Assessment of changes in selected parameters of Arnett’s soft tissue cephalometric analysis (STCA) in patients with maxillary constriction treated with the method of surgically assisted maxillary expansion using a bone-borne appliance

Background: Maxillary constriction is a common issue encountered in adult patients seeking orthodontic or surgical treatment and often requires surgical intervention. While the skeletal and dental outcomes of surgically assisted maxillary expansion have been widely studied, its effects on facial soft tissue remain less understood. This study aimed to assess changes in selected parameters of Arnett’s soft tissue cephalometric analysis in patients treated with bone-borne surgically assisted maxillary expansion. Methods: This retrospective study included 42 adult patients (24 males, 18 females; mean age: 27.67 years) diagnosed with transverse maxillary deficiency. All patients underwent surgically assisted maxillary expansion using a bone-borne distractor. Lateral cephalograms were obtained before treatment and 6–8 months after active distraction. Sixteen soft tissue cephalometric parameters and angular measurements (SNA, SNB, ANB) were evaluated. Cephalometric analysis was independently performed by two trained observers, each conducting duplicate measurements. Statistical analysis included the Wilcoxon signed-rank test for paired comparisons and Spearman’s rank correlation coefficient for assessing associations. Results: Significant clockwise rotation of both the maxillary and mandibular occlusal planes was observed. Vertical changes included an increase in maxillary anterior height and upper lip length. Sagittal soft tissue changes included reduced nasal tip projection and posterior displacement of the chin. Among airway parameters, only the dimension at the chin level showed a significant increase. The SNB angle decreased, while the ANB angle increased significantly, indicating a backward mandibular rotation. No significant differences were observed in parameter changes between skeletal class II and III subgroups. Significant correlations were found between occlusal plane rotation and changes in maxillary height and soft tissue projection. Conclusions: Bone-borne surgically assisted maxillary expansion results in both skeletal and measurable soft tissue changes. Clockwise occlusal plane rotation is associated with increased facial height and posterior repositioning of the chin. These findings highlight the relevance of soft tissue cephalometric analysis in treatment planning and patient communication.