Individualized three-dimensional finite element model of facial soft tissue and preliminary application in orthodontics.
- VernacularTitle:面部软组织三维有限元模型的个性化转换及临床应用初探
- Author:
Si CHEN
1
;
Tian-min XU
;
Hang-di LOU
;
Qi-guo RONG
Author Information
- Publication Type:Journal Article
- MeSH: Adult; Cephalometry; Computer Simulation; Cone-Beam Computed Tomography; Face; anatomy & histology; pathology; Facial Muscles; anatomy & histology; pathology; Female; Finite Element Analysis; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; methods; Jaw; anatomy & histology; pathology; Male; Malocclusion; pathology; Models, Anatomic; Orthodontics; methods; Skin; anatomy & histology; pathology; Tooth; anatomy & histology; pathology; Young Adult
- From: Chinese Journal of Stomatology 2012;47(12):730-734
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo get individualized facial three-dimensional finite element (FE) model from transformation of a generic one to assist orthodontic analysis and prediction of treatment-related morphological change of facial soft tissue.
METHODSA generic three-dimensional FE model of craniofacial soft and hard tissue was constructed based on a volunteer's spiral CT data. Seven pairs of main peri-oral muscles were constructed based on a combination of CT image and anatomical method. Individualized model could be obtained through transformation of the generic model based on selection of corresponding anatomical landmarks and radial basis functions (RBF) method. Validation was analyzed through superimposition of the transformed model and cone-beam CT (CBCT) reconstruction data. Pre- and post-treatment CBCT data of two patients were collected, which were superimposed to gain the amount of anterior teeth retraction and anterior alveolar surface remodeling that could be used as boundary condition. Different values of Poisson ratio ν and Young's modulus E were tested during simulation.
RESULTSAverage deviation was 0.47 mm and 0.75 mm in the soft and hard tissue respectively. It could be decreased to a range of +0.29 mm and -0.21 mm after a second transformation at the lip-mouth region. The best correspondence between simulation and post-treatment result was found with elastic properties of soft tissues defined as follows. Poisson ratio ν for skin, muscle and fat being set as 0.45 while Young's modulus being set as 90.0 kPa, 6.2 kPa and 2.0 kPa respectively.
CONCLUSIONSIndividualized three-dimensional facial FE model could be obtained through mathematical model transformation. With boundary condition defined according to treatment plan such FE model could be used to analyze the effect of orthodontic treatment on facial soft tissue.