Finite element analysis of bone stress after SARPE.
OBJECTIVE
This study investigated stress distribution in maxillas that underwent surgically assisted palatal expansion (SARPE).


METHODS
Five maxillary models were built: no osteotomy (M1), Le Fort I osteotomy with a step in the zygomaticomaxillary buttress (M2), Le Fort I osteotomy with a step in the zygomaticomaxillary buttress and the pterygomaxillary disjunction (M3), Le Fort I osteotomy without a step (M4), and Le Fort I osteotomy with pterygomaxillary disjunction and no step (M5). Displacement coherence and maximum stress (MS) analyses were used for all models.


RESULTS
Areas of tension spread to the maxilla and the region between the alveolar ridge and the palate and a critical point in the median suture for M2, M3, M4, and M5. In M2 and M4, MS spread farther toward and over the pterygoid process, contrary to what was found in M3 and M5. M3 had a better performance than the other models, and the tensile stress was interrupted by the posterior osteotomy, thus avoiding possible damage to the sphenoid bone or difficulties in expanding the posterior region of the maxilla.


CONCLUSIONS
The steps in the zygomaticomaxillary buttress and the pterygomaxillary disjunction seem to be important to decrease the harmful dissipation of tensions during SARPE.
Maranhao Federal University, Sao Luis, Brazil.
Diogo Souza Ferreira Rubim
DS
de Assis
Three-Dimensional Technologies Division, Renato Archer Technology Information Center, Campinas, Brazil.
Tathy Aparecida
TA
Xavier
Mechanical Engineer, Three-Dimensional Technologies Division, Renato Archer Technology Information Center, Campinas, Brazil.
Pedro Yoshito
PY
Noritomi
Department of Oral and Maxillofacial Surgery, Bauru Dentistry School, Sao Paulo University, Bauru, Brazil. Electronic address: eduardogoncales@usp.br.
Eduardo Sanches
ES
Gonçales
D000539:Alveolar Process / Q000503:physiopathology; D001641:Bicuspid / Q000503:physiopathology; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D003393:Cranial Sutures / Q000503:physiopathology; D020342:Finite Element Analysis; D006801:Humans; D007180:Incisor / Q000503:physiopathology; D008437:Maxilla / Q000503:physiopathology / Q000601:surgery*; D008953:Models, Anatomic; D008954:Models, Biological; D008963:Molar / Q000503:physiopathology; D019340:Osteotomy, Le Fort / Q000379:methods*; D010155:Palatal Expansion Technique; D010159:Palate / Q000503:physiopathology; D013100:Sphenoid Bone / Q000503:physiopathology / Q000601:surgery; D013314:Stress, Mechanical; D015050:Zygoma / Q000503:physiopathology / Q000601:surgery