2018 Volume 43 Issue 1 Pages 20-25
It is known that there is a higher incidence of supernumerary teeth in cases with cleft lip and/or palate than others. However, the relation between the appearance of supernumerary teeth, and the cleft type, cleft side and the direction of tooth eruption is still unclear. Thus, we performed a clinicostatistical study by examining cleft lip and/or palate cases at Meikai University Hospital.
One hundred and three non-syndromic cleft lip and/or palate cases were used in this study. There were 48 males and 55 females （aged 4 to 29 years old at first visit）. In this study, cases in whom it was difficult to determine late remaining deciduous teeth and supernumerary teeth were excluded. X-rays （panoramic radiograph, dental X-ray, occlusal X-ray and cone beam X-ray）, dental casts, facial and oral pictures, and treatment records were examined. Four unilateral cleft lip, 21 unilateral cleft lip and alveolus, 40 unilateral cleft lip, alveolus and palate, 4 bilateral cleft lip and alveolus, 9 bilateral cleft lip, alveolus and palate, 19 cleft hard and soft palate, and 6 cleft soft palate cases were used. The following points were examined: 1） ratio of cases with supernumerary teeth, 2） ratio of supernumerary teeth for each cleft type, 3） ratio of maxillary supernumerary teeth in cleft and non-cleft sides, 4） position of supernumerary teeth, 5） relationship between the position of the cleft and supernumerary tooth, 6） direction of supernumerary tooth eruption.
Cases with more than one supernumerary tooth accounted for 19 out of the 103 cases （18.4%, male 20.8% and female 16.4%）. The ratio was the highest among cases with unilateral cleft lip （75.0%）, followed in order by unilateral cleft lip and alveolus, unilateral cleft lip, alveolus and palate, bilateral cleft lip, alveolus and palate, and cleft hard and soft palate （42.9%, 12.5%, 11.1%, and 5.3%, respectively）. Supernumerary teeth were most frequently seen adjacent to the maxillary lateral incisors （82.5%）. In unilateral cleft cases, 93.8% were seen in the cleft sides, suggesting a close relation between the supernumerary tooth and cleft lip and/or alveolus. The normal direction of supernumerary tooth eruption was seen in 88.9%. All these findings indicate that the appearance of supernumerary teeth has a close relationship with cleft formation.
