Evaluation of the facial morphology of cleft lip and palate patients treated with nasoalveolar molding using three-dimensional photogrammetry in the mixed and early permanent dentition periods

Objective: This study aimed to evaluate the facial morphology of individuals with cleft lip and palate (CLP) treated with nasoalveolar molding (NAM) using three-dimensional facial morphology analysis (3D) and lateral cephalometric radiographs, and to compare individuals with different cleft types to Class I skeletal malocclusion individuals without clefts. Methods: A total of 82 individuals aged 7–14 years who had not yet started orthodontic treatment were included. All 42 individuals in the cleft group had undergone NAM therapy in infancy and were divided by cleft type into three groups: 21 with unilateral complete cleft lip and palate (UCLP), 11 with bilateral complete cleft lip and palate (BCLP), and 10 with unilateral cleft lip and alveolus (UCLA). Before treatment, 3D facial images and lateral cephalometric radiographs were obtained from all individuals. Skeletal, dental, and soft tissue features were compared across groups using linear, angular, proportional, surface area, and volumetric measurements. In the UCLP and UCLA groups, symmetry assessments were also performed by comparing the cleft and non-cleft sides. Additionally, corresponding measurements assessed in both 3D and cephalometric methods were compared. Results: Nasal and subalar widths were significantly higher in the UCLP and BCLP groups compared to the Class I group (p<0.05). Lower lip length was greater in the BCLP group (p<0.05). Upper lip projection was found to be lower in the UCLP group compared to other groups, and lower lip projection was also lower than in the Class I group (p<0.05). No significant differences were observed in nasal and paranasal volumes. Facial height and upper lip length were also similar across groups. In symmetry evaluations of unilateral cleft groups, Ac–Sn, Cph–Sn, Ac–Coronal Plane distances and the Bc–N'–Sn angle were significantly higher on the cleft side, while Ch–Ac distance was significantly lower, indicating asymmetry (p<0.05). In contrast, Ac–Prn, Bc–Coronal Plane, and Ck–Coronal Plane distances and the Sn–Prn/Ac–Prn ratio showed a symmetric pattern between cleft and non-cleft sides. Among corresponding measurements assessed in both 3D and cephalometric analyses, N'–Me' and N'–Sn distances, Li–Sl–Pg'° and N'–Prn–Pg'° angles, and N'–Sn/N'–Me' ratio were similar between methods. In contrast, Sn–Me' distance, Sn–Me'/N'–Me' ratio, and N'–Sn–Pg'° angle were significantly higher in cephalometric analysis compared to 3D analysis (p<0.05), while Sn–Sto and Sto–Me' distances and the C–Sn–Ls° angle were significantly higher in 3D analysis (p<0.05). Conclusion: Distinct morphological differences were observed between groups. Although NAM therapy may have contributed to achieving similar results to Class I individuals in terms of facial height, lip width, vermilion height, upper lip length, nasal tip projection, labiomental angle, vermilion area, nasal volume, and midface volume, this effect was not consistently reflected in other facial regions. Notably, the nasal region, philtrum, upper and lower lip projections, and chin area showed marked morphological differences across groups. Significant intergroup differences were also observed in nasal and facial angles.