Use of spherical coordinates to evaluate three-dimensional facial changes after orthognathic surgery.
OBJECTIVE
This study aimed to assess the three-dimensional (3D) facial changes after orthognathic surgery by evaluating the spherical coordinates of facial lines using 3D computed tomography (CT).


METHODS
A 19-year-old girl was diagnosed with class III malocclusion and facial asymmetry. Orthognathic surgery was performed after orthodontic treatment. Facial CT scans were taken before and after orthognathic surgery. The patient had a menton deviation of 12.72 mm before surgery and 0.83 mm after surgery. The spherical coordinates of four bilateral facial lines (ramal height, ramal lateral, ramal posterior and mandibular body) were estimated from CT scans before and after surgery on the deviated and opposite side.


RESULTS
The spherical coordinates of all facial lines changed after orthognathic surgery. Moreover, the bilateral differences of all facial lines changed after surgery, and no bilateral differences were zero.


CONCLUSIONS
The spherical coordinate system was useful to compare differences between the presurgical and postsurgical changes to facial lines.
Department of Oral and Maxillofacial Radiology, School of Dentistry, Chonnam National University, Gwangju, Korea.
Suk-Ja
SJ
Yoon
Department of Biologic and Material Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
Rui-Feng
RF
Wang
Department of Oral and Maxillofacial Surgery, School of Dentistry, Chonnam National University, Gwangju, Korea.
Sun-Youl
SY
Ryu
Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.
Hyeon-Shik
HS
Hwang
Department of Oral and Maxillofacial Radiology, School of Dentistry, Chonnam National University, Gwangju, Korea.
Byung-Cheol
BC
Kang
Department of Oral and Maxillofacial Radiology, School of Dentistry, Chonnam National University, Gwangju, Korea.
Jae-Seo
JS
Lee
Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, OH, USA.
Juan M
JM
Palomo
Facial Asymmetry; Orthognathic Surgery; Tomography, X-Ray Computed