• Imaging Science in Dentistry
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• v.44 no.2
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• pp.95-102
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• 2014

Purpose: This study was performed to evaluate the reproducibility of panoramic radiographs of dentulous and edentulous patients. Materials and Methods: The reproducibility of panoramic radiographs was evaluated using the panoramic radiographs acquired from 30 anterior dentulous patients by using a common biting positioning device (dentulous group) and 30 anterior edentulous patients by using chin-support devices to take a panoramic radiograph (edentulous group), respectively; these patients had undergone 3 or more panoramic radiographs. The widths and angles between the designated landmarks were measured on the panoramic radiographs, and the reproducibility was evaluated using the intraclass correlation coefficient (ICC) and the coefficient of variation. Results: In the dentulous and edentulous groups, the ICCs of the mandibular ramus and mandibular angle areas were higher than the condylar head and zygomatic areas. The mandibular ramus and angle areas showed statistically lower mean coefficients of variation than the condylar head and zygomatic areas in the dentulous group. The mandibular angle area showed a significantly lower mean coefficient of variation than the zygomatic area in the edentulous group. By comparing the two groups, each ICC of the edentulous group was lower than that of the dentulous group, and the mean coefficients of variation of the mandibular ramus area, zygomatic area, left condylar inclination, and ramus ratio between the right and the left in the edentulous group were significantly higher than those in the dentulous group. Conclusion: Biting positioning for dentulous patients provided better positioning reproducibility than chin-support positioning when performing panoramic radiography for edentulous patients.

• Imaging Science in Dentistry
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• v.40 no.4
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• pp.197-201
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• 2010

Osteopetrosis is a rare bone disease characterized by systemic osteosclerosis due to an osteoclast dysfunction that decreases bone resorption. This report demonstrates two cases of adult osteopetrosis with secondary osteomyelitis of the maxilla, in siblings who are 43-year old female and 55-year old, male respectively. The common radiographic features of these cases were increased radiopacity in skull, rib and vertebra. The radiographic features that differed between these two cases were the osteosclerotic pattern of the jaw bones, that is, diffuse patterns in the female case, while the male case showed nodular patterns that were confined to the root apices. The diagnosis of osteopetrosis may be complicated due to the varying degree of osteosclerosis on panoramic radiograph. Additional radiographs such as the chest and skull radiograph may be helpful for the diagnosis of osteopetrosis.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.193-204
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• 1998

The purpose of this study was to perform the radiographic measurements and temporomandibular joint evaluation in mandibular asymmetry. For this study, thirty-two patients who have mandibular asymmetry were selected and submentovertex, panoramic and lateral corrected tomographic radiographs were taken. Horizontal and vertical analysis using various landmarks on these radiographs were performed. Also radiographic and clinical evaluation of temporomandibular joint were obtained. The results were as follows ; 1. On the submentovertex radiograph, the mean distance of Pogonion to midline was 5.0±3.8mm. 2. The mean distance of Pogonion to Gonion was 100.6±9.2mm in deviated side and 104.3±9.1mm in contra-lateral side, and there was a significant difference between the deviated and the contra-lateral side (p<0.001). 3. The distance difference of Pogonion to Gonion between the deviated and the contra-lateral side was significantly related to the degree of asymmetry (p<0.001). 4. On panoramic radiograph, the condylar height of the contra-lateral side was significantly longer than the one of the deviated side(p<0.001). 5. On lateral corrected tomogram, bony changes of temporomandibular joint were observed in 11 condyles of the deviated side and 9 condyles of the contra-lateral side. Erosion and osteophyte were the most common changes in both the deviated and the contra-lateral sides.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.2
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• pp.100-107
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• 2010

Introduction: A cyst is a closed pathologic sac containing fluid or semi-solid material in central region. The most common conventional treatment for a cyst is enucleation. It was reported that spontaneous bone healing could be accomplished without bone grafting. We are trying to evaluate bone reconstruction ability by analyzing panorama radiograph and computed tomography (CT) scan with retrograde studying after cyst enucleation. In this way we are estimating critical size defect for spontaneous healing without bone graft. Materials and Methods: The study comprised of 45 patients who were diagnosed as cysts and implemented enucleation treatment without bone graft. After radiograph photo taking ante and post surgery for 6, 12, 18, 24 months, the healing surface and volumetric changes were calculated. Results: 1. Spontaneous bone healing was accomplished clinically satisfying 12 months later after surgery. But analyzing CT scan, defect volume changes indicate 79.24% which imply incomplete bone healing of defect area. 2. Comparing volume changes of defect area of CT scan, there are statistical significance between under $5,000mm^{3}$ and over $5,000mm^{3}$. The defect volume of $5,000mm^{3}$ shows $2.79{\times}1.91$cm in panoramic view. Conclusion: Bone defects, which are determined by a healed section using a panoramic view, compared to CT scans which do not show up. Also we can estimate the critical size of defects for complete healing.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.81-87
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• 1984

This study was performed to observe the secondary images and to analyse the relationships between the primary and secondary images in panoramic radiograph. Using the Moritta's Panex-EC panoramic x-ray machine and the human dry skull, the author analysed 17 radiographs which were selected from 65 radiographs of the dry skull that attached the radiopaque materials, and the attached regions of the radiopaque materials were the normal anatomical structures which were important and selected as a regions for the evaluation of the secondary images effectively. The results were as follows; 1. The cervical vertebrae showed three images. The midline image was the most distorted and less clear, and bilateral images were slightly superimposed over the posterior border of the mandibular ramus. 2. In mandible, the secondary image of the posterior border of the ramus was superimposed on the opposite ramus region, and this image was elongated from the anterior border of the ramus to the lateral side of the posterior border of the ramus. The secondary image of the condyle was observed on the upper area of the coronoid process, the sigmoid notch and the condyle in opposite side. 3. In maxilla, the posterior region of the hard palate showed the secondary image on the lower part of the nasal cavity and the medial wall of the maxillary sinus. 4. The primary images of the occipital condyle and the mastoid process appeared on the same region, and only the secondary image of the occipital condyle was observed symmetrically on the opposite side with similar shape to the primary one. 5. In the cranial base, the anatomical structures of the midsagittal portions like a inferior border of the frontal sinus, sella turcica, inferior borderr of the sphenoid sinus and inferior border of the posterior part of the occipital bone showed the simillar shape between the primary and secondary images symmetrically. 6. The petrous portion of the temporal bone showed the secondary image on the lateral side of the sella-turcica, and the secondary images of the posterior border of lesser wing, superior border of greater wing of the sphenoid bone and posterior border were observed on the anterior-superior and inferior region of the sella-turcica.

• Imaging Science in Dentistry
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• v.39 no.2
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• pp.89-92
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• 2009

Purpose: To assess the angle between mandibular canal and occlusal plane at each posterior tooth region and location of mental foramen on the panoramic radiographs. Materials and Methods: This study analysed 46 half-mandibles of panoramic radiographs. Inferior border of mandibular canal was traced. Occlusal plane was drawn from lingual cusp tip of the first premolar to distolingual cusp tip of the second molar. Perpendicular line from occlusal plane was drawn at each tooth region and then tangential lines were drawn from the crossing points at canal. the angle between occlusal plane and tangential line was measured. The location of mental foramen was also studied. According to the location of mental foramen, radiographs were divided into M (mesial) group and D (distal) group on the basis of the second premolar. and then inter-group analysis about mandibular canal angle was done. Results: The angles of mandibular canals were -17.7$^{\circ}$, -9.5$^{\circ}$, 8.2$^{\circ}$, 22.3$^{\circ}$, and 39.2$^{\circ}$at first premolar, second premolar, first molar, second molar, and third molar, respectively. The commonest position of the mental foramen was distal to the second premolar. Inter-group comparison showed statistically significant difference at the second premolar and the first molar(p<0.001). Conclusion: The knowledge of mandibular canal angle and location of mental foramen can help understanding the course of mandibular canal. (Korean J Oral Maxillofac Radiol 2009; 39: 89-92)

• The Journal of the Korean dental association
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• v.56 no.3
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• pp.134-141
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• 2018

Purpose: To measure the head tilting angle creating initial condylar cut-off and to find the head position inducing the superimposition of the cervical vertebrae over the mandibular ramus on panoramic radiograph. Materials and Methods: The panoramic radiographs were taken with Didactic skull on cervical spine model (Scientific GmbH, Hamburg, Germany) using Kodak 8000c Digital Panoramic radiography. For the inherent radiolucency of the plastic skull model, radiopaque 1 mm diameter lead wires were attached along the margin of the mandibular condyle, ramus, mandibular body, cervical vertebrae, and FH plane of the skull model. For measuring the head tilting angle creating the condylar head cutoff, panoramic radiographs were taken by tilting the FH plane downward in 5 degree increments. For finding the distance between transverse process of the third cervical vertebra and gonion inducing superimposition of cervical vertebrae on the mandibular ramus, panoramic radiographs were taken by decreasing the distance in 0.5 cm increments. Result and Conclusion: The condylar cutoff began to appear when the head of skull model was tilted downward by 15o. As the head tilting angle increasing, the condylar cutoff became more prominent. The superimposition of cervical vertebrae over the mandibular ramus began to appear when the distance between the gonion and third cervical vertebra was 1.0 cm. As the distance decreasing, the superimpostion became more prominent.

• Imaging Science in Dentistry
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• v.33 no.1
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• pp.35-41
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• 2003

Purpose: To aid in determining the volume of graft bone required before a maxillary sinus lift procedure and compare the alveolar bone height measurements taken by panoramic radiographs to those by CT images. Materials and Methods : Data obtained by both panoramic radiographs and CT examination of 25 patients were used in this study. Maxillary sinus volumes from the antral floor to heights of 5 mm, 10 mm, 15 mm, and 20 mm, were calculated. Alveolar bone height was measured on the panoramic images at each maxillary tooth site and corrected by magnification rate (PBH). Available bone height (ABH) and full bone height (FBH) was measured on reconstructed CT images. PBH was compared with ABH and FBH at the maxillary incisors, canines, premolars, and molars. Results: Volumes of the inferior portion of the sinuses were 0.55 ± 0041 ㎤ for 5 mm lifts, 2.11 ± 0.68 ㎤ for 10 mm, 4.26 ± 1.32 ㎤ for 15 mm, 6.95 ± 2.01 ㎤ for 20 mm. For the alveolar bone measurement, measurements by panoramic images were longer than available bone heights determined by CT images at the incisor and canine areas, and shorter than full bone heights on CT images at incisor, premolar, and molar areas (p<0.001). Conclusion: In bone grafting of the maxillary sinus floor, 0.96 ㎤ or more is required for a 5 mm-lift, 2.79 ㎤ or more for a 10 mm-lift, 5.58 ㎤ or more for a 15 mm-lift, and 8.96 ㎤ or more for a 20 mm-lift. Maxillary implant length determined using panoramic radiograph alone could result in underestimation or overestimation, according to the site involved.

• Imaging Science in Dentistry
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• v.51 no.3
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• pp.223-235
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• 2021

Purpose: This study aimed to summarize the impact of neck and head radiation treatment on maxillofacial structures detected on panoramic radiographs. Materials and Methods: In this systematic review, the authors searched PubMed Central, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar for original research studies up to February 2020 that included the following Medical Subject Headings keywords: words related to "radiotherapy" and synonyms combined with keywords related to "panoramic radiography" and "oral diagnosis" and synonyms. Only original studies in English that investigated the maxillofacial effects of radiotherapy via panoramic radiographs were included. The quality of the selected manuscripts was evaluated by assessing the risk of bias using Cochrane's ROBINS-I tool for non-randomized studies. Results: Thirty-three studies were eligible and included in this review. The main objectives pertained to the assessment of the effects of radiation on maxillofacial structures, including bone architecture alterations, periodontal space widening, teeth development abnormalities, osteoradionecrosis, and implant bone loss. The number of participants evaluated ranged from 8 to 176. Conclusion: The interaction between ionizing radiation and maxillofacial structures results in hazard to the tissues involved, particularly the bone tissue, periosteum, connective tissue of the mucosa, and endothelium. Hard tissue changes due to radiation therapy can be detected on panoramic radiographs.

• The korean journal of orthodontics
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• v.37 no.2 s.121
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• pp.150-158
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• 2007

Objective: The aim of this study was to determine the relationship between the status of a unilateral palatally impacted maxillary canine (as seen on the panoramic radiograph) and the orthodontic treatment duration. Methods: A total of 36 subjects were chosen (8 males and 28 females, $13.7{\pm}2.5$ years). All patients had undergone orthodontic traction of the impacted canine after a closed flap surgery. The position of impacted canine on the panoramic radiograph was traced and calculated with regard to the treatment duration. Results: The canine overlap over the lateral incisor (COGr) had significant statistical difference between the short-term and the long-term treatment duration groups (divided by average treatment time of 21 months) (p<0.05). Multiple regression indicated that the variables of significance (with treatment duration as the dependent variable) were the canine vertical height from the occlusal plane $(HCV,\;r^2=0.115;\;p<0.05)$ and the mandibular anterior width $(MnDW,\;r^2=0.142;\;p<0.05)$. The treatment duration, the canine angle to the incisor midline (CA), and HCV decreased from primary dentition (under 12 yrs) to permanent dentition (15 yrs). Howerer, these increased again at the adolescent ages (over 16 yrs). Conclusion: These findings suggested that orthodontic treatment of a palatally impacted canine would show good prognosis at an age of early permanent dentition with the canine showing smaller CA and HCV.