Corrective Outcomes after Bimaxillary Orthognathic Surgery for Developmental Facial Asymmetry (Changes of Head Posture & Upper Face)

Postural Change After Bimaxillary Orthognathic Surgery

For Developmental Facial Asymmetry

( Changes Of Head Posture & Upper Face)

Purpose

Most people have minor to moderate facial asymmetry which has no aesthetic or functional significance. But it may be associated with temporomandibular joint problems, and it could be one of the etiologic factor of developmental facial asymmetry. Patients tend to compensate their asymmetry by head tilting. TMJ problems and postural camouflage gradually change patient's posture and appearance such as exaggerated impression of orbital dystopia. The purpose of this study is to investigate posture and appearance changes following improvement of facial asymmetry after bimaxillary orthognathic surgery. We hypothesis that surgical correction of lower face asymmetry can correct upper face appearance and posture.

Figure 1. 19-year old female with developmental facial asymmetry.

Methods

10 patients with severe facial asymmetry were selected which is idiopathic in past 10 years. All of them underwent LeFort I osteotomy combined with bilateral sagittal split osteotomy of the mandible for facial asymmetry.

We took two 1:1 anteroposterior photos, one in standardized position and one in resting (camouflaged) position. We measured the area of eye opening with Image J program, degree of eye and head tilting using following reference lines (Figure 2.) in resting photo preoperatively and postoperatively.  

Figure 2. Preoperative and postoperative assessment with 1:1 AP photo

Results

 After bimaxillary orthognathic surgery, eye canting improved (decreased 2.6 to 1.5 degree on average) and eye and lip lines came closer to parallel than before surgery. Degree of head tilting becomes more vertical (decreased 3.4 to 1.3 degree on average). In addition, discrepancy in both eye opening area tends to decrease after surgery.

Conclusion

Facial asymmetry patients tend to camouflage their asymmetry by postural change and most of them have masked TMJ problems. These factors gradually change patient's overall impression. Severe asymmetry patients usually undergo bimaxillary orthognathic surgery to correct lower bony asymmetry and TMJ problems. In this study we noticed that it corrects not only lower facial asymmetry but also patient's posture and upper face appearance. Tilted head posture tends to go more vertical and orbital canting go more horizontal. Furthermore, eye blearing was improved.