The effect of differential modulation of N-methyl-D-aspartate receptor on the proliferation of primary cultured normal human oral keratinocytes: DNA synthesis rate analysis

In the present study, I investigated the effects of N-methyl-D-aspartate (NMDA), arachidonic acid (AA), and Nitric Oxide Synthase Inhibitor (NOSI), alone or in combination, on the proliferation of cultured primary normal human oral keratinocytes (NHOK). The purpose of this study was therefore the preliminary study for the examination of the interaction between these agents and NHOK in order to elucidate the mechanisms by which epithelial growth and regeneration are regulated. NHOK were obtained from gingival tissue of 20 individuals aged 20 to 29, and third passage (P3) cells were used for this study. The DNA synthesis was measured by the BrdU assay. Addition of low concentration of AA (1 micro M) and high concentration of AA with NMDA group (NMDA+AA 10 micro M) made DNA synthesis rate increase significantly at the early stage. Adding NNA (10 micro M) affected DNA synthesis rate to increase significantly in 4 hours. At the early stage, DNA synthesis was significantly active in the NOS-I with NMDA groups than in the control and the NMDA-only group, while it didn't become statistically meaningful in 24 hours. AA 1 micro M and NNA 10 micro M may induce the proliferation of the NHOK independently and NOS-I may induce the proliferation of the NHOK with NMDA. These reactions might be related to the NMDA receptor in the cell and the change of the intracellular calcium ion concentration.

An Evaluation of Validity of Measurements using Digital Caliper and Three-dimensional Virtual Dental Models / 대한해부학회지

The measurement of tooth and the space analysis of dental study models are essential for precise diagnosis and treatment plan for orthodontic or prosthodontic cases. Traditionally, these have been done on study models with instruments, such as a divider or a caliper. At present, three-dimensional (3-D) virtual dental models are available for clinicians, supplemented by dedicated software for performing needed measurements on them. For example, Autoscan system for dental application(TM) (ASDA; INUS technology INC, Korea) is one of these systems using a non-contact 3- D scanner. The accuracy of this system has been tested and validated by the Korea Testing Laboratory. However, the outline of dental models is not simple and has many undercuts. Therefore, we sought to evaluate the accuracy of measuring models using digital calipers or ASDA to compare these two techniques. From each ten study models, 10 duplicated stone and 10 virtual models were generated. Virtual models were scanned from duplicated model because of revival of clinical situation. Then, central incisors, canines, first molars, arch (intercanine and intermolar) width of original model were measured by a digital caliper, and the same items of virtual models were measured by software. All measurements were performed twice by two experienced observers. Data were statistically analyzed by 2-way Analysis of Variance (2-way ANOVA, SPSS Ver. 11.5). The results from this study have demonstrated that virtual model is highly valid and reliable for measuring both tooth size and arch width. Although some values of virtual model are higher or lower than original dental model, the significance value is still higher than 0.97. A digital caliper seems to be a more precise instrument to perform a scientific work, ASDA's accuracy is clinically acceptable. Furthermore, considering its present advantages and future possible applications, the examined or equivalent 3-D virtual models may become the standard for clinical use.

7 years of Longitudinal Study on Pneumatization of Maxillary Sinuses using Lateral Cephalogram / 대한해부학회지

Maxillary Sinus is one of the four sinuses located in human skull, which is pyramidal shape of varying size and form. It has 4 surfaces, which are facial, infratemporal, orbital and nasal surface. It originates from invagination of mucosa at the middle nasal meatus, and the diameter at birth is reported to be only 3~4 mm. The primary pneumatization site is the inferior medial site of ethmoidal infundibulum, and the secondary pneumatization starts at 5 month after birth, proceeding inferior to the nasal capsule and penetrating the spongy bone of maxilla. This pneumatization phenomenon contributes the growth of maxillary sinus, and has been studied by several authors for many years. However, the study of the growth of human maxillary sinus, especially the longitudinal study, has been very scanty because of many reasons. Therefore, we studied the patterns of pnematization of human maxillary sinuses using longitudinal lateral cephalometric data. From 1995 to 2001, that is for 7 years, the lateral cephalograms of total 410 children (from 6 years old to 12 years) were taken with no loss of follow-up, after discarding the data which include lack of even one year. After tracing the outline of maxillary sinus, the area, height, and sagittal length of maxillary sinuses were measured. And the annual increase or decrease and sum of it were calculated. The descriptive statistics including average and standard deviation, and correlation test for each sex were performed using SPSS ver 10.0. The average area of maxillary sinuses were 470.70mm2 at 6, 544.31mm2 at 7, 604.80mm2 at 8, 647.35mm2 at 9, 761.04mm2 at 11, 837.01mm2 at 12 years old, and the total increase from 6 to 12 years old was 78.86%. The result of this study showed that there was weak to moderate sexual difference of pneumatization of maxillary sinus. And the correlation between somatic growth and the growth of maxillary sinus were statistically significant. However, the correlations were substantively non-significant since the correlation coefficients were relatively low. Continuing studies are thought to be mandatory for thorough understanding the growth of human maxillary sinus and its relation to the somatic growth.

Immunohistochemical Study of the Expression of NCAM in the Fungiform Papilla of the Young Rat Tongue Following Single Dose Radiation / 대한해부학회지

Radiotherapy in the treatment of head and neck cancers is often used either alone or in addition to surgery. Radiation disrupts the proliferative capacity of the cancer while doing as little damage as possible to the normal tissue. Nevertheless, conventional radiotherapy of advanced head and neck tumors is frequently associated with severe oropharyngeal mucositis. The fungiform papillae are found on the dorsal surface of the anterior 2/3 of the tongue and have one taste bud which always located on the superior side. In recent years, many study have demonstrated the location of neuropeptides in the intragemmal cells of the taste buds. We used neural cell adhesion molecule (NCAM) in this study. NCAM is a membrane surface glycoprotein found in neural tissue that functions in cell -cell interactions such as adhesion and recognition and may contribute to neuronal and receptoneural synaptogenesis. However, to the best of our knowledge, there is no study about NCAM in relation to dysgeusia, especially after radiotherapy. Therefore, we studied the change of the expression of NCAM in the fungiform papilla of the young rat tongue following single dose radiation. Twenty days old 18 Sprague -Dawley rats were used. Twelve rats were irradiated with a single dose of 17 Gy gamma radiation. We sacrificed rats 1, 7, 20 days after radiation. The anterior part of tongues were removed and cut into at 30 micro gram on a cryocut. Using the free floating method, we immunostained sections. In control group, NCAM is expressed on some intragemmal cells which were located in the center of the bud and intragemmal nerve fibers. NCAM -immunoreactive (ir) perigemmal nerve fibers were rare, however basal plexus fibers and subpapillary nerve bundle showed strong immunoreactivity. One day after radiation, taste buds had no detectable changes of the expression of NCAM. However, seven days after radiation, the number of NCAM -ir intragemmal cells was reduced and the shape of ir cells was deformed. Immunoreactivity of basal plexus fibers and subpapillary nerve bundle was also decreased. The surface of the papilla was transformed into dome shape. Twenty days after radiation, overall forms of buds were recovered except a few deformed NCAM -ir intragemmal cells. NCAM was expressed in the intragemmal cells which are thought to be related with taste sensation, and we speculate that NCAM participate synaptogenesis. However, more studies using immunoelectron microscopic method are required.

An Immunohistochemical and Immunoelectron Microscopic Study of Distribution of Neuropeptide Y in the Cat Spinal Trigeminal Subnucleus Caudalis after Pulpectomy / 대한해부학회지

The purpose of this study was to investigate the distribution of neuropeptide Y (NPY) in the cat spinal trigeminal subnucleus caudalis following pulpectomy of mandibular premolars and molar by means of an immunohistochemical and immunoelectron microscopic study. The animals were divided into normal and experimental group which were sacrificed at 14 days after pulpectomy. The results were as follows; 1. On the light microscopic observation of the spinal trigeminal subnucleus caudalis in normal group, NPY-immunoreactivity (IR) was weak within lamina I and lamina II outer. In pulpectomy group, NPY-IR was strong and appeared to extend into lamina I and lamina II inner at 14 days. 2. On the immunoelectron microscopic observation of the spinal trigeminal subnucleus caudalis in normal group, NPY-IR was revealed in axon terminals, dendrites, myelinated axons and unmyelinated axons. NPY-IR was associated with membrane structures within microtubules, synaptic vesicles, outer membrane of mitochondria and inner surface of the axolemma. In NPY-immunoreactive structure, there was a small amount of DAB precipita-tions. 3. On the immunoelectron microscopic observation of the spinal trigeminal subnucleus caudalis at 14 days in pulpectomy group, the number of NPY-immunoreactive axon terminals, dendrites, myelinated axons and unmyelinated axons was increased than normal group. DAB precipitations in NPY-immunoreactive structure was increased than normal group. Some NPY-immunoreactive axon terminal formed synaptic glomerulus and axoaxonic synapse. 4. The results indicate that NPY-IR was increased in the spinal trigeminal subnucleus caudalis after pulpectomy, and it is speculated that the increased NPY by injury of peripheral nerve may participate in the processing of nociception.

A Study on the Variations in Arteries and Nerves of the Infratemporal fossa in Korean / 체질인류학회지

The purpose of this study was to investigate the courses of the maxillary artery and variations of the arteries and nerves in the infratemporal fossa from 36 Korean adult cadavers. The results were as follows; 1. In the majority of the cases (81.9%), course of the maxillary artery runs lateral to the lateral pterygoid muscle. 2. The variations of the arteries and nerves in the infratemporal fossa could be classified into six types. In the most common (type 2, 61.1%), the maxillary artery runs lateral to the lateral pterygoid muscle, and the inferior alveolar lingual and buccal nerves lie medial to the maxillary artery. In the next (type 1, 20.8%), the maxillary artery runs lateral to the lateral pterygoid muscle and the inferior alveolar and lingual nerves lie medial to the maxillary artery, and buccal nerve lies lateral to the maxillary artery. The remaining types were type 3 (7.0%), type 4 (4.2%), type 5 (5.6%) and type 6 (1.4%) in order.

A Clinical and Anatomical Study on the Mandible for Inferior Alveolar Nerve Conductive Anesthesia in Korean / 체질인류학회지

This study was to investigate the various parts of the mandible related to inferior alveolar nerve conductive anesthesia in 228 dry skulls of Korean adults. Five morphological variations were observed and four measurements were undertaken. The following results were obtained. 1. The Position of coronoid notch in the anterior border of the ramus of mandible is classified into three types and percentage of each type was as follows : Type I (Coronoid notch in the middle part of the anterior border of the ramus of mandible) : 83.3% Type II (Coronoid notch in the inferior part of the anterior border of the ramus of mandible) : 12.7% Type III (No coronoid notch in the anterior border of the ramps of mandible) : 4.0% 2. The position of the lingula of mandible to the imaginary line of the molar occlusal plane is classified into three types and percentage of each type was as follows : Type I (Above the imaginary line of the mandibular molar occlusal plane) : 87.3% Type II (Coincide with the imaginary line of the mandibular molar occlusal plane) : 8.6% Type III (Below the imaginary of mandibular molar occlusal plane) : 4.3% 3. The position of the lingula of the mandible in the internal oblique line-posterior border of the ramus of mandible dimension is classified into three types and percentage of each type was as follows : Type I (Anterior part in the internal oblique line-posterior border of the ramus of mandible dimension) : 82.9% Type II (Middle part in the internal oblique line-posterior border of the ramus of mandible dimension) : 11. 4% Type III (Posterior part in the internal oblique line-posterior border of the ramus of mandible dimension) : 5.7% 4. The position of the apex of the lingula of mandible to the deepest point of the coronoid notch in the anterior border of the ramus of mandible is classified into three types and percentage of each type was as follows : Type I (Coincide with the deepest point of the coronoid notch) : 82.0% Type II (Above the deepest point of the coronoid notch) : 13.2% Type III (Below the deepest point of the coronoid notch) : 4.8% 5. The position of the apex of the lingula of mandible to the imaginary line of the mandibular molar occlusal plane is classified into three types and percentage of each type was as follows : Type I (Above the 8mm) : 65.7% Type II (Above the 5mm) : 18.6% Type III (Above the 10mm) : 15.7% 6. Angle between the line connecting the apex of the lingula of mandible-1-2 premolars in the contralateral side and median line of the mandible is classified into three types and percentage of each type was as follows : Type I (50°) : 67.2% Type II (45°) 21.4% Type III (55°) : 11.4% 7. The averages of the measurement of the various bony landmarks of the mandible related to inferior alveolar nerve conductive anesthesia were as follows : ① Distance from deepest point of the coronoid notch to internal oblique line : 9.2mm ② Distance from internal oblique line to the apex of the lingula of mandible : 11.6mm ③ Distance from deepest point of the coronoid notch to apex of the lingula of mandible : 19.7mm ④ Height of the lingula of mandible : 9.8mm

A Study on Morphology and Size of the Maxillary Lateral Incisor in Korean Adult / 체질인류학회지

Authors examined the morphology and size in the maxillary lateral insicor from Korean adults and the following conclusion have been drawn. 1. In the shapes of labial surface in maxillary lateral incisors, the quite prominent middle lobe, moderate prominent middle lobe, less prominent midd1e lobe were 20.60%, 69.85%, 9.55%, respectively. 2. In the shapes of incisal margin in maxillary lateral incisors, the arc shaped to the distal, round, nearly straight were 24.96%, 60.20%, 15.11%, respectively. 3. In the shapes of incisal angle in maxillary lateral incisors, the equal sized mesioincisal angle and distoincisal angle, larger distoincisal angle, much larger distoincisal angle were 8.36%. 67.34%, 24.30%, respectively. 4. In the shapes of lingual surface in maxillary lateral incisors, the marked shovel (Ms), semi-shovel (Ss), trace shovel (Ts), no shovel (No) were 43.00%, 33.50%, 19.50%, 4.00%, respectively. 5. The size of the maxillary lateral incisors were as follows. 6. In comparison with Wheeler's data, crown length, crown width and crown thickness were larger in Korean adult, but the degree of cervical curvature were smallest.