Purpose: This report presents a unique case featuring real, ghost, and pseudo-ghost images on the panoramic radiograph of a patient wearing earrings. It also explains the formation of these images in an easy-to-understand manner.Material and MethodsOne real image and two ghost images appeared on each side of a panoramic radiograph of a patient wearing earrings on both sides. Of the two ghost images on each side, one was considered a typical ghost image and the other was considered a ghost-like real image (pseudo-ghost image). The formation zones of the real, double, and ghost images were examined based on the path and angles of the X-ray beam from the Planmeca ProMax. To simulate the pseudo-ghost and typical ghost images on panoramic radiography, a radiopaque marker was affixed to the right mandibular condyle of a dry mandible, and the position of the mandible was adjusted accordingly. Results: The center of rotation of the Planmeca ProMax extended beyond the jaw area, and the area of double image formation also reached beyond the jaw. The radiopaque-marked mandibular condyle, situated in the outwardly extending area of double image formation, exhibited triple images consisting of real, double (pseudo-ghost), and ghost images. These findings helped to explain the image formation associated with the patient's earrings observed in the panoramic radiograph. Conclusion Dentists must understand the characteristics and principles of the panoramic equipment they use and apply this understanding to taking and interpreting panoramic radiographs.

PURPOSE: The purpose of this study was to evaluate the clinical efficacy of enhancing deficient interdental papilla with hyaluronic acid gel injection by assessing the radiographic anatomical factors affecting the reconstruction of the interdental papilla. METHODS: Fifty-seven treated sites from 13 patients (6 males and 7 females) were included. Patients had papillary deficiency in the upper anterior area. Prior to treatment, photographic and periapical radiographic standardization devices were designed for each patient. A 30-gauge needle was used with an injection-assistance device to inject a hyaluronic acid gel to the involved papilla. This treatment was repeated up to 5 times every 3 weeks. Patients were followed up for 6 months after the initial gel application. Clinical photographic measurements of the black triangle area (BTA), height (BTH), and width (BTW) and periapical radiographic measurements of the contact point and the bone crest (CP-BC) and the interproximal distance between roots (IDR) were undertaken using computer software. The interdental papilla reconstruction rate (IPRR) was calculated to determine the percentage change of BTA between the initial and final examination and the association between radiographic factors and the reconstruction of the interdental papilla by means of injectable hyaluronic acid gel were evaluated. RESULTS: All sites showed improvement between treatment examinations. Thirty-six sites had complete interdental papilla reconstruction and 21 sites showed improvement ranging from 19% to 96%. The CP-BC correlated with the IPRR. More specifically, when the CP-BC reached 6 mm, virtually complete interdental papilla reconstruction via injectable hyaluronic acid gel was achieved. CONCLUSIONS: These results suggest that the CP-BC is closely related to the efficacy of hyaluronic acid gel injection for interdental papilla reconstruction.
Esthetics, Dental ; Gingiva* ; Humans ; Hyaluronic Acid* ; Male ; Needles ; Treatment Outcome

The basal cell nevus syndrome (BCNS) is an autosomal dominant disorder, characterized by basal cell carcinomas, odontogenic keratocysts and skeletal abnormalities. We experienced two cases that represented several characteristics of BCNS. Case 1: a thirty three year-old man visited CSU hospital. His radiographs showed four cystic lesions at both maxillary sinus and both mandibular angle, with bifid rib and ectopic calcification of falx cerebri. After marsupialization and enucleation, recurrent and newly developing tendency were found on his follow-up radiographs. Case 2: a seventeen year-old man had four large cystic lesions which were diagnosed as odontogenic keratocysts. He had craniofacial anomalies which included ectopic calcification and frontal bossing.
Basal Cell Nevus Syndrome ; Follow-Up Studies ; Jaw Cysts ; Nevus ; Odontogenic Cysts ; Ribs ; Tooth, Impacted

A 40-year-old man suffered from a repeatedly recurrent desmoplastic ameloblastoma in the right maxillary anterior and premolar regions. During the first visit, the patient was provisionally histopathologically diagnosed with a developmental cyst, and it was confirmed to be unicystic ameloblastoma and resected. Four years later, the lesion recurred, and was diagnosed as a desmoplastic type of ameloblastoma and removed again. Then, 5 years after the second surgery, the lesion recurred again, and was diagnosed as a type containing a follicular pattern, recurrent ameloblastoma. A panoramic radiograph showed a multilocular and mixed radiolucent/radiopaque expansile lesion at the first visit, a unilocular cystic lesion confined to the premolar area at the second visit, and a small soap bubble appearance in the molar area in the final visit. Cone-beam computed tomographic images of the final recurrence of the tumor revealed multiple small cyst-like structures in the right maxillary anterior and posterior regions.
Adult ; Ameloblastoma ; Bicuspid ; Cone-Beam Computed Tomography ; Humans ; Molar ; Radiography, Panoramic ; Recurrence ; Soaps

PURPOSE: This study aimed to provide comparative measurements of the effective dose from direct and indirect digital panoramic units according to phantoms and exposure parameters. MATERIALS AND METHODS: Dose measurements were carried out using a head phantom representing an average man (175 cm tall, 73.5 kg male) and a limbless whole body phantom representing an average woman (155 cm tall, 50 kg female). Lithium fluoride thermoluminescent dosimeter (TLD) chips were used for the dosimeter. Two direct and 2 indirect digital panoramic units were evaluated in this study. Effective doses were derived using 2007 International Commission on Radiological Protection (ICRP) recommendations. RESULTS: The effective doses of the 4 digital panoramic units ranged between 8.9 microSv and 37.8 microSv. By using the head phantom, the effective doses from the direct digital panoramic units (37.8 microSv, 27.6 microSv) were higher than those from the indirect units (8.9 microSv, 15.9 microSv). The same panoramic unit showed the difference in effective doses according to the gender of the phantom, numbers and locations of TLDs, and kVp. CONCLUSION: To reasonably assess the radiation risk from various dental radiographic units, the effective doses should be obtained with the same numbers and locations of TLDs, and with standard hospital exposure. After that, it is necessary to survey the effective doses from various dental radiographic units according to the gender with the corresponding phantom.
Female ; Fluorides ; Head ; Humans ; Lithium ; Lithium Compounds ; Radiation Dosage ; Radiography, Dental, Digital ; Radiography, Panoramic

Synovial chondromatosis is an uncommon disorder characterized by metaplastic formation of multiple cartilaginous and osteocartilaginous nodules within connective tissue of the synovial membrane of joints. Osteochondroma is a benign lesion of osseous and cartilagenous origin. It is frequently found in the general skeleton, but is rare in the mandibular condyle. We experienced 2 patients with abnormal appearance of temporomandibular joint. Histologic diagnoses were not obtained, because surgery was unwarranted in view of the lack of symptoms and the benign differential diagnosis. We describes 2 cases that show the characteristics of both disease simultaneously.
Chondromatosis, Synovial ; Connective Tissue ; Diagnosis, Differential ; Humans ; Joints ; Mandibular Condyle ; Osteochondroma ; Skeleton ; Synovial Membrane ; Temporomandibular Joint

Given that tooth loss is a degenerative change, the number of residual teeth may be used to specify a particular age range as a marker for age estimation. This study examined changes in the number of teeth with age using a nationwide oral survey database and derived the age distribution of the Korean population according to the number of teeth. Data on the number of teeth and age were extracted from the oral examination data of the Korean National Health and Nutrition Examination Survey (KNHANES) from 2016 to 2018. Statistical analyses of a complex sample survey were performed using weighted values. The distribution range of the number of teeth by age was broad. The proportion of young people decreased progressively as the number of remaining teeth decreased. In contrast, the proportion of those from the older age group decreased slightly as the number of teeth increased. The number of teeth was subdivided into groups of four, age was categorized into 5-year intervals, and the distribution of age groups by the number of teeth was analyzed. We attempted to determine the age group threshold at approximately 95th percentile for age. In summary, we found that if there were ≤4, 5-12, and 13-20 residual teeth, the estimated age was ≥60, ≥55, and ≥50 years, respectively, with an approximately 95% probability. When many teeth are lost and it is difficult to apply conventional dental age estimation methods, our method may assist in narrowing the age range, although it is not an accurate age determination method.

The aim of the present study was to investigate the pathophysiological etiology of osteoarthritis that is mediated by the apoptosis of chondrocytes exposed to 25-hydroxycholesterol (25-HC), an oxysterol synthesized by the expression of cholesterol-25-hydroxylase (CH25H) under inflammatory conditions. Interleukin-1β induced the apoptosis of chondrocytes in a dose- dependent manner. Furthermore, the production of 25-HC increased in the chondrocytes treated with interleukin-1β through the expression of CH25H. 25-HC decreased the viability of chondrocytes. Chondrocytes with condensed nucleus and apoptotic populations increased by 25- HC. Moreover, the activity and expression of caspase-3 were increased by the death ligand-mediated extrinsic and mitochondria-dependent intrinsic apoptotic pathways in the chondrocytes treated with 25-HC. Finally, 25-HC induced not only caspasedependent apoptosis, but also induced proteoglycan loss in articular cartilage ex vivo cultured rat knee joints. These data indicate that 25-HC may act as a metabolic pathophysiological factor in osteoarthritis that is mediated by progressive chondrocyte death in the articular cartilage with inflammatory condition.

The aim of the present study was to investigate the pathophysiological etiology of osteoarthritis that is mediated by the apoptosis of chondrocytes exposed to 25-hydroxycholesterol (25-HC), an oxysterol synthesized by the expression of cholesterol-25-hydroxylase (CH25H) under inflammatory conditions. Interleukin-1β induced the apoptosis of chondrocytes in a dose- dependent manner. Furthermore, the production of 25-HC increased in the chondrocytes treated with interleukin-1β through the expression of CH25H. 25-HC decreased the viability of chondrocytes. Chondrocytes with condensed nucleus and apoptotic populations increased by 25- HC. Moreover, the activity and expression of caspase-3 were increased by the death ligand-mediated extrinsic and mitochondria-dependent intrinsic apoptotic pathways in the chondrocytes treated with 25-HC. Finally, 25-HC induced not only caspasedependent apoptosis, but also induced proteoglycan loss in articular cartilage ex vivo cultured rat knee joints. These data indicate that 25-HC may act as a metabolic pathophysiological factor in osteoarthritis that is mediated by progressive chondrocyte death in the articular cartilage with inflammatory condition.

In children and adolescents, dental age estimation is performed with the development of the teeth. Various statistical analysis methods have been used to determine the relationship between age and dental maturity and develop an accurate method of age calculation. This study attempted to apply a neural network model for the statistical analysis of dental age estimation in children and evaluated its applicability. This study used 1196 panoramic radiographs of patients aged 3–16 years, and 996 and 200 were randomly classified into training and test sets, respectively. The dental maturity of the mandibular left teeth was evaluated using Demirjian's method, the neural network model using the backpropagation algorithm was derived using training sets, and the errors were evaluated using 100 radiographs of each male and female as test sets. In addition, multiple linear regression analysis was conducted on the same training set, and the error was calculated by applying it to the test set and comparing it with the error of the neural network model. In the neural network model, the mean absolute error (MAE) and root mean squared error (RMSE) were 0.589 and 0.783 in male subjects and 0.529 and 0.760 in female subjects, respectively. In the multiple linear regression model, the MAE and RMSE were 0.600 and 0.748 in male subjects and 0.566 and 0.789 in female subjects, respectively. When applying the neural network model to the statistical analysis of the dental developmental stage, the results were as accurate as those of conventional statistical analysis methods. This study’s approach is expected to be useful for estimating the ages of children.