著者

Kiyomi Kohinata Kunihito Matsumoto Toshihiro Suzuki Mari Tsunoda Yusuke Hayashi Masao Araki Koji Hashimoto Kazuya Honda

出版者

日本大学歯学部

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.58, no.1, pp.29-34, 2016 (Released:2016-03-26)

参考文献数

22

被引用文献数

5 1

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As part of our ongoing investigation of risk and predictive factors associated with temporomandibular disorders, we used magnetic resonance imaging (MRI) to identify risk factors for sideways disk displacement of the temporomandibular joint in 26 patients with MRI-confirmed unilateral pure sideways disk displacement (medial or lateral disk displacement) and normal positioning of the contralateral temporomandibular joint. Coronal morphologic harmonization between the condyle and fossa, angle between the axis of the ramus and condyle, and angle between the lateral pterygoid muscle (LPM) and condyle were evaluated. Only angle of the LPM related to the condyle was significantly correlated with mediolateral disk position; the angles of joints with medial, normal, and lateral disk positions were 70.2°, 66.7°, and 60.1°, respectively. These results suggest that a greater angle of the inferior head of the LPM to the axis of the condyle on axial MRI images may cause medial disk displacement, while a smaller angle may result in lateral disk displacement. (J Oral Sci 58, 29-34, 2016)

著者

Masao Araki Shunsuke Namaki Toshihiko Amemiya Kunihito Matsumoto Kazuya Honda Yoshiyuki Yonehara Naoyuki Matsumoto Masatake Asano

出版者

日本大学歯学部

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.58, no.4, pp.533-537, 2016 (Released:2016-12-23)

参考文献数

32

被引用文献数

3

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The occurrence of ameloblastic fibro-odontoma (AFO) in the oral region is unusual and accounts for 1-3% of all odontogenic tumors. AFO presents mixed radiopaque patterns within the lesion with diverse findings; therefore, it is important to compare this tumor with other odontogenic tumors that radiographically present with calcified bodies. Herein, we observed the calcification patterns within the lesion in seven AFO cases (five males, two females; mean age, 8.3 years; age range, 4-13 years). Periapical and panoramic radiographs were obtained from all seven cases. Five cases underwent conventional computed tomography (CT) scanning, and one underwent cone beam CT. Classification of the calcifications primarily involved the following two characteristics on the X-rays: appearance and location of the lesions. All seven cases were located in the molar regions of the mandible in association with impacted teeth. The calcification patterns of these AFOs were mixed or inhomogeneous within the lesion with various findings, including complex odontoma-like calcifications. However, the patterns differed between panoramic radiography and CT in some cases. The radiolucent lesions in AFO demonstrated varying calcification patterns and were associated with impacted teeth on the CT images.(J Oral Sci 58, 533-537, 2016)

著者

Masao Araki Takeshi Kiyosaki Mai Sato Kiyomi Kohinata Kunihito Matsumoto Kazuya Honda

出版者

日本大学歯学部

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.57, no.4, pp.373-378, 2015 (Released:2015-12-13)

参考文献数

43

被引用文献数

5

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We measured the gonial angle (GA) on panoramic radiography (PR) and analyzed the correlation between the GA on PR and lateral cephalometric radiography (LCR). In total, 49 PR films and LCR films from dentate young adults were evaluated. Orthodontists plotted four points (articulare, menton, posterior gonion, and lower gonion) on the PR and carefully traced them. Using a protractor, two radiologists measured the GA on LCR images. A simultaneous experimental study of two dry skulls was performed to compare the GA on LCR and PR. The GA was slightly smaller on the PR of the dry mandible than on the LCR and tended to decrease continuously with magnitude toward the Frankfort horizontal plane. The mean GA was 115.1 ± 5.2° on PR and 122.2 ± 6.4° on the LCR. The values were highly correlated (Pearson product-moment correlation coefficient, 0.801). The GA on PR was nonsignificantly smaller than that measured on LCR. The difference may be due to head position, the inclination angle of the mandibular body, and/or the direction of the incident X-ray beam. (J Oral Sci 57, 373-378, 2015)