以牙根尖片攝影測量齒槽骨之骨質密度及骨厚度

Measurement of the alveolar bone mineral density and thickness by periodical radiographs

許筑翔(Chu-hsiang Hsu)

指導教授 ： 張振榮

中臺科技大學/健康科學院/放射科學研究所/碩士(2010年)

摘要

齒槽骨骨質密度(bone mineral density, BMD)與齒槽骨厚度在植牙手術中扮演著重要的角色，良好的骨質密度可以加速植體(implant)植入齒槽骨後之骨整合(osseo-integration)，而選擇較大的植體可讓植體植入後更加穩定，卻會對於較薄之齒槽骨造成骨骼崩解。目前臨床上用於檢測骨質密度的方法有雙光子能量X光吸收儀(dual X-ray absorptiometry, DXA)與定量式超音波骨質密度儀(quantitative ultrasound, QUS)；另一方面齒槽骨厚度則利用牙科電腦斷層(dental computed tomography)或是錐形射束電腦斷層(cone beam computed tomography, CBCT)來進行測量，然而上述儀器成本皆較高，量式超音波骨質密度儀雖較便宜但其敏感度(sensitivity)只有71%，特異度(specificity)只有73%。本實驗提出一種新型的骨質密度參考階層(reference level)，該參考階層具有五層銅(copper)階層，其相對骨質密度(relative BMD)為0.31-1.41 g/cm2，符合人體骨質密度之範圍，並具有體積小及成本低的優勢，且檢測敏感度達95%以上。齒槽骨厚度的測量則利用一種輔助攝影夾具，實驗之結果與中段齒槽骨之誤差<0.5mm，可快速且準確的測量齒槽骨厚度。

關鍵字

植牙 ； 齒槽骨骨質密度 ； 齒槽骨厚度 ； 根尖片攝影

並列摘要

Alveolar bone mineral density (BMD) and Alveolar bone thickness play a unique and critical role in dental implant. Investigators have demonstrated that high BMD may accelerate the osseointegration, but low BMD may reduce the success of implant surgery. A large implant increases the stability of the implants, but also increases the risk of alveolar collapse. Quantitative ultrasound (QUS) and dual X-ray absorptiometry (DXA) are widely used in BMD measurement. Dental computed tomography (dental CT) and cone-beam computed tomography (CBCT) are used to measure the thickness of alveolar bone. However, the cost of DXA, dental CT and CBCT system are too expensive for clinics to afford. And the sensitivity and specificity of QUS were 71% and 73%. Therefore, a BMD reference level was developed for alveolar BMD measuring, the relative BMD of reference level is in the range of human body (0.31-1.41g/cm2), and the sensitivity was over 95%; an economic and convenient diagnostic x-ray machine and image analysis system are utilized to measure the thickness of the alveolar bone, the error was less than 0.5 mm. Thus, proposed methods can be widely used to replace the instruments that clinical used.

並列關鍵字

Periodontal radiography ； Implant ； Alveolar bone mineral density ； Alveolar bone thickness

參考文獻

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