• Imaging Science in Dentistry
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• v.47 no.2
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• pp.87-92
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• 2017

Purpose: The aim of this study was to determine whether the panoramic mandibular index (PMI) is useful for assessing bone mineral density. We also analyzed the potential correlations between PMI parameters and patient age. Materials and Methods: Four observers measured the PMI of both sides of the mental foramen using a picture archiving and communication system and images in the Digital Imaging and Communications in Medicine format. They studied 300 panoramic radiographic images of patients belonging to the following age groups: 40-49 years, 50-59 years, 60-69 years, 70-79 years, and 80-89 years. The observers were allowed to zoom in or out and to adjust the contrast of the images. Further, they were instructed to record the reasons for any measurements that could not be made. Then, we conducted a reliability analysis of the measured PMI and assessed the correlations between different patient age groups and the 3 parameters used for determining the PMI from the available data. Results: Among the 600 data items collected, 23 items were considered unmeasurable by at least 1 observer for the following 4 reasons: postoperative state, lesion, unidentified mental foramen, and alveolar bone loss. The intraobserver reproducibility of the measurable data was 0.611-0.752. The mandibular cortical width (MCW) decreased significantly as patient age increased. Conclusion: PMI had limited usability when the margin of the mental foramen was not clear. In contrast, MCW, a parameter used for determining the PMI, had fewer drawbacks than the PMI with respect to bone mineral density measurements and exhibited a significant correlation with patient age.

• The Korean Journal of Pain
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• v.36 no.4
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• pp.465-472
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• 2023

Background: Percutaneous radiofrequency thermocoagulation (RFTC) has been widely utilized in the management of trigeminal neuralgia. Despite using image guidance, accurate needle positioning into the target area still remains a critical element for achieving a successful outcome. This study was performed to precisely clarify the anatomical information required to ensure that the electrode tip is placed on the sensory component of the mandibular nerve (MN) at the foramen ovale (FO) level. Methods: The study used 50 hemi-half heads from 26 South Korean adult cadavers. Results: The cross-sectioned anterior and posterior divisions of the MN at the FO level could be distinguished based on an irregular boundary and color difference. The anterior division was clearly brighter than the posterior one. The anterior division of the MN at the FO level was located at the whole anterior (38.0%), anteromedial (6.0%), anterior center (8.0%), and anterolateral (22.0%) parts. The posterior division was often located at the whole posterior or posterolateral parts of the MN at the FO level. The anterior divisions covered the whole MN except for the medial half of the posterolateral part in the overwrapped images of the cross-sectional areas of the MN at the FO level. The cross-sectional areas of the anterior divisions were similar in males and females, whereas those of the posterior divisions were significantly larger in males (P = 0.004). Conclusions: The obtained anatomical information is expected to help physicians reduce unwanted side effects after percutaneous RFTC within the FO for the MN.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.117-124
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• 2020

Purpose: The purpose of this study was to evaluate possible differences in the location of the inferior alveolar canal in male and female Egyptians. Materials and Methods: This cross-sectional retrospective study involved the evaluation of 210 CBCT scans of Egyptian individuals (18-70 years old). The inferior alveolar canal was localized by measuring 8 linear dimensions: 2 for the vertical localization of the mental foramen (superior and inferior to the mental foramen), 4 at the first molar bifurcation for the vertical and horizontal localization of the inferior alveolar canal (superior, inferior, buccal, and lingual to the inferior alveolar canal), and 2 for the horizontal localization of the mandibular foramen (anterior and posterior to the mandibular foramen). The measurements were statistically analyzed via comparative analysis, stepwise logistic regression, and receiver operating characteristic (ROC) curve analysis. Results: Six of the 8 measured distances differed to a statistically significant extent between the sexes. Regression analysis suggested a logistic function with a concordance index of 84%. The diagnostic accuracy capabilities of the linear measurements as sex predictors were calculated using ROC analysis, and the 6 best predictors for sex determination were selected and ranked from highest to lowest predictive power. Moreover, combining these 6 predictors increased the predictive power to 84%. Conclusion: The location of the inferior alveolar canal in the Egyptian population varies significantly by sex; accordingly, this anatomic landmark could be used as a reliable indicator of sexual dimorphism.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.6
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• pp.263-268
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• 2013

Objectives: The interforminal region, between the mandibular foramen, is known as a relatively safe area that is free of anatomic structures, such as inferior alveolar nerve, submandibular fossa, and lingual side of the mandible is occasionally neglected for its low clinical importance. Even in the case of a severely constricted alveolus, perforation of the lingual cortical bone had been intended. However, anterior extension of the inferior alveolar canal, important anatomic structure, such as concavity of lingual bone, lingual foramina, and lingual canal, has recently been reported through various studies, and untypical bleeding by perforation of the lingual plate on implantation has also been reported. Therefore, in this study, we performed radiographic and statistical analysis on distribution and appearance frequencies of the lingual foramina that causes perforation of the mandibular lingual cortical bone to prevent complications, such as untypical bleeding, during surgical procedure. Materials and Methods: We measured the horizontal length from a midline of the mandible to the lingual foramina, as well as the horizontal length from the alveolar crest to the lingual foramina and from the lingual foramina to the mandibular border by multi-detector computed tomography of 187 patients, who visited Dankook University Dental Hospital for various reasons from January 1, 2008 to August 31, 2012. Results: From a total of 187 human mandibles, 110 (58.8%) mandibles had lingual foramina; 39 (20.9%) had bilateral lingual foramen; 34 (18.2%) had the only left lingual foramen; and 37 (19.8%) had the only right lingual foramen. Conclusion: When there is consistent bleeding during a surgical procedure, clinicians must consider damages on the branches of the sublingual artery, which penetrate the lingual foramina. Also, when there is a lingual foramina larger than 1 mm in diameter on a pre-implantation computed tomography, clinicians must beware of vessel damage. In order to prevent these complications and progress with a safe surgical procedure, a thorough radiographic examination before the surgery is indispensable. Further, clinicians should retract lingual flap definitely to confirm the shape of the lingual bone and existence of the lingual foramina.

• The korean journal of orthodontics
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• v.49 no.5
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• pp.326-337
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• 2019

Objective: The objective of this study was to develop new parameters based on the foramina of the trigeminal nerve and to compare them with the conventional cephalometric parameters in different facial skeletal types. Methods: Cone-beam computed tomography (CBCT) scans and cephalograms from 147 adult patients (57 males and 90 females; mean age, 26.1 years) were categorized as Class I ($1^{\circ}$ < ANB < $3^{\circ}$), Class II (ANB > $5^{\circ}$), and Class III (ANB < $-1^{\circ}$). Seven foramina in the craniofacial area-foramen rotundum (Rot), foramen ovale (Ov), infraorbital foramen, greater palatine foramen, incisive foramen (IF), mandibular foramen (MDF), and mental foramen (MTF)-were identified in the CBCT images. Various linear, angular, and ratio parameters were compared between the groups by using the foramina, and the relationship between the new parameters and the conventional cephalometric parameters was assessed. Results: The distances between the foramina in the cranial base did not differ among the three groups. However, the Rot-IF length was shorter in female Class III patients, while the Ov-MTF length, MDF-MTF length, and Ov-MDF length were shorter in Class II patients than in Class III patients of both sexes. The MDF-MTF/FH plane angle was larger in Class II patients than in Class III patients of both sexes. Most parameters showed moderate to high correlations, but the Ov-MDF-MTF angle showed a relatively low correlation with the gonial angle. Conclusions: The foramina of the trigeminal nerve can be used to supplement assessments based on the conventional skeletal landmarks on CBCT images.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.125-132
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• 2020

Purpose: The positions of the mandibular foramen (MnF) and the lingula affect the success rate of inferior alveolar nerve block. The objective of this study was to investigate aspects of the MnF and the lingula relevant for mandibular block anesthesia using cone-beam computed tomography (CBCT). Materials and Methods: Fifty CBCT scans were collected from a picture archiving and communications system. All scans were taken using an Alphard Vega 3030 (Asahi Roentgen Co. Ltd., Kyoto, Japan). Fifty-eight MnFs of 30 subjects were included in the study. The position of the MnF, the size of the MnF, the position of the lingula, the size of the lingula, and the shape of the lingula were measured and recorded. All data were statistically analyzed at a significance level of P<0.05. Results: The position of MnF was 0.1 mm and 0.8 mm below the occlusal plane in males and females, respectively. The horizontal position of the MnF was slightly anterior to the center of the ramus in males and in the center in females (P<0.05). The vertical position of the MnF was lower in females than in males(P<0.05). The MnF was an oval shape with a longer anteroposterior dimension. The height of the lingula was 9.3 mm in males and 8.2 mm in females. The nodular type was the most common shape of the lingula, followed by the triangular, truncated, and assimilated types. Conclusion: CBCT provided useful information about the MnF and lingula. This information could improve the success rate of mandibular blocks.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.183-189
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• 2019

The purpose of this study was to investigate the changes of the position of the mental foramen according to age by using panorama of children with mixed and early permanent dentition. 180 panorama of 6 to 13-year-old boys and girls were analyzed and PiView(Infinitt, Korea) program was used. The horizontal position of the mental foramen was evaluated by the relative position of the teeth. The vertical position of the mental foramen was evaluated by the ratios between the distance from the center of the mental foramen to the inferior border of the mandible and the distance from to the alveolar crest to the inferior border of the mandible. The mental foramen was horizontally located in the anterior aspect of the second primary molar(premolar), and vertically slight below the half of mandibular body. As the age increased, it moved to the posterior and the downward and showed a significant correlation with age.

• Restorative Dentistry and Endodontics
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• v.3 no.1
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• pp.7-11
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• 1977

One hundred and thirteen human mandibular first molars were injected with china ink, decalcified, cleared and used in study, in vitro, to determine the number of root, the number of root canals, canals per root, frequency and location of transverse anastomoses, frequency and location of lateral canals and frequency of the apical deltas. The results were as follows; 1. Most of the teeth showed three canals, but 21. 25% of the teeth were found to have two canals and 21. 25% of them four canals. 2. In so far as observing two canals per root, 77.0% of teeth were found to have two canals in mesial root and 25.7% of them in distal root. 3. In roots with two canals, the separated apical foramen appeared 59.8% in mesial side and 40.0% in distal side, and the common apical foramen 40.2% in mesial side and 60.0% in distal side. 4. Of the two root canals in one root, 37.3% of the canals were found to have transverse anastomoses and were usually located in the apical third of the root. 5. 25.7% of 113 teeth were found to have lateral canals, and ramifications were mainly located in the apical third of the root.

• Restorative Dentistry and Endodontics
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• v.7 no.1
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• pp.59-63
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• 1981

Ninety four human mandibular third molars were chosen to study the anatomy of the root canal. The experimental teeth were injected with china ink, decalcified, cleared and used in study, in vitro, to determine the number of root, the number of root canals, canals per root, frequency and location of transverse anastomoses, frequency and location of lateral canals and frequency of the apical deltas. The results were as follows: 1. Most of the teeth showed two canals, but 17.0% of the teeth were found to have one canal, 17.0% of them three canals, 3.2% of them four canals and l.1% of them five canals. 2. In so far as observing one canal per root, 17.0% of the teeth were found to have one canal in single-rooted tooth, 48.9% of them in mesial root and 58.5% of them in distal root. 3. In roots with two or three canals, the separated apical foramen appeared in 55.6% in single-rooted tooth, 64.3% in mesial side and 80.0% in distal side, and the common apical foramen appeared in 44.4% in single-rooted tooth, 35.7% in mesial side and 20.0% in distal side. 4. Of the two root canals in one root, 19.1% of the canals were found to have transverse anastomoses and were usually located in the apical third of the root. 5. 63.8% of 94 teeth were found to have lateral canals, and ramifications were mainly located in the apical third of the root.

• Restorative Dentistry and Endodontics
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• v.5 no.1
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• pp.47-51
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• 1979

Fifty two human mandibular second molars were chosen to study the anatomy of the root canal. The experimental teeth were injected with china ink, decalcified, cleared and used in study, in vitro, to determine the number of root, the number of root canals, canals per root, frequency and location of transverse anastomoses, frequency and location of lateral canals and frequency of the apical deltas. The results were as follows; 1. Most of the teeth showed three canals, but 19.2% of the teeth were found to have two canals and 9.6% of them four canals. 2. In so far as observing two canals per root, 80.8% of the teeth were found to have two canals in mesial root and 9.6% of them in distal canal. 3. In roots with, two canals, the seperated apical foramen appeared in 59.5% in mesial side and 40.0% in distal side, and the common apical foramen appeared in 40.5% in mesial side and 60.0% in distal side. 4. Of the two root canals in one root, 36.2% of the canals were found to have transverse anastomoses and were usually located in the apical third of the root. 5. 23.1% of 52 teeth were found to have lateral canals, and ramifications were mainly located in the apical third of the root.