Effect of Minor Amendments of Patient's Position on the Accuracy of Linear Measurements Yielded from Cone Beam Computed Tomography.

STATEMENT OF PROBLEM: Image distortion in intra and extra-oral radiographs are an unavoidable phenomenon. Patient's positional changes from the routine alignments is an important issue for this unwanted alteration, Therefore the accuracy of the dimensional measurements will be affected. PURPOSE: Our purpose is to find out the effect of minor changes (possibly happening in the clinic) in the position of a human dry skull on the accuracy of the measurements acquired by Cone Beam Computed Tomography (CBCT). MATERIALS AND METHOD: In this study, 3 locations on the skull were pointed with radio- opaque markers. Imaging process with Kodak 9000 CBCT was performed in standard and 10 analytically miss- oriented positions. Then 2 distances were measured between the centers of markers. Later, these measurements were compared with the standard position values. RESULTS: There was not any imperative difference in the measurements of the 10 altered positions yielded in this study with standard position values. CONCLUSION: According to our results, apparently, the accuracy of linear measurements in CBCT images is endorsed by unintentional small changes in the patient's position during the projections.

Accuracy of computerized automatic identification of cephalometric landmarks by a designed software.

OBJECTIVES: The purpose of this study was to design software for localization of cephalometric landmarks and to evaluate its accuracy in finding landmarks. METHODS: 40 digital cephalometric radiographs were randomly selected. 16 landmarks which were important in most cephalometric analyses were chosen to be identified. Three expert orthodontists manually identified landmarks twice. The mean of two measurements of each landmark was defined as the baseline landmark. The computer was then able to compare the automatic system's estimate of a landmark with the baseline landmark. The software was designed using Delphi and Matlab programming languages. The techniques were template matching, edge enhancement and some accessory techniques. RESULTS: The total mean error between manually identified and automatically identified landmarks was 2.59 mm. 12.5% of landmarks had mean errors less than 1 mm. 43.75% of landmarks had mean errors less than 2 mm. The mean errors of all landmarks except the anterior nasal spine were less than 4 mm. CONCLUSIONS: This software had significant accuracy for localization of cephalometric landmarks and could be used in future applications. It seems that the accuracy obtained with the software which was developed in this study is better than previous automated systems that have used model-based and knowledge-based approaches.

Follicular ameloblastoma presenting as a sinonasal tumor.

A case of follicular ameloblastoma of the left maxilla in a 74-year-old man is reported. The tumor was presented as a radiographically solid mass filling the left sinonasal cavity and invaded maxillary alveola. After radical surgery, the patient has pursued a non-aggressive clinical course after 4 years of follow-up. The radiopathological features of this tumor were reviewed and the possibility of its sinonasal epithelium origin was discussed.

Tuberculosis case--finding and treatment in the central prison of Qazvin province, Islamic Republic of Iran.

As a part of a comprehensive programme of tuberculosis (TB) control in the central prison in Qazvin, Islamic Republic of Iran, a programme of active case-finding was carried out from February 2004 to July 2005. From the 768 prisoners examined, 41 (5.3%) were suspected of TB and gave sputum samples. A total of 7 smear-positive TB cases were found, giving a TB prevalence in the prison of 910 per 100,000, 113 times the total TB prevalence in Qazvin province in the same year. From 7 diagnosed and treated patients, 4 were cured with the category 1 standard regimen, 1 completed treatment and 2 failed to complete treatment. Improvements are needed in TB case recognition of prisoners, especially newcomers.

Tuberculosis case-finding and treatment in the central prison of Qazvin province, Islamic Republic of Iran

As a part of a comprehensive programme of tuberculosis [TB] control in the central prison in Qazvin, Islamic Republic of Iran, a programme of active case-finding was carried out from February 2004 to July 2005. From the 768 prisoners examined, 41 [5.3%] were suspected of TB and gave sputum samples. A total of 7 smear-positive TB cases were found, giving a TB prevalence in the prison of 910 per 100 000, 113 times the total TB prevalence in Qazvin province in the same year. From 7 diagnosed and treated patients, 4 were cured with the category 1 standard regimen, 1 completed treatment and 2 failed to complete treatment. Improvements are needed in TB case recognition of prisoners, especially newcomers