Material properties of the dentate maxilla

Abstract

The aim of this study was to determine regional variability of material properties in the dentate maxilla. Cortical samples were removed from 15 sites of 15 adult dentate fresh-frozen maxillas. Cortical thickness, density, elastic properties, and the direction of greatest stiffness were obtained. Results showed that cortical bone in the alveolar region tended to be thicker, less dense, and less stiff. Cortical bone from the body of the maxilla was thinner, denser, and stiffer. Palatal cortical bone was intermediate in some features but overall was more similar to cortical bone from the alveolar region. The principal axes of stiffness varied regionally. The regions with the greatest consistency were the alveolar area and the frontomaxillary pillar, where the grain of the cortical bone was aligned vertically from the incisors to the medial external aspect of the orbit. Elastic properties in the human maxilla, especially the orientation of the principal axes of stiffness, were more variable than in the mandible. Incorporation of these properties into finite-element models should improve their accuracy and reliability. Anat Rec Part A, 288A:962-972, 2006. Key words: ultrasonic; cortical bone; biomechanics; function; finite-element modelingIn comparison to the mandible, understanding the biomechanics of the maxilla presents greater difficulties. The complexity of the maxilla results from the large number of sutures between the maxilla and bones contiguous with it and the sinuses that occupy almost the entire internal region of the body of the maxilla. The bone's unique gross morphology and shape allow for a variety of functions, including deglutition, respiration, and sensation (smell and sight), as well as serving as anchorage for a small portion of the masseter muscle. Due to this complexity, adaptation of the maxilla to function is not well understood.The maxilla is comprised of several distinct anatomical regions, including the palate, nasal floor, alveolus, and body. Crossing these regions are structures or pillars that are interpreted as supports for biting and mastication including the zygomaticomaxillary pillar, the temporozygomatic pillar, and frontomaxillary pillar (Sicher and DuBrul, 1970).Little is known experimentally about variability of the mechanical characteristics of the human dentate maxilla. In the monkey maxilla, patterns of bone strain suggest that significant loads are borne locally during mastication and biting and that bone sutures and adjacent cavities buffer occlusal forces (Saijo and Sugimuro, 1993). As occlusal forces are dispersed at different tooth positions, maxillary surfaces bend outward away from the sinuses. Presumably, mechanical stimuli caused by mastication and biting are important in the maintenance of cortical bone structure in the maxilla and result in variations of function depending on location relative to different elements of the dentition and muscle attachments.

Stability comparison between commercially available mini-implants and a novel design: Part 1

“…The bone block was composed of two layers: 2-mm-thick 20 30 pounds per cubic foot (PCF) cortical bone simulation 11 and 10 pcf trabecular bone (Table 2). A 1-mm-thick plastic sheet was used to simulate soft-tissue thickness.…”

Three-Dimensional Finite Element Analysis of Maxillary Sinus Floor Augmentation with Optimal Positioning of a Bone Graft Block

“…Peterson et al analyzed the physical behavior of bone tissue in the maxilla [22] by measuring and comparing different areas of the maxilla. Based on Peterson's data, a 3D constitutive law describing the macroscopic mechanical behavior of cortical and trabecular bone was defined [23].…”

Maxillary and Mandibular Dentoalveolar Heights of French-Canadians 10 to 15 Years of Age

“…16 The increased variability observed suggests that the maxillary dentoalveolar region has greater adaptive capacity than the mandibular dentoalveolar region, perhaps due to differences in the amounts of eruption that occur or to differences in bone quality. 17 The utility of reference data depends largely on how precise and representative they are. Because our sample sizes were usually two or three times larger than existing reference data, 7,8 the estimates might be expected to be more precise.…”