Biomedical subjects

Min-Suk Heo

Publications and source records attributed to Min-Suk Heo.

10 recordsLinked to original sources

PubMed2006

Relationship between two-dimensional and three-dimensional bone architecture in predicting the mechanical strength of the pig mandible.

OBJECTIVES: To investigate the relationship between two-dimensional (2D) and three-dimensional (3D) bone imaging parameters. STUDY DESIGN: Bone specimens were obtained from the mandibles of five male pigs weighing around 110 kg each. A total of 111 samples were measured two-dimensionally with using solid state digital intraoral radiography. Of these 111 samples, 43 were selected for 3D analysis and measured by microcomputed tomography. Through destructive mechanical testing, strength parameters were obtained. RESULTS: Correlations between the 2D and 3D parameters were rare; however, both 2D and 3D parameters separately showed significant correlations with strength. Multiple linear regression analyses using both 2D and 3D parameters together showed greater predictability than those using only 2D or only 3D parameters. CONCLUSION: Architectural parameters in 2D and 3D independently affect trabecular strength; the combination of the two can be used to improve bone strength predictability.

Animals↗

PubMed2005

Quantitative analysis of errors in alveolar crest level caused by discrepant projection geometry in digital subtraction radiography: an in vivo study.

OBJECTIVE: This study compared the difference between 3 intraoral radiographic techniques on digital subtraction radiography (DSR) in vivo that are commonly used in a clinical setting. STUDY DESIGN: We evaluated and statistically analyzed the errors in the DSR image in 6 regions with 3 radiographic techniques: paralleling technique with a bite block attached to XCP, paralleling technique using XCP, and bisecting-angle technique. RESULTS: The amount of error using the bisecting-angle technique was too large for DSR, compared to that of the paralleling technique with a bite block attached to XCP. In the mandibular anterior region, the paralleling technique using XCP was not different from paralleling technique with a bite block attached to XCP. The lowest degree of error was present in the anterior region whereas the highest was present in the molar region. CONCLUSION: Bisecting-angle technique should be avoided, and paralleling technique using XCP can be used in the mandibular anterior region for DSR.

Adult↗

PubMed2005

ROI-based image registration for digital subtraction radiography.

OBJECTIVE: We evaluated the influence of surrounding anatomical structures on the registration accuracy of a diagnostically important region, by varying the ROI (region of interest) window used in an automatic ROI-based digital subtraction method. STUDY DESIGN: Pairs of radiographs were taken at 2 molar regions using paralleling techniques of XCP devices (Rinn Co., Elgin, Ill) attached with and without a bite block. The global and local registration accuracies were measured by the RMS (root mean square) of subtraction images for various ROIs. RESULTS: No significant differences were found in global registration accuracies among various ROI sizes in all the paralleling techniques. The local registration accuracies decreased with extension of the ROI size. CONCLUSION: Registration using an ROI restricted to the anatomical region of diagnostic interest provides higher accuracy than using a larger ROI.

Algorithms↗

PubMed2005

Automatic noise robust registration of radiographs for subtraction using strategic local correlation: an application to radiographs of dental implants.

Most of digital subtraction methods in dental radiography are based on registration using manual landmarks. We have developed an automatic registration method without using the manual selection of landmarks. By restricting a geometrical matching of images to a region of interest (ROI), we compare the cross-correlation coefficient only between the ROIs. The affine or perspective transform parameters satisfying maximum of cross-correlation between the local regions are searched iteratively by a fast searching strategy. The parameters are searched on the 14 scale image coarsely and then, the fine registration is performed on the original scale image. The developed method can match the images corrupted by Gaussian noise with the same accuracy for the images without any transform simulation. The registration accuracy of the perspective method shows a 17% improvement over the manual method. The application of the developed method to radiographs of dental implants provides an automatic noise robust registration with high accuracy in almost real time.

Dental Implants↗

PubMed2004

Benign fibrous histiocytoma in the mandible.

PURPOSE: Benign fibrous histiocytoma (BFH) is a very rare benign tumor occurring in the jaw. The purpose of this article is to describe the clinical, radiographic, and microscopic appearance of BFH occurring in the mandible. STUDY DESIGN: A 42-year-old man had an asymptomatic swelling of the left mandibular posterior area. RESULTS: Conventional radiographs revealed a well-defined multilocular radiolucency involving the left mandibular body, ramus, coronoid process, and condylar head. The lesion showed the thinning and expansion of the cortex. There were many thin, indistinct septa in the lesion. The computed tomography (CT) scans showed bone destruction with marginal sclerosis and a heterogeneous soft-tissue mass expanding the mandible. Microscopic examination revealed a cellular tumor composed of uniform spindle-shaped cells arranged in a storiform pattern. CONCLUSIONS: BFH is a very rare benign tumor occurring in the jaw, so more cases should be reported to understand the characteristics of the lesion.

Adult↗

PubMed2004

Development and evaluation of digital subtraction radiography computer program.

OBJECTIVE: We developed a new program for digital subtraction radiography (DSR) having useful functions to get the DSR image more accurately and efficiently. The purpose of this study was to evaluate the accuracy of the DSR image acquired using the new program as compared with the ready-made program. STUDY DESIGN: Four observers performed the DSR process using our program and the ready-made program for digital intraoral radiographs taken from incisor, premolar, and molar regions. The statistical difference was evaluated between the programs, between the observers, and between the regions. RESULTS: The DSR image using our program was superior to that with the ready-made program in all the observers and all the radiographed regions. Also, there was the statistical difference among the observers, especially in our program. CONCLUSION: The DSR image using the new program was very accurate compared with ready-made program, so the program was useful to get an accurate DSR image.

Humans↗

PubMed2003

Use of advanced imaging modalities for the differential diagnosis of pathoses mimicking temporomandibular disorders.

The medical records of 3 patients who visited our hospital with preauricular pain and limited jaw movement were retrospectively reviewed. All were clinically evaluated, diagnosed through the use of conventional radiographs, and initially treated as having temporomandibular disorders (TMD). However, their symptoms did not improve and even increased or facial swelling occurred, so advanced imaging modalities were used to make a differential diagnosis. The final diagnoses of the patients were cellulitis, an inflammatory pseudotumor, and pigmented villonodular synovitis. In addition to these 3 patients, 50 others who were initially misdiagnosed during a clinical examination as having TMD on conventional radiographs were reviewed in the English-language literature. When diagnosing patients with TMD symptoms, we must consider the possibility of unusual causes, including tumors and infections or inflammations. Furthermore, in addition to usual TMD treatment procedures, an advanced radiologic examination should be performed to aid in the differential diagnosis of all patients with unceasing pain and mouth-opening limitation.

Adult↗

PubMed2003

Effects of botulinum toxin type A on bilateral masseteric hypertrophy evaluated with computed tomographic measurement.

BACKGROUND: A paucity of reports exist on the use of botulinum toxin type A injections as an alternative noninvasive treatment for masseteric hypertrophy. OBJECTIVE: To evaluate the effects of botulinum toxin type A on masseteric hypertrophy using computed tomography. METHODS: Percutaneous intramuscular injections of botulinum toxin type A of 30 U per side was carried out in 11 subjects with masseteric hypertrophy. The changes in the masseteric muscle volume before and 12 weeks after injection were evaluated using computed tomography. The changes in the lower facial contours on the photographs were evaluated as excellent, good, fair, and no changes. RESULTS: Nine of the 11 subjects showed a mean reduction of approximately 22% in the masseteric muscle volume. The maximum reduction was 35.4% (range, 8.1% to 35.4%). Nine subjects showed aesthetically good results with a grade of good or excellent at 12 weeks after treatment. CONCLUSION: Botulinum toxin injections are a noninvasive alternative method for treating masseteric hypertrophy.

Adult↗

PubMed2003

Three new cases of salivary duct carcinoma in the palate: a radiologic investigation and review of the literature.

Salivary duct carcinoma (SDC) is a rare, extremely aggressive malignancy arising in the ductal epithelium of the salivary glands. Radiologic investigations of and reports on minor salivary gland SDC are very rare. We present 3 cases of SDC of the palate with the attendant radiologic features and clinicopathologic findings. We also review English-language reports with radiologic findings regarding SDC and minor salivary gland SDC. MR imaging findings such as low signal intensity on T2-weighted images, infiltrative margins, and poor enhancement, in particular, should be recognized as indicators of high-grade malignancy such as SDC and, as such, should be considered when making a differential diagnosis.

Adult↗

PubMed2002

Fractal analysis of mandibular bony healing after orthognathic surgery.

OBJECTIVES: We evaluated the radiographic changes to the operational sites after orthognathic surgery by using fractal analysis. STUDY DESIGN: Panoramic radiographs from 35 patients who underwent orthognathic surgery on the mandible without any complications during the osseous healing process were selected. The radiographs taken before the operation (stage 0) and 1 or 2 days (stage 1), 1 month (stage 2), 6 months (stage 3), and 12 months (stage 4) after the operation were digitized at 600 dpi with 256 gray levels. The fractal dimension was calculated by means of a tile-counting method in the region of interest centered on the operational site and was statistically analyzed according to its stages. RESULTS: The fractal dimension was decreased immediately after the operation and increased gradually according to the time lapse (P <.05). The fractal dimension in the region of interest 12 months postoperatively was similar to that preoperatively. CONCLUSION: This result suggests that fractal dimension can be used to evaluate the bony healing process after orthognathic surgery.

Adult↗