Three-Dimensional Outcome Assessments of Cleft Lip and Palate Patients Undergoing Maxillary Advancement

Background: The aim of this retrospective case series study was to compare three- dimensional postsurgical outcomes of patients with cleft lip and palate following maxillary advancement. Methods: Fifty consecutive cleft lip and palate patients who underwent wholepieced Le Fort I advancements were assigned to the major (advancement = 5 mm) or minor (advancement < 5 mm) groups. Three- dimensional surgical simulation was used for presurgical evaluation and planning. Virtual triangles of the presurgical, simulated, and 6- month postoperative stages were used for comparison. Translational and angular changes of each endpoint (A- point, MxR, and MxL) on the virtual triangles and reference planes were recorded and analyzed. Relationships between possible related variables and outcome discrepancies from simulations among all subgroups were also investigated. Results: Analysis of covariance and the least significant difference test revealed that the outcome discrepancy measurements were affected by different combinations of independent variables. The reliability test showed high consistency of the authors' method for three- dimensional measurements. Conclusions: The actual surgical outcomes of cleft lip and palate patients differed from the virtual simulations. The outcome discrepancies are impacted by multiple factors. The outcome discrepancies of all rotational surgical corrections (roll, yaw, and pitch) were positively correlated to the degree of planned surgical movement. Meanwhile, bilateral cleft lip and palate patients are more likely to incur outcome discrepancies in yaw correction with major maxillary advancement. However, a maxillary advancement cutoff value of 5 mm would not necessarily lead to significant translational outcome discrepancies among cleft lip and palate patients.