Three-dimensional soft tissue prediction using finite elements. Part II: Clinical application.
OBJECTIVE
The goal of this study was to analyze the validity and prediction accuracy of a newly-developed procedure for three-dimensional soft tissue prediction based on Finite Element Method, and to compare the results with prediction produced using an existing two-dimensional prediction program (Dentofacial Planner Plus).


METHODS
In twelve patients who underwent combined surgical-orthodontic treatment, profile prediction was generated using both procedures preoperatively and then compared at predefined measurement points with the patient's actual postoperative soft tissue status.


RESULTS
The deviations observed depended on the facial region, whereby the prediction errors for both procedures were much greater in the lower facial third than in the midfacial third. Calculating in all the measurement points, the mean horizontal prediction error was 0.32 mm for the Finite Element Method and 0.75 mm for the Dentofacial Planner Plus. Overall, we were able to demonstrate the new procedure's superior validity and quality of visualization. In addition to profile prediction, the procedure allows a differentiated three-dimensional assessment of esthetically important regions such as the cheeks, nasolabial folds and the nasal wings. Additional X-radiation is not necessary in this risk-free and stress-free procedure.


CONCLUSIONS
Three-dimensional soft tissue prediction employing finite element modeling is a useful aid for implementing esthetically-optimized treatment planning.
Holberg
Christof
C
Department of Orthodontics, University of Munich, Germany. christof.holberg@med.uni-muenchen.de
Heine
Anne-Kathrin
AK
Geis
Philipp
P
Schwenzer
Katja
K
Rudzki-Janson
Ingrid
I
D000328:Adult; D003198:Computer Simulation; D003238:Connective Tissue / Q000033:anatomy & histology* / Q000502:physiology*; D017266:Dental Prosthesis; D005145:Face / Q000033:anatomy & histology* / Q000502:physiology*; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D053685:Laser Therapy; D007834:Lasers; D008297:Male; D008953:Models, Anatomic; D008954:Models, Biological; D009970:Orthodontics / Q000379:methods*; D011379:Prognosis; D019919:Prosthesis Implantation / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013813:Therapy, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome