Fluid dynamics in patients with nasal disease

Computational fluid dynamics （CFD） analysis is useful for quantitative assessment in patients with upper airway obstructions. We compared CFD analysis with rhinomanometry （RM） and acoustic rhinometry （AR）. Twenty patients with nasal and paranasal diseases who required computed tomography assessment underwent RM and AR. We measured the pressure and velocity at four parts of the upper airway using CFD analysis. Then we evaluated the correlation among CFD analysis, RM, and AR. CFD analysis detected obstruction sites in the nasal airway and pharynx in 14 and 2patients, respectively. High negative pressure accompanied the nasal obstruction, even behind the nasal cavity. Nasal airway pressure measured using CFD analysis strongly correlated with nasal resistance in RM （Spearman correlation coefficient＝0.853）. CFD analysis’s sensitivity and specificity to detect the obstruction were 84.6％ and 57.1％, respectively （compared to those of RM） and 83.3％ and 50.0％, respectively （compared to those of AR）. The CFD analysis’s ability to detect obstruction was comparable to that of RM and AR; therefore, it may help evaluate the upper airways in patients with nasal and paranasal diseases. We found impaired nasal ventilation also affected other parts of the upper airway. Further studies with a larger sample size are required to validate the use of CFD analysis for assessing the degree of upper airway ventilation disorders

Computational fluid dynamics analysis in patients with nasal disease

Computational fluid dynamics （CFD） analysis is useful for quantitative assessment in patients with upper airway obstructions. We compared CFD analysis with rhinomanometry （RM） and acoustic rhinometry （AR）. Twenty patients with nasal and paranasal diseases who required computed tomography assessment underwent RM and AR. We measured the pressure and velocity at four parts of the upper airway using CFD analysis. Then we evaluated the correlation among CFD analysis, RM, and AR. CFD analysis detected obstruction sites in the nasal airway and pharynx in 14 and 2patients, respectively. High negative pressure accompanied the nasal obstruction, even behind the nasal cavity. Nasal airway pressure measured using CFD analysis strongly correlated with nasal resistance in RM （Spearman correlation coefficient＝0.853）. CFD analysis’s sensitivity and specificity to detect the obstruction were 84.6％ and 57.1％, respectively （compared to those of RM） and 83.3％ and 50.0％, respectively （compared to those of AR）. The CFD analysis’s ability to detect obstruction was comparable to that of RM and AR; therefore, it may help evaluate the upper airways in patients with nasal and paranasal diseases. We found impaired nasal ventilation also affected other parts of the upper airway. Further studies with a larger sample size are required to validate the use of CFD analysis for assessing the degree of upper airway ventilation disorders

Predicting the course of hematopoietic neoplasm through oral bacterial examination

Many medical institutions have recently conducted studies on the relationship between patients with hematopoietic neoplasms and oral cavity. Statistical analysis of the bacterial populations was performed in this study to identify how oral microflora and health conditions （e.g., dental caries and periodontal diseases） affect the prognosis of patients with hematopoietic neoplasms. Patients undergoing inpatient treatment from January to December 2020 at the Department of Hematology at Showa University, Japan, who required perioperative oral management were included in the study. The oral health of the patients was examined at the initial dental visit, and oral bacterial samples were collected from the tongue, buccal mucosa, and palate of 47 patients who consented to participate after receiving an explanation about the study. Statistical analyses performed after dividing the subjects into two groups following the treatment course showed that Stenotrophomonas maltophilia and Gemella sanguinis were significantly more common in the poor-course group. However, no significant difference in bacterial examination results was noted among the four groups （myeloid neoplasm chemotherapy, myeloid neoplasm hematopoietic stem cell transplantation （HSCT）, lymphoid neoplasm chemotherapy, and lymphoid neoplasm HSCT groups） classified based on disease and treatment method. The detection rate of bacteria potentially causing infectious diseases at the initial dental examination tended to be higher in this study in the poor-course group. The findings of the current study suggest that early detection of pathogenic bacteria after commencing hematology treatment could predict the poor-course that may lead to mortality or severe infections

Changes in Pediatric Patient Trends in Eating and Swallowing Disorders: A Comparison between the First and Fifth Year after Establishment of the Special Needs Dental Center

A Special Needs Dental Center （hereafter referred to as the Center） was established at Showa University Dental Hospital in April 2012 to treat patients who need special care. In cooperation with the Division of Dentistry for Persons with Disabilities, the Division of Hygiene and Oral Health is mainly engaged in the treatment of patients with eating and swallowing disorders. It has been five years since the establishment of the Center. The present study was aimed to establish an effective medical support method through a comparative study of changes in patient trends. A total of 65 patients who visited the Center from April 2017 to March 2018 were examined and their statistics were compared with those of 60 previously reported patients who initially visited the Center for medical examination in 2012. In 2012, many visits occurred during the nursing period; however, in 2017, the number of patients who visited after the weaning period increased. Other noted trends were increased diversity in primary disease, more patient referrals, fewer patients with severe swallowing dysfunction, and more patients with oral dysfunction. The necessity of eating and swallowing practice is thought to increase when lifestyle and oral environment change. The treatment of eating and swallowing disorders is important in the dental profession. Due to the introduction of insurance coverage in Japan in 2018 for developmental insufficiency of oral function, more pediatric patients with eating and swallowing disorders will likely be treated in the future

Clinical Statistics for Dysphagia Patients ≦ 18 Years of Age in the Center of Special Needs Dentistry, April 2012-March 2013

In April 2012, the Center of Special Needs Dentistry (SND) was established at Showa University Dental Hospital to provide function training for children with eating and swallowing disorders. A statistical clinical assessment was performed on new patients ≤18 years of age who visited the Center over a 1-year period (April 2012–March 2013) to assess the conditions present at the initial visit. In all, 60 patients (29 boys, 31 girls, mean (± SD) age 4.2±4.1 years, range 0-18 years of age) were included in the study. Most patients were <1 year of age (32%) and most came from one of four cities in the Johnan area (Shinagawa City, Meguro City, Ota City and Setagaya City). The most common primary diseases at the initial visit were cerebral palsy and cleft lip and palate. The third largest patient group was of healthy children with oral function problem. Over 60% of patients attended the Center of SND because of an eating-related complaint. More than 50% of patients were obtaining nutrients via oral intake; the remaining patients were obtaining nutrients via non-oral or a combination of oral and non-oral intake. Because of the young age of the patients and the fact that most were from neighboring areas, it can be inferred that effective community health care is being provided. It is necessary for the Center of SND to continue to provide professional treatment for dysphagia and to contribute to community medicine

Characteristics and Alterations of Food Intake in Children with Pervasive Developmental Disorders: Behavioral Analysis of Spoon Feeding

Studies on feeding behaviors of children with pervasive developmental disorders (PDD) have focused mainly on problematic behaviors such as food selectivity and how to deal with them. Few studies have addressed the motor aspects of feeding behavior. This study aimed to determine the characteristics of feeding behavior of children with PDD using a spoon. The study participants consisted of 8 children with PDD attending a childrens disability center (6 boys and 2 girls; mean±SD=36.1±4.2 months). Feeding behaviors of the participants at lunch time were videotaped. They were also assessed with the Enjoji Scale of Infant Analytical Development Test on the same day. These 2 assessment procedures were repeated about one year later. The control group consisted of 5 healthy children (2 boys and 3 girls; mean±SD=43.2±7.4 months). The following results were obtained. Comparison between the children with PDD and controls showed significant differences in “motion of lips during food intake" and “neck rotation". Correlations between the feeding assessment and the Enjoji Scale were as follows. On the first assessment, “motion of the lips during food intake" did not correlate significantly with any items of the Enjoji Scale. However, on the second assessment, this item showed significant correlations with all Enjoji Scale items. The characteristics of children with PDD were considered to lesser motion of the lips and neck rotation. We speculate that development of lip motions might be greatly influenced by therapeutic education

In vitro demineralization of artificial large-scale hydroxyapatite single crystal: Implications of fluoridized tooth enamel for acid resistance

Fluoride treatment has been well known to improve acid resistance of tooth enamel, leading to the widespread use of fluoride therapies in dentistry such as fluoride rinse and fluoride-releasing dental materials. The effect of fluoridation is likely based on the chemical properties of fluoridized hydroxyapatite; however, nanoscale tiny hydroxyapatite crystals in tooth enamel make it difficult to observe the demineralization pattern of fluoridated enamel versus the untreated enamel at a single crystal level. The purpose of this study was to mimic the demineralization patterns of fluoridated and untreated enamel by means of the newly developed hydrothermally enlarged enamel-like hydroxyapatite single crystals at Showa University. Large-scale hydroxyapatite single crystals were hydrothermally produced from polyphosphoric acid and calcium oxide. The crystals were stored in sodium fluoride solutions with four different concentrations for 30days, then exposed to 3％ citric acid solution for up to 60min. The degradation patterns of each sample were observed using a conventional scanning electron microscope and were analyzed using F K-edge X-ray absorption near edge structure spectra. The surfaces of the hydroxyapatite crystals treated by relatively low concentrations of fluoride showed degradation in citric acid as well as in the untreated control. The hydroxyapatite crystals treated with 1,500 and 9,000ppm F revealed that the fluoridated outer pillar of the crystals remained mostly intact which made calcium fluoride detectable. Fluoridization of tooth enamel might be preventive of an early acid erosion at a crystal level with a caution of sufficient fluoride concentration and exposure over time. The remaining substantial portion of the crystal pillar implies of highly fluoridized crystals, and a possible remineralization occurs as long as saliva provides minerals required for enamel remineralization by in vivo regulation

Assessment of Feeding and Swallowing by Cone Beam Computed Tomography: Changes in Oropharyngeal Airway Shape with Aging

With super aged society in Japan, the death rate from choking due to blockage of the oropharynx has increased; it is now greater than that from traffic accidents and it is believed that this rate will continue to increase. The shape and function of the oropharyngeal crossing with the respiratory tract are most influential in ensuring that food is carried from the oral cavity to the pharynx and the esophagus. We sought to clarify the changes in the shape and features of the oropharyngeal airway from teenagers to those in their 70 s. A total of 57 patients were grouped by age (teenagers, 20s, 30s, 40s, 50s, 60s and 70s), and all underwent cone beam computed tomography (CBCT) to measure the oropharynx volume, height, cross-sectional area, and length of the superior and inferior extremities. Kruskal-Wallis analysis indicated that the volume and height of the oropharynx did no significant difference among age groups, but there was a different tendency when cross-sectional areas of the superior and inferior extremities were compared between younger and older patients. Further, the shape of the inferior extremity was also different features between younger and older patients. In humans, the oropharyngeal airway plays an important role in carrying food through the esophagus and facilitating phonation. Ideally, it is important for this airway to maintain a constant volume and height. Recently, there has been an increase in the incidence of oropharyngeal airway blockage accidents among the elderly. Declines in feeding and swallowing functions and changes in the form of the oropharynx are major factors in these accidents