**5.1 Prevalence**

Studies have examined the need for orthognathic surgery in UCLP patients who underwent primary lip-palate repair procedures in childhood [3, 8, 36, 37]. Ross [37] stated that the midface is close to normal only in 25% of patients, and there is a need for orthognathic surgery in the remaining patients, with interventions at early stages worsening the situation. In other similar studies, the rate of orthognathic surgery needed in repaired UCLP patients was 48–59.3% [3, 8].

### **5.2 Orthodontic approach**

In adolescent or adult UCLP patients with maxillary hypoplasia and deficient bone grafts, there are two maxillary segments separated by the cleft. Each segment has varying degrees of dysplasia on the sagittal, vertical, and horizontal directions.
