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Single-tooth extraction site bone loss ---- functional disuse or overuse?

单牙拔除部位骨质流失----功能废用还是过度使用？

基本信息

批准号：
8032444
负责人：
Zongyang Sun
金额：
$ 11.44万
依托单位：
OHIO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-02-18 至 2013-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8032444
关键词：
Affect Alveolar Alveolar ridge Anatomy Animal Model Biological Bite Force Bone Resorption Bone remodeling Cell Proliferation Clinical Contralateral Data Dental Implants Dentistry Disease Disuse Atrophy Edentulous Mouth Environment Etiology Family suidae Goals Grant Growth Harvest Homeostasis Human Implantation procedure Inflammation Jaw Mandible Mastication Measurement Measures Mechanics Methods Mixed Dentition Modeling Molecular Oral cavity Pathogenesis Phase Prevention Prevention strategy Relative (related person)Research Research Personnel Residual state Resistance Reverse Transcriptase Polymerase Chain Reaction Role Sampling Side Signal Transduction Site Staining method Stains Stimulus Structure TNFSF11 gene Techniques Testing Time Tissues Tooth Extraction Tooth Loss Tooth root structure Tooth structure Trauma Western Blotting alveolar bone base bone bone cell bone lead bone loss bone metabolism design in vivo medical specialties osteoclastogenesis permanent tooth prevent public health relevance restoration theories

项目摘要

DESCRIPTION (provided by applicant): The alveolar ridge at an extraction site is characterized by progressive bone loss, a common and serious clinical problem termed residual ridge resorption (RRR). The pathogenesis of RRR is not clear, but disuse (lack of functional stimulation) has been widely considered a cause. The in vivo mechanical environment of the extraction site, however, has never been characterized. While it is likely true that multiple extractions reduce masticatory stimulation to the bone, this may not be the case for a single-tooth extraction. Masticatory loading, as reflected by bone strain at a single-tooth extraction site, may be increased rather than decreased because 1) occlusal force is not necessarily reduced with a single extraction, and 2) the structural resistance of alveolar bone to occlusal force is compromised due to trauma and the loss of tooth root support. Using a pig model, we propose to measure and compare masticatory strain at the buccal alveolar bone of an extraction site and a contralateral non-extraction (control) site immediately (baseline control) and 6 weeks (experimental) after the extraction (Aim 1). These studies will provide the first direct recordings of functional mechanics surrounding a single-tooth extraction site. Further, we will investigate the post-extraction change of the alveolar bone as compared to the control side and correlated with mechanical strains (Aim 2). Alveolar bone structure and remodeling will be examined using histomorphometric methods. Cellular features including proliferation and osteoclastogenesis will be examined by immunohistochemical methods. Expression of bone remodeling (OPG, RANKL and RANK) and differentiation (Runx2) regulators will be examined using real-time RT-PCR and Western blot techniques. Overall, we hypothesize that alveolar bone at a single-extraction site will be overstrained during mastication due to its compromised structural resistance to loading, which will stimulate alveolar bone remodeling and lead to bone loss (RRR). This study features a direct characterization of the mechanical environment at a single-tooth extraction site and clarifies the relationship between functional mechanics and RRR. The findings of this study will contribute in directing the course of future research on the pathogenesis and prevention of this severe clinical entity affecting millions. Public Health Relevance: Tooth loss, a clinical entity affecting millions, leaves a residual alveolar ridge undergoing progressive bone resorption. Restoring an absorbed edentulous ridge is challenging and costly. The proposed research will characterize functional (masticatory) mechanics, a critical factor for bone metabolism, at a single-tooth extraction site alveolar ridge and examine its relationship with bone change. The results will guide researchers and clinicians in seeking effective preventive strategies for this disease.

描述（由申请人提供）：拔牙部位的牙槽嵴以进行性骨质流失为特征，这是一种常见且严重的临床问题，称为残余牙槽嵴吸收（RRR）。RRR的发病机制尚不清楚，但不使用（缺乏功能刺激）已被广泛认为是一个原因。然而，提取部位的体内机械环境从未被描述过。虽然多次拔牙可能会减少对骨骼的咀嚼刺激，但单颗拔牙可能不是这样。单牙拔牙部位的骨应变所反映的咀嚼负荷可能会增加而不是减少，因为1)单牙拔牙不一定会降低咬合力，2)牙槽骨对咬合力的结构阻力由于创伤和牙根支持的丧失而受到损害。使用猪模型，我们建议在拔牙后立即（基线对照）和6周（实验）测量和比较拔牙部位和对侧非拔牙（对照）部位的颊牙槽骨咀嚼应变（Aim 1）。这些研究将提供围绕单个拔牙部位的功能力学的第一个直接记录。此外，我们将研究拔牙后牙槽骨与对照组相比的变化及其与机械应变的关系（目的2）。用组织形态学方法检查牙槽骨结构和重塑。细胞特征包括增殖和破骨细胞发生将通过免疫组织化学方法检查。使用实时RT-PCR和Western blot技术检测骨重塑（OPG， RANKL和RANK）和分化（Runx2）调控因子的表达。总的来说，我们假设在咀嚼过程中，单一拔牙部位的牙槽骨由于其结构抵抗负荷的能力受损而过度紧张，这将刺激牙槽骨重塑并导致骨质流失（RRR）。本研究对单个拔牙部位的力学环境进行了直接表征，阐明了功能力学与RRR之间的关系。这项研究的结果将有助于指导未来研究这一影响数百万人的严重临床实体的发病机制和预防过程。