• Imaging Science in Dentistry
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• v.43 no.2
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• pp.105-109
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• 2013

Purpose: Preoperative radiographic assessment of the mandibular third molars is essential to prevent inferior alveolar nerve damage during extraction. The purpose of this study was to assess the reliability of panoramic signs of association between the roots of teeth and the canal, and to compare the panoramic signs with cone beam computed tomography (CBCT) findings. Materials and Methods: CBCT images of 132 impacted mandibular third molars were evaluated to determine the association of the root to the canal. The CBCT findings were compared with the corresponding panoramic images. Logistic regression analysis was used to define the diagnostic criteria of the panoramic images. Results: Among the panoramic signs, loss of the cortical line was the most frequent radiographic sign predicting association (sensitivity: 79.31). Contact of the tooth with the canal was observed in all cases in which the loss of cortical line of the canal or darkening of the roots was found on the panoramic radiographs. Conclusion: Darkening of the roots and loss of the cortical line on panoramic radiographs might be highly suggestive of the risk of nerve injury.

• 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.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.287-295
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• 1995

The purpose of this study was to evaluate the prevalence, the distribution, and the relation with adjacent roots of idiopathic osteosclerosis in the jaws by means of analysis of 7,837 persons' panoramic radiographs. The following results were obtained ; 1. The prevalence of idiopathic osteosclerosis in the jaws in panoramic radiographs was revealed to be 9.76％ in total examined persons. There was a higher prevalence in males(10.10％) than in females(9.76％). 2. There was also a higher prevalence in the mandible(97.92％) than in the maxilla(2.08％). The most frequently involved area was the mandibular molar area(34.72％), followed by mandibular premolar area(33.37％). 3. According to the types of idiopathic osteosclerosis with relation to adjacent roots, separated type(51.59％) was the most frequent, followed by apical type(32.52％), interradicular type(7.95％), apical and interradicular type(7.95％) in descending order of frequency.

• 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.38 no.3
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• pp.163-167
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• 2008

Purpose : The purpose of this study is to evaluate the position of the mandibular canal in relation to the mandibular third molar by cone beam CT in cases showing a close relationship between the third molar and the mandibular canal on the panoramic radiograph. Materials and Methods : The panoramic images and cone beam CT scans of 87 impacted mandibular third molars in 60 patients were evaluated to assess the tooth relationship to the mandibular canal. The clearness of the canal wall and the vertical depth of the lower third molar were evaluated on panoramic radiographs. The lower third molars were assessed using cone beam CT to determine the proximity and position of the canal relative to the roots. Results : In the 66 cases where the canal wall was unclear on the panoramic radiographs, 58 (87.9%) of the third molars had contact between the canal and root; 34 (51.5%) canals were showed an inferior position and 22 (33.3%) showed a linguoinferior position on cone beam CT. Conclusion : Interruption of the canal wall on panoramic radiographs was highly predictive of contact between the mandibular canal and the third molar. Cross sectional CT may be indicated for localization of the mandibular canal in such cases.

• Imaging Science in Dentistry
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• v.43 no.4
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• pp.235-243
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• 2013

Purpose: This study was performed to assess the correlation of calcified carotid atheromatous plaque (CCAP), the mandibular cortical index, and periodontal bone loss in panoramic radiographs. Materials and Methods: One hundred eighty-five panoramic radiographs with CCAP and 234 without this finding were evaluated by 3 observers for the presence of osseous changes related to osteoporosis and periodontal bone loss. Chi-squared and Mann-Whitney U tests were used to compare the two groups for an association of CCAP with the mandibular cortical index and periodontal bone loss, respectively. Results: There was a statistically significant coincidence of CCAP and osseous changes related to osteopenia/osteoporosis, with a p-value <0.001. There was no statistically significant coincidence of CCAP and periodontal bone loss. When comparing the 2 groups, "With CCAP" and "Without CCAP", there was a statistically significant association with the mean body mass index (BMI), number of remaining teeth, positive history of diabetes mellitus, and vascular accidents. There was no statistically significant association with gender or a history of smoking. Conclusion: This study identified a possible concurrence of CCAP and mandibular cortical changes secondary to osteopenia/osteoporosis in panoramic radiographs. This could demonstrate the important role of dental professionals in screening for these systemic conditions, leading to timely and appropriate referrals resulting in early interventions and thus improving overall health.

• 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 korean journal of orthodontics
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• v.54 no.3
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• pp.185-195
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• 2024

Objective: This study aimed to retrospectively analyze the prevalence of orthodontic problems and the proportion of patients who underwent orthodontic diagnosis among children aged 6 (n = 300), 7 (n = 400), and 8 (n = 400) years who had undergone panoramic radiography. Methods: Children were divided into five groups according to their chief complaint and consultation: conservative dentistry, oral and maxillofacial surgery, orthodontics, periodontics, and prosthodontics). Chief complaints investigated included first molar eruption, lack of space for incisor eruption, frequency of eruption problems, lack of space, impaction, supernumerary teeth (SNT), missing teeth, and ectropion eruption. The number of patients whose chief complaint was not related to orthodontics but had dental problems requiring orthodontic treatment was counted. The proportion of patients with orthodontic problems who received an orthodontic diagnosis was also examined. Results: Dental trauma and SNT were the most frequent chief complaints among the children. The proportion of patients with orthodontic problems increased with age. However, the orthodontic diagnosis rates based on panoramic radiographs among children aged 6, 7, 8 years were only 1.5% (6 years) and 23% (7 and 8 years). Conclusions: Accurate information should be provided to patient caregivers to correct misconceptions regarding the appropriateness of delaying orthodontic examination until permanent dentition is established.

• Imaging Science in Dentistry
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• v.42 no.3
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• pp.183-190
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• 2012

Purpose: The purpose of this study was to investigate the level of clinical image quality of panoramic radiographs and to analyze the parameters that influence the overall image quality. Materials and Methods: Korean dental clinics were asked to provide three randomly selected panoramic radiographs. An oral and maxillofacial radiology specialist evaluated those images using our self-developed Clinical Image Quality Evaluation Chart. Three evaluators classified the overall image quality of the panoramic radiographs and evaluated the causes of imaging errors. Results: A total of 297 panoramic radiographs were collected from 99 dental hospitals and clinics. The mean of the scores according to the Clinical Image Quality Evaluation Chart was 79.9. In the classification of the overall image quality, 17 images were deemed 'optimal for obtaining diagnostic information,' 153 were 'adequate for diagnosis,' 109 were 'poor but diagnosable,' and nine were 'unrecognizable and too poor for diagnosis'. The results of the analysis of the causes of the errors in all the images are as follows: 139 errors in the positioning, 135 in the processing, 50 from the radiographic unit, and 13 due to anatomic abnormality. Conclusion: Panoramic radiographs taken at local dental clinics generally have a normal or higher-level image quality. Principal factors affecting image quality were positioning of the patient and image density, sharpness, and contrast. Therefore, when images are taken, the patient position should be adjusted with great care. Also, standardizing objective criteria of image density, sharpness, and contrast is required to evaluate image quality effectively.

• Imaging Science in Dentistry
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• v.31 no.3
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• pp.129-133
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• 2001

Purpose: To compare the copper equivalent values measured at premolar and molar areas in the copper equivalent images of panoramic and intraoral radiographs and to evaluate the possibility of the copper equivalent images of panorama for the assessment the bone density. Materials and Methods : Intraoral radiograms at mandibular premolar and molar area and panoramas of 6 human dry skulls were taken with copper-step wedge by Heliodent MD (Siemens Co., Germany) and by Planmeca (PM 2002 CC, Planmeca, Helsinki, Finland) were used for experiment. The copper equivalent values measured at premolar and molar areas in the copper equivalent im ages of panorama and intraoral film were compared. Results: The copper equivalent values were ranged 0.20 mmCu-0.44 mmCu at the molar areas, 0.05 mmCu-0.31 mmCu at the premolar areas on panoramic images. There were no significant differences (p>0.5) between the copper equivalent values on intraoral images and those on panoramic images measured at premolar areas and molar areas respectively. The correlation coefficient between the copper equivalent values on intraoral images and those on panoramic images was respectively 0.8495 at molar areas and 0.6184 at premolar areas. Conclusions : The copper equivalent images of panorama for the assessment the bone density appeared to be significant at molar area compared with the one of intraoral radiograph.