive diagnosis over a 5-month period from October 2013 through March 2014 at our specialized pediatric dental clinics. The results indicated that maxillary anterior supernumerary teeth are more common in males,with a male to female ratio of 7 : 2, while the direction of eruption was normal for 17 and inverted for 23 teeth. In addition, 22 patients had 1 and 9 had 2 impacted supernumerary teeth. Based on the distance from the inferior margin of the bottom of the nasal cavity to the alveolar crest in panoramic radiographs, we evaluated the position of impacted supernumerary teeth by classifying vertical depth (type I−III), which showed that 5, 26, and 9 teeth were type I, II, and III, respectively. The 3-dimensional positional depth of the impacted supernumerary teeth was also investigated by classifying their position as 1, 2, or 3 from the palatine bone to the alveolar bone in sagittal CBCT images. Those results indicated that 8, 23, and 9 teeth were in position 1, 2, and 3, respectively.Together, our results demonstrated that the positions of supernumerary teeth shown by CBCT coincided with those shown by panoramic radiography in 92.5% of the examined cases. Prior to extraction of a maxillary anterior supernumerary tooth, depth classification based on panoramic radiography findings exhibited a statistically significant correlation even when converted to a three-dimensional positional relationship, suggesting their use as diagnostic criteria for indication of extraction.
