口腔病理科 On-Line KMU Student Bulletin
原文題目(出處)： A Method of Gauging Dental Radiographs during Treatment Planning for Dental Implants The journal of contemporary dental practice 2007 September ;
(8)6:082~088
原文作者姓名： Sukumaran Anil & Hamdan S.Al-Ghamdi 通訊作者學校： College of Dentistry at King Saud University in
Riyadh.Kingdom of Saudi Arabia.
報告者姓名(組別)： Intern E 組 張凱蓉
報告日期： 2007/10/9
內文：
<< Introduction >>
z Radiography examination is indispensable for comprehensive diagnosis and treatment planning of dental implant therapy.
9 Morphology & anatomical structure
9 Dimension, number & orientation of implant z The goal of radiographic examination :
9 Appropriate radiographic equipment Æ more information about jawbones.
9 Minimal p’t radiation & cost.
z 63.8% of dentists prescribed only panoramic & periapical radiographic for implant assessment.
Æ provide preliminary evidence of the general data in M-D & vertical dimension.
Æ inherent distortion : amount of alveolar bone in horizontal plane.
z Computer assisted analysis system : high level of accuracy & reliability
9 Convert the pixel size of the images to a linear scale based on the distortion factor computed from the known dimension of R-O object.
9 No cost & no special equipment is needed.
9 Conjunction with cross sectional CT Æ locate anatomical landmarks
<< Methods & Materials >>
z Image Analysis Software :
Research services branch of national institutes of health of the United States.
9 Macintosh computer Æ NIH image 9 Windows Æ Scion image
Function :
1. contrast enhancement 2. density profiling
3. smoothing & sharpening 4. edge detection
5. spatial convolution
6. measure area, mean, centroid, length and angle z Digitizing & calibrating conventional radiographs
Calibrate by using a radiopaque reference device of known dimension.
9 Extracted tooth or root, dummy implant, spherical metal ball( most recommended to avoid the distortion )
- 1 -
口腔病理科 On-Line KMU Student Bulletin
Using a custom fabricated stent to hold it in place.
Care should be taken to :
1. Place the guide close to the implant site 2. Perpendicular to the long axis of X-ray beam
Placing more than one guide near the area of interest is advised.
The amount of distortion for this guide will be used as the standard to measure the linear and area measurement in the pano and periapical radiographs.
Applied to conventional tomographic images Æ anatomical landmarks & bone quantity in B-L dimension.
<< Discussion >>
z The rapid adoption of these sophisticated techniques into routine practice might lead to a significant increase in the radiation burden on patients without a proper
risk-benefit analysis.
z European Association of Osseointegration :
The use of cross-sectional imaging based on clearly identifiable needs & clinical requirements.
z To date, there’s a lack of consensus regarding guidelines for pre-implant radiographic planning.
z Intraoral and panoramic radiography Æ Low radiation dose Computerized tomography Æ High radiation exposure
<< Summary >>
- 2 -
口腔病理科 On-Line KMU Student Bulletin
- 3 -
z The technique described here is useful to obtaining important information without additional cost or exposure to radiation.
Æ inferior alveolar canal Æ floor of maxillary sinus
Æ space between adjacent tooth roots Æ height & width of alveolar crest
題號 題目
1 關於mental foramen在X光片判讀之敘述，下列何者錯誤?
(A) Mental foramen約位於齒槽脊到下顎骨下緣的中間
(B) Mental foramen約位於第二小臼齒的根尖處
(C) 常會被誤認為第二小臼齒的根尖的根尖病變
(D) Mental foramen周圍都是緻密的齒槽骨，故X光片上可看出完整
的外型
答案(D) 出處：Oral Radiology Principles and Interpretation (fifth edition) P138.
題號 題目
2 有關環口攝影術鬼影(ghost image)的敘述下列何者正確?
(A) 物體位於X光光源與旋轉中心之間
(B) 所造成的影像之比例通常近似原物體
(C) 成像位置較真實影像低
(D) 此種影像無法投射於X光片上
答案(A) 出處：Oral Radiology Principles and Interpretation (fifth edition) P２０ ７~２０８
