Abstract: Objective　 To assess the alveolar bone thickness and morphology and the prevalence of fenestration and dehiscence of maxillary anterior teeth in patients with the different types of cleft lip and palate(CLP) using cone-beam CT(CBCT). Methods　Fifty-one males and thirty-four females with CLP at an average age of 14.65, who visited the Affiliated Stomatological Hospital of Nanjing Medical University from August 2016 to October 2019, were selected. There were nineteen patients with unilateral incomplete cleft lip and alveolus (UCLA), fifty-two patients with unilateral complete cleft lip and palate (UCLP) and fourteen patients with bilateral complete cleft lip and palate (BCLP). CBCT was taken in maxillofacial region before orthodontic treatment. Image J software was used to measure the alveolar bone thickness (ABT) of the upper anterior teeth. The prevalence of fenestration and dehiscence was calculated. The differences of ABT and fenestration and dehiscence of the maxillary anterior maxilla among the patients with different types of CLP were compared. Results The prevalence of upper anterior teeth dehiscence in affected side of UCLP and UCLA (34.9%, 42.7%) was significantly higher than that of healthy side (10.7%, 11.1%), but there was no significant difference in the prevalence of fenestration. The prevalence of dehiscence in healthy upper central incisors (5.9%) and lateral incisors (9.4%) in UCLP was lower than that in UCLA. There was no significant difference in the prevalence of dehiscence and fenestration of upper central incisor, lateral incisor, canine among UCLA, UCLP and BCLP. The ABT of the affected side of UCLP and UCLA was smaller than that of the healthy side in multiple parts. In addition, except for the affected lateral incisors, the labial ABT of UCLA, UCLP and BCLP was lower than that of palatal side. The cervical ABT of upper incisors and canines on the affected side of UCLP was higher than that of UCLA. Conclusion　 The prevalence of dehiscence of the affected upper anterior teeth in patients with unilateral cleft lip and palate is higher than that of the healthy side, while labial ABT of upper anterior teeth is smaller than that of healthy side in many parts. The labial mean ABT of the three types of patients is smaller than that of the palatal side. There are significant differences in the prevalence of dehiscence in the healthy upper central incisors and lateral incisors, the cervical alveolar bone thickness of the affected lateral incisors and canines between unilateral complete cleft lip and palate and cleft lip and alveolus patients, while there is no difference in the incidence of fenestration, dehiscence and alveolar bone thickness between unilateral and bilateral complete cleft lip and palate.

Key words: cleft lip and palate, fenestration, Alveolar bone dehiscence, alveolar bone thickness