Ameloblastoma with dystrophic calcification: A case report with 3-dimensional cone-beam computed tomographic images of calcification.

This report presents a rare case of ameloblastoma with histopathologic and radiographic calcification, including 3-dimensional cone-beam computed tomographic (CBCT) images. A 22-year-old woman had hard swelling on the right mandible. Panoramic and CBCT images showed multilocular radiolucencies with internal calcification foci in the right mandible. Three-dimensional images clearly showed varying-sized radiopacities within the lesion from various angles. A histopathologic examination showed central squamous differentiation and more densely packed peripheral palisading ameloblastic cells. Many areas of keratin pearls and calcifications were also seen. Four previous reports have described 5 cases of ameloblastoma showing histopathologic calcification. This might be the first report to present the calcification of ameloblastoma on panoramic and CBCT images, especially on 3-dimensional images.

Unexpected radiopaque foreign bodies encountered in dental practice.

OBJECTIVES: The purpose of the present study was to determine the presence of radiopaque foreign bodies on oral and maxillofacial radiographs and classify them. METHOD AND MATERIALS: The Study Comment section of the Picture Archiving and Communication System of Chonnam National University Dental Hospital was searched using 30 key words to identify images with radiopaque foreign bodies recorded between November 2008 and March 2017. A total of 503 cases of radiopaque foreign bodies were selected from among the recovered images. The radiopaque foreign bodies were sorted into 19 types, which were subsequently divided into two categories according to whether the foreign bodies were inserted intentionally or unintentionally. The two categories were subdivided into five groups based on the cause of insertion: Treatment, Esthetics, Cultural, Iatrogenesis, and Accident. RESULTS: In this study, the proportions of foreign bodies inserted intentionally (48%) and unintentionally (52%) were similar. When the foreign bodies were grouped based on the cause of insertion, the following frequencies were observed: Treatment, 41%; Esthetics, 7%; Cultural, <1%; Iatrogenesis, 51%; and Accident, 1%. CONCLUSION: For adequate case management and to avoid unnecessary embarrassment and misinterpretation of unexpected radiopacities, clinicians should be familiar with the various types of foreign bodies and should ensure that detailed patient medical/dental history is obtained.

Radiographic features of lingual mandibular bone depression using dental cone beam computed tomography.

OBJECTIVES: To describe accurately the radiographic characteristics of lingual mandibular bone depression (LMBD) using CBCT images. METHODS: This study included 30 cases of LMBD with CBCT images from 29 patients. Age, sex, location, shape, size, and the relationships of the LMBDs to adjacent anatomical structures such as the mandibular inferior cortex and mandibular canal were recorded. The correlation between age and size was evaluated using Pearson's correlation coefficient. RESULTS: The average age of the patients was 57 years. LMBDs occurred primarily in males (93%), occurrence in the right (n = 14) and left (n = 16) mandibles was approximately equal. The shapes were ovoid, round, peanut, triangular, or rectangular on panoramic radiographs. The occurrences in the molar, distal to the molar, and ramus regions were 63.3, 33.3, and 3.3% respectively. The mean size on CBCT was 15.4 mm in length, 11.2 mm in height, and 6.4 mm in depth. The relationship to the mandibular canal was categorized as separated (48.2%), contacted (31%), or go-through (20.7%). The relationship to the mandibular inferior cortex was classified as separated (20.7%), contacted (27.6%), or resorbed (51.7%). The Pearson's correlation coefficient showed a positive correlation between age and depth (r = 0.38; p = 0.038). CONCLUSIONS: The typical features of a LMBD were ovoid, round or mutilobated radiolucent shape, well-defined sclerotic border, and position in the posterior area of the mandible between the mandibular canal and inferior mandibular cortex. The buccolingual depth of LMBD was deeper with increasing age.

A comparative study of the deviation of the menton on posteroanterior cephalograms and three-dimensional computed tomography.

PURPOSE: Facial asymmetry has been measured by the severity of deviation of the menton (Me) on posteroanterior (PA) cephalograms and three-dimensional (3D) computed tomography (CT). This study aimed to compare PA cephalograms and 3D CT regarding the severity of Me deviation and the direction of the Me. MATERIALS AND METHODS: PA cephalograms and 3D CT images of 35 patients who underwent orthognathic surgery (19 males and 16 females, with an average age of 22.1±3.3 years) were retrospectively reviewed in this study. By measuring the distance and direction of the Me from the midfacial reference line and the midsagittal plane in the cephalograms and 3D CT, respectively, the x-coordinates (x1 and x2) of the Me were obtained in each image. The difference between the x-coordinates was calculated and statistical analysis was performed to compare the severity of Me deviation and the direction of the Me in the two imaging modalities. RESULTS: A statistically significant difference in the severity of Me deviation was found between the two imaging modalities (Δx=2.45±2.03 mm, p<0.05) using the one-sample t-test. Statistically significant agreement was observed in the presence of deviation (k=0.64, p<0.05) and in the severity of Me deviation (k=0.27, p<0.05). A difference in the direction of the Me was detected in three patients (8.6%). The severity of the Me deviation was found to vary according to the imaging modality in 16 patients (45.7%). CONCLUSION: The measurement of Me deviation may be different between PA cephalograms and 3D CT in some patients.

The location of midfacial landmarks according to the method of establishing the midsagittal reference plane in three-dimensional computed tomography analysis of facial asymmetry.

PURPOSE: The purpose of this study was to evaluate the influence of methods of establishing the midsagittal reference plane (MRP) on the locations of midfacial landmarks in the three-dimensional computed tomography (CT) analysis of facial asymmetry. MATERIALS AND METHODS: A total of 24 patients (12 male and 12 female; mean age, 22.5 years; age range, 18.2-29.7 years) with facial asymmetry were included in this study. The MRP was established using two different methods on each patient's CT image. The x-coordinates of four midfacial landmarks (the menton, nasion, upper incisor, and lower incisor) were obtained by measuring the distance and direction of the landmarks from the MRP, and the two methods were compared statistically. The direction of deviation and the severity of asymmetry found using each method were also compared. RESULTS: The x-coordinates of the four anatomic landmarks all showed a statistically significant difference between the two methods of establishing the MRP. For the nasion and lower incisor, six patients (25.0%) showed a change in the direction of deviation. The severity of asymmetry also changed in 16 patients (66.7%). CONCLUSION: The results of this study suggest that the locations of midfacial landmarks change significantly according to the method used to establish the MRP.

Deviation of landmarks in accordance with methods of establishing reference planes in three-dimensional facial CT evaluation.

PURPOSE: This study aimed to investigate the deviation of landmarks from horizontal or midsagittal reference planes according to the methods of establishing reference planes. MATERIALS AND METHODS: Computed tomography (CT) scans of 18 patients who received orthodontic and orthognathic surgical treatment were reviewed. Each CT scan was reconstructed by three methods for establishing three orthogonal reference planes (namely, the horizontal, midsagittal, and coronal reference planes). The horizontal (bilateral porions and bilateral orbitales) and midsagittal (crista galli, nasion, prechiasmatic point, opisthion, and anterior nasal spine) landmarks were identified on each CT scan. Vertical deviation of the horizontal landmarks and horizontal deviation of the midsagittal landmarks were measured. RESULTS: The porion and orbitale, which were not involved in establishing the horizontal reference plane, were found to deviate vertically from the horizontal reference plane in the three methods. The midsagittal landmarks, which were not used for the midsagittal reference plane, deviated horizontally from the midsagittal reference plane in the three methods. CONCLUSION: In a three-dimensional facial analysis, the vertical and horizontal deviations of the landmarks from the horizontal and midsagittal reference planes could vary depending on the methods of establishing reference planes.

Diagnostic reference levels for panoramic and lateral cephalometric radiography of Korean children.

Pediatric patients are considered to be more radiosensitive than adults; thus, radiation dose evaluations based on radiologic examinations are particularly important in this population. However, no national diagnostic reference levels (DRLs) are available for pediatric patients in the Republic of Korea. Therefore, the aim of this study was to determine the usage of panoramic and cephalometric radiography under the National Health Insurance (NHI) scheme and to investigate the current DRLs for child panoramic and lateral cephalometric radiography using dose area product (DAP). DAP values were obtained for standard child exposure settings used routinely by dentists. Analysis was performed on data obtained from 28 panoramic and 20 cephalometric x-ray units for the DAP investigation. DRLs for child panoramic and cephalometric radiography were found to be 95.9 mGy cm and 121.3 mGy cm, respectively. These DRLs are higher than those recommended in the UK and Germany, which indicates that further effort is required to reduce pediatric doses in the Republic of Korea.

Interobserver agreement on the diagnosis of carotid artery calcifications on panoramic radiographs.

PURPOSE: This study was performed to investigate the interobserver agreement on the detection of carotid artery calcifications on panoramic radiographs. MATERIALS AND METHODS: This study consisted of panoramic radiographs acquired from 634 male patients of the age of 50 years or older. Having excluded carotids of no diagnostic quality, 1008 carotids from the panoramic radiographs of the patients were interpreted by two oral and maxillofacial radiologists independently for the presence of carotid artery calcifications. Statistical analysis was used to calculate the interobserver agreement. RESULTS: Interobserver agreement was obtained for 932 carotids (92.4%). Inconsistent interpretation of 76 carotids (7.5%) between the two observers was found. Cohen's kappa value was 0.688 (p<0.001). CONCLUSION: The probability of a match between the two observers was substantially high.

Use of spherical coordinates to evaluate three-dimensional facial changes after orthognathic surgery.

PURPOSE: This study aimed to assess the three-dimensional (3D) facial changes after orthognathic surgery by evaluating the spherical coordinates of facial lines using 3D computed tomography (CT). MATERIALS AND METHODS: A 19-year-old girl was diagnosed with class III malocclusion and facial asymmetry. Orthognathic surgery was performed after orthodontic treatment. Facial CT scans were taken before and after orthognathic surgery. The patient had a menton deviation of 12.72 mm before surgery and 0.83 mm after surgery. The spherical coordinates of four bilateral facial lines (ramal height, ramal lateral, ramal posterior and mandibular body) were estimated from CT scans before and after surgery on the deviated and opposite side. RESULTS: The spherical coordinates of all facial lines changed after orthognathic surgery. Moreover, the bilateral differences of all facial lines changed after surgery, and no bilateral differences were zero. CONCLUSION: The spherical coordinate system was useful to compare differences between the presurgical and postsurgical changes to facial lines.

Adenomatoid odontogenic tumor associated with unerupted first primary molar.

Adenomatoid odontogenic tumors (AOTs) are an uncommon benign odontogenic tumor. Both central and peripheral forms occur. Radiographically, the central variants are comprised of a follicular type (those associated with the crown of an embedded tooth) and an extrafollicular type (those with no embedded tooth). A review of the literature showed that only 3 cases of an association between AOT and unerupted primary teeth have been published. The purpose of this paper was to report a rare case of adenomatoid odontogenic tumor associated with an unerupted primary first molar in a 7-year-old boy.

Application of spherical coordinate system to facial asymmetry analysis in mandibular prognathism patients.

PURPOSE: The purpose of this study was to compare asymmetric mandibular prognathism individuals with symmetric mandibular prognathism individuals using a new alternate spherical coordinate system. MATERIALS AND METHODS: This study consisted of 47 computed tomographic images of patients with mandibular prognathism. The patients were classified into symmetric and asymmetric groups. Mandibular and ramal lines were analyzed using an alternate spherical coordinate system. The length as well as midsagittal and coronal inclination angle of the lines was obtained. The bilateral differences of the spherical coordinates of the facial lines were statistically analyzed in the groups. RESULTS: There were significant differences between the groups in bilateral difference of the length and midsagittal inclination angle of the lines (p<0.05). The bilateral difference of the length and midsagittal inclination angle of the lines has significant correlation with chin deviation (p<0.05). CONCLUSION: The new alternate spherical coordinate system was able to effectively evaluate facial lines. The bilateral difference of lengths and midsagittal inclination of the facial lines might contribute to the facial asymmetry in mandibular prognathism individuals.

Dichloromethane fraction from Gardenia jasminoides: DNA topoisomerase 1 inhibition and oral cancer cell death induction.

CONTEXT: A growing body of evidence shows that compounds of plant origin have the ability to prevent cancer. The fruit of gardenia, Gardenia jasminoides Ellis (Rubiaceae), has long been used as a food additive and herbal medicine, and its pharmacological actions, such as protective activity against oxidative damage, cytotoxic effect, and anti-inflammatory and anti-tumor activity, have already been reported. OBJECTIVE: The purpose of the present study was to investigate the presence of DNA topoisomerase 1 inhibitor in various solvent fractions of Gardenia extract and examine the induction of oral cancer cell death upon treatment with Gardenia extract. MATERIALS AND METHODS: The methanol extract of Gardenia was partitioned with n-hexane, dichloromethane, ethyl acetate, n-butanol, and water. RESULTS: In the DNA topoisomerase 1 assay, n-hexane and dichloromethane fractions inhibited topoisomerase 1 and led to a decrease in the cell viability of KB cells. The dichloromethane fraction (0.1 mg/mL) also showed 77% inhibition of cell viability in KB cells compared with HaCaT cells. Treatment with dichloromethane fraction led to apoptotic cell death as evidenced by flow cytometric analysis and morphological changes. In addition, treatment with Gardenia extract dichloromethane fraction led to the partial increase of caspase-3, caspase-8 and caspase-9 activities and the cleavage of poly (ADP-ribose) polymerase. CONCLUSION: Taken together, these results suggest that the dichloromethane fraction from Gardenia extract induces apoptotic cell death by DNA topoisomerase 1 inhibition in KB cells. These findings suggest the possibility that Gardenia extract could be developed as an anticancer modality.

Reference dose levels for dental panoramic radiography in Gwangju, South Korea.

This study assessed the reference dose levels for dental panoramic radiography in Gwangju city, South Korea based on the dose width product (DWP) and compared them with those already established elsewhere. A total of 44 panoramic dental radiographic sets (36 digital and 8 analogue panoramic sets) in 41 dental clinics in Gwangju city were chosen. The third quartile DWP was determined from 429 surface dose measurements of the adult surface dose in panoramic dental radiography. The third quartile DWP for panoramic radiography was 60.1 mGy mm. The proposed DWP reference levels of 60.1 mGy mm were less than or equal to those previously reported in other countries, such as Italy and UK, and acceptable for panoramic radiography in Gwangju, South Korea.

Maxillofacial 3-dimensional image analysis for the diagnosis of facial asymmetry.

The advent of computed tomography has greatly reduced magnification errors from geometric distortions that are common in conventional radiographs. Recently introduced 3-dimensional (3D) software enables 3D reconstruction and quantitative measurement of the maxillofacial complex; 3D images are also useful in understanding asymmetrical structures. This article describes the use of 3D images in the diagnosis of facial asymmetry. A step-by-step procedure for 3D analysis developed by the authors is described by using the example of a 23-year-old man with a chin deviation to 1 side.