We did immunohistochemical staining for the expression of p16 and p73 to examine the cell proliferating ability in three different histological patterns of adenoid cystic carcinomas(aCC).In cribriform aCC, the p16 immunoexpression was observed in the nuclei of the inner cells of the cancer nests, while p73 was observed in the nuclei of the peripheral cells of the cancer nests and the cells facing pseudocysts. In tubular aCC, tubules were composed of two layer cells and the immunoexpression of p16 was observed in the ductal cells surrounding lumen, while p73 was observed in the nuclei of the outermost cells in the tumor nests. In solid aCC, p16-positive cells and p73-positive cells were intermingled in cancer nests. These findings suggest that p16 and p73 might be associated with cell proliferation.
It has been reported that 95% of diabetes mellitus patients in Japan exhibit the noninsulin dependent type II disease. We examined the development of connective tissue papillae in the free gingiva of the external marginal epithelium on the lingual side of mandibular first molars using normal rats and type II diabetes model rats under light and scanning electron microscopy. The development was poor in the diabetes mellitus (DM) group compared to the normal group. There were distinct morphological differences. Diabetes may not only impair the development of connective tissue papillae by causing regressive changes, but also delay periodontal tissue healing and aggravate periodontal disease.
We investigated the effect that different internal flexible mechanisms placed on implant had on occlusal contacts in the intercuspal position (ICP) when the implants were in mandibular unilateral free-end cases. We selected five subjects who had excellent clinical progression for five years or more after placement of the prostheses on IMZ implants. Informed consent was obtained from the subjects. Each of the three internal flexible mechanisms, the intramobile element (IME), the intramobile connector (IMC), and the titanium element (Ti), was placed inside the prosthesis. The registration of occlusal contacts using silicone impression materials was made during clenching in ICP at the two levels of 10 and 30% maximum voluntary clenching (MVC). We used the add-picture inspection method, which visualizes occlusal contacts by digital image processing, to quantitatively analyze the silicone occlusal records. We observed variations in the number and area of occlusal contacts between the two occlusal strengths. Statistical analysis was performed using the Wilcoxon test, Kruskal-Wallis test, and Friedman test to compare the occlusal contacts of the three mechanisms at two clenching levels (significance level : p<0.05). As the occlusal strength was increased from 10% to 30% MVC, the number and area of occlusal contacts on natural teeth increased significantly, regardless of the type of mechanism. although there was no significant difference in the number of occlusal contacts on the prostheses, the area of occlusal contacts increased significantly. although there was no significant difference in the rate of increase between natural teeth and the prostheses when IME and IMC were placed, a significant difference was seen when Ti was placed. These results indicate that there was an appropriate change in occlusal contacts because of displacements of the opposing teeth and strain on their supporting tissues irrespective of internal different flexible mechanism. We concluded that the influence of flexible mechanisms was not significant in the same individual.
We investigated various factors associated with deepbite malocclusion, which is generally thought to be difficult to treat. Standardized lateral cephalograms were taken on 60 adult Taiwanese females who had deep overbite when their teeth were in occlusion. We recorded vertical, horizontal and angular measurements and determined the degree of correlation between the overbite and 46 variables. Previous reports supported the findings of our study that overbite has a strong correlation with the vertical position of the canines and the inclination of the maxillary canines. Our results showed that orthodontists must first reduce the overbite in the canines before controlling the deep overbite in the incisors.
We clinically compared absorbent and non-absorbent membranes used in guided tissue regeneration at 3, 6, and 12 months after placement. We found a greater decrease in gingival recession, pocket depth, and attachment level with the non-absorbent membranes throughout the observation period. However, the difference was not significant. although the clinical findings improved at 6 and 12 months compared with 3 months. also, the differences at 6 and 12 months were slight regardless of the type of membrane used.
We investigated the use of ultrasonic imaging for orthodontic diagnosis by recording conventional cephalograms and ultrasonic images of 10 males and 10 females between the ages of 16 and 20 years who had normal occlusion. The ultrasonic device had a high frequency probe with a range of 9 to 14 MHz. When angular and linear measurements were calculated, we found that the average maximum difference between the measurements on the cephalograms and the ultrasonic images was 1.80 degrees for the angular measurements and 0.9 mm for the linear measurements. These results indicate that it is possible to use ultrasonic imaging for measurement of the craniofacial structures in the diagnosis of orthodontic patients without exposing the patient to x-radiation.
We used the medical charts of 136 patients seen at Osaka Dental University Hospital and Chibune Hospital during the past 16 years to determine the time of day when facial nerve palsy (FNP) occurred. FNP includes Bell's palsy (BP)and Hunt's syndrome (HS). The morning : afternoon : night ratio of occurrence was 68 : 10 : 27 for BP and 12 : 7 : 12 for HS. While 64.8% of the BP cases occurred in the morning, 38.7% of the HS cases occurred during this time. Our results for BP did not differ greatly from those of other reports. We concluded that BP is closely related to disturbances in the autonomic nervous system (aNS) or circadian rhythm. From this view point, we discussed the mechanism of onset of FNP.
We used quantitative light-induced fluorescence (QLF) clinically to quantitatively assess changes in white spot lesions of permanent enamel for different age groups and to determine the efficacy of a fluoride dentifrice on remineralization of these lesions. One hundred twenty-nine patients between 10 and 48 years of age were assigned randomly to a fluoride group and a placebo group. Sixty-five subjects used a fluoride dentifrice containing 950 ppm fluoride as sodium fluoride, and 64 used a non fluoride (placebo) dentifrice. The subjects were required to brush their teeth twice each day with the respective dentifrices for one year. Remineralization was evaluated by three QLF parameters : mineral loss ΔQ(%・mm2); lesion area S (mm2); and maximum lesion depth ΔMax(%). Measuremerits were made at three, six and twelve months after the baseline examination. We concluded that fluoride dentifrice promoted remineralization of clinical white spot lesions in all age groups. We also found that QLF was an effective method for measuring and quantifying the magnitude of this effect.
We investigated the dentofacial cephalometric changes of treatment with the headgear and bionator appliance on children with Class II division 1 malocclusion and mandibular retrusion. standardized lateral cephalograms were taken on 70 growing children before and after treatment. The control sample was obtained from the files of the Department of Orthodontics, Osaka Dental University. We compared the results with the data of a study on normal occlusion and evaluated the effectiveness of the appliances by comparing the experimental subjects before and after treatment with normal subjects during growth. The results showed that there was little change in the SNB angle in the experimental group compared with the controls. However, the headgear and bionator treatment produced a significant decrease in the SNa angle, aNB angle, and the angle of convexity, as well as a significant increase in the a-B plane angle, and the length of the mandible. Changes in the lingual inclination of the maxillary and the mandibular incisors were also observed. These results seem to indicate that the correction of a Class II division 1 malocclusion with the headgear and bionator appliance is achieved not only by a combination of maxillary and mandibular skeletal effects, but also by significant dental changes.
Cyclic mechanical stimuli on synovial cells have been implicated in pathogenesis of cartilage degradation and joint destruction, such as temporomandibular joint disease and rheumatoid arthritis. However, the precise mechanism of how tissue degradation is caused by cyclic mechanical loading has not been elucidated. Previously, we examined the short-term mechanical effects on matrix remodeling of three-dimensional (3 D) tissues containing human synovium-derived cells. However we did not examine the long-term effects. This study investigates the long-term effects of cyclic compressive loading on collagen-based engineered tissue containing human synovium-derived cells. Human synovium-derived cells were seeded in a collagen scaffold made of atellocollagen (Koken, Tokyo, Japan) to construct 3 D engineered tissue. Unconfined axial compressive loading was applied for 5 or 15 days at 0, 5 or 20 kPa at 0.5 Hz for 1 hour/day using a custom-designed cyclic load bioreactor. We examine the histology and mRNA expression levels for MMP-1, MMP-3, TIMP-1, IL-8, SOX9, type II collagen and aggrecan. Three-dimensional deformation was also measured every 5 days during the mechanical loading. Cell distribution and construction of the extracellular matrix were unaffected by mechanical loading at 5 and 20 kPa for 5 days. The collagen scaffold was fragmented only by loading at 20 kPa after 15 days. MMP-1, MMP-3, and IL-8 mRNA expression levels were up-regulated by the mechanical loading both at 5 and 15 days. Deformation of the 3D constructs significantly increased after 10 days at 20 kPa loading. This study showed that cyclic mechanical loading for longer period causes fragmentation of collagen-based 3D tissue with human synovium-derived cells, and that MMP-1 and MMP-3 might play a role in this process.
We investigated how guided tissue regeneration affected subsequent orthodontic tooth movement of the maxillary right first molars of Wistar rats. The animals were divided into three groups of 20 each. The buccal bone was reduced apical to the cementoenamel junction in two of the groups. In the experimental group, Gore-Tex GTR membrane was adapted and sealed to the root surface before suturing the flaps. No membrane was placed in the second, sham operation, group. No surgical procedure was done in the third, control, group. The membrane was removed after four weeks and orthodontic force was applied at that time to all the animals. Orthodontic force was removed after two weeks, and the amount of tooth movement was measured at that time and again two weeks later. Movement was greatest in the sham operation group, followed by the experimental and control groups, in that order. After two weeks of retention, the amount of relapse in the experimental group was almost the same as that in the sham and control groups. These results suggest that orthodontic treatment is possible following guided tissue regeneration.
We studied how changes in the occlusal plane of elementary school students affect growth and development. Lateral cephalograms were exposed of 16 male and 19 female Japanese elementary school children in the second and sixth grades. The subjects selected were all in Hellman's developmental stages IIC-IIIC at the time they were in the second grade, and had an ANB angle between 2 and 5.5 degrees. The angle formed by the occlusal plane and the mandibular plane (the OM angle) increased an average of 3.5 degrees during the four years. Twenty-eight of the 35 students had an increase in the OM angle, four showed a decrease, and three were essentially unchanged. In the majority of students who showed an increase, the total alveolar vertical growth of the mandibular incisors and maxillary molars was greater than the total alveolar vertical growth of the maxillary incisors and mandibular molars. In 23 of the 28 students who showed an increase in the OM angle, the ANB angle either decreased or remained essentially unchanged. These results suggest that changes in the occlusal plane affect craniofacial growth.
A thorough understanding of dentofacial growth is indispensable for treatment of children with skeletal malocclusion. We did a longitudinal study to assess changes in the posterior face, dentoalveolar area and occlusal plane in school children with untreated skeletal maxillary protrusion. Lateral cephalograms were obtained for 16 boys and 10 girls in the second grade of elementary school (mean age 7 years 8 months) who exhibited skeletal maxillary protrusion with an ANB angle greater than 5.5 degrees. Analysis indicated that their OM angle (the angle between the occlusal plane and the mandibular plane) was on average 2.5 degrees greater than normal. Four of the 26 children had an apparent increase in the OM angle that ranged from 2.3 to 3.4 degrees. There was no indication that this increase in the OM angle correlated with changes in the SNA, SNB or ANB angles measured in the children during the second and sixth grades. The increase, however, did correlate with growth of the mandibular ramus. These findings indicated that growth of the dentofacial profile in school children, in particular vertical growth of the mandibular ramus and molar region, has significant influence on lower face morphology. The occlusal plane also had a strong influence.