Effect of Orthognathic Surgery on Movement of the Cheilion.

The cheilion (Ch), corner of the mouth, is the soft-tissue landmark where the upper and lower lips intersect. Orthognathic surgery can modify Ch position, which can affect facial esthetics. The aims were to evaluate Ch movements resulting from Le Fort I maxillary advancement with maxillary impaction or downgrafting, and with mandibular advancement or setback, and to investigate relationships between surgical movements and Ch movements. The 45 patients had undergone bilateral sagittal split ramus osteotomy with Le Fort I advancement surgery. They were divided into 4 groups according to surgical movement direction. Preoperative and postoperative photographs were calibrated. Standardized methods were used to identify and measure preoperative and postoperative Ch positions. Significant correlations were detected between extent of maxillary downgrafting and inferior movement of the Ch in group 1 ( r =0.988, P =0.001) and group 3 ( r =0.915, P =0.001). Also, significant correlations were detected between extent of mandibular advancement and anterior movement of the Ch in group 3 ( r =0.561, P =0.046) and group 4 ( r =0.661, P =0.005). The findings indicate that, in patients who undergo bilateral sagittal split ramus osteotomy/Le Fort I surgeries, mandibular advancement moves Ch anteriorly and maxillary downgrafting moves Ch inferiorly.

Comparison of scleral show alterations following Le Fort I osteotomy with either maxillary impaction or lengthening.

This study aimed at evaluating changes in scleral show following Le Fort I osteotomy with either impaction or lengthening of the mid face. Patients who underwent Le Fort I osteotomy were included. The patients were divided according to the direction of the movement: group 1 underwent maxillary advancement and impaction, while group 2 underwent maxillary advancement and lengthening. Standardized preoperative and 6-month postoperative photos were superimposed using Microsoft PowerPoint. The inferior visible scleral area was assessed with landmarks and measured separately using ImageJ software. Marked scleral surface area was determined using pixel count. A total of 36 consecutive patients were included. The mean maxillary advancement in the patients was 4.16 ± 2.14 mm. The mean impaction in group 1 (n= 21) was 1.06 ± 1.49 mm, while the mean vertical lengthening in group 2 (n = 15) was 1.54 ± 1.65 mm. The difference in improvement in the inferior scleral show between the groups was not statistically significant. Preoperative (180 ± 118.2 mm) and postoperative (147.75 ± 92.2 mm) scleral show significantly improved (p = 0.012) in both groups. Scleral show can be overlooked for movements under 6 mm while planning for maxillary orthognathic movement, as it improves regardless of the desired movement.