Abstract
To understand the actual conditions of the use of orthodontic anchor screws （OASs） in patients with cleft lip and/or palate （CLP） at the Department of Orthodontics and Speech Therapy for Craniofacial Anomalies in Tohoku University Hospital, we conducted a clinico-statistical survey of the use of OASs in CLP patients treated with edgewise appliances during the seven-year period from April 2014 to March 2021, and compared the results with the conditions in non-cleft （non-CLP） patients.
1. The numbers of CLP patients and non-CLP patients surveyed were 62 （1：1 male-to-female ratio） and 53 （1：2.5 male-to-female ratio）, respectively.
2. The distribution of cleft types of CLP patients was as follows: cleft lip: 6.5％, cleft lip and alveolus: 27.4％, cleft lip and palate: 43.5％, cleft palate: 22.6％. Types of malocclusion of CLP patients included crossbite, crowding and maxillary protrusion in order of number. Types of malocclusion of non-CLP patients included maxillary protrusion, crossbite, and congenitally missing teeth in order of number.
3. The mean ages of placement were 17.1 years in CLP patients and 19.2 years in non-CLP patients. CLP patients were significantly younger than non-CLP patients.
4. The maxillary buccal posterior region was the most common site of placement: 51.7％ in CLP patients and 40.6％ in non-CLP patients. The mandibular buccal posterior region was the next most common.
5. The total number of OASs used in CLP patients was 176, of which 143 OASs were successful and 33 OASs failed, resulting in an overall success rate of 81.3％. The total number of OASs used in non-CLP patients was 155, of which 124 OASs were successful and 31 OASs failed, resulting in an overall success rate of 80.0％. There was no significant difference in the success rate between CLP patients and non-CLP patients.
6. There was no significant difference in the success rates among placement sites, age, gender, diameter of OAS, or length of OAS in both CLP patients and non-CLP patients. There was no significant difference in these success rates between CLP patients and non-CLP patients either.
