Association between Facial Profile and Dentoskeletal Changes in High-Angle Skeletal Class II Patients before and after Orthodontic Treatment: A Retrospective Cephalometric Study

Abstract

<p>BACKGROUND: High-angle skeletal class II patients pose a challenge to orthodontists due to the potential of resulting in an unsatisfactory facial profile. No previous study has examined the association between facial profile changes and dentoskeletal changes for high-angle skeletal class II orthodontic patients.</p><p>AIM: To investigate the relationship between changes in the facial profile and dentoskeletal structures in high-angle skeletal Class II patients before and after fixed-appliance orthodontic treatment.</p><p>MATERIALS/METHODS: This retrospective study analysed twenty-one Southern Chinese patients, aged 19.8 ± 3.1 years, with skeletal Class II (ANB>5°) and high mandibular plane angle (SN-MP>38.5°). All patients had completed fixed appliance orthodontic treatment at the Orthodontic Department of the University of Hong Kong. Lateral cephalograms of the patients taken before and after fixed appliance treatment were retrieved and analysed. Facial profile and dentoskeletal changes were assessed using linear, angular, and proportional parameters. Pearson correlation coefficients were calculated to study the relationship between different pairs of facial profile changes and dentoskeletal changes.</p><p>RESULTS: Strong correlations were found between changes in the soft tissue facial angle and changes in skeletal facial angle and skeletal Y-axis (r>0.8, p<0.001). Changes in the soft tissue facial convexity was significantly correlated with changes in the sagittal positions of the skeletal supramentale, gnathion, and menton (r>0.7, p<0.001). Significant correlations were found between changes in the nasolabial angle and changes in sagittal position (r=-0.75, p<0.001) and inclination (r=-0.52, p<0.05) of the upper incisal edge. However, there were no significant correlations between the changes in sagittal positions of the skeletal subspinale and</p><p>pogonion and changes in the soft tissue convexity and facial angle (r<0.4, p>0.05). A moderate but significant correlation was detected for changes in vertical facial proportions between soft and hard tissues (r=0.57, p<0.01).</p><p>CONCLUSIONS: Changes in facial angle, facial convexity, facial proportion and nasolabial angle were significantly correlated with dentoskeletal changes for high-angle skeletal Class II patients who underwent fixed-appliance orthodontic treatment. However, no significant correlations were detected between soft tissue facial profile changes and hard tissue changes in the sagittal position of the subspinale and pogonion.</p>