Harikrishnan Pandurangan, Magesh Varadaraju
Department of Orthodontics, Faculty of Dental Sciences, SGT University, Gurugram, Haryana 122505 India.
Teeth "N" Jaws Center, Lake Area, Nungambakkam, Chennai, Tamil Nadu 600034 India.
J Maxillofac Oral Surg. 2023 Apr 22;22(4):1-5. doi: 10.1007/s12663-023-01924-5.
Biting forces from the teeth are distributed to the facial bones and to the skull through the stress trajectories. The presence of a bony defect in either the maxilla or mandible might lead to variations in the stress distribution. The aim of this study was to evaluate the stress distribution and variations in stress trajectories from biting forces in a human skull with maxillofacial defect using a finite element (FE) model.
In this study, a cone beam computed tomography (CBCT) of an adult male patient with a maxillectomy defect consequent to surgical treatment of mucormycosis is evaluated for the stress distribution from the biting forces of the remaining posterior teeth. Finite element model without the mandible was constructed from the patient's CBCT data. Occlusal loading forces of 600 N were applied on each side of the maxillary teeth. Stress trajectories were visualised through the stress distribution pattern.
The results showed deviations in the normal stress distribution during occlusal loading and variations in zygomatic and pterygoid stress trajectories in the maxillofacial and skull regions in our FE model due to the bony defect.
We conclude that a skeletal maxillofacial defect should be reconstructed to resume proper stress distribution during functional forces to maintain a healthy craniofacial skeleton.
牙齿的咬合力通过应力轨迹传递至面部骨骼和颅骨。上颌骨或下颌骨中存在骨缺损可能会导致应力分布的变化。本研究的目的是使用有限元（FE）模型评估存在颌面缺损的人类颅骨中咬合力作用下的应力分布及应力轨迹变化。
在本研究中，对一名因毛霉菌病手术治疗导致上颌骨切除缺损的成年男性患者的锥形束计算机断层扫描（CBCT）进行评估，以分析剩余后牙咬合力产生的应力分布。根据患者的CBCT数据构建不含下颌骨的有限元模型。在上颌牙齿的每一侧施加600 N的咬合加载力。通过应力分布模式可视化应力轨迹。
结果显示，由于骨缺损，在我们的有限元模型中，咬合加载过程中正常应力分布出现偏差，颌面和颅骨区域的颧骨和翼状骨应力轨迹发生变化。
我们得出结论，应重建颌面部骨骼缺损，以在功能力作用期间恢复适当的应力分布，从而维持健康的颅面骨骼。
