記述言語：英語   掲載種別：研究論文（学術雑誌）  

Among the anatomical spaces in the head and neck area, the buccal space has often been studied in dental/oral surgery and cosmetic surgery because it contains the facial vessels, mandibular and facial nerves, and adipose tissue called the buccal fat pad. In addition, as the space can communicate with other spaces, it can be significant in infections. Although the anatomy of the buccal space has been reported in several studies, there have been discrepancies concerning its boundaries, and its communications have often been overlooked. The aim of this review is to examine the anatomy of buccal space including its boundaries, contents, continuity with adjacent spaces, and clinical significance. A literature review was performed on Google Scholar and PubMed. The literature has depicted the anterior, medial, and lateral boundaries more or less consistently, but descriptions of the posterior, superior, and inferior borders are controversial. The buccal space includes the facial arteries, veins, facial nerves, parotid duct, and lymph nodes, which can be described differently depending on definitions and the extent of the space. As it communicates with other anatomical spaces including the masticatory space, it can be a reservoir and a channel for infections and tumors. Buccal fat pads have various clinical applications, from a candidate for flap reconstruction to a target for removal for cosmetic purposes. This review will help understand the anatomy of the buccal space including its boundaries, residing structures, and communication with other spaces from surgical and radiological perspectives.

DOI： 10.1097/SCS.0000000000010411

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掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s11282-023-00734-2

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担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s40846-024-00848-w

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担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）  

Purpose: The current supraomohyoid neck dissection (SOHND) is performed above the omohyoid muscle to dissect levels I, II, and III in the levels of cervical lymph nodes. However, the anatomical boundary between levels III and IV is the inferior border of the cricoid cartilage. We investigated the anatomical relationship between the omohyoid muscle and cricoid cartilage using contrast-enhanced CT (CE-CT) images to assess the validity of the current SOHND. Methods: CE-CT images of the head and neck regions in patients were reviewed. The patients were divided into two groups: “malignant tumors” and “others”. The vertebral levels corresponding to the positions of anatomical structures such as the intersection of the omohyoid muscle and internal jugular vein (OM-IJ), and the inferior border of the cricoid cartilage (CC), were recorded. Results: The OM-IJ was located around the seventh cervical to the first thoracic vertebra. There was a significant difference between the malignant tumor and others groups in females (p = 0.036). The CC was located around the sixth to seventh cervical vertebrae. There was a significant sex difference in each group (malignant tumor: p < 0.0001; others: p = 0.008). Both sexes tended to have lower OM-IJ than CC, and females had significantly lower OM-IJ than males. Conclusion: This study provides clear anatomical evidence showing the difference between the SOHND dissection area and levels I, II, and III. It could be considered that in most cases SOHND invades level IV, not just levels I, II, and III, especially in female patients.

DOI： 10.1007/s00276-024-03453-3

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The mylohyoid is one of the suprahyoid muscles, along with the geniohyoid, digastric, and stylohyoid muscles. It lies between the anterior belly of the digastric muscle inferiorly and the geniohyoid superiorly. In Part I, the anatomy and embryology of the mylohyoid muscle will be reviewed in preparation for the clinical discussion in Part II.

DOI： 10.1097/SCS.0000000000009812

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The mylohyoid is one of the suprahyoid muscles along with the geniohyoid, digastric, and stylohyoid muscles that lies between the anterior belly of the digastric muscle inferiorly and the geniohyoid superiorly. In Part II, the radiology and clinical/surgical importance of the mylohyoid muscle will be discussed.

DOI： 10.1097/SCS.0000000000009797

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Spandidos Publications  

DOI： 10.3892/ol.2023.13980

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記述言語：日本語   出版者・発行元：(一社)日本口腔内科学会  

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記述言語：英語  

A collision tumor refers to the coexistence of two diagnostically distinct tumors in a common anatomic space. Collision tumors are rare in the oral and maxillofacial region. The present study reported on the case of an 82-year-old female with a collision tumor in the maxillary sinus consisting of small cell carcinoma (SmCC) and squamous cell carcinoma (SCC). Computed tomography (CT) imaging revealed a mass in the right maxillary sinus. The lesion exhibited heterogeneous low signal intensity (SI) on T1-weighted imaging (T1WI), high SI on short T1 inversion recovery and heterogeneous solid enhancement on contrast-enhanced T1WI. The histopathology result of a biopsy specimen confirmed SmCC. After the patient received a course of chemoradiotherapy, follow-up CT revealed a residual tumor. In a second surgery, a remaining tumor and histopathology revealed SCC with no evidence of SmCC. The final diagnosis was a collision tumor made up of SCC and SmCC.

DOI： 10.3892/mco.2022.2529

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: To examine the diagnostic usefulness and procedures of ultrasonography (US) for mass lesions in the soft tissue of the oral region. METHODS: This study involved patients with mass lesions (tumorous lesions and cysts) who had undergone US and histopathological examinations from January 2017 to December 2019. The following points were evaluated by two observers using an evaluation scale: vascularity, echo intensity level, boundary, margin shape, distribution of internal echoes, and capsule. The usefulness of each point for differential diagnosis of tumorous lesions and cysts was statistically analyzed. RESULTS: Forty-five mass lesions in the soft tissue of the oral region (33 tumorous lesions and 12 cysts) were analyzed. There were significant differences in four evaluation points between the tumorous lesions and cysts: vascularity, echo intensity level, boundary, and margin shape. Cysts were almost completely excluded diagnostically, especially when vascularity was observed. There were also significant differences in two evaluation points between nonvascular tumorous lesions and cysts: echo intensity level and boundary. CONCLUSIONS: In US examination for mass lesions in the oral region, it was possible to diagnose tumorous lesions and exclude cysts when vascularity was observed. When vascularity was not observed, however, tumorous lesions and cysts could be identified using two evaluation points: echo intensity level and boundary.

DOI： 10.1007/s11282-022-00605-2

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To focus on the effects of the presence of mesiodens on adjacent teeth and to investigate the timing of its safe removal. Materials and Methods: Cone-beam computed tomography examinations, obtained at Okayama University Hospital over a three-year period, were inspected. Data were recorded including the number of mesiodens; associated abnormalities; and the relationship with neighboring structures. Depending on multiple factors, the risk of developing complications due to early extraction of a mesiodens was divided into three categories: high, medium, and low risk. Results: A total of 5,958 cone-beam computed tomography exams were obtained, 460 patients aged 3-85 years were diagnosed with a total of 568 mesiodens, 382 (67.3%) of which were discovered in young patients (age <10 years), and 333 (87.2%) of these were associated with abnormalities. Regarding the risk categories, 11 (1.9%) were considered to be in the high-risk, five (0.9%) in the medium-risk and 552 (97.2%) in the low-risk categories. Moreover, eight out of 11 high-risk mesiodens were extracted and no post-operative complications have been seen. Conclusion: As the results showed that no postoperative complications were seen in all the extracted cases of high-risk mesiodens, this indicates the possibility of safe extraction at an early age which could reduce related future complications.

DOI： 10.5624/isd.20210218

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：BENTHAM SCIENCE PUBL LTD  

Background:An odontogenic myxoma is an intraosseous tumor characterized by stellate and spindle-shaped cells embedded in an abundant myxoid or mucoid extracellular matrix. We herein describe an odontogenic myxoma that expanded not only to the bone marrow but also to the outside of the alveolar bone. Diagnosis of an odontogenic myxoma in a tooth-deficient region by imaging findings alone was difficult because the positional relationship between the tumor and the tooth is unknown. Furthermore, some of these odontogenic myxomas reportedly show rapid growth.Case Report:Here, we present the case of a patient, a 44-year-old man, who had a hard, bone-like swelling on his right mandible molar region and mild paresthesia on his right cheek. An odontogenic myxoma and ameloblastoma were suspected based on the imaging findings; however, pathological examination of the biopsy led to a diagnosis of odontogenic myxoma. Right segmental mandibulectomy was performed, and there was no recurrence observed after surgery.Conclusion:To improve the accuracy of imaging diagnosis, it is important to compare the imaging findings with the pathological findings of the surgical specimen. This comparison in the present case revealed differences in the magnetic resonance imaging signal intensity in regions with different types of cell components.

DOI： 10.2174/18742106-v16-2202140

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Since cone-beam computed tomography was developed, a number of radiological studies on the bifid mandibular canals (BMCs) and trifid mandibular canals (TMCs) have been reported. However, many of the suggested subtypes of the BMC described in the literature seem to be normal branches of the inferior alveolar nerve. This might be due to a lack of revisiting classic anatomical studies in the field of radiology. Therefore, such studies are revisited here. METHODS: A database search using PubMed and Google Scholar was conducted on BMC and TMC. Eighty-nine articles underwent full-text assessment. The reported three classifications of BMC and the six modified classifications were reviewed and compared to the intramandibular inferior alveolar nerve branches. RESULTS: Some subtypes of BMC and TMC simply represent normal inferior alveolar nerve branches, i.e., retromolar branch, molar branch (alveolar branch/dental branch), large mental branch, or communicating branch. Others such as Naitoh's type III BMC and forward canal might be a true BMC. CONCLUSION: We found that the bifid mandibular canal is an additional intramandibular canal running parallel to the mandibular canal with/without confluence with the main canal through comparison of classifications of BMC/TMC between the radiology and anatomy fields.

DOI： 10.1007/s00276-021-02862-y

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPANDIDOS PUBL LTD  

Immune checkpoint inhibitors (ICIs) targeting programmed death ligand-1 (PD-L1) are highly promising therapies for oral squamous cell carcinoma (OSCC). The assessment of PD-L1 expression may help predicting the therapeutic effect of ICIs and, thus, benefit patient selection. Contrast index (CI) parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) have been proven as efficient to assess microvessel density (MVD) in OSCC. The present study aimed to determine the correlation between DCE-MRI parameters and MVD and between DCE-MRI parameters and PD-L1 expression to determine whether DCE-MRI could be used non-invasively to evaluate PD-L1 expression in patients with OSCC. A total of 21 patients with primary OSCC who had undergone a 3T MRI scan, including DCE-MRI, were included in the present study, and CI curve-derived parameters were examined. The MVD and PD-L1 expression in the surgically resected specimens were analyzed using immunohistochemistry (IHC) staining for CD31 and IHC staining for PD-L1, respectively. The results demonstrated that the expression levels of these markers were correlated with DCE-MRI parameters. PD-L1 expression levels were found to be significantly correlated with the maximum CI (CI-max; P=0.007), peak CI (CI-peak; P=0.007), maximum CI gain (CI-gain; P=0.006) and MVD (P=0.001) values. The mean CI-max, CI-peak, CI-gain and MVD values were significantly higher in tumors with high PD-L1 expression (P<0.05). MVD levels were also significantly correlated with the time of CI-max (T-max; P=0.003) and CI-gain (P=0.037). The mean CI-gain was significantly increased, and the mean T-max was significantly shorter in high MVD tumors (P<0.05 and P<0.01, respectively). In summary, the findings from the present study confirmed the correlation between CI parameters, derived from DCE-MRI, and MVD, and suggested that these parameters may be correlated with PD-L1 expression in OSCC tumor cells.

DOI： 10.3892/ol.2021.13039

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

PURPOSE: The displacement of the tooth/tooth fragment into the floor of mouth sometimes happens during the lower third molar surgery and the patients are usually referred to oral and maxillofacial surgeons. To date, however, there is no consensus how to manage the displaced tooth due to the lack of available data. METHODS: In this study, we have retrospectively analyzed the management of the displaced lower third molar into the floor of mouth. Our institute experienced seven cases during 2010 to 2020. RESULTS: Incidence rate of the lingual nerve injury caused by displacement of the lower third molar was 1/7. Six patients out of seven underwent surgical removal of the displaced fragment. The direct approach was used when the fragment was palpable superficially and the fragment was horizontally located away from the lingual plate (2 cases), while when the fragment was not palpable, or was palpable and adjacent to the lingual plate, the lingual mucoperiosteal flap was selected (4 cases). CONCLUSION: We conclude that the palpation and preoperative diagnosis with computed tomographic images are significantly important to decide a better and most effective surgical approach.

DOI： 10.1007/s10006-021-01012-3

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その他リンク： https://link.springer.com/article/10.1007/s10006-021-01012-3/fulltext.html

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

The purpose of this study was to evaluate the risk of injury to the facial (FA) and related arteries during mandibular third molar (MTM) extraction using contrast-enhanced computed tomography (CE-CT). CE-CT images of the MTM region were retrospectively reviewed. The area of the MTM was equally divided into three zones in the coronal images from mesial to distal, that is, zone 1, zone 2, and zone 3. The FA, submental artery (SMA), and sublingual artery (SLA) were identified. The distance from the mandible to FA, SMA, and SLA and the diameter of the FA, SMA, and SLA was measured in three zones, respectively. The thickness of the facial soft tissues and width of the mandible were measured at their maximum. The mean distance from the FA to the buccal cortical bone in zone 1, zone 2 and zone 3 was 2.24 mm, 2.39 mm and 1.67 mm, respectively. The SMA and SLA were found to be distal to the mandible. The mean diameter of the FA was 1.26 mm in males and 1.04 mm in females, respectively (p < 0.0001). The distance between the FA and buccal cortical bone of the mandible, and the patients' weight showed moderate correlation in zones 1 and 2. Based on our findings, the FA can be damaged if the surgical invasion reaches the facial soft tissues during MTM surgery. The patients' weight might be a good predictor for FA injury when CE-CT is not available.

DOI： 10.1002/ca.23779

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The general principles of anatomical terminology indicate that the "mandibular canal" should be named the "inferior alveolar canal" as it accommodates the inferior alveolar neurovascular bundles. Therefore, we performed a Delphi study to evaluate the current understanding and use of the terminology in different geographical regions and areas of expertise and to determine the appropriate terminology for this bony canal. A Delphi panel was formed and questions sent and answered via email about: field of expertise (anatomy, oral surgery/oral and maxillofacial (OMF) surgery, oral radiology/OMF radiology, plastic surgery, ENT surgery, or dentistry with the exception of oral/OMF surgery and oral/OMF radiology), years of experience in the field of expertise, country currently working in, "what is the name of the bony canal that contains the inferior alveolar neurovascular bundle," and "what should the structure above be called, in general?" A total of 52 participants responded to the questionnaire. Half or more of the experts in anatomy, oral/OMF surgery, and ENT/plastic surgery considered "mandibular canal" to be the most appropriate name for this bony canal. In contrast, more than half of all experts in oral/OMF radiology and dentistry, that is, most fields of dentistry, considered "either mandibular canal or inferior alveolar canal" to be the appropriate name. The results of the Delphi study and general principles suggest that an alternative term for the "mandibular canal" should be "inferior alveolar canal."

DOI： 10.1002/ca.23740

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Lower third molar removal is the most commonly performed dental surgical procedure. Nevertheless, it is difficult to ensure that all the informed consent forms given to patients are based on the best evidence as many newer publications could change the conclusions of previous research. Therefore, the goal of this review article is to cover existing meta-analyses, randomized control trials, and related articles in order to collect data for improved and more current informed consent.

DOI： 10.1002/ca.23693

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: The purpose of this study was to evaluate the usefulness of Hounsfield unit (HU) assessment with multislice-CT in the differentiation of radicular cysts (RCs), dentigerous cysts (DCs) and odontogenic keratocysts (OKCs). METHODS: In total, 307 odontogenic cysts (RCs, DCs and OKCs) were included in this study. Cysts with lesion diameter <10 mm, cysts with artefacts affecting measurement of HU values, cysts involving infection and recurrent cysts were regarded as exclusion criteria. Images were acquired in three different types of CT scanners: Aquilion ONE, Discovery CT750 HD and SOMATOM Definition Flash. Differences in HU values among scanners and among types of odontogenic cysts were assessed using one-way analysis of variance; multiple comparisons were performed post hoc, using the Tukey-Kramer honestly significant difference test. RESULTS: In total, 164 cysts were analysed in this study (64 RCs, 57 DCs and 43 OKCs). Regardless of the type of lesion, the Aquilion ONE scanner demonstrated a significant difference in HU value, compared with the Discovery CT750 HD scanner. Regardless of CT scanner model, HU values significantly differed between DCs and OKCs (p < 0.0001), as well as between OKCs and RCs (p < 0.0001). CONCLUSIONS: HU values were found to vary among CT scanners and should always be associated with other lesion imaging features while interpreting and elaboration diagnostic hypothesis. Notably, the results suggested that OKCs might be able to be differentiated from DCs and RCs by using HU values.

DOI： 10.1259/dmfr.20200188

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記述言語：英語  

DOI： 10.1016/j.radonc.2020.12.007

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

The numbers of abnormal findings incidentally detected in adjacent regions are increasing with advances in imaging modalities. The present study aimed to examine the prevalence and characteristics of incidental findings in the thyroid gland on computed tomography (CT) images of the oral and maxillofacial region. CT scans of the oral and maxillofacial region in patients obtained between January 2012 and December 2016 were retrospectively reviewed. Images that revealed incidental findings in the thyroid gland, including nodules, were recorded, together with the sizes and characteristics of the findings. The Japan Association of Breast and Thyroid Sonology (JABTS) guidelines were used for classification. The rate of descriptions of these findings in the radiographic interpretation reports were also examined. Of the 1,135 patients examined, 326 (28.7%) had several types of incidental findings. In particular, 169 (14.9%) of the 1,135 patients had nodules >5 mm in diameter, for which further careful examination is recommended in the JABTS guideline. The description rate for nodules >5 mm in diameter in the radiographic interpretation reports was 30.8% (52/169 patients), of whom 17.3% (9/52 patients) were referred to the endocrinology department for further careful examination. Incidental findings in the thyroid gland were relatively common on CT images of the oral and maxillofacial region. Oral radiologists tend to focus specifically on the oral and maxillofacial region during diagnosis on oral and maxillofacial CT images, but should pay the same careful attention to observe adjacent regions, such as the thyroid gland.

DOI： 10.3892/ol.2020.11298

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: To determine the optimum cone beam computed tomography exposure parameters for specific diagnostic tasks. METHODS: A Teflon phantom attached to a half-mandible in a large container was scanned in dental (D), implant (I), and panoramic (P) modes. An identical phantom in a small container was scanned in D mode. Both were scanned at 60, 80, 100, and 120 kV. We evaluated the image quality of five anatomical structures [dentinoenamel junction (1), lamina dura and periodontal ligament space (2), trabecular pattern (3), cortex-spongy bone junction (4), and pulp chamber and root canal (5)] and analyzed the diagnostic image quality with cluster signal-to-noise analysis. We then evaluated correlations between the two image qualities and calculated the threshold of acceptable diagnostic image quality. Optimum exposure parameters were determined from images with acceptable diagnostic image quality. RESULTS: For the small container, the optimum exposure parameters were D mode, 80 kV for (1), (3), and (4) and D mode, 100 kV for (5). For the large container, they were D mode, 120 kV for (1), (3), and (5) and D mode, 100 kV for (4). I mode, 120 kV reached the acceptable level for (4). No images reached the acceptable level for (2). CONCLUSIONS: No optimum exposure parameters were identified for the evaluation of the lamina dura and periodontal ligament space. D mode was sufficient for the other structures; however, the tube voltage required for each structure differed. Smaller patients required lower tube voltage. I mode, 120 kV may be used for larger lesions.

DOI： 10.1007/s11282-018-0348-6

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

Adenoid cystic carcinoma (ACC) is a rare epithelial tumor of the head and neck region, and one of the most common malignant tumors of the salivary glands. ACC is a slow-growing tumor characterized by perineural invasion and often has a high-recurrence rate. We describe a case of oropharyngeal ACC invading the mandibular bone through the mandibular foramen that showed a rare pattern of origin and invasion. A 70-year-old woman complained of noise and pain around the right temporomandibular joint. Osteomyelitis was suspected on the initial imaging examinations, although the findings were slightly atypical. However, a mass was observed in the right oropharyngeal wall on subsequent imaging examinations, and mandibular bone invasion, rather than osteomyelitis, was additionally suspected. The mass in the right oropharyngeal wall and right mandible was surgically excised. On postoperative histopathological examination, the mass was finally diagnosed as ACC. As tumor cells were also observed around the inferior alveolar nerve, mandibular bone invasion through the mandibular foramen was suspected. An oropharyngeal ACC invading the mandibular bone through the mandibular foramen is extremely rare. The present case suggests that bone invasion should be considered carefully with several imaging examinations when a malignant tumor such as ACC is observed around the jaw bone.

DOI： 10.1007/s11282-018-0359-3

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：KOREAN ACAD ORAL & MAXILLOFACIAL RADIOLOGY  

Purpose: The prevalence of supernumerary teeth has been reported to be between 0.1% and 3.8%. The aim of this study was to determine the prevalence, clinical significance, and associated pathologies of fourth molars based on a retrospective study and a literature review. Materials and Methods: A 5-year retrospective prevalence study was conducted at the Department of Oral Diagnosis and Dentomaxillofacial Radiology of Okayama University Hospital, Okayama, Japan. The study involved extracting data from the digital records of patients from January 1, 2013 through December 31, 2017. The sampling frame included all patients who had panoramic radiographs, cone-beam computed tomography (CT), and multislice CT images during the period under review. Results: A total of 26,721 cases were reviewed and 87 fourth molars were identified. The prevalence of fourth molars in the 5-year study at Okayama was calculated as 0.32%. The mean age of patients with a fourth molar was 30.43 years, and the male-to-female ratio was 1:0.98. The vast majority of cases were in the maxilla (92%) and had normal shapes (89.7%); furthermore, 82.8% of cases were unerupted. Conclusion: The prevalence of fourth molars in the study population was found to be 0.32%, and fourth molars occurred with approximately equal frequency in males and females. Fourth molars were more common in the maxilla and were predominantly unerupted and small.

DOI： 10.5624/isd.2019.49.1.27

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Tokyo  

OBJECTIVES: (1) We sought to assess correlation among four representative parameters from a cluster signal-to-noise curve (true-positive rate [TPR] corresponding to background noise, accuracy corresponding to background noise, maximum TPR, and maximum accuracy) and the diagnostic accuracy of the identification of the mandibular canal using data from observers in a previous study, under the same exposure conditions. (2) We sought to clarify the relationship between the hole depths of a phantom and diagnostic accuracy. METHODS: CBCT images of a Teflon plate phantom with holes of decreasing depths from 0.7 to 0.1 mm were analyzed using the FindFoci plugin of ImageJ. Subsequently, we constructed cluster signal-to-noise curves by plotting TPRs against false-positive rates. The four parameters were assessed by comparing with the diagnostic accuracy calculated from the observers. To analyze image contrast ranges related to detection of mandibular canals, we determined five ranges of hole depths, to represent different contrast ranges-0.1-0.7, 0.1-0.5, 0.2-0.6, 0.2-0.7 and 0.3-0.7 mm-and compared them with observers' diagnostic accuracy. RESULTS: Among the four representative parameters, accuracy corresponding to background noise had the highest correlation with the observers' diagnostic accuracy. Hole depths of 0.3-0.7 and 0.1-0.7 mm had the highest correlation with observers' diagnostic accuracy in mandibles with distinct and indistinct mandibular canals, respectively. CONCLUSIONS: The accuracy corresponding to background noise obtained from the cluster signal-to-noise curve can be used to evaluate the effects of exposure conditions on diagnostic accuracy.

DOI： 10.1007/s11282-018-0325-0

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：British Institute of Radiology  

OBJECTIVES: To compare the results of a new quantitative image quality evaluation method that requires no observers with the results of receiver operating characteristic (ROC) analysis in detecting the mandibular canal (MC) in cone beam CT (CBCT) images. METHODS: A Teflon (polytetrafluoroethylene) plate phantom with holes of different depths was scanned with two CBCT systems. One CBCT system was equipped with an image intensifier (Experiment 1), and the other was equipped with a flat panel detector (Experiment 2). Holes that were above the threshold gray value (ΔG), calculated using just-noticeable difference (JND), were extracted. The number of extracted holes was used as the index of the image quality, and was compared with the Az values calculated by ROC analysis to detect the MC. RESULTS: The number of extracted holes reflected the influence of different scanning conditions, and showed a strong correlation with the Az values calculated by ROC analysis. Indices of the number of extracted holes corresponding to high Az values for detecting the MC were obtained in both experiments. CONCLUSIONS: Our image quality evaluation method applying JND to images of a standardized phantom is a quantitative method that could be useful for evaluating the detectability of the MC in CBCT images.

DOI： 10.1259/dmfr.20170369

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：British Institute of Radiology  

OBJECTIVES: (1) To develop an observer-free method of analysing image quality related to the observer performance in the detection task and (2) to analyse observer behaviour patterns in the detection of small mass changes in cone-beam CT images. METHODS: 13 observers detected holes in a Teflon phantom in cone-beam CT images. Using the same images, we developed a new method, cluster signal-to-noise analysis, to detect the holes by applying various cut-off values using ImageJ and reconstructing cluster signal-to-noise curves. We then evaluated the correlation between cluster signal-to-noise analysis and the observer performance test. We measured the background noise in each image to evaluate the relationship with false positive rates (FPRs) of the observers. Correlations between mean FPRs and intra- and interobserver variations were also evaluated. Moreover, we calculated true positive rates (TPRs) and accuracies from background noise and evaluated their correlations with TPRs from observers. RESULTS: Cluster signal-to-noise curves were derived in cluster signal-to-noise analysis. They yield the detection of signals (true holes) related to noise (false holes). This method correlated highly with the observer performance test (R2 = 0.9296). In noisy images, increasing background noise resulted in higher FPRs and larger intra- and interobserver variations. TPRs and accuracies calculated from background noise had high correlation with actual TPRs from observers; R2 was 0.9244 and 0.9338, respectively. CONCLUSIONS: Cluster signal-to-noise analysis can simulate the detection performance of observers and thus replace the observer performance test in the evaluation of image quality. Erroneous decision-making increased with increasing background noise.

DOI： 10.1259/dmfr.20170147

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Bentham Science Publishers B.V.  

Background: We herein described a rare case of schwannoma of the hypoglossal nerve in the submandibular region with diagnostic imaging and histopathological findings. Case Report: A 31-years-old woman has had a palpable firm, rubbery, freely mobile mass in the submandibular region. Of imaging, MR images showed homogeneous isointensity on T1-weighted imaging (T1-WI), heterogeneous hypointensity on T2-WI, heterogeneous hyperintensity on short T1 inversion recovery (STIR), and heterogeneous enhancement on contrast-enhanced T1-WI. A clear capsule was observed on the margin and showed hypointense on T2-WI. Dynamic MRI showed heterogeneous gradual increased enhancement. The uptake of contrast medium was regionally slow. Diagnostic imaging using CT and MRI was suspected of salivary gland tumor or neurogenic tumor. In consideration of imaging diagnosis, a pleomorphic adenoma or a schwannoma was suspected. Final diagnosis was confirmed on the basis of histopathological finding and intraoperative findings. Conclusion: 1. Histopathologic examination is inevitable, because MR findings are not specific.2. Schwannomas were said to have specific MRI properties, including specific signs (split-fat sign, fascicular sign, target sign). However, they are not always observed.3. This case confirmed the differential diagnosis on the basis of the intraoperative finding that the tumor was continuous with the hypoglossal nerve.

DOI： 10.2174/1874210601812010012

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Society for Hard Tissue Regenerative Biology  

DOI： 10.2485/jhtb.27.275

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記述言語：日本語   出版者・発行元：(NPO)日本歯科放射線学会  

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その他リンク： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2019&ichushi_jid=J00567&link_issn=&doc_id=20190411290002&doc_link_id=10.11242%2Fdentalradiology.58.58&url=https%3A%2F%2Fdoi.org%2F10.11242%2Fdentalradiology.58.58&type=J-STAGE&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00007_3.gif

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：BRITISH INST RADIOLOGY  

OBJECTIVES: The purpose of this study was to clarify the effects of exposure parameters and image-processing methods when using CBCT to detect clear and unclear mandibular canals (MCs). METHODS: 24 dry half mandibles were divided into 2 groups with clear and unclear MCs based on a previous CBCT study. Mandibles were scanned using a CBCT system with varying exposure parameters (tube voltages 60 kV, 70 kV and 90 kV; and tube currents 2 mA, 5 mA, 10 mA and 15 mA) to obtain a total of 144 scans. The images were processed with different slice thicknesses using ImageJ software (National Institutes of Health, Bethesda, MD). Five radiologists evaluated the cross-sectional images of the first molar region to detect the MCs. The diagnostic accuracy of varying exposure parameters and image-processing conditions was compared with the area under the curve (Az) in receiver-operating characteristic analysis. RESULTS: The Az values for clear MCs were higher than those for unclear MCs (p < 0.0001). With increasing exposure voltages and currents, Az values increased, but no significant differences were found with high voltages and currents in clear MCs (p = 1.0000 and p = 0.9340). The Az values of serial images were higher than those of overlaid images (p < 0.0001), and those for thicker slices were higher than those for thinner slices (p < 0.0001). CONCLUSIONS: Our findings indicate that detection of unclear MCs requires either higher exposure parameters or processing of the images with thicker slices. To detect clear MCs, lower exposure parameters can be used.

DOI： 10.1259/dmfr.20160315

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：BRITISH INST RADIOLOGY  

OBJECTIVES: To develop an observer-free method for quantitatively evaluating the image quality of CBCT images by applying just-noticeable difference (JND). METHODS: We used two test objects: (1) a Teflon (polytetrafluoroethylene) plate phantom attached to a dry human mandible; and (2) a block phantom consisting of a Teflon step phantom and an aluminium step phantom. These phantoms had holes with different depths. They were immersed in water and scanned with a CB MercuRay (Hitachi Medical Corporation, Tokyo, Japan) at tube voltages of 120 kV, 100 kV, 80 kV and 60 kV. Superimposed images of the phantoms with holes were used for evaluation. The number of detectable holes was used as an index of image quality. In detecting holes quantitatively, the threshold grey value (ΔG), which differentiated holes from the background, was calculated using a specific threshold (the JND), and we extracted the holes with grey values above ΔG. The indices obtained by this quantitative method (the extracted hole values) were compared with the observer evaluations (the observed hole values). In addition, the contrast-to-noise ratio (CNR) of the shallowest detectable holes and the deepest undetectable holes were measured to evaluate the contribution of CNR to detectability. RESULTS: The results of this evaluation method corresponded almost exactly with the evaluations made by observers. The extracted hole values reflected the influence of different tube voltages. All extracted holes had an area with a CNR of ≥1.5. CONCLUSIONS: This quantitative method of evaluating CBCT image quality may be more useful and less time-consuming than evaluation by observation.

DOI： 10.1259/dmfr.20160331

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記述言語：日本語   出版者・発行元：(NPO)日本歯科放射線学会  

平均的な観察者が識別可能な最小輝度差である輝度弁別閾(JND)を検出閾値の設定に利用した画質評価法を開発し、観察者評価に替わり得るか否かを検討した。撮影対象は厚さを1mmずつ増加させた12段のアルミニウム製ブロックで、計7個の直径1mmのホールを有していた。デジタル口内法X線画像システムはDigora、Digora Optime、YCR-21XGの3機種を使用して撮影し、解析および観察により検出されなかったホール数(ホール非検出数)を画質視標とした。開発した評価法では、JNDインデックスを用いてホール非検出数の理論値を算出した。その結果、JNDを利用した評価法は、画像処理を行った場合の機種間の比較には注意を要するものの、おおむね観察者と同様の評価が可能であることが示された。更に、観察値と解析値について回帰分析を行った結果、得られた回帰式の決定係数は0.80を超え、観察値は解析値により高い精度で推定できることが確認された。なお、解析値と観察値のばらつきを比較した結果、解析値のばらつきは著明に小さかった。

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その他リンク： https://search-tp.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2016&ichushi_jid=J00567&link_issn=&doc_id=20170529210006&doc_link_id=%2Fcg7dentr%2F2016%2F005601%2F006%2F0027-0032%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fcg7dentr%2F2016%2F005601%2F006%2F0027-0032%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1186/s13075-015-0751-x

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記述言語：日本語   出版者・発行元：(公社)日本歯科医師会  

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記述言語：日本語   出版者・発行元：(公社)日本歯科医師会  

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記述言語：日本語   出版者・発行元：(一社)日本病理学会  

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記述言語：日本語   出版者・発行元：岡山歯学会  

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記述言語：日本語   出版者・発行元：岡山歯学会  

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J-GLOBAL

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記述言語：英語   出版者・発行元：(NPO)日本口腔科学会  

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記述言語：英語   出版者・発行元：(NPO)日本口腔科学会  

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記述言語：日本語   出版者・発行元：(一社)日本口腔診断学会  

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記述言語：日本語   出版者・発行元：(一社)日本口腔診断学会  

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記述言語：日本語  

J-GLOBAL

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記述言語：日本語   出版者・発行元：(一社)日本口腔内科学会  

J-GLOBAL

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記述言語：日本語   出版者・発行元：(一社)日本口腔内科学会  

J-GLOBAL

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記述言語：英語   出版者・発行元：(NPO)日本歯科放射線学会  

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担当区分：筆頭著者  

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記述言語：日本語   出版者・発行元：(NPO)日本歯科放射線学会  

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記述言語：日本語   出版者・発行元：(NPO)日本歯科放射線学会  

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開催年月日： 2022年3月

記述言語：日本語   会議種別：シンポジウム・ワークショップ パネル（公募）  

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開催年月日： 2022年3月

記述言語：日本語   会議種別：シンポジウム・ワークショップ パネル（公募）  

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開催年月日： 2022年3月

記述言語：日本語   会議種別：シンポジウム・ワークショップ パネル（公募）  

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開催年月日： 2021年11月

記述言語：日本語   会議種別：ポスター発表  

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開催年月日： 2021年10月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2021年5月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2021年5月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2021年5月

記述言語：日本語   会議種別：ポスター発表  

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開催年月日： 2021年4月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2021年4月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2021年4月

記述言語：英語   会議種別：ポスター発表  

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開催年月日： 2021年4月

記述言語：英語   会議種別：口頭発表（一般）  

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開催年月日： 2020年12月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2020年10月

記述言語：日本語  

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開催年月日： 2020年10月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2020年10月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2020年10月

記述言語：日本語  

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開催年月日： 2019年12月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2019年12月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2019年8月

記述言語：英語   会議種別：ポスター発表  

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開催年月日： 2019年6月

記述言語：日本語   会議種別：ポスター発表  

開催地：東京  

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開催年月日： 2019年1月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鹿児島  

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開催年月日： 2018年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京  

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開催年月日： 2018年9月

記述言語：英語   会議種別：ポスター発表  

開催地：インド  

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開催年月日： 2018年9月

記述言語：日本語   会議種別：ポスター発表  

開催地：横浜  

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開催年月日： 2018年5月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：名古屋  

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開催年月日： 2018年5月

記述言語：日本語   会議種別：ポスター発表  

開催地：神奈川  

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開催年月日： 2018年5月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：神奈川  

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開催年月日： 2018年5月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：名古屋  

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開催年月日： 2017年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：広島  

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開催年月日： 2017年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：盛岡  

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開催年月日： 2017年9月

記述言語：日本語   会議種別：ポスター発表  

開催地：札幌  

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開催年月日： 2017年9月

記述言語：日本語   会議種別：ポスター発表  

開催地：札幌  

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開催年月日： 2017年6月

記述言語：英語   会議種別：ポスター発表  

開催地：鹿児島  

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開催年月日： 2017年4月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Kaohsiung, Taiwan  

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開催年月日： 2016年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡  

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開催年月日： 2016年11月

記述言語：英語   会議種別：ポスター発表  

開催地：Chiangmai, Thailand  

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開催年月日： 2016年11月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Chiangmai, Thailand  

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開催年月日： 2016年6月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Seoul, Republic of Korea  

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開催年月日： 2016年6月

記述言語：日本語   会議種別：ポスター発表  

開催地：大阪  

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開催年月日： 2016年5月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Buenos Aires, Argentina  

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開催年月日： 2015年6月

記述言語：日本語   会議種別：ポスター発表  

開催地：仙台  

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開催年月日： 2015年3月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡  

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開催年月日： 2014年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：長崎  

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開催年月日： 2014年6月

記述言語：日本語   会議種別：ポスター発表  

開催地：東京  

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開催年月日： 2013年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京  

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会議種別：ポスター発表  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：ポスター発表  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：ポスター発表  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：シンポジウム・ワークショップ パネル（公募）  

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記述言語：日本語   会議種別：ポスター発表  

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記述言語：日本語   会議種別：ポスター発表  

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記述言語：日本語   会議種別：ポスター発表  

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記述言語：日本語   会議種別：口頭発表（一般）  

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