• Imaging Science in Dentistry
• /
• v.49 no.1
• /
• pp.71-77
• /
• 2019

Primary intraosseous squamous cell carcinoma is a rare malignant central jaw tumor derived from odontogenic epithelial remnants. Predominantly, it affects mandible, although both jaw bones may be involved. This report describes a 60-year-old man who was initially misdiagnosed with a periapical infection related to the right lower wisdom tooth. After four months, the patient presented to a private dental clinic with a massive swelling at the right side of the mandible. Panoramic radiographs and advanced imaging revealed a lesion with complete erosion of the right ramus, which extended to the orbital floor. A biopsy from the mandibular angle revealed large pleomorphic atypical squamous cells, which is the primary microscopic feature of a poorly differentiated squamous cell carcinoma.

• Journal of Oral Medicine and Pain
• /
• v.45 no.4
• /
• pp.115-119
• /
• 2020

Infectious myositis, an infection of the skeletal muscles, is a rare condition and potentially life-threatening if not detected and treated in the early stages. This clinical entity may arise from various pathogens, such as bacteria, fungi, parasites, and viruses. A propagation of contiguous infection, penetrating trauma, vascular insufficiency, or hematogenous spreading of microorganisms can cause infectious myositis. Though several cases have been reported in large muscle groups in the lower extremities, there are only a few reports on infectious myositis of the masticatory muscles. We report three cases of infectious myositis presenting jaw pain and trismus. Unlike a common head and neck infection caused by the spreading of odontogenic origin, the early diagnosis of infectious myositis was difficult because no specific lesion suspected to be the infection source was observed in the physical examination and the plain radiographs. Advanced imaging modalities such as computed tomography and magnetic resonance imaging, and laboratory evaluation is useful for the early detection of infectious myositis.

• The korean journal of orthodontics
• /
• v.30 no.5 s.82
• /
• pp.643-655
• /
• 2000

In Patients with severe skeletal discrepancy, surgical orthodontic treatment must be accompanied, and recently two jaw surgery has become a common procedure, resulting in improved esthetics and function. Choosing the position of the occlusal plane in this two jaw surgery is an important factor in postoperative stability Therefore this must be taken into consideration during the diagnosis and treatment plan. In this study, among patients with skeletal Class III occlusion, 25 patients(8 male, 17 female, average age $23.2{\pm}3.17$) who have undergone two jaw surgery, setting the ideal occlusal plane according to Delaire's architectural and structural cranial analysis. In comparing preoperative($T_1$). postoperative($T_2$, average of 15.4 days), and long-term postoperative($T_3$, average of 32.6 months) lateral cephalometric radiography, the following conclusions have been made. 1. There were no significant changes of the occlusal plane angle after the two jaw surgery, and there were no significant differences between the surgical technique(SSRO and IVRO). 2. The postoperative changes of the occlusal Plane had no relationship with the amount of jaw movement, amount of posterior impaction, nor the time relapse after surgery. 3. After two jaw surgery, in the SSRO group there was significant forward movement of the mandible, and in the IVRO group the lower incisors extruded as the mandible moved backward and downward which makes the genial angle and the mandibular plane angle significantly increased

• Journal of dental hygiene science
• /
• v.10 no.1
• /
• pp.11-16
• /
• 2010

The subjects of this study were patients at scaling practice, the total number of the subjects was 249 of 138 men and 111 women. The results were analyzed using SPSS 12.0. 1. In oral health care, among tooth brushing methods, scrub method was found to be 65.9%(164 patients), and 83.9%(209 patients) did not use oral care aids. 2. Mean calculus index was $0.57{\pm}0.22$. 3. For calculus index per tooth brushing method, there was statistically significant difference in all of the upper jaw, the lower jaw, the anterior portion, and the posterior portion(p < 0.05). 4. For calculus index per frequency of tooth brushing, there was statistically significant difference in the upper jaw, the lower jaw, and the posterior portion(p < 0.05). 5. For calculus index per time of tooth brushing and per use of oral care aids, there was statistically significant difference in all of the upper jaw, the lower jaw, the anterior portion, and the posterior portion(p < 0.05). 6. For factors influencing calculus index, as a result of applying stepwise method based on 0.05 of significance level, age, use of oral care aids, sex, and time of tooth brushing were found to influence calculus index. Final regression model was calculus index = $0.362^*age+0.216^*$use of oral care aids - $0.161*sex-0.127^*$time of tooth brushing, and explanatory power of the model was 23.4%. $0.362^*age+0.216^*$use of oral care aids - $0.161^*sex-0.127^*$time of tooth brushing, and explanatory power of the model was 23.4%.

• Journal of Korean Dental Science
• /
• v.8 no.2
• /
• pp.65-73
• /
• 2015

Purpose: Parathyroid hormone (PTH) therapy has drawn attention, as an alternative to anti-resorptive drugs since PTH accelerates bone density by anabolic action. The purpose of this study was to identify the effect of intermittent PTH administration on jaw bones of rat undergone bilateral ovariectomy. Materials and Methods: Nine female Sprague-Dawley rats were divided into three groups. PTH group was ovariectomized (OVX) to induce osteoporosis and PTH $30{\mu}g/kg$ was administered 1 week after the surgery. In OVX group, ovariectomy was performed and only vehicle was administered by subcutaneous injection 3 times per week. Control group was subjected to sham surgery. The animals were sacrificed 8 weeks after the surgery and specimens were obtained from ilium and upper and lower jaw bones. Histological investigation was carried out by using an optical microscope and micro-computed tomography was taken to examine structural property changes in each bone sample. Result: In the ilium, the bone volume ratio (bone volume/total volume, BV/TV) of PTH, OVX and control groups was $53.75%{\pm}7.57%$, $50.61%{\pm}12.89%$, $76.20%{\pm}5.92%$ (P=0.061) and bone mineral density (BMD) was $1.12{\pm}0.09$, $0.88{\pm}0.48$, $1.38{\pm}0.07g/cm^3$ (P=0.061). In the mandible, BV/TV of PTH, OVX and control groups was $64.60%{\pm}12.17%$, $58.26%{\pm}9.63%$, $67.54%{\pm}14.74%$(P=0.670) and BMD was $1.21{\pm}0.17$, $1.19{\pm}0.13$, $1.27{\pm}0.18g/cm^3$ (P=0.587). In the maxilla, BV/TV of PTH, OVX and control groups was $61.19%{\pm}8.92%$, $52.50%{\pm}11.22%$, $64.60%{\pm}12.17%$ (P=0.430) and BMD was $1.20{\pm}0.11$, $1.11{\pm}0.16$, $1.21{\pm}0.17g/cm^3$ (P=0.561). No statistically significant difference was found in any variables in all groups. Histological observation revealed that the ilium in OVX group demonstrated sparsely formed trabecular bones compared with other groups. However, upper and lower trabecular bones did not present significant differences. Conclusion: Intermittent administration of PTH appears to affect the microstructure of rat jaw bones, but statistical significance was not found. However, the measurements in this study partly implicated the possible anabolic effect of PTH in vivo.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.23 no.2
• /
• pp.107-114
• /
• 2001

Objectives : To compare jaw bone density of young adults (control group) and post-menopausal women(experimental group) in periapical and panoramic film. Materials and Methods : The bone mineral density values of lumbar and femur were measured by dual-energy X-ray absorptiometry(DEXA) and T scores of lumbar were obtained. T scores were classified into 3 group (T<-2.5, $-2.5{\leqq}T<-1$, $-1{\leqq}T$). Radiographic densities of alveolar bones were measured from interdental bones of premolar, molar areas in the maxilla and mandible and expressed into copper step wedge thickness by Scion $Image^{(R)}$ program. We considered these values of step wedge thickness as bone density of alveolar bone. Panorama mandibular index(PMI) was calculated by the method that the height of the inferior cortex of the mandible was divided by the height from the lower border of the mandible to the superior edge of the mental foramen. Bone density of alveolar bone and PMI were analysed statistically. Results : There were significant differences in bone mineral density of lumbar and femoral neck between control and experimental groups. There were also significant differences in bone density of premolar and molar area of jaw between control and experimental groups by MANOVA test. When considered lumbar T variables, there was only difference in interdental bone density of maxillary molar area between control and experimental group, but there was interaction. Interdental bone density of experimental group was appeared higher in $-1{\leqq}T$ group and lower in T<-2.5 group than control group. There was significant difference in PMI between control and experimental groups, but there was also inter action, thus, PMI of experimental group was appeared higher in $-1{\leqq}T$ group and lower in T<-2.5 group than control group. Conclusion : There were significant differences of alveolar density and cortical bone thickness between young men and post-menopausal women in periapical and panoramic film. These differences were dependent on lumbar T.

• The Korean Journal of Physiology
• /
• v.3 no.1
• /
• pp.33-44
• /
• 1969

Electoromyographic studies were performed on the action of the muscles of the temporomandibular joints following exfoliation of the deciduous teeth. The subjects examined, being 50 children. between the age of 6 and 13 years, divided into 5 groups. They were; 1) Deciduous dentition were complete in the first group. 2) Deciduous incisors were missing in either upper or lower jaw in the second group. 3) Deciduous canine and molars were missing in the left side of either upper or lower jaw in the third group. 4) Deciduous canine and molars were missing in the right side of either upper or lower jaw in the fourth group. 5) Permanent dentition completed in the fifth group(except third molars). Electromyogram was recorded with 4 channel polygraph (Grass model VII modified for 7P3). Electrodes which were the cup-typed gold discs, 9 millimeters in the diameter, were located on the anterior, middle and posterior lobes of the temporal muscles, and also on the superficial and deep layers of the masseter muscles. Paired electrodes were held by electrode cream so that they were pressed on the skin surface at right angle, adhesive tape being used to anchor them. The distance of the pair electrodes was about 5 millimeters. The results obtained were as follow: 1) In rest position of mandible; All groups showed slight, electrical activities in the muscles involved, but in the middle lobe of temporal muscle they were slightly higher. 2) In molar occlusion of mandible; High activity-anterior lobe of temporal muscle and superficial layer of masseter muscle. Moderate activity-deep layer of masseter muscle. Low activity-middle and posterior lobes of masseter muscle. There were no differences among the first, the second and the fifth groups. In the third group the muscle activity was weaker than that of the right, and in the fourth group opposite characteristics was revealed. 3) In incisal bite of mandreble; Hight activity-superficial layer of masseter muscle. Modertae activity-deep layer of masseter muscle. Low activity-anterior, middle and posterior lobes of temporal muscle. The first, the third, the fourth and the fifth groups showed no differences but the second group showed less activity than those of others. 4) In protrusion of mandible; High activity-deep layer of masseter muscle Moderate activity-superficial layer of masseter muscle. Low activity-anterior, middle and posterior lobes of temporal muscle. In the first, the fourth and the fifth groups, there were no differences in the activities, but the second group showed less activity than the others. 5) In retrusion of mandible; High activity-deep layer of masseter muscle. Moderate activity-superficial layer of masseter muscle. Low activity-anterior, middle and posterior lobes of temporal muscle. In the first, the third, the fourth and the fifth groups, there were no differences but the second group showed less activity than the others. 6) In lateral excursion of the mandible (either direction); High activity-posterior lobe of temporal muscle. Moderate activity-anterior and middle lobes of temporal muscle. Low activity-superficial and deep layers of masseter muscle. The muscle action potentials were weaker than those of the right side in the third group and vice ver'sa in the fourth group. 7) In chewing movement; Temporal muscle activities were higher than those of masseter, especially in the middle lobe of temporal muscle the activity was highest. Right side muscle activities were higher than those of the left in the third group and, on the contrary, the left side was dominant over the right in the fourth group.

• Korean Journal of Ichthyology
• /
• v.5 no.1
• /
• pp.85-95
• /
• 1993

Sexual dimorphism of the matured chum salmon, Onchorhynchus keta, have been studied based on biometrical measurements and osteological characters. Male chum salmon has an elongated and hooked upper jaw and canine-like teeth on the upper and lower jaw. The ratios of snout length (SnL) and upper jaw length (UJ) to head length of male were larger than those of the female, whereas eye diameter (ED) and postorbital part of head (CK) of the male were smaller than those of the female's. The ratios of body depth, caudal peduncle depth, anal fin length and adipose fin length to the standard length (PBL) of the male were also larger than those of the female. On sexual dimolrphism was detected in number of fin rays, gill rakers and pyloric ceaca, where as number of lateral line scales and caudal vertebrae of the female was larger than those of the male. Glossohyal and vomer bones has no sexual difference. The ratio of width to length of supraethmoid bone of the male was larger than that of the female. The ratio of frontal part to posterior part of parasphenoid bone of the male was smaller than that of the female.

• The Journal of Korean Academy of Prosthodontics
• /
• v.38 no.3
• /
• pp.310-320
• /
• 2000

Statement of the problem. The record base in fabricating procedures of the complete denture, as a temporary form for reproducing denture base, is used to record upper and lower jaw relation and to align artificial teeth and try-in it in the mouth. The accuracy of jaw relation record is affected by the accuracy, stiffness and stability of the record base. So, the accuracy of record base is the most important requirements of jaw relation records. Purpose of study. The purpose of this study was to evaluate the gap that occurred over the palatal area of a maxillary record base fabricated with autopolymerizing resin and light-curing resin. Methods/material. The maxillary record bases were fabricated out of autopolymerizing resin that is used the most frequently in clinics and light-curing resin that attracts special attention for its several merits. The light-curing resin was made by two kinds of polymerization methods, which are one step curing method and multiple step curing method. All record bases were cut in certain positions of the master cast 1 hour and 1 day later after fabrication and the accuracy of the master cast was measured and analyzed with a microscope. Results. A pattern of gap formation between the record base and the maxillary cast was observed in all specimens. According to kinds of resins, autopolymerizing resin was significantly more accurate than light-curing resin. There was no statistical difference according to time lapse, and in all three groups, the maximum discrepancy occurred at the posterior border in the mid-palatal region. Conclusion. The autopolymerizing resin is better than light-curing resin, and multiple step curing method is more accurate than one step curing method when using light-curing resin.

• Journal of Periodontal and Implant Science
• /
• v.23 no.1
• /
• pp.127-134
• /
• 1993

The purpose of this study was to observe the control effect of hypersensitivity after periodontal treatment in the 19% microcrystalline hydroxyapatite containing toothpaste for the subject of 85 persons of both sexes, who complained hypersensitivity. At 2 weeks and 4 weeks after periodontal treatment, comparison of control effect was performed between the 19% microcrystalline hydroxyapatite containing toothpaste group and control group. The result were as follows, 1. The main causes of dentin hypersensitivity are the root exposure with gingival recession and cervical abrasion. 2. The occurance rate of hypersensitive tooth in the upper jaw was higher than that of the lower jaw, and more or less, the molar area showed more occlurance of hypersensitivity than the premolar and incisor area in both jaw. 3. Patients showed very sensitive response to the thermal stimulus, especially cold stimulus. 4. Exellent control effect of hypersensitivity in 19% microcrystalline hydroxyapatite containing toothpaste group showed 83.02% at 2weeks, 92.45% at 4weeks and these values were higher than the control group. In conclusion, we find that 19% microcrystalline hydroxyapatite containing toothpaste have the control effect of hypersensitivity and the proper toothbrushing method is the key in attaining more effectiveness of the toothpaste.