The Physiological Function of Deglutition and Swallowing in Patients With Maxillary Protrusion After Mandibular Advancement.

The objective of this study was to determine the tongue-palatal contact changes in patients with skeletal maxillary protrusion after sagittal split ramus osteotomy (SSRO) during swallowing. In this study, 15 patients with maxillary protrusion and 10 normal subjects participated. Before and 3 months after surgery, tongue-palatal contact patterns during swallowing of patients with maxillary protrusion as well as controls were evaluated by electropalatography. The electrode contact number in the alveolar, palatal, and velar parts was examined. The swallowing duration of each phase was also evaluated. In the lateral area of the velar part, incomplete electrode contact was shown at 0.3 seconds in patients with maxillary protrusion. The electrode contact number in the velar part at 0.3 seconds before tongue-palatal complete contact was significantly less in the preoperative patients compared with the controls ( P < 0.05). A small increase in the electrode contact number of the velar part was shown in the postoperative patients at 0.3 and 0.2 seconds before tongue-palatal complete contact ( P < 0.05). The pharyngeal phase duration was significantly larger in the patients with maxillary protrusion before SSRO compared with the controls ( P < 0.05). After SSRO, the pharyngeal phase duration was significantly shortened. It was shown that the tongue-palatal contact pattern during swallowing in patients with maxillary protrusion improved after orthognathic surgery, and the pharyngeal phase duration was also shortened. It is suggested that the changes in the mesiodistal mandibular position by orthognathic surgery can improve tongue posture and movement during swallowing.

Camouflage Correction of Skeletal Class III Severe Open Bite with Tooth Ankylosis Treated by Temporary Anchorage Devices: A Case Report.

Tooth ankylosis is a disorder characterized by the fusion of tooth and alveolar bone. This case report describes the treatment of a severe open bite due to tooth ankylosis. A 14-year-old female patient with a chief complaint of masticatory dysfunction was diagnosed with skeletal Class III severe anterior open bite and tooth ankylosis. She visited our university hospital with a chief complaint of an anterior open bite. After the surgical luxation of the ankylosed maxillary right central incisor, the tooth was orthodontically retracted using a nickel-titanium wire. The right mandibular lateral incisor and canine were luxated and retracted using intermaxillary elastics from a temporary anchorage device (TAD), which was inserted in the opposite jaw. During the treatment, skeletal Class III malocclusion deteriorated due to anterior growth of the mandible. Therefore, TADs were inserted into the retromolar pad on both sides of the mandible and retracted into the mandibular dental arch. Although the mandibular right canine was luxated several times, it could not be brought to the occlusal line, and was thus extracted; the extraction space was replaced with a prosthesis. Consequently, a normal overjet and overbite with a straight profile were achieved. Extrusion of ankylosed teeth by intermaxillary elastics from a TAD is a valid treatment option for patients with severe open bites.

Correction of Severe Skeletal Class II High Angle with Mandibular Retrusion and Gummy Smile by Double-Jaw Surgery.

This report describes the treatment of severe skeletal Class II malocclusion in a young woman with a gummy smile and pronounced lower anterior facial height. Overjet and overbite were +12.0 mm and -1.0 mm, respectively. Cephalometric analysis revealed inferior positioning of the maxilla and severe mandibular retrusion with clockwise rotation. Both the upper and lower anterior teeth showed labial inclination. Based on a diagnosis of a skeletal Class II high angle with mandibular retrusion and a gummy smile, double-jaw orthognathic surgeries for upper and lower premolar extraction were chosen to gain ideal occlusion and an improvement in the esthetic facial profile. Le Fort I osteotomy was performed to move the anterior and posterior teeth upward by 4.0 mm and achieve mandibular counterclockwise rotation. Short lingual sagittal split ramus osteotomy was performed to move the mandible forward by 3.0 mm. As a result, normal overjet and overbite were achieved together with a straight profile and a good smile. After surgery, electromyographic evaluation of anterior temporal muscle activity showed an improvement in the percentage overlapping coefficient value (a symmetric index of bilateral muscle activity) from 28.1% to 63.2% compared to at pre-treatment. The pattern of jaw movement also showed an improvement. These results suggest that orthognathic surgery in skeletal Class II cases can improve not only malocclusion and the skeletal relationship of the jaws, but also masticatory function and jaw movement.

Functional regulation of osteoblastic MC3T3E-1 cells by hyperbaric oxygen treatment.

OBJECTIVES: The purpose of the present study was to examine the influence of hyperbaric oxygen (HBO) on the function of osteoblastic MC3T3-E1 cells. DESIGN: Murine MC3T3-E1 cells were exposed to HBO treatment (at 2.5 absolute atmospheric pressure with 100% oxygen, 90 min per day) for 28 days. Alkaline phosphatase (ALP) staining, activity, and calcium (Ca) content were measured. Gene expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), hypoxia-inducible factor-1α (HIF-1α), type 1 collagen (COL1), and osteocalcin (OCN) was assessed using real-time quantitative polymerase chain reaction after a single HBO exposure for 1.5, 6, and 12 h. Furthermore, adenosine triphosphate (ATP) levels were measured using a luminescent cell viability assay. RESULTS: ALP activity and Ca content were higher in the HBO group compared to those in the control group. Gene expression of bFGF, COL1, and OCN was upregulated in the HBO group; however, that of VEGF and HIF-1α significantly decreased in the HBO group in comparison with that in the control group. ATP levels were significantly higher in the HBO group compared to those in the control group. CONCLUSIONS: These findings suggest that HBO accelerates bone formation by increasing the ATP levels of osteoblasts, and bFGF can act as a substitute for VEGF in vascularization by HBO application.

Changes in tongue-palatal contact during swallowing in patients with skeletal mandibular prognathism after orthognathic surgery.

This study aimed to evaluate improvement of tongue-palatal contact patterns during swallowing after orthognathic surgery in mandibular prognathism patients. Thirty patients with mandibular prognathism treated by orthognathic surgery (average age of 27 years, 3 months) and 10 controls (average age 29 years, 6 months) participated in this study. Tongue-palatal contact patterns of patients before and three months after surgery were evaluated by electropalatography (EPG) as well as controls. Whole total of tongue-palatal contact at 0.3, 0.2, and 0.1 sec before complete tongue-palatal contact during swallowing were evaluated. The duration of swallowing phases was also examined. Complete contact of tongue-tip in the alveolar part of individual artificial EPG plate were shown at 0.3, 0.2, and 0.1 sec before complete tongue-palatal contact in the controls, although incomplete contact in the alveolar part were shown at 0.3 sec in mandibular prognathism patients. Whole total of tongue-palatal contact at 0.3 and 0.2 sec before complete tongue-palatal contact was significantly lower in the patients before surgery than in the controls (p<0.05). However, these values increased after surgery. The duration of oral and pharyngeal phase was significantly longer in the patients before surgery than in the controls and the patients after surgery (p<0.01). This study demonstrated that the tongue-palatal contact pattern improved and the duration of oral and pharyngeal phase was shortened in mandibular prognathism patients during swallowing after orthognathic surgery. It is suggested that changes in maxillofacial morphology by orthognathic surgery can induce normal tongue movement during swallowing. (The data underlying this study have been uploaded to figshare and are accessible using the following DOI: https://doi.org/10.6084/m9.figshare.14101616.v1).

An Investigation of Tongue-Palatal Contact Changes in Patients With Skeletal Mandibular Lateral Deviation After Sagittal Split Ramus Osteotomy.

ABSTRACT: This study aimed to investigate the changes in tongue-palatal contact patterns in patients with mandibular lateral deviation by electropalatography (EPG) before and after sagittal split ramus osteotomy (SSRO). Ten mandibular asymmetry patients who underwent SSRO participated in the study. Tongue-palatal contact patterns for the production of /t/ and /s/ sounds were observed using EPG before surgery and 3 months after surgery, and the changes in EPG pattern were examined. The number of electrode contacts in the 2 vertical columns of the EPG plate was calculated both in the mandibular deviation side and the nondeviation side. The EPG patterns for /t/ and /s/ showed asymmetry before surgery but became normal after surgery. Before surgery, the number of electrode contacts in the 2 vertical columns in the mandibular deviation side was significantly lower than that in the nondeviation side and the normal participants during /t/ and /s/ articulation. However, the number of electrode contacts in the deviation side significantly increased after surgery. This study demonstrated that the tongue-palatal contact patterns for /t/ and /s/ articulation shifted to the direction of mandibular deviation and improved after SSRO.

Effects of hyperbaric oxygen treatment on calvarial bone regeneration in young and adult mice.

OBJECTIVE: The present study aimed to investigate the effects of hyperbaric oxygen (HBO) treatment on calvarial bone regeneration in young and adult mice. METHODS: Calvarial defects of 6.0 mm diameter were created in sixteen 3-week (young) and sixteen 32-week old (adult) mice. The mice were divided into two groups of eight animals each (HBO-treated and control). The 90-min HBO treatment at 2.5 absolute atmospheric pressure and 100 % oxygen was performed for five days a week for 12 weeks. After 2-weeks from the operation, micro-computerized tomography and video microscopy were used to evaluate the regenerated bone volume and microcirculation every two weeks. The protein concentrations of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in exudates of the calvarial tissue field were measured at 1, 2, 3, and 4 weeks after surgery. After 12 weeks, histochemical examination of regenerated calvarial bone was conducted. RESULTS: Regenerated bone was formed earlier in young mice than in adult mice treated with HBO. HBO stimulates angiogenesis in the periosteum around regenerated bone area in both young and adult mice at 2 weeks. VEGF concentrations in the calvarial tissue field were lower in the HBO group than in the control 1 week after operation, although bFGF were higher till the 2nd week in the HBO group than in the control. CONCLUSIONS: HBO accelerates bone regeneration earlier in young mice than in adult mice. In the HBO-treated group, bFGF expression was promoted at an early stage, although the expression of VEGF was inhibited.

Effect of continuous compressive force on the expression of RANKL, OPG, and VEGF in osteocytes.

The present study aimed to investigate the effect of a compressive force (CF) on the expression of receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), and vascular endothelial growth factor (VEGF) in murine osteocytes (MLO-Y4) as well as animal study. After application of a CF for 1, 3, 6, and 12 h, gene and protein expression of RANKL, OPG, and VEGF in MLO-Y4 cells were determined by real-time PCR and enzyme-linked immunosorbent assay (ELISA). Furthermore, the effect of a stretch-activated (S-A) channel was examined by gadolinium (Gd3+) administration. In an animal experiment, the expression of these factors in osteocytes of alveolar bone was examined after experimental tooth movement in rats. After CF application, significant increases in RANKL, VEGF and RANKL/OPG ratio were shown. The upregulated gene and protein levels of these factors were reduced by Gd3+ administration. After tooth movement, upregulated RANKL and VEGF were imunohistochemically shown in osteocytes of alveolar bone. These findings suggest that CF application on osteocytes elevates expression of osteoclast-inducing factor and angiogenesis factor in vivo and vitro.

Nutrient adequacy of Japanese schoolchildren on days with and without a school lunch by household income.

BACKGROUND: Evidence for whether the nutrient intakes of Japanese schoolchildren differ according to household income is sparse. OBJECTIVE: We investigated the role of school lunches for nutrient adequacy among Japanese primary school children using dietary reference intakes in a cross-sectional survey. DESIGN: Participants were 10- to 11-year-old (5th grade) children from 19 public primary schools in four prefectures of East Japan, and 836 children were analyzed. The participants completed 24-h dietary records with photographs of their meals for 4 consecutive days, composed of 2 days with and 2 days without a school lunch. -Children's household income was obtained from questionnaires that were completed by the participants' guardians and divided into the following three categories: low (0.2236-2.2361 million yen; n = 319), middle (2.3333-2.8868 million yen; n = 194), and high (3.1305-6.3640 million yen; n = 323). Logistic regression analyses were used to estimate the odds ratios for whether participants had poor nutrient intakes, with adjustment for confounders. RESULTS: On days without a school lunch, the prevalence of nutrient shortages was significantly higher compared with those on days with a school lunch for most macro- and micronutrients among all three levels of household income. Children from low-income households had higher rates of nutrient shortages for vitamin B6, pantothenic acid, K, Mg, P, Fe, and Zn than those from middle-income households on days without a school lunch (P = 0.004, 0.001, 0.001, 0.006, 0.037, <0.001, and 0.015, respectively), but those differences were not significant on days with a school lunch. CONCLUSION: The findings suggest that school lunches are important for achieving adequate nutrient intakes in schoolchildren and reduce disparities of adequate nutrient intake by household income levels.

Association between parents' work hours and nutrient inadequacy in Japanese schoolchildren on weekdays and weekends.

OBJECTIVES: Evidence is sparse concerning whether the nutrient intake in schoolchildren differs according to parents' work hours. The aim of this study was to investigate the relationship between parents' work hours and nutrient inadequacy among Japanese primary schoolchildren using dietary reference intakes on days with and without a school lunch. METHODS: Participants included 10- to 11-y-old children in grade 5 from 19 public primary schools in four prefectures of east Japan. Data for 699 children were analyzed. Participants completed 24-h dietary records with photographs of their meals for 4 d consecutively, which included of 2 d of weekdays and 2 d of weekends. Their mothers' and fathers' work hours were obtained from questionnaires that were completed by the participants' guardians. Logistic regression analyses were used to estimate the odds ratios for whether participants had poor nutrient intake, with adjustment for confounders. RESULTS: Children whose mothers worked ≥40 h/wk had significantly higher rates of nutrient shortages for vitamins A, E, K, and B6, pantothenic acid, potassium, magnesium, and iron (P = 0.007, 0.003, 0.007, 0.023, 0.021, 0.045, 0.004, and 0.009, respectively) than those in the 0 h/wk group. These differences were not significant based on fathers' working hours, with the exception of vitamin A (≥40 versus 0-39 h/wk, P = 0.032). Additionally, nutrient shortages for children were more pronounced on weekdays than on weekends. CONCLUSIONS: This evidence revealed the necessity to improve nutrition intake in children whose mothers work more than statutory working hours, which would enable children to have adequate nutrient intake, especially on weekdays.

Correction of skeletal class II severe open bite with temporomandibular joint disorder treated by miniscrew anchorage and molar extraction: a case report.

BACKGROUND: Little information is available on the treatment of open bite with temporomandibular joint disorder by intrusion of molars using miniscrews. CASE PRESENTATION: This case report describes a 42-year-old Japanese woman with a skeletal class II severe anterior open bite and temporomandibular joint disorder. The pretreatment magnetic resonance imaging of both temporomandibular joints revealed osteoarthritis and anterior disc displacement without reduction in both temporomandibular joints. A stabilization splint was used before orthodontic treatment and bilateral upper and lower premolars were extracted. Miniscrews were inserted into the palatal region to intrude the maxillary molars and avoid loss of anchorage. The maxillary left first molar was also extracted to improve the molar relationship and the dental midline. Normal overjet and overbite with Angle class I molar relationship were achieved, and the upper and lower midlines coincided. Our patient's teeth continued to be stable and her temporomandibular joint was asymptomatic after a retention period of 2 years. CONCLUSIONS: Intrusion of molars by miniscrews is available for skeletal class II severe open bite.

Acetaminophen reduces apical root resorption during orthodontic tooth movement in rats.

OBJECTIVE: The present study aimed to investigate the inhibitory effect of acetaminophen on apical root resorption during orthodontic tooth movement by controlling inflammation in the periodontal ligament and apical pulp tissue. METHODS: Human periodontal ligament and pulp cells were subjected to 10 kPa of cyclic tensile force (CTF) in a Flexcell Strain Unit for 48 h. Then, 10 and 100 µM acetaminophen were added to the culture medium, and the expression of interleukin (IL)-1B, receptor activator of nuclear factor kappa-B ligand (RANKL), tumor necrosis factor (TNF)α, and colony stimulating factor 1 (CSF1) were evaluated. In an animal experiment, the upper first molars of 7-week-old rats were moved mesially by applying 10 g of orthodontic force. After 30 days of force application, the effects of acetaminophen on apical root resorption were examined. RESULTS: In both the periodontal ligament and pulp cells, the expression levels of IL-1B, TNFα, RANKL, and CSF1 were significantly higher in the CTF-treated group than in the control group. However, the expression levels of these factors were decreased by acetaminophen administration. High expression of IL-1B, TNFα, RANKL, and CSF1 at the root apex were also detected immunohistochemically in rats after tooth movement, but were decreased by acetaminophen administration. In addition, the number of odontoclasts and the amount of apical root resorption were significantly decreased in the acetaminophen group. Importantly, no significant difference in tooth movement was observed between the acetaminophen and control groups. CONCLUSIONS: These results suggest that acetaminophen can reduce severe root resorption in the apex area without disturbing orthodontic tooth movement.

Effects of loxoprofen on the apical root resorption during orthodontic tooth movement in rats.

Studies have revealed that severe apical root resorption during tooth movement is caused by the noninfective inflammatory reaction of apical root tissues. We hypothesized that loxoprofen can suppress apical root resorption during tooth movement. Cyclic tensile force (CTF) of 10 kPa was applied to the human pulp cells for 48 hours by the Flexcell Strain Unit. Loxoprofen (10 and 100 µM) was added to the culture cells, and expression of cyclooxygenase (COX)-1, COX-2, interleukin (IL)-1ß, receptor activator of nuclear factor kappa-B ligand (RANKL), tumor necrosis factor (TNF)-α, and macrophage colony-stimulating factor (M-CSF) were examined. To determine the effects of loxoprofen sodium on apical root reabsorption during tooth movement, the upper first molars of 7-week-old rats were subjected to mesial movement by 10g force for 30 days with or without the oral administration of loxoprofen. Gene expression and protein concentration of COX-1, COX-2, IL-1ß, TNF-α, RANKL and M-CSF were significantly higher in the CTF group than in the control group. However, these levels were decreased by loxoprofen administration. After orthodontic tooth movement, the expression of IL-1ß, TNF-α, RANKL and M-CSF decreased in the loxoprofen group than in the control group by immunohistochemical staining. In comparison to control group, less number of odontoclasts and a decrease in the amount of apical root resorption was observed in the loxoprofen group. Many osteoclasts became visible on the pressure side of the alveolar bone in the both groups, and the amount of tooth movement did not show a significant difference. These findings demonstrate that severe apical root resorption may be suppressed by loxoprofen administration, without a disturbance of tooth movement.

Household income is associated with food and nutrient intake in Japanese schoolchildren, especially on days without school lunch.

OBJECTIVE: The present study aimed to examine the association between household income and the intake of foods and nutrients by Japanese schoolchildren, and any differences between days with and without school lunch. DESIGN: This was a cross-sectional study. Children, with the support of their parents, kept dietary records with photographs for 4 d (2 d with school lunch and 2 d without). The socio-economic status of each family was obtained from a questionnaire completed by the parents. SETTING: Japan. SUBJECTS: All students in 5th grade (10-11 years old) at nineteen schools in four prefectures and their parents (1447 pairs of students and parents) were invited to take part in the study; 836 pairs of complete data sets were analysed. RESULTS: The average results of four days of dietary records showed that lower income level was associated with a lower intake of fish/shellfish, green vegetables and sugar at the food group level, a lower intake of protein and several micronutrients, and a higher energy intake from carbohydrates at the nutrient level among the children. These associations between income and food/nutrient intake were not significant on days with school lunches, but were significant on days without school lunch. CONCLUSIONS: Our study confirmed an association between household income and the amount of foods and nutrients consumed by Japanese schoolchildren, and suggested that school lunches play a role in reducing disparities in the diets of children from households with various incomes.

Irradiation effects of low temperature multi gas plasma jet on oral bacteria.

The purpose of this study is to evaluate the sterilization effects of a newly developed low temperature multi gas plasma jet on oral pathogenic microorganisms (Streptococcus mutans [S. mutans], Lactobacillus fermentum [L. fermentum], Aggregatibacter actinomycetemcomitans [A. actinomycetemcomitans]). Plasma gas which generated from O2, N2, Ar and 50% (O2+N2) was irradiated to the microbes. Effect of O2 plasma irradiation on S. mutans under scanning electron microscopy (SEM) was also observed. O2 plasma was directly applied to dental plaque on human extracted tooth. Then, the depth of enamel resorption area was noted by nanoscale hybrid microscope. O2 had the best sterilizing effect for all microbes. The potent bactericidal effect of plasma irradiation was also observed by SEM. Decalcification of enamel was noted significantly lower in plasma irradiated tooth surface compared to no plasma exposure group. These findings revealed that multi gas plasma jet has great potential to be used for dental treatment.

Associations between Japanese schoolchildren's involvement in at-home meal preparation, their food intakes, and cooking skills.

BACKGROUND/OBJECTIVES: This study aimed to examine the association of Japanese schoolchildren's involvement in at-home meal preparation with food intake and cooking skill. SUBJECTS/METHODS: We included 1,207 fifth-grade children aged 10-11 years and one parent of each child. A cross-sectional survey was used to collect data on involvement in at-home meal preparation. Correspondence analysis was used to classify involvement in at-home meal preparation into three groups: food-related activities (cooking only or with other activities such as shopping, table-setting, clean up, and dishwashing), non-food-related activities (table-setting and/or clean up), and no (helping) activities. Food intake was assessed using a food frequency questionnaire. Logistic regression models were used to examine involvement in at-home meal preparation associations. RESULTS: The sample consisted of 1,207 fifth-grade children. Vegetable intake was lower in the no (helping) activities group than the food-related activities group (95% CI; boys: 1.2, 5.1, girls: 2.0, 8.9). Fewer children in the non-food-related activities group reported they were able to make a portion of their meals compared with the food-related activities group (95% CI; boys: 1.6, 3.5; girls: 1.5, 3.2). CONCLUSIONS: Children in the food-related activities group showed more favorable food intake and cooking skills than children in the no (helping) activities or non-food-related activities group.

Changes in body mass index among Tongan adults in urban and rural areas between the 1970s and 2000s.

The purpose of this study was to determine trends in body physique among Tongan adults, between the late 1970s and the 2000s. Two areas were studied: Kolofo'ou town (as an urban area) and 'Uiha village (as a rural area). Measurements of body weight and height were taken 4 times for all residents in both areas in 1977/79, 1983, 1990, and 2001. The number of the subjects in 1977/1979, 1983, 1990, 2001 were 130, 138, 102, 71 in the urban area and 92, 89, 90, 66 in the rural area respectively. The mean body mass index (BMI, kg/m2) values of males in the rural area increased significantly, from 28.0 kg/m2 in 1977 to 31.0 kg/m2 in 2001 (p=0.001); in females, mean BMI values were 30.6 kg/m2 in 1977 and 33.3 kg/m2 in 2001, this change was not statistically significant. However, the BMI values did not significantly change in males or females in the urban area. The proportion of rural males with a BMI>or=30 kg/m2 had increased from 24.5% in 1977 to 55.5% in 2001 (p=0.012). Although the mean BMI values for males and females were higher in the urban area than in the rural area until 1990, the differences between the two areas were not observed in 2001, due to an increase of BMI in the rural area. Changes of the mean BMI values in the rural and urban areas studied, between the late 1970s and 2000s, were 10% and 4%, respectively.