J Korean Assoc Oral Maxillofac Surg.  2012 Oct;38(5):271-275. 10.5125/jkaoms.2012.38.5.271.

Three-dimensional finite element analysis of the stress distribution and displacement in different fixation methods of bilateral sagittal split ramus osteotomy

• Yun KI
• Cho YG
• Lee JM
• Park YH
• Park MK
• Park JU

• KMID: 1434327
• DOI: http://doi.org/10.5125/jkaoms.2012.38.5.271

Abstract

OBJECTIVES
This study evaluated a range of fixation methods to determine which is best for the postoperative stabilization of a mandibular osteotomy using three-dimensional finite element analysis of the stress distribution on the plate, screw and surrounding bone and displacement of the lower incisors.
MATERIALS AND METHODS
The model was generated using the synthetic skull scan data, and the surface model was changed to a solid model using software. Bilateral sagittal split ramus osteotomy was performed using the program, and 8 different types of fixation methods were evaluated. A vertical load of 10 N was applied to the occlusal surface of the first molar.
RESULTS
In the case of bicortical screws, von-Mises stress on the screws and screw hole and deflection of the lower central incisor were minimal in type 2 (inverted L pattern with 3 bicortical repositioning screws). In the case of plates, von-Mises stress was minimal in type 8 (fixation 5 mm above the inferior border of the mandible with 1 metal plate and 4 monocortical screws), and deflection of the lower central incisor was minimal in types 6 (fixation 5 mm below the superior border of the mandible with 1 metal plate and 4 monocortical screws) and 7 (fixation 12 mm below the superior border of the mandible with 1 metal plate and 4 monocortical screws).
CONCLUSION
Types 2 and 6 fixation methods provide better stability than the others.

Keyword

3D finite element analysis; Fixation techniques; Sagittal split ramus osteotomy

MeSH Terms

Displacement (Psychology)
Finite Element Analysis
Incisor
Mandible
Mandibular Osteotomy
Osteotomy, Sagittal Split Ramus
Skull

Figure

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  Fig. 1 Finite element model. A. Type 1. B. Type 2. C. Type 3. D. Type 4. E. Type 5. F. Type 6. G. Type 7. H. Type 8.

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  Fig. 2 Boundary conditions of the finite element model of the mandible. (A: fixed, B: force, C: force)

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