For patients with partial jaw defects, cysts and dental implants, doctors need to take panoramic X-ray films or manually draw dental arch lines to generate Panorama images in order to observe their complete dentition information during oral diagnosis. In order to solve the problems of additional burden for patients to take panoramic X-ray films and time-consuming issue for doctors to manually segment dental arch lines, this paper proposes an automatic panorama reconstruction method based on cone beam computerized tomography (CBCT). The V-network (VNet) is used to pre-segment the teeth and the background to generate the corresponding binary image, and then the Bezier curve is used to define the best dental arch curve to generate the oral panorama. In addition, this research also addressed the issues of mistakenly recognizing the teeth and jaws as dental arches, incomplete coverage of the dental arch area by the generated dental arch lines, and low robustness, providing intelligent methods for dental diagnosis and improve the work efficiency of doctors.
Humans ; Radiography, Panoramic/methods* ; Cone-Beam Computed Tomography/methods* ; Head ; Image Processing, Computer-Assisted/methods*

During the automatic reconstruction of panoramic images, the effect of dental arch curve fitting will affect the integrity of the content of the panoramic image. Metal implants in the patient's mouth usually lead to a decrease in the contrast of the panoramic image, which affects the doctor's diagnosis. In this paper, an automatic oral panoramic image reconstruction method was proposed. By calculating key image areas and image extraction fusion algorithms, the dental arch curve could be automatically detected and adjusted on a small number of images, and the intensity distribution of teeth, bone tissue and metal implants on the image could be adjusted to reduce the impact of metal on other tissues, to generate high-quality panoramic images. The method was tested on 50 cases of cone beam computed tomography (CBCT) data with good results, which can effectively improve the quality of panoramic images.
Humans ; Radiography, Panoramic/methods* ; Cone-Beam Computed Tomography/methods* ; Tooth ; Algorithms ; Image Processing, Computer-Assisted/methods*

OBJECTIVES: Pentoxifylline (PTX) is a methylxanthine derivative that has been implicated in the pathogenesis of peripheral vessel disease and intermittent lameness. The purpose of this study was to investigate the effect of PTX and tocopherol in patients diagnosed with osteoradionecrosis (ORN), bisphosphonate-related osteonecrosis of the jaw (BRONJ), and chronic osteomyelitis using digital panoramic radiographs.MATERIALS AND METHODS: This study was performed in 25 patients who were prescribed PTX and tocopherol for treatment of ORN, BRONJ, and chronic osteomyelitis between January 2014 and May 2018 in Seoul National University Dental Hospital. Radiographic densities of the dental panorama were compared prior to starting PTX and tocopherol, at 3 months, and at 6 months after prescription. Radiographic densities were measured using Adobe Photoshop CS6 (Adobe System Inc., USA). Blood sample tests showing the degree of inflammation at the initial visit were considered the baseline and compared with results after 3 to 6 months. Statistical analysis was performed using the Mann–Whitney test and repeated measurement ANOVA using IBM SPSS 23.0 (IBM Corp., USA).RESULTS: Eight patients were diagnosed with ORN, nine patients with BRONJ, and the other 8 patients with chronic osteomyelitis. Ten of the 25 patients were men, average age was 66.32±14.39 years, and average duration of medication was 151.8±80.65 days (range, 56–315 days). Statistically significant increases were observed in the changes between 3 and 6 months after prescription (P<0.05). There was no significant difference between ORN, BRONJ, and chronic osteomyelitis. Only erythrocyte sedimentation rate (ESR) was statistically significantly lower than before treatment (P<0.05) among the white blood cell (WBC), ESR, and absolute neutrophil count (ANC).CONCLUSION: Long-term use of PTX and tocopherol can be an auxiliary method in the treatment of ORN, BRONJ, or chronic osteomyelitis in jaw.
Bisphosphonate-Associated Osteonecrosis of the Jaw ; Blood Sedimentation ; Humans ; Inflammation ; Jaw ; Leukocytes ; Male ; Methods ; Neutrophils ; Osteomyelitis ; Osteoradionecrosis ; Pentoxifylline ; Prescriptions ; Radiography, Panoramic ; Seoul ; Tocopherols

PURPOSE: To determine the impact of an image processing technique on diagnostic accuracy of digital panoramic radiographs for the assessment of anatomical structures in paediatric patients with mixed dentition. MATERIALS AND METHODS: The study consisted of 50 digital panoramic radiographs of children aged from 6 to 12 years, which were later on processed using a dedicated image processing method. A modified clinical image quality evaluation chart was used to evaluate the diagnostic accuracy of anatomical structures in maxillary and mandibular anterior and maxillary premolar region of processed images. RESULTS: A statistically significant difference was observed between pre and post-processed evaluation of anatomical structures (P < 0.05) in the maxillary and mandibular anterior region. The anterior region was found to be more accurate in post-processed images. No significant difference was observed in the maxillary premolar region (P>0.05). The Inter-observer and intra-observer reliability of both pre and post processed images were excellent (>0.82) for anterior region and good (>0.63) for premolar region. CONCLUSION: The application of image processing technique in digital panoramic radiography can be considered a reliable method for improving the quality of anatomical structures in paediatric patients with mixed dentition.
Bicuspid ; Child ; Dentition, Mixed ; Diagnosis ; Humans ; Methods ; Radiography ; Radiography, Panoramic

OBJECTIVE: To explore the value of estimating chronologic age based on the grades of mandibular third molar development. To evaluate whether mandibular third molar could be used as an indicator for estimating the age under or over 18 years. METHODS: The mineralization status of mandibular third molar of 1 845 individuals aged 10 - 30 was graded and marked based on Demirjian's classification of grades reformed by Orhan. Gender difference was examined by t-test. A cubic regression model was established to analyze the correlation between third molar and chronologic age. Each grade of age cumulative distribution diagram and ROC curve was respectively performed to evaluate the relationship between third molar and the age of 18. Using Bayes discriminant analysis, an equation was established for estimating the age of 18. RESULTS: The inner-rater reliability was 0.903. Statistical analysis showed a moderate correlation between age and grade. Significant differences of both genders were found only in grade D and H (P < 0.05). Males at the grades from 1 to D and females at the grades from 1 to C were under 18 years old, and both males and females at grade H were over 18 years old. The area under the ROC curve was 0.797 (P < 0.05). CONCLUSION Third molar development shows a high correlation with age, and combined with other indicators, it can be used to estimate the age of 18.
Age Determination by Teeth/methods* ; Asian People ; Bayes Theorem ; China ; Female ; Forensic Dentistry ; Humans ; Male ; Molar, Third/diagnostic imaging* ; Radiography, Panoramic ; Reproducibility of Results ; Sex Characteristics

PURPOSE: The aim of this study was to obtain statistical data on the residual bone height at different natural tooth positions by panoramic radiography in edentulous Korean patients aged 60-90 years. MATERIALS AND METHODS: The study included the diagnostic panoramic radiographs of 180 randomly selected edentulous patients without systemic diseases affecting bone. The radiographic selection criteria included absence of obvious facial asymmetry, clearly visible anatomic structures, and no surgical and fracture history. The panoramic radiographs of 79 patients met these criteria and were used in the analysis. The same researcher processed all the radiographs by using a standardized method. The height of the residual bone was measured at 18 predetermined sites (7 in the maxilla and 11 in the mandible) on digitized and printed radiographs by using a Digimatic caliper, triangle, and ruler. Gender- and age-related differences were statistically analyzed by using the t-test and rank-sum test (alpha=0.05). RESULTS: The maxillary residual bone height did not show significant gender-related differences, but male patients had significantly higher residual bone in the mandible(P<.05). No significant height differences at the measured sites were noted among the 60s, 70s, and 80s age groups. CONCLUSION: Dentists should pay greater attention to older female edentulous patients because they are more prone to rapid residual bone resorption. Residual bone resorption may not be affected by age.
Alveolar Bone Loss ; Bone Resorption ; Dental Implants ; Dentists ; Denture, Complete ; Facial Asymmetry ; Female ; Humans ; Male ; Mandible ; Maxilla ; Methods ; Patient Selection ; Radiography ; Radiography, Panoramic* ; Tooth

PURPOSE: This study was performed to determine the prevalence and characteristics of pneumatized articular tubercle or eminence among a defined group of Iranian people. MATERIALS AND METHODS: Digital panoramic radiographs of 1694 patients in the Department of Oral and Maxillofacial Radiology, Hamadan Dental School, Iran were evaluated retrospectively to detect the above lesion. Finally, 1563 radiographs were selected according to inclusion criteria. Then, a review was done of 10 large case series found using a MEDLINE search of the literature. Chi-squared test was used to analyze the differences in variables such as age, gender, laterality, and locularity in our case series. RESULTS: The average age of our samples was 32.6+/-7.63 years. Pneumatized articular tubercle was found in 98 cases, representing a prevalence of 6.2% with a mean age of 22.8+/-7.9 and a range of 8 to 60 years. Sixty-four (65.3%) pneumatized articular tubercles were unilateral, with 30 lesions on the right and 34 on the left side. Bilateral lesions were found in 34 (34.7%) patients. 52 (53.06%) of the pneumatized articular tubercles were of the unilocular type and 46 (46.94%) were multilocular. The results showed no statistically significant differences regarding age (p=0.454), gender (p=0.634), laterality (p=0.252), or locularity (p=0.807) among the samples. CONCLUSION: Among ten large case series from other countries, the prevalence of pneumatized articular tubercle (6.2%) in Iranian patients was higher than that of all eight of the case series that used the same detection method as the present study of panoramic radiography.
Humans ; Iran ; Mastoid ; Methods ; Prevalence* ; Radiography, Panoramic ; Retrospective Studies ; Schools, Dental ; Temporal Bone

Adult ; Bone Screws ; Denture, Partial ; Female ; Humans ; Male ; Middle Aged ; Molar ; diagnostic imaging ; pathology ; Orthodontic Anchorage Procedures ; instrumentation ; methods ; Radiography, Panoramic ; Tooth Movement Techniques ; methods

OBJECTIVETo evaluate the long-term clinical outcome of delayed implant placements after maxillary sinus floor augmentation with autologous bone or Bio-Oss grafting.

METHODSEighteen patients underwent maxillary sinus floor augmentation and delayed implant placements from January, 2002 to December, 2008. Bone grafting and sinus floor augmentation were performed in 21 sides of maxilla and 46 implants were placed 6 - 8 months later. Residual bone height was less than 4 mm. The cases were divided to 2 groups and different materials (autologous bone + Bio-Oss and Bio-Oss alone) were grafted relatively. The bone resorption was assessed by panoramic X-ray and the stability of the implant was reviewed postoperatively.

RESULTSThe average follow-up time was 54 months. Only one implant was lost and the implant survival rate was 98%. X-ray showed that the bone resorption was observed in both groups. The absorption ratio of autologous bone + Bio-Oss group was 18.65% and that of the Bio-oss group was 1.93%. The difference was significantly different.

CONCLUSIONSThe result of maxillary sinus floor augmentation with bone grafting was predictable. More bone absorption occurred in the Bio-Oss than in autologous bone + Bio-Oss.

Adult ; Bone Substitutes ; therapeutic use ; Bone Transplantation ; methods ; Collagen ; therapeutic use ; Dental Implantation, Endosseous ; methods ; Female ; Follow-Up Studies ; Humans ; Jaw, Edentulous, Partially ; diagnostic imaging ; surgery ; Male ; Maxilla ; diagnostic imaging ; Middle Aged ; Minerals ; therapeutic use ; Radiography, Panoramic ; Sinus Floor Augmentation ; methods ; Young Adult

Aged ; Female ; Humans ; Immediate Dental Implant Loading ; methods ; Jaw, Edentulous ; diagnostic imaging ; rehabilitation ; surgery ; Male ; Mandible ; diagnostic imaging ; surgery ; Maxilla ; diagnostic imaging ; surgery ; Middle Aged ; Radiography, Panoramic ; Surgery, Computer-Assisted ; methods