Association of cortical shape of the mandible on panoramic radiographs with mandibular trabecular bone structure in Japanese adults: a cone-beam CT-image analysis

Cone beam computed tomography analysis of mandibular inferior cortical thickness and bone texture in cemento-osseous dysplasia

OBJECTIVE

This study compared mandibular cortical thickness (CTh) and fractal dimension (FD) in patients with cemento-osseous dysplasia (COD) and controls, as measured with cone beam computed tomography.

STUDY DESIGN

In total, 28 female patients with COD and 28 age-matched controls were selected retrospectively. Inferior cross-sectional CTh was measured at the symphysis (sCTh), anterior (aCTh), mental foramen (mfCTh), molar (mCTh), and posterior (pCTh) regions. The alternate measurement of mean CTh of the volume including buccal, lingual, and inferior cortices between the mental foramina (alternate CTh) was measured in ImageJ. FD was calculated in cortical and trabecular bone. Data were analyzed for significance of differences in CTh and FD between patient groups and for correlation of inferior and alternate CTh measurements.

RESULTS

Inferior CTh values were lower overall in the patients with COD than in the controls (P = .01), specifically at sCTh, mCTh, and pCTh (P ≤ .042). Alternate CTh was also significantly lower in the COD group (P = .005). There was a significant correlation between inferior and alternate CTh measurements (r = 0.636, P < .001). No significant differences were observed in cortical or trabecular FD between groups (P ≥ .072).

CONCLUSIONS

Female patients with COD had significantly lower inferior and alternate CTh than healthy controls. Both groups had similar cortical and trabecular bone textures.

Use of fractal analysis in dental images: a systematic review

OBJECTIVES

This study reviewed the use of fractal analysis (FA) in dental images.

METHODS

A search was performed using PubMed, MEDLINE, LILACS, Web of Science and SCOPUS databases. The inclusion criteria were human studies in the English language, with no date restriction.

RESULTS

78 articles were found in which FA was applied to panoramic radiographs (34), periapical radiographs (21), bitewing radiographs (4), cephalometric radiograph (1), cone beam CT (15), micro-CT (3), sialography (2), and ultrasound (2). Low bone mineral density (21) and systemic or local diseases (22) around the bone of dental implants were the main subjects of the study of FA. Various sizes and sites of the regions of interest were used to evaluate the bone structure. Different ways were used to treat the image and to calculate FA. FA of 43 articles showed significant differences in the comparison of groups, mainly between healthy and sick patients.

CONCLUSIONS

FA in Dentistry has been widely applied to the study of images. Panoramic and periapical radiographs were those most frequently used. The Image J software and the box-counting method were extensively adopted in the studies reviewed herein. Further studies are encouraged to improve clarification of the parameters that directly influence FA.

Clinical guidelines for dental cone-beam computed tomography

Dental cone-beam computed tomography (CBCT) received regulatory approval in Japan in 2000 and has been widely used since being approved for coverage by the National Health Insurance system in 2012. This imaging technique allows dental practitioners to observe and diagnose lesions in the dental hard tissue in three dimensions (3D). When performing routine radiography, the examination must be justified, and optimal protection should be provided according to the ALARA (as low as reasonably achievable) principles laid down by the International Commission on Radiological Protection. Dental CBCT should be performed in such a way that the radiation exposure is minimized and the benefits to the patient are maximized. There is a growing demand for widespread access to cutting-edge health care through Japan's universal health insurance system. However, at the same time, people want our limited human, material, and financial resources to be used efficiently while providing safe health care at the least possible cost to society. Japan's aging population is expected to reach a peak in 2025, when most of the baby boomer generation will be aged 75 years or older. Comprehensive health care networks are needed to overcome these challenges. Against this background, we hope that this text will contribute to the nation's oral health by encouraging efficient use of dental CBCT.