• Imaging Science in Dentistry
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• v.54 no.1
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• pp.93-104
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• 2024

Chronic nonbacterial osteomyelitis(CNO) is histologically characterized by nonspecific osteitis. This inflammatory disorder, which lacks an infectious origin, typically presents with chronic pain and swelling at the affected site that can persist for months or even years. However, it is rare for CNO to affect the mandible. A 10-year-old girl presented with a primary complaint of pain in her left mandible. She had no significant medical or dental history. On examination, swelling was visible on the left buccal side, and imaging revealed radiolucent bone deterioration within the left mandible. This case report presents the radiological changes observed over a 12-year follow-up period. Variations in radiopacity, radiolucency, and periosteal reactions were noted periodically. This case highlights the radiological characteristics and findings that are crucial for the diagnosis of CNO, a condition for which no clear diagnostic criteria are currently available.

• The Journal of the Korean dental association
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• v.5 no.1
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• pp.75-78
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• 1964

1.The author have had a case of partial andontia. 2. The first examination of mandible development and intra-oral sign was reexamined four years later. 3. The disturbance was shown on the mandible development and mastication.

• The Journal of Korean Academy of Prosthodontics
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• v.8 no.1
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• pp.95-100
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• 1968

The author measured the vertical and horizontal change in molars and incisors of mandible arch by means of lateral roentgeno-cephalometric tracing. The subjects measured here were 244 healthy Korean male and female at the range of 5. 7. 10. 15 and 20 years old, respectively. Following results were obtained; 1. The horizontal measurements of lower first molar to mandible arch were as follows; 5 years of male; $43.14{\pm}0.84mm$ 5 years of female; $40.66{\pm}0.91mm$ 20 years of male; $43.08{\pm}1.59mm$ 20 years of female; $39.88{\pm}1.35mm$ None of the significant changes with age showed. 2. The horizontal measurements of lower incisors to mandible arch were as follows; 5 years of male; $8.14{\pm}0.68mm$ 5 years of female; $7.90{\pm}0.64mm$ 20 years of male; $10.02{\pm}1.68mm$ 20 years of female; $7.38{\pm}1.27mm$ None of the significant changes with age showed. 3. The vertical measurements of lower first molar to mandible arch were as follows; 5 years of male; $24.92{\pm}1.17mm$ 5 years of female; $25.02{\pm}1.64mm$ 20 years of male; $39.04{\pm}1.66mm$ 20 years of female; $35.25{\pm}1.03mm$ The vertical height of lower first molar showed statistically significant increments. 4. The vertical measurements of lower incisors to mandible arch were as follows; 5 years of male; $27.54{\pm}1.52mm$ 5 years of female; $27.62{\pm}1.78mm$ 20 years of male; $48.73{\pm}1.51mm$ 20 years of female; $45.52{\pm}0.82mm$ The vertical height of incisors showed statistically significant increments. 5. The growth and development of lower first molars and incisors revealed significant increment rates vertically with age. 6. It semed that the vertical and horizontal changes in male were greater than those in female.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.17 no.1
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• pp.209-222
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• 1987

The author invested the gonial angle, the angle of mandibular and mental canal to the lower border of the mandible, and a relationship of the position of the mandibular canal to the root apex of the posterior teeth and the cortical plate of the lower of the mandible. The materials consisted of 458 pantomograms in male and female aged 11-40 and divided into 5 groups at 5 year intervals and subdivided into 3 groups by gonial angle. The results were as follows; 1. The gonial angle decreased with age, but slight increase occurred over 26-30 years. 2. The average angle of the mandibular canal to the lower border of the mandible was 151.6° and did not correlate with age. 3. The average angle of the mental canal to the lower border of the mandible was 36.9° and didn't correlate with age. 4. The angles of mandibular and mental canal to the lower border of the mandible correlated with gonial angle. 5. The distance from the root apex of the posterior teeth to the upper wall of the mandibular canal was most short at the region of the distal root of the mandibular second molar and increased with age at the region of the mandibular second molar. 6. The distance from the lower wall of the mandibular canal to the cortical plate of the lower border of the mandible was most short at the region of the mesial root of the mandibular first molar and didn't correlate with age.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.1
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• pp.24-30
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• 2002

The facial patterns were expressed by the interrelation of variable factors such as heredity, function and environment. Such variable factors have an effect on the growth and development of maxillofacial bones. The malocclusions with skeletal discrepancies are caused by abnormal forms, sizes and positions of cranial base, maxilla and mandible. For the proper diagnosis and treatment planning, the analysis of such structures is necessary. Lateral cephalograms of 54 adults with class III malocclusion patients (test group) and 61 adults with normal occlusion (control group) were analyzed. Anteroposterior relations and sizes of cranial base, maxilla, mandible were estimated to compare with those of normal ones. In test group, the anterior cranial base length was within normal range, but posterior cranial base, maxilla and mandibular body were longer than those in control group, significantly. Based on the cranial base, the location of maxilla in test group was normal, but the location of mandible was more anterior than that in control. Based on the maxilla, the location of mandible was more anterior in test group than that in control. Both mandibular body and ramus anteroposterior lengths in test group were larger than those in control. Both mandibular plane angle and upper gonial angle were within normal range, but lower gonial angle was significantly high in test group.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.286-318
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• 1992

The objective of preventive dentistry is the maintenance of a healthy dentition for the life of a patient. Unfortunately, if an individual has not received the benefit of a comprehensive program of preventive dentistry and has finally reached the edentulous state, as a consequence, he receives a set of complete denture. Dentures are mechanical devices and subject to the principles of mechanics. In some cases, the general health and nutritional status of the patient are felt to be the causative factors. But, the most important thing in residual ridge resorption is felt to be caused by the unequal distribution of functional forces. This study was to analyze mandibular stresses of complete denture occlusion by three dimensional finite element method. The results were as follows ; 1. As deformation and stress distribution of the complete denture of the mandible were concentrated on the upper lingual side of the mandible, alveolar ridge resorption of the mandible occurred from lingual side to labio-buccal side. 2. Analyzing by three dimensional F. E. M., the mandible is a very effective form for tolerating stress and deformation biomechanically. 3. According to the concentration of stress distibution in the upper buccal side of the lower posteriors, buccal shelf area must be a primary stress bearing area in the lower complete denture. 4. Lower complete denture moved horizontally to the balancing side under lateral occlusal force. 5. Bilateral balanced occlusion should be constructed in the complete denture for denture stability, especially in the protrusive movement. 6. Physical property of the denture base material was as important for stress distribution in the denture base as or even more than that in the mandible. 7. Impression technique is very important because of most of stress was concentrated between them due to close contact of the mandible and the denture base.

• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.218-226
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• 2012

PURPOSE. The purpose of this study was to propose finite element (FE) modeling methods for predicting stress distributions on teeth and mandible under chewing action. MATERIALS AND METHODS. For FE model generation, CT images of skull were translated into 3D FE models, and static analysis was performed considering linear material behaviors and nonlinear geometrical effect. To find out proper boundary and loading conditions, parametric studies were performed with various areas and directions of restraints and loading. The loading directions are prescribed to be same as direction of masseter muscle, which was referred from anatomy chart and CT image. From the analysis, strain and stress distributions of teeth and mandible were obtained and compared with experimental data for model validation. RESULTS. As a result of FE analysis, the optimized boundary condition was chosen such that 8 teeth were fixed in all directions and condyloid process was fixed in all directions except for forward and backward directions. Also, fixing a part of mandible in a lateral direction, where medial pterygoid muscle was attached, gave the more proper analytical results. Loading was prescribed in a same direction as masseter muscle. The tendency of strain distributions between the teeth predicted from the proposed model were compared with experimental results and showed good agreements. CONCLUSION. This study proposes cost efficient FE modeling method for predicting stress distributions on teeth and mandible under chewing action. The proposed modeling method is validated with experimental data and can further be used to evaluate structural safety of dental prosthesis.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.271-276
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• 2009

The aim of this study was to evaluate the effect of Bone Mineral Density(BMD) at mandible. So, we studied how to measure the BMD at mandible using DEXA(Dual energy X-ray absorptiometry, DEXA) by Horner er al (1996) and knew reproducibility of the measurements. Thirty-five patients (13 men, 22 women, mean age : 25.4 years) were examined using the GE Lunar Prodigy Advance(LUNAR Corporation, madison, USA). They were examined in Semiprone position of their body and true lateral position of their mandible selected the Lumbar lateral mode. We used the custom mode in analysis when ROI (area $30{\times}2.5\;mm^2$). Three ROIs ($30{\times}2.5\;mm^2$, $50{\times}2.5\;mm^2$, $20{\times}2.5\;mm^2$) were located each at the two different sites of the mandible (angle of mandible and mental symphysis) and BMD was measured. Differences in BMD measurement was statistically compared according to the size and location of ROI. BMD was $1.320{\pm}0.358g/cm^3$ in men and was $1.152{\pm}0.340g/cm^3$ in women. BMD at the angle of mandible was $1.201{\pm}0.361g/cm^3$ in men and was $1.025{\pm}0.377g/cm^3$ in women. BMD of men at the mental symphysis was $1.434{\pm}0.341g/cm^3$ and that of women was $1.19{\pm}0.358g/cm^3$. With the ROI of $20{\times}2.5\;mm^2$, BMD was $1.262{\pm}0.384g/cm^3$ in men and was $1.113{\pm}0.357g/cm^3$ in women. With the ROI of $50{\times}2.5\;mm^2$, BMD of men was $1.320{\pm}0.358g/cm^3$ and that of women was $1.129{\pm}0.340g/cm^3$. There was a statistically significant difference of BMD according to the size and location of ROI. When measuring mandible BMD, there are good for increasing ROI and locate between ramus and mental symphysis. Especially following exam, refer to same size and location with fore exam. According to study which measure mandible BMD, It's correct to measure better a portion of mandible then whole of BMD. Using DEXA protocol is studied good for the additional study to compare the BMD at mandible. Later date, It will be good for measurement value in implant and bone graft quantitatively. Using DEXA method gain BMD threshold value in korean.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.4
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• pp.549-564
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• 1993

The purpose of this study was to research the condylar path and the anterior angle of glenoid fossae and classify the patterns of condylar path. Thirty male and female dental students with normal occlesion and masticatory system ranging in age from 21 to 30, without present symptoms and an)r history of TM joint disturbance, were selected for this study. Transcranial radiographs of TM joints under mandibular lateral movement were obtained. By the computer analysis on the radiographs, the angle of posterior slope of articular eminance, the sagittal condylar guidance angie, condylar movement patterns and the height of glenoid fossa was measured respectively, and studied their interrelationship comparatively. The results obtained were as follows : 1. The total distance of condylar movement on balancing side during mandibular lateral movement was 4.55mm for Lt. and 4.78mm for Rt. when mandible moved from C.R. to canine to canine relation and 7.86mm for the Lt. and 8.10mm for the Rt. when mandible moved from C.R. to 7.5mm. 2. The horizontal distance of condylar movement on balancing side during mandibular lateral movements was 3.16mm for the Lt. and 3.52mm for the Rt. when mandible moved from C.R. to canine to canine relation and 6.10mm for the Lt. and 6.30mm for the Rt. when mandible moved from C.R. to 7.5mm. 3. The sagittal condylar guidance angle on balancing side during mandibular lateral movements was $45.96^{\circ}$ for the Lt. and $43.22^{\circ}$ for the Rt. when mandible moved from C.R. from canine to canine relation and $41.14^{\circ}$ for the Lt. and $39.77^{\circ}$ for the Rt. when mandible moved from C.R. to 7.5mm. 4. The height of glenoid fossa was 8.23mm for the Lt. and 7.80mm for the Rt. and the angle of posterior slope of articular eminence was $38.30^{\circ}$ for the Lt. and $38.79^{\circ}$ for the Rt. by method-A and $55.61^{\circ}$ for the Lt. and $55.64^{\circ}$ for the Rt. by method-B. 5. The sequence of the frequency of condylar movement patterns on balancing side during mandibular lateral movement were concave type(30 cases), convex type(16 cases), reverse S shape curve(9 cases) and S shape curve(5 cases) when mandible moved from C.R. to canine to canine relation and concave type(27 cases), 5 shape curve(13 cases), convex type(11 cases) and reverse S shape curve(9 cases) when mandible moved from C.R. to 7.5mm.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.5
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• pp.315-322
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• 2003

Background : Important factors to determine treatment method and prognosis of oral cancer are anatomical site, tumor size, metastatic lesion, histologic cell differenciation and microvascular invasion. Anatomical site has great effect to oral cancer patient's survival rate because each site's accessibility and lymph node metastasis is different but this factor was't studied much than other factors. Patients and Methods : 228 patients with squamous cell carcinoma of common primary sites(Mandible, Maxilla, Floor of Mouth and Tongue) in oral cavity who were diagnosed in the Korea Cancer Center Hospital from January 1989 to December 1999, were clinically studied and analyzed on survival rate. Results : 1. Survival rates of each anatomical sites were Tongue(36.8%), Mandible(33.3%), Maxilla(28.7%) and Floor of Mouth(24.5%). Survival rates difference between Tongue and Floor of Mouth has significance(p<0.05). 2. Survival rates for early cancer of each site were Maxilla(100%), Mandible(57.1%), Tongue(54.2%) and Floor of Mouth(46.7%). Survival rates difference between Maxilla and Floor of Mouth has significance(p<0.05). 3. Survival rates by surgery method of each site were Maxilla(60.6%), Tongue(56.9%), Mandible(44.8%) and Floor of Mouth(26.3%). Survival rates difference between Maxilla and Floor of Mouth has significance(p<0.05). 4. Survival rates by radiation or chemo method of each site were Floor of Mouth(23.5%), Mandible(20.0%), Maxilla(9.5%), and Tongue(9.1%). Survival rates difference between each site doesn't have significance(p>0.05). 5. In advance stage, Survival rates by single therapy of each site were Tongue(33.6%), Mandible(23.5%), Floor of Mouth(16.7%), Maxilla(0%), and Survival rates difference between Maxilla and Tongue has significance (p<0.05). Survival rates by combination therapy of each site were Mandible(38.1%), Maxilla(30.0%), Floor of mouth(18.2%), Tongue(12.5%), and Survival rates difference between Mandible and Tongue has significance(p<0.05). Conclusion : Survival rate of tongue is higher than the other sites, early detection of oral cancer can increase survival rate at any site and combination therapy is the most effetive method, especially at maxilla.