The relationship between changes in occlusal support and masticatory performance using 6-year longitudinal data from the SONIC study.

OBJECTIVES: Reduced occlusal support is thought to be related to a decline in masticatory performance. However, previous research in this field was based on cross-sectional studies. In this study, we conducted a 6-year longitudinal observation of older adults living in the community and examined the associations of changes in occlusal support with masticatory performance. METHODS: Of the 864 participants aged 72-74 years in the SONIC study, 488 who were followed up (median follow-up period 5.92 years) and had no missing data were included in this study. Participants were divided into three groups according to the number of occlusal support zones in the posterior area: Complete occlusion (four zones), Reduced occlusion (one to three zones), and Collapsed occlusion (no occlusal support zone). Longitudinal analysis of the relationship between occlusal support and masticatory performance was undertaken with linear mixed-effects models. RESULTS: Sex, occlusal force, number of unreplaced missing teeth, aging, and occlusal support change were significantly related to masticatory performance. Furthermore, the interaction term between change in occlusal support and aging was a significant explanatory variable for the decline in masticatory performance. The interaction was strongest in the group that changed from Complete or Reduced occlusion to Collapsed occlusion. This result indicates that the loss of occlusal support is a major factor contributing to declining masticatory performance. CONCLUSIONS: The decline of occlusal support was greatly associated with the deterioration of masticatory performance. Our results suggest that older adults need to prevent the collapse of posterior occlusal support to maintain their masticatory performance. CLINICAL SIGNIFICANCE: Occlusal support is important for preserving masticatory performance in older adults. Preventing the loss of molars and retaining occlusal support may contribute to maintaining food intake diversity and nutritional status, thereby improving quality of life. Dental professionals need to carefully examine dental status to assess the risk of occlusal collapse.

Relationship between the number of teeth, occlusal force, occlusal contact area, and dietary hardness in older Japanese adults: The SONIC study.

PURPOSE: Individuals with impaired masticatory function tend to prefer soft foods, which results in decreased masticatory muscle activity. This study examined the association between the oral condition (number of teeth, occlusal force, and occlusal contact area) and dietary hardness using a daily dietary questionnaire. METHODS: This cross-sectional study evaluated 1841 participants aged 69-71 and 79-81 years. Registered dentists examined the number of teeth, occlusal force, and occlusal contact area. Dietary hardness was defined as the estimated masticatory muscle activity required for a habitual diet. Habitual diet during the preceding month was assessed using a brief self-administered diet history questionnaire. Confounding factors, such as age, sex, socioeconomic status, smoking habits, history of chronic diseases (hypertension, hyperlipidemia, and diabetes), and cognitive function were also evaluated. Multivariate linear regression analyses were performed to assess the association between dietary hardness and each oral condition. RESULTS: Occlusal force (standardized regression coefficients [ß]=0.08, P < 0.01) and occlusal contact area (ß=0.06, P < 0.01) were significantly associated with dietary hardness after adjusting for the confounding factors. Number of teeth was not significantly associated with dietary hardness. In addition, the associations between dietary hardness, sex, and a history of diabetes were stronger than those between dietary hardness and oral factors. CONCLUSIONS: Occlusal force and contact area were significantly associated with dietary hardness as estimated from the masticatory muscle activity using a daily diet questionnaire.

Effective oral function improvement by restoration-driven implant treatment after mandibular resection with a scapular flap: a case report.

BACKGROUND: The extensive loss of teeth and surrounding tissues due to mandibulectomy for an oral tumor not only impacts negatively on appearance, but also often causes various functional disorders, decreasing quality of life (QOL). In the present case, reconstruction with a scapular flap was carried out along with segmental mandibulectomy, aiming for functional restoration through restoration-driven implant treatment. A good outcome was obtained, with improvement of masticatory function and QOL following the prosthetic treatment. CASE PRESENTATION: The patient was a 37-year-old woman diagnosed with ossifying fibroma in the left side of the mandible. Segmental mandibulectomy and reconstruction with a scapular flap were carried out. Implant diagnostic simulation was performed, and based on the result, secondary reconstruction using a particulate cancellous bone and marrow graft was carried out by an oral surgeon. After wound healing was complete, implant placement was performed twice, and the final prosthodontic treatment was completed. Masticatory performance and maximum bite force, which are indices of masticatory function, were improved from before to after prosthetic treatment. In addition, oral health-related QOL was improved from before to after prosthetic treatment. CONCLUSION: In the present case, restoration-driven implant treatment was performed in a patient following segmental mandibulectomy for a mandibular tumor, with a good outcome. Planning the treatment measures with a focus on the final prosthetic vision can lead to improvement of oral function in patients with extensive mandibular defects.

Suitable indicators to determine tsunami impact on coastal areas in Northern Japan, Aomori Prefecture.

The 2011 Tohoku-oki tsunami released and mobilized many anthropogenic and natural organic compounds and, hereby, left a clear signature in its sedimentary remnants. In this study, a wide variety of organic marker substances were analyzed in 15 sediment profiles from the Aomori coast (Northern Japan). Total organic carbon (TOC) and fine grain fraction normalization have been tested with the wide dataset, and the already more frequently used TOC normalization was proven to be the more suitable one. Concentration profiles and specific ratios have been interpreted using two different approaches. Differentiation of marine and terrestrial matter characterized mixing processes due to the tsunami impact. Linking constituents to anthropogenic emission sources pointed not only to pollution revealed by the tsunami damages but also to dispersion processes, in particular erosion, transport, mixing and redeposition of particle-associated contaminants. Both approaches have been proved to identify unambiguously tsunamites in sedimentary archives and to reveal detailed insights into the tsunami-driven dispersion of particle-associated organic matter. Generally, the organic geochemical proxies as tested in this study can be reliably used to identify and characterize tsunami deposits in the sedimentary record. Finally, this strategy can be transferred to other locations affected by tsunamis for an in-depth characterization of the destruction and environmental changes induced by tsunami events.

Decline of oral functions in old-old adults and their relationship with age and sex: The SONIC study.

BACKGROUND: Many physical functions decline with aging, but it is not known whether oral functions vary according to sex or decline with aging, as it occurs with physical functions. The present study aimed to examine the association of sex, age, and elapsed years with occlusal force and tongue pressure using a generalized linear mixed-effect model (GLMM) over a 3-year period among old-old Japanese adults. METHODS: Participants were community-dwelling older adults who participated in a survey (June 2014-March 2017) and a follow-up survey (July 2017-December 2019) after 3 years (n = 951: 70-year group, n = 466; 80-year group, n = 391; 90-year group, n = 94). Dental examinations including the number of teeth, occlusal force, and tongue pressure were conducted, and a GLMM was used to estimate the association of sex, age, and elapsed years with occlusal force and tongue pressure, adjusting for the number of teeth. RESULTS: The GLMM showed that occlusal force was significantly associated with sex (reference; male, non-standardized coefficient: B = -66.9 [female], p < 0.001), age (reference; 70-year group, B = -81.7 [80-year group], p < 0.001, B = -87.2 [90-year group], p < 0.001), and the number of teeth (B = 13.8, p < 0.001), but did not significantly decrease with elapsed years. Tongue pressure was significantly associated with sex (reference; male, B = -0.94 [female], p = 0.034) and age (reference; 70-year group, B = -1.78 [80-year group], p < 0.001, B = -5.47 [90-year group], p < 0.001). Tongue pressure decreased significantly with elapsed years (B = -0.82, p < 0.001). CONCLUSIONS: These findings suggest that tongue pressure significantly decreased over time, but occlusal force did not. Tongue-related muscles may be more susceptible to aging than masticatory muscles.

Oral Functions Are Associated with Muscle Strength and Physical Performance in Old-Old Japanese.

Grip strength and walking speed are considered to be important indicators of physical frailty. However, no study has contemporaneously examined any association of multiple oral functions with grip strength and walking speed. The purpose of this study was to examine which oral functions are associated with muscle strength (grip strength), physical performance (walking speed) or both. The study participants were 511 community-dwelling people (254 men and 257 women) aged 77-81 years old. Six oral functions-oral wetness, occlusal force, tongue-lip motor function, tongue pressure, masticatory performance and swallowing function-were measured. Grip strength and walking speed were also measured. A partial correlation analysis, adjusted for gender, showed that occlusal force, tongue-lip motor function, masticatory performance and swallowing function were significantly associated with both grip strength and walking speed. In addition, tongue pressure was significantly associated with grip strength. A general linear model showed that tongue pressure and occlusal force were significantly associated with grip strength. Swallowing function and tongue-lip motor function were significantly associated with walking speed. It is suggested that there are different oral function measures for muscle strength and physical performance, and these oral function measures could be a useful proxy for physical frailty.

Influence of Implant Distribution and Palatal Coverage on the Strain of Splinted Implant and Overdenture in Maxillary Implant Overdentures.

PURPOSE: Implant overdentures with splinted attachments have been used in clinical practice, and the effect of splinting on implants has been reported frequently. However, the effect of implant configuration of more than four implants and covering the palate with an overdenture has not been sufficiently examined. The purpose of this study was to reveal the effects of implant configuration and palatal coverage on both implant and denture strain in maxillary implant overdentures using splinted implants. MATERIALS AND METHODS: Six implants were placed in the anterior, premolar, and molar areas in a maxillary edentulous model. Four strain gauges were attached to the implant surface, and Dolder bar attachments were used to splint implants distributed in various configurations. Two types of maxillary experimental dentures (with/without palatal coverage) were fabricated, and two strain gauges were attached at the midline. A vertical load of 98 N was applied, and the strains on the dentures and implants were measured. The strain measurements were compared using one-way analysis of variance and t test (P = .05). RESULTS: When comparing the implant strains, the strain was significantly smaller on the anterior and premolar implants when six implants were used, but there was no significant difference among the different implant configurations in the strain on the molar implants. Strains on anterior implants of the palateless overdenture were significantly greater than those of the overdenture with palatal coverage. When four implants were used, the strain on the palatal side of dentures without palate was significantly greater than that on those with palatal coverage. When six implants were used, there was no significant difference in the strain on either side between two types of dentures. CONCLUSION: When implants were splinted to each other using a denture without palatal coverage, the strain of dentures when six or two anterior and two posterior implants were used was lower. The difference of denture strains between two types of dentures was not significant when six implants were used, but was significant for all other configurations. Also, the difference of implant strains between two dentures was significant in anterior implants regardless of implant configuration.

Tracing woody-organic tsunami deposits of the 2011 Tohoku-oki event in Misawa (Japan).

With a minimum of three reported waves, the 2011 Tohoku-oki tsunami's destructive force caused massive damage along the northern Japanese Aomori coast. At Misawa the coastal control area was inundated up to 550 m inland and sandy sediment remnants can be traced to c. 350 m (c. 61-63% of the maximum inundation) from the shoreline. Linking the discovery of floatable plastic objects within a woody and organic layer to our analytical data lead to the detection of a yet undocumented woody-organic tsunami deposit first appearing on top of the sandy deposit but then reaching even further inland (approx. 69-72% of the max. inundation). By this observation our understanding of the documented part of the tsunami inundation may be improved. As a consequence, sand sheets of historic and paleo-tsunamis represent minimum estimates for the coastal inundation and underestimation may be reduced by addressing the woody and organic fraction of a tsunami's inundation.

Characterization of three GH35 ß-galactosidases, enzymes able to shave galactosyl residues linked to rhamnogalacturonan in pectin, from Penicillium chrysogenum 31B.

Three recombinant ß-galactosidases (BGALs; PcBGAL35A, PcBGAL35B, and PcGALX35C) belonging to the glycoside hydrolase (GH) family 35 derived from Penicillium chrysogenum 31B were expressed using Pichia pastoris and characterized. PcBGAL35A showed a unique substrate specificity that has not been reported so far. Based on the results of enzymological tests and 1H-nuclear magnetic resonance, PcBGAL35A was found to hydrolyze ß-1,4-galactosyl residues linked to L-rhamnose in rhamnogalacturonan-I (RG-I) of pectin, as well as p-nitrophenyl-ß-D-galactopyranoside and ß-D-galactosyl oligosaccharides. PcBGAL35B was determined to be a common BGAL through molecular phylogenetic tree and substrate specificity analysis. PcGALX35C was found to have similar catalytic capacities for the ß-1,4-galactosyl oligomer and polymer. Furthermore, PcGALX35C hydrolyzed RG-I-linked ß-1,4-galactosyl oligosaccharide side chains with a degree of polymerization of 2 or higher in pectin. The amino acid sequence similarity of PcBGAL35A was approximately 30% with most GH35 BGALs, whose enzymatic properties have been characterized. The amino acid sequence of PcBGAL35B was approximately 80% identical to those of BGALs from Penicillium sp. The amino acid sequence of PcGALX35C was classified into the same phylogenetic group as PcBGAL35A. Pfam analysis revealed that the three BGALs had five domains including a catalytic domain. Our findings suggest that PcBGAL35A and PcGALX35C are enzymes involved in the degradation of galactosylated RG-I in pectin. The enzymes characterized in this study may be applied for products that require pectin processing and for the structural analysis of pectin.

Synthesis of 5-hydroxymethylfurfural from highly concentrated aqueous fructose solutions using activated carbon.

An efficient and environmentally friendly system for producing 5-hydroxymethylfurfural (5-HMF) from fructose has been proposed. Substrate concentration is an important factor for practical application of the process; however, use of a high concentration of fructose has rarely been tested in the reaction because the conditions accelerate intermolecular side reactions to form adhesive humins. Humin byproducts stuck on reactor surfaces can make the production of 5-HMF on an industrial scale difficult. Therefore, developing a catalytic reaction system that can promote the synthesis of 5-HMF from highly concentrated fructose without causing adhesion of humins to reactors is needed. The present study demonstrated that activated carbons are promising materials for this system. Activated carbon catalyzed the conversion of fructose to 5-HMF without adhesion of humins to reactor vessels under practical conditions of high substrate concentration up to 73.2%. The catalytic activity was determined not only by the amount of surface weakly acidic oxygenated groups but also by the adsorption of fructose. In addition, strong adsorption of 5-HMF led to low selectivity of 5-HMF and the formation of adhesive humins. This is the first report to describe the synthesis of 5-HMF from solutions containing a fructose concentration greater than 70%.

Biochemical characterization of a GH53 endo-ß-1,4-galactanase and a GH35 exo-ß-1,4-galactanase from Penicillium chrysogenum.

An endo-ß-1,4-galactanase (PcGAL1) and an exo-ß-1,4-galactanase (PcGALX35C) were purified from the culture filtrate of Penicillium chrysogenum 31B. Pcgal1 and Pcgalx35C cDNAs encoding PcGAL1 and PcGALX35C were isolated by in vitro cloning. The deduced amino acid sequences of PcGAL1 and PcGALX35C are highly similar to a putative endo-ß-1,4-galactanase of Aspergillus terreus (70% amino acid identity) and a putative ß-galactosidase of Neosartorya fischeri (72%), respectively. Pfam analysis revealed a "Glyco_hydro_53" domain in PcGAL1. PcGALX35C is composed of five distinct domains including "Glyco_hydro_35," "BetaGal_dom2," "BetaGal_dom3," and two "BetaGal_dom4_5" domains. Recombinant enzymes (rPcGAL1 and rPcGALX35C) expressed in Escherichia coli and Pichia pastoris, respectively, were active against lupin galactan. The reaction products of lupin galactan revealed that rPcGAL1 cleaved the substrate in an endo manner. The enzyme accumulated galactose and galactobiose as the main products. The smallest substrate for rPcGAL1 was ß-1,4-galactotriose. On the other hand, rPcGALX35C released only galactose from lupin galactan throughout the reaction, indicating that it is an exo-ß-1,4-galactanase. rPcGALX35C was active on both ß-1,4-galactobiose and triose, but not on lactose, ß-1,3- or ß-1,6-galactooligosaccharides even after 24 h of incubation. To our knowledge, this is the first report of a gene encoding a microbial exo-ß-1,4-galactanase. rPcGAL1 and rPcGALX35C acted synergistically in the degradation of lupin galactan and soybean arabinogalactan. Lupin galactan was almost completely degraded to galactose by the combined actions of rPcGAL1 and rPcGALX35C. Surprisingly, neither rPcGAL1 nor rPcGALX35C released any galactose from sugar beet pectin.

Purification, characterization of GH11 endo-ß-1,4-xylanase from thermotolerant Streptomyces sp. SWU10 and overexpression in Pichia pastoris KM71H.

We have previously described two forms of an endo-ß-1,4-xylanase (XynSW2A and XynSW2B) synthesized by thermotolerant Streptomyces sp. SWU10. Here, we describe another xylanolytic enzyme, designated XynSW1. The enzyme was purified to homogeneity from 2 L of culture filtrate. Its apparent molecular mass was 24 kDa. The optimal pH and temperature were pH 5.0 and 40 °C, respectively. The enzyme was stable in a wide pH ranges (pH 1-11), more than 80 % of initial activity remained at pH 2-11 after 16 h of incubation at 4 °C and stable up to 50 °C for 1 h. Xylobiose and xylotriose were the major xylooligosaccharides released from oat spelt xylan by the action of XynSW1, indicating of endo-type xylanase. The complete xynSW1 gene contains 1,011 bp in length and encode a polypeptide of 336 with 41 amino acids of signal peptide. The amino acid sequence analysis revealed that it belongs to glycoside hydrolase family 11 (GH11). The mature xynSW1 gene without signal peptide sequence was overexpressed in Pichia pastoris KM71H. The recombinant XynSW1 protein showed higher molecular mass due to the differences in glycosylation levels at the six N-glycosylation sites in the amino acid sequence and exhibited better physicochemical properties than those of the native enzyme including higher optimal temperature (60 °C), and specific activity, but lower optimal pH (4.0). Because of their stability in a wide pH ranges, both of native and recombinant enzymes of XynSW1, may have potential application in several industries including food, textile, biofuel, and also waste treatment.

Characterization of an exo-ß-1,3-D: -galactanase from Sphingomonas sp. 24T and its application to structural analysis of larch wood arabinogalactan.

A type II arabinogalactan-degrading enzyme, termed Exo-1,3-Gal, was purified to homogeneity from the culture filtrate of Sphingomonas sp. 24T. It has an apparent molecular mass of 48 kDa by SDS-PAGE. Exo-1,3-Gal was stable from pH 3 to 10 and at temperatures up to 40 °C. The optimum pH and temperature for enzyme activity were pH 6 to 7 and 50 °C, respectively. Galactose was released from ß-1,3-D: -galactan and ß-1,3-D: -galactooligosaccharides by the action of Exo-1,3-Gal, indicating that the enzyme was an exo-ß-1,3-D: -galactanase. Analysis of the reaction products of ß-1,3-galactotriose by high-performance anion-exchange chromatography revealed that the enzyme hydrolyzed the substrate in a non-processive mode. Exo-1,3-Gal bypassed the branching points of ß-1,3-galactan backbones in larch wood arabinogalactan (LWAG) to produce mainly galactose, ß-1,6-galactobiose, and unidentified oligosaccharides 1 and 2 with the molar ratios of 7:19:62:12. Oligosaccharides 1 and 2 were enzymatically determined to be ß-1,6-galactotriose and ß-1,6-galactotriose substituted with a single arabinofuranose residue, respectively. The ratio of side chains enzymatically released from LWAG was in good agreement with the postulated structure of the polysaccharide previously determined by chemical methods.