Comparison of the change in inferior sclera exposure after maxillary protraction with or without skeletal anchorage

The aim of this retrospective study was to evaluate the change in inferior sclera exposition after maxillary protraction with or without skeletal anchorage in patients with maxillary retrognathia.

Fifteen patients (Group 1) who applied maxillary protraction with teeth-supported appliance and fifteen patients who applied maxillary protraction with skeletal anchorage (Group 2) were compared in order to investigate the effect of different maxillary protraction methods on the visibility of sclera. The patients in both groups had dental and skeletal Class III malocclusion with maxillary retrusion (ANB <0; SNA <80), increased vertical growth pattern (SnGoGn> 32) (long face), increased sclera exposure, and no congenital anomalies and dentofacial deformities. Pre- and posttreatment records were used to assess the amount of visible sclera on facial photographs using Adobe Photoshop CS6 program and the change in the movement of maxilla on cephalometric film. The pretreatment and after maxillary protraction values were compared statistically by the Wilcoxon signed-rank test (level of significance, P < 0.05).

The amount of inferior sclera exposure to eye height decreased in the right and left eyes of the 30 patients with maxillary protraction. The amount of inferior sclera exposure to eye height of the right and left eyes decreased from 3.59 to 3.5 and from 3.44 to 3.39, respectively, in Group I (P = 0.001 and P < 0.001, respectively). The amount of inferior sclera exposure to eye height of the right and left eyes decreased from 4.17 to 3.93 and from 3.86 to 3.68, respectively, in Group II (P = 0.001 and P < 0.001, respectively).

There were important results in both of the two methods. Although more improvement was obtained in the skeletal anchorage group, statistically no significant differences were found between the groups.