We examined changes in the pharyngeal airway space of skeletal open bite patients receiving orthodontic treatment. To compare jaw relationships, the position of the hyoid bone and pharyngeal airway space were examined for each case using sets of three lateral cephalometric radiographs that were taken before treatment (A1), after treatment (A2) and for control (N). Craniofacial skeletal measurements revealed no significant differences in ∠SNA between Groups A1 to A2. Although ∠SNB and the ∠MP showed a slight increase between Groups A1 and A2, the difference was not significant.
Measurements of the cervical vertebrae, tongue and velum revealed that HSN and S-H were significantly greater in Group A1 than in Group N. Both HSN and S-H increased significantly between Groups A1 to A2. C3-H in Group A1 was significantly less than in Group N, and showed a significant decrease between Groups A1 and A2. ∠SP was significantly less in Groups A1 and A2 than in Group N. No significant difference was seen between the measurements of Groups A1 and A2. The values for D1 in Groups A1 and A2 were significantly greater than for Group N. There were significant differences between Groups A1 and A2. Measurements of the superior posterior pharyngeal airway space, SPPS, and the middle pharyngeal airway space, MPS, in Group A1 were significantly less than in Group N, indicating a narrowing of the pharyngeal airway width. SPPS and MPS in Group A2 were significantly decreased compared with Group A1, indicating a narrowing after treatment. There were no significant differences in the palatal pharyngeal space, PPS, and the epiglottic pharyngeal space, EPS, in Groups A1 and A2, respectively.
These results suggest that the pharyngeal airway space decreased after orthodontic treatment of skeletal open bite caused by posterior inclination of the soft palate.

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We investigated how different surgical procedures affect pharyngeal airway changes through a comparative analysis of skeletal mandibular prognathism patients treated by sagittal split ramus osteotomy surgery (SSRO) with and without Le Fort I osteotomy surgery. Twenty patients who were diagnosed as having skeletal mandibular prognathism were divided into two groups : 10 patients who underwent mandibular setback surgery using SSRO (SSRO group) and 10 who underwent two-jaw surgery using Le Fort I osteotomy and SSRO surgery (Two-jaw group). To compare the jaw relationship, the position of the hyoid bone and pharyngeal airway morphology were examined in each group using lateral cephalometric radiographs that were taken before surgery (T0) and after more than one year and six months post-surgery (T1). The surgical changes between T0 to T1 were calculated and statistically compared for the two groups. The result, tongue position did not appear to change significantly between the two groups. The palatal pharyngeal space increased significantly in the Two-jaw group, while there was no significant difference in the SSRO group. The superior posterior and middle pharyngeal space decreased significantly in the SSRO group, while there was no significant difference in the Two-jaw group. All changes showed significant difference between the two groups. In contrast, the epiglottic pharyngeal space decreased in both groups. The ratio was bigger in the SSRO group than in the Two-jaw group. We concluded that the surgical method influences the pharyngeal airway space for patients treated only with SSRO and for those who recieved two-jaw surgery.

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We investigated the granule interspaces created for vascular formation when a bone defect is filled with four sizes of β-TCP granules. Bone defects in experimental animals and models were filled with the granules. Images were obtained from the samples using micro-CT imaging, and the average volume of the granule interspaces was measured by 3D image analysis software. When a bone defect was filled with granules, the larger granules created lager interspaces. It is thought that maintenance of the granule interspaces when filling the defect may favor microvascular development and new bone formation. Therefore, we speculated that granule resorption might be faster with a smaller granule size. However, it is also thought that smaller interspaces might lead to less microvascular formation, further delaying new bone formation.

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We investigated how granule interspaces affected vascular formation when a bone defect is filled with different sizes of β-TCP granules. Bone defects in the experimental animals were filled with four sizes of β-TCP granules. Bone and microvascular corrosion cast specimens were then prepared for SEM, and the volume of the newly-formed vascular network was calculated from the SEM images. Newly-formed vasculature was observed in the granule interspaces with all sizes of granules. In particular, the newly-formed vasculature in smaller granules was uniformly distributed. The volume of the newly-formed vasculature was approximately equal in both the experimental and control animals. When β-TCP granules were used to fill bone defects, newly-formed vessels were more uniformly distributed in defects filled with small granules, which are considered advantageous for microvascular formation.

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Although it is thought that protease-containing tablets with rough surfaces may be effective for cleaning the tongue surface, no studies have been reported. We investigated how the surface roughness and enzyme content of the tablets decreased the number of bacteria on the tongue. Four types of tablets were used : tablets comprised of several sugars with different solubilities with and without protease (actinidine), and tablets of one type of sugar, also with and without protease. The subjects were 20 healthy young adults and 20 elderly persons requiring support/nursing care. All gave informed consent. They used two tablets of each of the four types, and their efficacy at removing the tongue coating was evaluated employing a crossover study design.
The number of bacteria on the tongue was significantly decreased in the enzymecontaining tablets compared to the non-enzyme-containing group. When the surface property was considered, no significant difference was noted between the tablets prepared with several types of sugar and those prepared with a single type in either of the groups. It was suggested that the presence of protease is more effective at removing the tongue coating than was the rough surface formed by several sugars.

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We studied the influence of sympathetic nerve and taste stimulation on salivary immunoglobulin A secretion in the rat submandibular gland. Although the flow of the saliva evoked by β-adrenoceptor stimulation was very small in volume, secretion evoked by both acidity and bitterness stimulation was greater than from sympathetic stimulation. A marked secretion of peroxidase was found evoked by isoprenaline. Similar levels of SIgA secretion were evoked by each stimulus. Amylase secretion was enhanced by isoprenaline, citric acid and quinine stimulation. In particular, citric acid was significantly different compared with isoprenaline. A similar level of SIgA secretion was evoked by each of the stimuli. SIgA secretion evoked by both isoprenaline and quinine was significantly inhibited by propranolol. Propranolol had only a slight inhibitory effect on citric acid stimulation. The peroxidase level in response to isoprenaline was remarkably reduced by propranolol administration. Although propranolol was less effective on peroxidase secretion evoked by citric acid, quinineinduced peroxidase stimulation was inhibited by propranolol. However, the amylase activity evoked by acidity was weaker than that of sympathetic stimulated saliva. This difference was attributable to the influence of the nervous system on IgA secretion through input to the submandibular gland via not only the sympathetic nerves, but also the parasympathetic nerves. These results indicate that the salivary secretion of SIgA is regulated by nerve impulses and that acidity imparts a greater effect on SIgA secretion than does solitary sympathetic stimulation alone.

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Daily oral care is an established part of a healthy lifestyle in Japan. Self-care by tooth brushing is the primary way of cleaning the oral cavity. However, a large amount of dental plaque remains in the proximal areas of the teeth even after brushing. As a result, the use of dental floss or an interdental brush for cleaning areas between the teeth is commonly used to complement oral cleaning.
We compared the red plaque removal efficacy of plaque disclosed with red disclosing solution by an interdental brush with that by a manual toothbrush. Oral examination and quantitative light-induced fluorescence (QLF) were performed and two parameters were analyzed from the digital images : the mean ΔR (%) and the area (mm²) of the plaque. We examined 10 subjects between 20 and 50 years of age who were students and staff members at Osaka Dental University Hospital. The digital image analysis revealed that plaque could be detected in about 33 regions (41.3%) of the 80 proximal areas measured on QLF digital images of the subjects. When using the interdental brush, the mean ΔR in the experimental group was 33% after tooth brushing had been suspended for 3 days, 26% after 7 days (representing a decrease in the mean ΔR of 20%), and 24% after 14 days (a decrease in mean ΔR of 26%). Although the downward trend in mean ΔR was not observed in the controls, it decreased significantly in the experimental group.
The mean area of red plaque after using the interdental brush in the experimental group was 0.18 mm² after 7 days (a decrease in the area of plaque of 71%), and 0.12 mm² after 14 days (a decrease in area of 80%). We found that the mean area of plaque decreased significantly in the experimental group.
These results suggest that when using an interdental toothbrush we could get about 60% more plaque removal efficacy than when only a conventional toothbrush was used.

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We evaluated the chondrocyte differentiation potential of dedifferentiated fat cells (DFATs) and adipose stem cells (ASCs) from the human buccal fat pad (BFP). We isolated the cells from two patients who underwent oral and maxillofacial surgery. Chondrocyte differentiation was evaluated based on gene and protein expression analysis in addition to histological analysis of DFATs and ASCs seeded in an atelocollagen sponge and cultured for up to 21 days. The gene expression levels of chondrocyte differentiation markers such as aggrecan, collagen type 2, and SOX9 were higher in DFATs than in ASCs cultured for 14 and 21 days, whereas protein expression levels were higher in DFATs at all time points tested. Additionally, the levels of the embryonic stem cell markers Nanog, SOX2, and OCT4 were higher in DFATs than in ASCs at 72 h. The extracellular matrix of both the cultured ASCs and DFATs was Alcian blue-positive, indicating production of sulfated glycosaminoglycans, and was aggrecan-positive.
The chondrocyte differentiation ability of human DFATs was higher than that of ASCs. Isolation of DFATs from the BFP offers an aesthetic advantage, as the BFP can be obtained from the oral cavity without surface scarring. Therefore, we propose that BFP-derived DFATs are an ideal cell source for cartilage tissue engineering. This study provides evidence that DFATs from the BFP are an ideal cell source for cartilage tissue engineering.

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Refractory and atypical cases of osteomyelitis of the jaws are increasing with the emergence of resistant bacteria. Treatment of this condition can be agonizing. Here, we report a study conducted of 109 cases diagnosed with osteomyelitis of the jaws at the First Department of Oral and Maxillofacial Surgery, Osaka Dental University Hospital during the past 10 years. The cases were classified as Type A (acute suppurative osteomyelitis), 5 cases ; Type B (chronic suppurative osteomyelitis), 76 cases ; and Type C (chronic diffuse sclerosing osteomyelitis), 28 cases. There were 58 males and 51 females, aged 25 to 88 years (median 61 years). The most common site of onset observed (95 cases) was the posterior mandible. In 54 cases, the most common cause was odontogenic infection. Radiographic findings revealed isolated sequestrum in 38 cases. A combination of surgical and conservative treatment with antimicrobial agents was the most common method of treatment. Penicillin was the antimicrobial agent most frequently used. Surgical treatment mainly consisted of sequestrectomy. Most of the cases made good progress and there were few relapses.

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To define the properties of side population (SP) cells of the oral squamous cell carcinoma cell line SCC-4, we compared their gene expression profile with that of main population (MP) cells. SP cells accounted for approximately 1.5% of the cell population. The gene expression profile in SP cells versus MP cells revealed that 15.8% of genes were up-regulated by more than 10%, and 16.6% were down-regulated by more than 10%. Gene Ontology and KEGG pathway enrichment analyses were carried out on the DAVID online tool for 26,879 distinct probes (p<0.05). The terms involved in immune/inflammatory responses, cell migration and angiogenesis were detected as up-regulated genes. The terms related to DNA replication, DNA metabolic process, mismatch repair and base excretion repair were detected as down-regulated genes. Moreover, mRNAs encoding the ABC transporters ABCG2/BCRP1 and ABCC2/MRP2, which mediate the excretion of anti-cancer drugs such as cisplatin and gefitinib, respectively, were expressed at higher levels. In contrast, the level of mRNA encoding the SLC transporter SLC29A1/ENT1, which mediates the uptake of anti-cancer drugs such as fluorouracil, was decreased. These results indicate that SCC-4 SP cells might be potentially resistant to anti-cancer drugs.

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In order to collect morphological data on the mesopharynx, we measured the distances between the skull and epiglottic vallecula and between the external naris and epiglottic vallecular, and investigated the influences of gender and age on the major axis of the mesopharynx. The subjects were 186 patients (100 males and 86 females) who underwent computed tomography (CT) to diagnose suspected head and neck cancers or to evaluate the patient for third molar extraction, at the Department of Dental Radiology, Osaka Dental University Hospital, between January 2011 and April 2014. We used a multi-detector/multi-slice-type CT scanner.
The reference point of the skull was set to the lowest point of the inner contour of the sella turcica (Si), and the facial measurement point was set to the opening of the external naris (En). Reference points were also set to the lowest point of the palatine uvula (Pu) and the deepest point of the epiglottis (Ev), and the region between these was defined as the mesopharynx. The Si-Pu, Si-Ev, Pu-Ev, and En-Ev distances (4 regions) were measured and analyzed.We found that all distances were significantly greater in males than females. On analysis of the relationships between age and distances, we found correlations among Si-Ev, Pu-Ev and En-Ev in males. The results of this experiment showed that gender differences in the mesopharynx should be taken into consideration when positioning the head for swallowing pressure measurements.

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In this study, as part of investigations on the exposure concentration of isopropyl alcohol, which is used for disinfection at the time of intravenous catheterization, in the breathing zone, we surveyed the distance between the disinfection area and breathing zone. The mean distance between the patient's vein and the nasal cavities of dental anesthesiologists was 50.3 cm, which is 5 cm greater than that during reading. This distance was not affected by the subject's age, years of experience, or sex.

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With the recent development of three-dimensional (3D) technologies and the advent of orthodontic anchor screws that do not require patient intervention, accurate predictions of treatment results have become highly achievable. We reviewed the history of setting treatment goals and estimating treatment based on lateral roentgenographic cephalograms and study models, and assessed the validity of this approach. The subjects of this study were 39 Caucasian male and female patients (mean age of approximately 14 years) who had maxillary protrusion with a mean ANB angle of 5.5° and who had received orthodontic treatment using the same procedure. We compared the following parameters : results of measurements based on cephalometric tracing before and after treatment ; treatment goals ; the planned treatment duration established at the initiation of treatment ; the actual treatment duration at each treatment stage ; and the validity of the treatment duration and outcome predictions.
Comparison of the ANB angle before and after treatment showed that the value decreased. There were no significant differences in the treatment goals or results. The distances from U1 to NA showed no differences between the objective value before treatment and the actual value after treatment. Although comparison of preoperative and postoperative values for mandibular L1 to NB showed a decrease after surgery, there was no difference between the objective and post-operative value. Although the FMA tended to decrease slightly, no significant difference was found. Even though there was a margin of error at each of the treatment steps, there were no significant differences between the number of treatment months planned before treatment and the actual number required.
The decreased ANB angle and lack of differences between the objectives and the results suggest that treatment goals close to the target had been achieved. Because no significant differences were found between the treatment duration planned before surgery and the actual duration, the findings suggest that the time of treatment could be estimated at the initiation of treatment.
The use of the treatment procedure described in this study was valid for predicting the treatment period as well as the treatment goals pertaining to the ANB angle and the positions of the maxillary and mandibular anterior teeth. The slight decrease in the FMA and the dynamics of the maxillary anterior teeth after treatment suggest that the procedure described in this study was effective in the treatment of maxillary protrusion.

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We examined the facial characteristics of Chinese children with normal occlusion using Steiner analysis. Ninety boys and 90 girls who were selected from 5,417 students in a primary school in Taipei, Taiwan, were classified by Hellman's developmental stage (IIIA, IIIB and IIIC) and chronological age stage IV (11 y 0 m - 13 y 10 m). Angular and linear measurements were determined. In comparison with pre-existing measurement values for Japanese, the SNA angle, SNB angle, SND angle, interincisal angle, and SL values for the Chinese subjects were significantly larger for stages IIIC and IV, while L1 to NB, ∠L1 to NB, occlusal plane to SN, GoGn to SN, and SE values were significantly smaller. Compared to measurement values for Caucasians, the mean of SNA angle, ANB angle, U1 to NA, ∠U1 to NA, L1 to NB, ∠L1 to NB, and occlusal plane to SN angle were larger among our subjects (stages IIIC and IV) and the interincisal angle, SL and SE were smaller. These results demonstrate that Chinese have a more robust growth of the maxilla than Japanese and Caucasians.
We also found that although the skeletal Class II tendency in Chinese was lower than in Japanese, it was higher than in Caucasians. Although the amount of growth of the mandible in Chinese was greater than in Japanese, it was less than in Caucasians. Although clockwise rotation was also less than in Japanese, it was greater than in Caucasians. Regarding dental structure, although anterior teeth in Chinese tended to have less bimaxillary protrusion than in Japanese, they had greater bimaxillary protrusion than in Caucasians. Although the occlusal plane was flatter than that of Japanese, it was steeper than that of Caucasians. The above findings suggest that when performing orthodontic treatments on Chinese, greater attention is needed when the features of malocclusion are similar to Caucasians.

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Artificial porcelain denture teeth have many outstanding properties. In addition to being hygienic, they are the most resistant to abrasion of all currently used dental materials, maintain long-lasting cusps, and are resistant to denture plaque deposition and discoloration. However, they are vulnerable to impact and easily fracture, tend to make occlusal sounds, and do not bind to denture resins. For these reasons they are rarely used. We focused this study on their susceptibility to fracture, which is one reason preventing their more widespread use, and investigated the fractures that occurred. The experimental materials were the upper and lower first molars of six commercially available brands of porcelain teeth.
Experiments were carried out using an abrasion-testing device developed in our laboratory, adapted to deliver a specific impact force. An upper artificial tooth was placed on the top of the abrasion-testing device and a lower artificial tooth was placed on the bottom in normal physiologic relation. The device was set to deliver occlusal contact at a load of 162.2 N. The upper artificial tooth made repeated occlusal contact with the lower artificial tooth 60 times/minute in a tapping movement, which was repeated until one of the teeth fractured or for a maximum of 2,000 times, and the number of impacts until fracture was counted. This test was carried out on ten teeth for each of the six brands of porcelain teeth.
Of the six brands, five teeth from one brand, three from another, and one from a third did not fracture, even after 2,000 impacts. For all brands, more fractures occurred among upper teeth than among lowers. A total of 56 upper and lower artificial teeth fractured, with these fractures occurring at the marginal ridge in 25 cases, associated with the marginal ridge in 19, and not associated with it in 12. Aside from the teeth that did not fracture even after 2,000 impacts, analysis of the number of impacts until fracture showed that the teeth that lasted longest before breaking underwent an average 1,029 impacts. The next longest withstood an average of 794 impacts. The artificial tooth that fractured after the smallest number of impacts withstood only 16 taps. The next smallest number was 121 impacts.
Our results indicate that the susceptibility to fracture varies among the different brands of artificial teeth, and that in many cases, fracture is associated with occlusal contact with the marginal ridge.

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