The objective of this study to analyze stress distribution in craniofacial structures of zygomatic osseointegrated implants.An integrated system for DICOM data was utilized to create a three-dimensional model of craniofacial structures. The stress analysis was merely comparative, allowing us to relate the amount and distribution of the main stresses.The stress analysis was performed using the three-dimensional finite elemental analysis method. The system allowed visual confirmation and analysis of stress distribution as well as the convenient and simple construction of a digital biomechanical model that provided details of anatomical structures in regions of interest. To compare zygomatic implants with or without connected implants supporting the superstructure. Stresses in severely resorbed maxillae with connected implants were not concentrated around the alveolar bone supporting zygomatic implants. Stresses without connected implants tended to be generated in the zygomatic bone, at the middle part of zygomatic implant and at the joint of the fixture-abutment.Stress due to occlusal forces is mainly supported by the zygomatic bone, is transferred predominantly through the infrazygomatic crest and is divided into the frontal and temporal process of the zygomatic bone in various directions.

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The purpose of this study was to analyze changes in the internal structure of zygomatic bone using a micro-finite element analysis model (muFEA) and compare angular orientation of trabeculae against compressive force in edentulous and dentulous jaws. Twenty zygomatic bones from dentulous jaws and 20 zygomatic bones from edentulous jaws harvested from Japanese male cadavers were used. From 2-dimensional slice images, we reconstructed 3-dimensional (3D) structure by the volume rendering method using micro-computed tomography (micro-CT). To analyze mechanical properties, all voxels were converted to muFEA models. The angle between the strongest direction of trabecular bone and the axial loading direction (angle alpha) was then determined using the muFEA models. In the 3-D reconstruction images, trabecular density in dentulous jaws was higher than that in edentulous jaws at all loci. Trabeculae in dentulous jaws showed a plate-like structure. The muFEA modeling revealed that the angle of the trabeculae at the Jugale in edentulous jaws was lower than that in dentulous jaws. This suggests that the internal structure of trabeculae is influenced by occlusal force in zygomatic bone from edentulous jaws.

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