Alveolar bone reconstruction simulation is an effective means for quantifying orthodontics, but currently, it is not possible to directly obtain human alveolar bone material models for simulation. This study introduces a prediction method for the equivalent shear modulus of three-dimensional random porous materials, integrating the first-order Ogden hyperelastic model to construct a computed tomography (CT) based porous hyperelastic Ogden model (CT-PHO) for human alveolar bone. Model parameters are derived by combining results from micro-CT, nanoindentation experiments, and uniaxial compression tests. Compared to previous predictive models, the CT-PHO model shows a lower root mean square error (RMSE) under all bone density conditions. Simulation results using the CT-PHO model parameters in uniaxial compression experiments demonstrate more accurate prediction of the mechanical behavior of alveolar bone under compression. Further prediction and validation with different individual human alveolar bone samples yield accurate results, confirming the generality of the CT-PHO model. The study suggests that the CT-PHO model proposed in this paper can estimate the material properties of human alveolar bone and may eventually be used for bone reconstruction simulations to guide clinical treatment.
Humans ; Tomography, X-Ray Computed/methods* ; Porosity ; Alveolar Process/physiology* ; Bone Density ; Computer Simulation ; Elasticity ; X-Ray Microtomography ; Stress, Mechanical ; Finite Element Analysis ; Models, Biological

OBJECTIVES: This study explores the differences in fluid flow within alveolar cancellous bone at various sites under orthodontic forces and elucidates the relationship between fluid shear stress and bone remodeling. These fin-dings lay the groundwork for understanding the biomechanical mechanisms of orthodontic tooth movement. METHODS: Stress relaxation tests were performed on human alveolar bone samples to determine material parameters by using the Prony series. An inverse model of alveolar bone was then developed for numerical simulations of fluid-structure interactions to calculate fluid flow within cancellous bone. Meanwhile, a rat model of tooth movement was established to investigate variations in bone remodeling speeds across different regions. RESULTS: The microstructural distribution of cancellous alveolar bone was similar in humans and rats. The bone volume fraction and trabecular thickness gradually decreased from root cervical region to root apical region, while the trabecular space gradually increased. Under the influence of orthodontic forces, fluid shear stress within cancellous bone showed spatial variability across different levels, with the highest shear stress occurring at the root apical region, ranging from 0 to 0.936 6 Pa. Additionally, the rat model of tooth movement indicated that bone remodeling occurred more rapidly at the root apical region. CONCLUSIONS Fluid stimulation has a remarkable effect on al-veolar bone remodeling, causing changes in the structure of alveolar bone and ultimately regulating the speed of structu-ral remodeling.
Bone Remodeling ; Animals ; Tooth Movement Techniques ; Rats ; Alveolar Process/physiology* ; Stress, Mechanical ; Humans ; Biomechanical Phenomena ; Cancellous Bone/physiology* ; Shear Strength

PURPOSE: This study aimed to evaluate the effects of fibronectin and oxysterol immobilized on machined-surface dental implants for the enhancement of cell attachment and osteogenic differentiation, on peri-implant bone healing in the early healing phase using an experimental model in dogs. METHODS: Five types of dental implants were installed at a healed alveolar ridge in five dogs: a machined-surface implant (MI), apatite-coated MI (AMI), fibronectin-loaded AMI (FAMI), oxysterol-loaded AMI (OAMI), and sand-blasted, large-grit, acid-etched surface implant (SLAI). A randomly selected unilateral ridge was observed for 2 weeks, and the contralateral ridge for a 4-week period. Histologic and histometric analyses were performed for the bone-to-implant contact proportion (BIC) and bone density around the dental implant surface. RESULTS: Different bone healing patterns were observed according to the type of implant surface 2 weeks after installation; newly formed bone continuously lined the entire surfaces in specimens of the FAMI and SLAI groups, whereas bony trabecula from adjacent bone tissue appeared with minimal new bone lining onto the surface in the MI, AMI, and OAMI groups. Histometric results revealed a significant reduction in the BIC in MI, AMI, and OAMI compared to SLAI, but FAMI demonstrated a comparable BIC with SLAI. Although both the BIC and bone density increased from a 2- to 4-week healing period, bone density showed no significant difference among any of the experimental and control groups. CONCLUSIONS: A fibronectin-coated implant surface designed for cell adhesion could increase contact osteogenesis in the early bone healing phase, but an oxysterol-coated implant surface designed for osteoinductivity could not modify early bone healing around implants in normal bone physiology.
Alveolar Process ; Animals ; Bone and Bones ; Bone Density ; Cell Adhesion ; Dental Implants ; Dogs* ; Fibronectins ; Models, Theoretical ; Osteogenesis ; Physiology ; Surface Properties ; Titanium

Alveolar Process ; physiology ; Animals ; Biocompatible Materials ; therapeutic use ; Bone Matrix ; transplantation ; Bone Regeneration ; physiology ; Bone Transplantation ; methods ; Dental Implantation ; methods ; Esthetics, Dental ; Guided Tissue Regeneration, Periodontal ; methods ; Humans ; Prosthodontics ; methods ; Tooth Extraction ; methods

OBJECTIVETo study the remodeling of the anterior alveolar bone with parodontium under physiology loading using finite element method (FEM) and theory of bone remodeling.

METHODSA FEM model of the maxillary central incisor with parodontium was established, and the change of bone density during the remodeling of alveolar bone was investigated under physiology loading (60 - 150 N) based on the theory of bone remodeling about strain energy density (SED). The finite element analysis software Abaqus user material subroutine (UMAT) were used.

RESULTSWith the increase of physiology loading, the pressure stress on the buccal cervical margin increased gradually while the density was decreased gradually. The cortical bone was lower than its initial density 1.74 g/cm(3), which was 1.74 - 1.63 g/cm(3). The density of cancellous bone was 0.90 - 0.77 g/cm(3), which was lower than its intial density 0.90 g/cm(3). The lingual cervical margin was under tensile stress which also increased with loading, the density had no significant change. When the achieve to 120 N, the density of cortical bone was 1.74 - 1.73 g/cm(3). No significant change was found in the cancellous bone.

CONCLUSIONSThe simulation of the perodontium remodeling is achieved and proved to be effective by the relevant research based on the method of the study. And the result will be helpful to form the basis of analysis bone remodeling process and predict the results in the clinical work.

Alveolar Process ; physiology ; Bone Density ; Bone Remodeling ; physiology ; Computer Simulation ; Dental Stress Analysis ; methods ; Finite Element Analysis ; Humans ; Incisor ; physiology ; Maxilla ; physiology ; Periodontium ; physiology ; Stress, Mechanical

OBJECTIVETo evaluate the combination of surgical grade calcium sulfate hemihydrate (SGCS) and platelet-rich plasma (PRP) for alveolar ridge preservation prior to implant placement.

METHODSChanges of bone quantity and quality in extraction sites following the SGCS/PRP and SGCS implantations were investigated by spiral computer tomography scan, bone scintigraphy, radiographic, histological and histomorphometric examinations.

RESULTSThe placement of SGCS/PRP reduced the resorption of the alveolar ridge. It also promoted bone metabolism and bone-to-implant contact. The addition of PRP to SGCS achieved the enhancement of the bone metabolism only at the early healing phase.

CONCLUSIONSIn this animal experiment, SGCS/PRP may be used as fresh extraction sockets graft for alveolar ridge preservation prior to implant placement.

Alveolar Bone Loss ; prevention & control ; Alveolar Process ; pathology ; surgery ; Animals ; Bone Substitutes ; therapeutic use ; Calcium Sulfate ; therapeutic use ; Dental Implants ; Dogs ; Male ; Mandible ; pathology ; surgery ; Osseointegration ; physiology ; Osteogenesis ; physiology ; Platelet-Rich Plasma ; Radiopharmaceuticals ; Tomography, X-Ray Computed

OBJECTIVETo observe the movement of rat's tooth in the area of defective alveolar bone filled with bioglass in comparison with contralateral tooth.

METHODSForty female Wistar rats were selected. Defects in alveolar bones were created and filled with bioglass. Orthodontic appliances were fixed to mesially guide the maxillary first molars.

RESULTSThe rats' teeth were mesially moved in the area filled with bioglass. There were no significant differences between two sides in movement distance of the first molars and in thickness of periodontal tissues with paired t-test (P > 0.05).

CONCLUSIONSThe rat's tooth can be mesially moved in the area filled with bioglass.

Alveolar Process ; injuries ; surgery ; Animals ; Biocompatible Materials ; Female ; Glass ; Molar ; physiology ; Periodontal Ligament ; physiology ; Periodontal Prosthesis ; Rats ; Rats, Wistar ; Tooth Movement Techniques

The aim of this study was to evaluate the injectability, histocompatibility, function and other properties of the injectable bioactive bone repairing material of nano-hydroxyapatite and polyamide-66 (n-HA/PA66) composite. The XRD pattern, the relationship between the injectability and liquid-powder ratio, setting time and liquid-powder ratio, compressive strength and liquid-powder ratio were assessed. The size of the composite was determined to be 70 nm in length and 30 to 50 nm in width, and the molecular weight of polyamides-66 was 18000. The diameter of pores of the composite was about 200 to 400 micrometer. To evaluate the histocompatibility and function, 8 male dogs were studied with the injectable n-HA/PA66 composite implanted in the artificial defected alveolus of mandible on only one side to be compared with the intact alveolus on the other side. The specimens were taken at 4, 8, 12, 16 months after the implantation and the results were evaluated. The XRD pattern of the solidificated n-HA/PA66 composite was the same as the powdered n-HA/PA66 composite. The injectable n-HA/PA66 composite had a good injectability, 25 to 30 minutes setting time and about 37 MPa compressive strength when the liquid-powder ratio was 0.50. The healing of the gingiva was well at the implanted areas in all animals. The height of the repaired alveolar bone was obvious higher than that of the blank control. The earlier sign of ossification was histologically observed at 16 weeks after implantation. The injectable n-HA/PA66 composite has good biocompatibility and osteoconductive property. As an injectable material, with good maneuverability, it is useful for repairing irregular bone defects, especially in oral and maxillofacial surgery.
Alveolar Process ; drug effects ; physiology ; Animals ; Bone Regeneration ; drug effects ; physiology ; Bone Substitutes ; administration & dosage ; pharmacology ; Dogs ; Durapatite ; Injections ; Male ; Materials Testing ; Nylons ; Prosthesis Implantation ; methods ; X-Ray Diffraction

OBJECTIVETo investigate the effect of unilateral mastication on glenoid fossae by means of animal experiment.

METHODSAn animal model of unilateral mastication was established by extracting right mandibular molars of Wistar rats. The rats were sacrificed in different period to examine the location changes of glenoid fossae through sagittal and horizontal plane.

RESULTSThe anterior points of glenoid fossae in non-masticatory side of experimental groups were more anterior than those in masticatory sides. The anterior points of the glenoid fossae of non-masticatory sides in experimental groups were more anterior than those of the same sides in the control groups after inducing unilateral mastication for two and four months. After inducing unilateral mastication for two and four months, the anterior and the posterior points of the glenoid fossae of non-masticatory sides in experimental groups became closer to the midline by comparison with masticatory sides as well as the same sides in control groups. Locations of glenoid fossae in masticatory sides showed no changes in comparison with the same side of the control groups.

CONCLUSIONThe forward and inward remodeling of the glenoid fossae can be observed after unilateral mastication was induce to the non-masticatory sides of experimental rats. It is concluded that unilateral mastication might be one of the etiologic factor of temporomandibular joint disorders.

Alveolar Process ; growth & development ; pathology ; Animals ; Facial Asymmetry ; physiopathology ; Female ; Mandible ; growth & development ; pathology ; Mandibular Condyle ; growth & development ; pathology ; Mastication ; physiology ; Maxilla ; growth & development ; Maxillofacial Development ; physiology ; Rats ; Rats, Wistar ; Temporomandibular Joint ; growth & development ; pathology ; Temporomandibular Joint Disc ; physiopathology

OBJECTIVETo assess sensory function of inferior alveolar nerve in monkeys with mandibular distraction osteogenesis by use of trigeminal somatosensory evoked potential (TSEP).

METHODSeven young monkeys, 4 approximately 6 kg, were undergone a 13.5 mm bilateral or right-side mandibular lengthening with mandibular angle osteotomy and intraoral bone-born appliance. The inferior alveolar nerve function was assessed with TSEP before surgery, at the completion of distraction, and after four weeks of fixation.

RESULTSNo significant differences in latencies and amplitudes of TSEP between the left and right inferior alveolar nerves before surgery. At the completion of distraction, latencies of TSEP showed significant elongation (P < 0.01, P < 0.001) and amplitudes also significantly decreased (P < 0.001). After four weeks of fixation, various degrees of TSEP recovery were identified. The latencies and the amplitude were slightly improved.

CONCLUSIONSMandibular distraction osteogenesis affects sensory function of inferior alveolar nerves in studied monkeys evaluated with SEP, but recovery is observed four weeks after surgery.

Alveolar Process ; innervation ; Animals ; Evoked Potentials, Somatosensory ; Female ; Haplorhini ; Male ; Mandible ; surgery ; Osteogenesis, Distraction ; Trigeminal Nerve ; physiology