Development of 3D statistical mandible models for cephalometric measurements.
OBJECTIVE
The aim of this study was to provide sex-matched three-dimensional (3D) statistical shape models of the mandible, which would provide cephalometric parameters for 3D treatment planning and cephalometric measurements in orthognathic surgery.


METHODS
The subjects used to create the 3D shape models of the mandible included 23 males and 23 females. The mandibles were segmented semi-automatically from 3D facial CT images. Each individual mandible shape was reconstructed as a 3D surface model, which was parameterized to establish correspondence between different individual surfaces. The principal component analysis (PCA) applied to all mandible shapes produced a mean model and characteristic models of variation. The cephalometric parameters were measured directly from the mean models to evaluate the 3D shape models. The means of the measured parameters were compared with those from other conventional studies. The male and female 3D statistical mean models were developed from 23 individual mandibles, respectively.


RESULTS
The male and female characteristic shapes of variation produced by PCA showed a large variability included in the individual mandibles. The cephalometric measurements from the developed models were very close to those from some conventional studies.


CONCLUSIONS
We described the construction of 3D mandibular shape models and presented the application of the 3D mandibular template in cephalometric measurements. Optimal reference models determined from variations produced by PCA could be used for craniofacial patients with various types of skeletal shape.
Department of Oral and Maxillofacial Radiology, School of Dentistry, Seoul National University, Seoul, Korea.
Sung-Goo
SG
Kim
Won-Jin
WJ
Yi
Soon-Jung
SJ
Hwang
Soon-Chul
SC
Choi
Sam-Sun
SS
Lee
Min-Suk
MS
Heo
Kyung-Hoe
KH
Huh
Tae-Il
TI
Kim
Helen
H
Hong
Ji Hyun
JH
Yoo