Occlusal Force Research Articles

Association Between Oral Hypofunction and Maximum Gait Speed in Older Adults: A Cross-Sectional Study.

Previous studies have reported an association between oral hypofunction and normal gait speed as a marker for physical function; however, the association between maximum gait speed as a more sensitive marker for physical function and poor oral function has not been investigated. To elucidate associations of oral hypofunction, comprising seven elements, with both normal and maximum gait speeds in an older population. Participants were recruited in 2018 from a hospital-based health checkup in Kyoto Prefecture. Seven oral function tests (oral hygiene, oral dryness, occlusal force or number of teeth, tongue-lip motor function, tongue pressure, masticatory function and swallowing function) were performed. Oral hypofunction was defined as an abnormality in at least three of these items. Gait speed was measured as normal and maximum gait speeds. The relationship between oral hypofunction and maximum gait speed was analysed using logistic regression. This study included 198 participants (130 men and 68 women; mean age: 75.0 years). Among them, 152 (76.7%) had oral hypofunction. After adjustment for age, sex and body mass index, oral hypofunction was significantly associated with a low maximum gait speed (odds ratio: 2.75, 95% confidence interval: 1.41-5.37). Oral hypofunction is associated with maximum gait speed in older people. The prevention of oral hypofunction may help maintain walking speed and promote an increase in healthy life expectancy.

A Fully Integrated Orthodontic Aligner With Force Sensing Ability for Machine Learning-Assisted Diagnosis.

Currently, the diagnosis of malocclusion is a highly demanding process involving complicated examinations of the dental occlusion, which increases the demand for innovative tools for occlusal data monitoring. Nevertheless, continuous wireless monitoring within the oral cavity is challenging due to limitations in sampling and device size. In this study, by embedding high-performance piezoelectric sensors into the occlusal surfaces using flexible printed circuits, a fully integrated, flexible, and self-contained transparent aligner is developed. This aligner exhibits excellent sensitivity for occlusal force detection, with a broad detection threshold and continuous pressure monitoring ability at eight distinct sites. Integrated with machine learning algorithm, this fully integrated aligner can also identify and track adverse oral habits that can cause/exacerbate malocclusion, such as lip biting, thumb sucking, and teeth grinding. This system achieved 95% accuracy in determining malocclusion types by analyzing occlusal data from over 1400 malocclusion models. This fully-integrated sensing system, with wireless monitoring and machine learning processing, marks a significant advancement in the development of intraoral wearable sensors. Moreover, it can also facilitate remote orthodontic monitoring and evaluation, offering a new avenue for effective orthodontic care.

Mandibular Periostitis Ossificans in a 17-Week-Old Male Great Dane.

This case report describes the clinical, radiographic, and histopathological features of a self-limiting mandibular swelling in a juvenile, large breed dog with a diagnosis of mandibular periostitis ossificans (MPO). This is a pathologic syndrome of immature large breed dogs that presents with a unilateral, nonpainful, caudal mandibular swelling centering on the erupting first molar tooth. This condition affects dogs with a median age of approximately 4 months. The diagnosis of MPO, in this case, resulted from the assimilation of clinical and radiographic findings, along with woven bone proliferation on histopathology. A distinct "double cortex" seen on radiographs of the caudal mandible is a defining characteristic of MPO that is most likely due to an additional cortical bone layer being produced on the mandible. MPO spontaneously resolved indicating that treatment with benign neglect was successful. The pathogenesis of periostitis ossificans is likely to be multifactorial and the mandibular bone of young, large breed dogs appears to be intrinsically predisposed. Trauma, occlusal forces, and foreign bodies are considered risk factors in the development of MPO. In this case report, trauma from a previous bite wound when the dog was 9 weeks old was a risk factor for this dog in developing MPO.

Comparison of Luting Cement Solubility: A Narrative Review.

Background: Dental restoration success relies on the physical properties of luting cements. Luting cements fill the space between teeth and the restoration, provide retention and protection from occlusal forces, and act as a barrier to microleakages in the oral environment. Objective: This review aims to evaluate and compare the solubility of the three most used dental luting cements: glass ionomer (GI), resin-modified glass ionomer (RMGI), and resin cement (RC). Methods: The studies selected for review compared the solubilities of combinations of GI, RMGI, and RC in solutions with different pH levels to replicate acidic oral pH. Results: A review of the studies concluded that resin cement had the overall lowest degree of solubility at all pH values and all storage periods, followed by RMGI and GI cement. Conclusions: The success of the restoration is dependent upon the choice of luting cement. The results of the studies reviewed show that all dental luting cements showed some degree of dissolution. Resin cement overall demonstrated the least amount of solubility, followed by RMGI and GI cement.

In vitro analysis of flowable and high viscosity bulk fill composite versus conventional composite in core build up of endodontically treated teeth

This study aimed to test the load to fracture of flowable and high viscosity bulk-fill composites compared to a convetional (packable) composite used to build up pulpless teeth. 45 endodontically treated premolars were restored with fiber posts then divided into three groups (N = 15) according to the core build-up material. SDR group: (Smart Dentine Replacement), (BF): Filtek One Bulk Fill and (CC) Filtek Z350 packable composite. After core build up the teeth received full coverage crowns. Load to fracture (Newton) was recorded for each specimen. One-way ANOVA and Tukey multiple comparisons test were used. The highest load at fracture was shown by (CC) group (1067 N), followed by (BF) group (879 N), and the SDR group (838 N). One way ANOVA and Tukey’s multiple comparisons test demonstrated no significant differences between CC, SDR, and BF groups (p > 0.05). The three materials showed comparable load to fracture. Further studies with simulation to occlusal forces and oral temperature are required.

Association of oral health with nutritional status of the older adults: a cross-sectional study.

The potential association between oral health and nutritional status of the very old, has been poorly investigated. Thus, we carried out the cross-sectional study to evaluate the association of oral health with the nutritional status of the older adults. 210 participants aged over 75 years were included in the study. Nutritional status was assessed by the Short-form Mini-Nutritional Assessment (MNA-SF) and body composition measurement. Data were available for self-reported oral health (10-item Eating Assessment Tool (EAT-10) and Chewing Function Questionnaire (CFQ)) and specific experimental tests including salivary flow, tongue and lip pressure, occlusal force, water swallow test and taste test for the detection of oral functions. Spearman rank correlation was used to analyze the correlation between body composition and oral health. Logistic regression and restricted cubic spline models were applied to examine the association of oral health with malnutrition. The study reveals that poor oral health is related to the malnutrition. The tongue pressure and molar occlusal force were significantly associated with malnutrition in an L-shaped dose-response relationship after adjustment for potential confounding factors. The higher the tongue pressure and molar occlusal force, the lower the risk of malnutrition. Besides, the CFQ score, salty, sour, and bitter taste, are risk factors for malnutrition. The presence of malnutrition is significantly associated with poor oral health in older adults. Our study supposes that the design of food suitable for oral conditions of the older adults may be another feasible solution to the nutritional problems among them.

Quantitative Comparison of Age-Related Development of Oral Functions During Growing Age.

This cross-sectional study aimed to investigate the age-related development of five major oral functions-tongue pressure, lip pressure, masticatory efficiency, bite force, and occlusal contact area-in subjects aged 5-20 years. Ninety-two subjects were divided into four age groups: 5-8, 9-12, 13-16, and 17-20 years. Oral functions were evaluated using standardized methods, including Chew Check Gum for assessing masticatory efficiency, Dental Prescale II for measuring occlusal force and contact area, JMS tongue pressure measuring device for evaluating tongue pressure, and Ripple-Kun for measuring lip pressure. Occlusal contact area, maximum bite force, tongue pressure, and masticatory efficiency gradually increased with age, whereas lip pressure remained stable. The occlusal contact area temporarily decreased between 5 and 12 years of age, likely due to the replacement of erupting lateral teeth. Some differences were observed between males and females; however, overall trends in oral function parameters were similar. Spearman's rank correlation analyses revealed significant positive correlations between age and occlusal contact area, bite force, tongue pressure, and masticatory efficiency. Oral function parameters exhibited different age-related development patterns. Occlusal contact area, maximum bite force, tongue pressure, and masticatory efficiency gradually increased with age. Interestingly, the occlusal contact area tended to reduce temporarily between 5 and 12 years of age due to the replacement of erupting lateral teeth. Conversely, lip pressure was almost stable during this period. Our findings provide valuable insights into the developmental patterns of oral functions during the growing years.

Comparison of Postorthodontic Occlusal Force Distributions between Nonextraction and Extraction Treatment Approaches of Premolars for Orthodontic Treatment by Using T-Scan III System.

To compare bite force distributions in corresponding mouth regions between postorthodontic patients who underwent nonextraction and extraction approaches using the T-Scan III system (Tekscan, Inc, Massachusetts, United States). Thirty-six postorthodontic patients were divided into two groups: (1) 18 subjects with the nonextraction treatment and (2) 18 subjects with the extraction of four first-premolar treatments. The measurements were performed using the T-Scan to collect the occlusal bite force at the maximal intercuspal position to generate the bite force in the anterior region (incisors and canines) and posterior region (premolars and molars), the bite force in individual teeth, and the anteroposterior bite force ratio (A-P ratio). The mean bite force in each region, individual teeth, and the A-P ratio were compared between the two groups by the Mann-Whitney's U-tests. Within-group comparisons of the mean bite force in each region were performed using Wilcoxon's signed rank tests. The bite force in anterior and posterior regions, and the A-P ratio of the nonextraction group show no significant difference compared with the extraction group (p > 0.05). For individual teeth (central incisors, lateral incisors, canines, second premolars, first molars, and second molars), each tooth exhibited nonsignificantly different bite forces (p > 0.05) except for the second molars. The second molars in the nonextraction group had significantly less bite force than in the extraction group (p = 0.001). The comparison of occlusal bite force between the right and left sides showed that in the nonextraction group, the right side had significantly greater force (p < 0.05). In the extraction group, there was no significant difference between the sides (p > 0.05). Both nonextraction and extraction orthodontic treated patients exhibited the similar bite force distribution patterns in regions and individual teeth except for the higher occlusal force on the second molars in the extractions compared with the nonextractions.

Finite element analysis of maxillary orthodontic therapies with variable alveolar bone grafts under occlusal forces in patient with unilateral cleft lip and palate.

To investigate the biomechanical effects of maxillary orthodontic treatment on different alveolar bone grafting positions loaded with occlusal forces in an unilateral cleft lip and palate (UCLP) patient. Finite element analysis was employed to simulate clinical scenarios more accurately by loading with occlusal forces on 8 bone-grafted models during maxillary orthodontic treatment. Displacement and von Mises stress pattern during maxillary protraction, expansion, and combined protraction and expansion were analyzed. The seven bone-grafted models exhibited significantly smaller horizontal displacements at the non-cleft side landmarks during maxillary protraction and expansion compared to non-bone grafted models. Additionally, alveolar cleft bone grafted in the upper 1/3 and middle 1/3 exhibited greater asymmetry displacement and stress under maxillary protraction and expansion. The study highlights the necessity of considering occlusal forces in finite element study on orthodontic therapies for UCLP patients. The upper 1/3 and middle 1/3 bone graft conditions may require secondary bone graft supplementation to ensure the effectiveness of maxillary orthodontic treatment.

Oral function status of older patients seeking dental implant treatment.

In recent years, dental implant treatment has become an option for prosthetic treatment for missing teeth and is often performed in older patients. However, the complex oral functional decline in old age presents challenges in terms of frailty prevention, making oral function management after prosthetic treatment crucial. Nonetheless, the actual status of oral function in older patients seeking dental implant treatment remains unclear. In this study, we aimed to assess the oral function status of older patients seeking dental implant treatment. Among patients receiving prosthetic treatment for missing teeth, 227 older patients (111 in the pre-dental implant group and 116 in the pre-bridge/denture group) who underwent a thorough examination of their oral function were included in this study. Age, sex, comorbidities, smoking status, number of functional teeth, and occlusal support status were obtained from the medical records. Statistical analyses were performed using the t-test, chi-square test, and logistic regression (p < 0.05). Compared with the pre-bridge/denture group, the pre-dental implant group had significantly better oral hygiene, occlusal force, tongue-lip motor function, tongue pressure, masticatory function, and swallowing function and a significantly lower prevalence of oral hypofunction. Older age and decreased occlusal support were associated with the diagnosis of oral hypofunction, even after adjusting for confounding factors including prosthetic treatment. Although older patients seeking dental implant treatment have a higher oral function than those seeking general prosthetic treatment, older age and a lower number of occlusal supports suggest that appropriate oral function management is needed.

Testing the strength of thin feather-edge monolithic multilayered zirconia crowns: A pilot study with a novel acoustic test

Intoduction: Limited research has explored the mechanical characteristics of recently introduced multilayered monolithic zirconia (MZC) crowns with feather-edge margins design. Moreover, most of the conventional techniques for evaluating the mechanical behavior of brittle dental ceramics rely on destructive tests, making it impossible to precisely evaluate real strength values due to premature crack initiation detection failure. Objectives: The main objective of the study was to assess the load capacity of translucent multilayered monolithic zirconia crowns with feather-edge margin thicknesses of 0.4 mm and 0.5 mm. Additionally, the research introduced a novel non-destructive acoustic emission testing (AET) technique in the laboratory to identify early cracks in dental ceramics. Methods: Forty multilayered zirconia crowns produced using computer-aided design and computer-aided manufacturing (CAD/CAM) technology were evenly divided into two groups, each with distinct feather-edge margin thicknesses: 0.5 mm (group 1) and 0.4 mm (group 2). These crowns were securely cemented onto customized polymethyl methacrylate (PMMA) dies using a universal restorative glass ionomer. Subsequently, the crowns underwent a compressive axial loading test, controlled by an innovative AET crack detection system rooted in the principles of non-destructive laboratory testing. Fractographic analysis was conducted to determine the location of crack or eventual fracture. Results: The proportion of MZCs with a crack was statistically higher than the proportion with a fracture in the whole sample (p&lt;0.001). In addition, the results showed that the crowns in group 1 exhibited higher loading values than those in group 2. The mean loading capacity in group was 911.2 N ± 614.7 N. Two locations of crack and fracture were registered: occlusal and marginal. No statistical association was observed between the two groups for the location of cracks or fractures. Conclusions: The feather-edge crowns with a 0.5 mm margin thickness had a higher loading capacity than those with a 0.4 mm. However, the latter supports loads that exceed occlusal force in the oral cavity suggesting that 0.4 mm feathered edge MZCs may be a valid and less invasive alternative to thicker margins. The novel load-to-fracture AET setup proved effective in detecting early crack initiation, suggesting it as a promising method for assessing the mechanical properties of brittle materials prior to failure, potentially impacting the field of dentistry. However more advanced research is needed to enhance the accuracy of the proposed technique. Clinical implications: The examined MZC demonstrates the ability to withstand occlusal forces in a patient’s mouth, offering clinical practitioners the option of embracing minimally invasive dentistry through the use of 0.4 mm feather-edge MZC in their treatment options. Furthermore, the positive results from the innovative acoustic emission testing technique, facilitating early crack detection, indicate a promising future for studying the behavior of brittle materials in dental laboratory testing.

Evaluation of cortical bone thickness at the nasomaxillary and zygomaticomaxillary buttresses using cone-beam computed tomography imaging for Le Fort I osteotomy

Background/PurposeStudies have indicated that 50%–55% of the population have malocclusion, and approximately 5%–10% require orthognathic surgery to correct this condition. Optimal placement of plates and screws significantly affects the success rate of the surgery and postoperative stability. This study evaluates the cortical thickness of the maxillary bone in the nasomaxillary and zygomaticomaxillary buttress regions in Taiwanese patients based on cone-beam computed tomography (CBCT) images. Materials and methods128 Patients undergoing Le Fort I osteotomy were selected for this study. Their CBCT images were input into medical imaging software to simulate the placement of titanium screws and plates. The cortical bone thickness at these positions was measured to assess the thickness in the nasomaxillary buttress (surrounding the nasal opening) and the zygomaticomaxillary buttress (surrounding the maxillary zygomatic process). Associations of these thicknesses with gender, age, and screw position were analyzed. ResultsIn the nasomaxillary region, cortical bone was thicker on the upper and lower vertical regions, with men generally having thicker bone. The zygomaticomaxillary region had increased thickness near the zygomatic end and distal region. Younger adults had significantly greater bone thickness in certain areas than those over 30 years. ConclusionThe nasomaxillary region's upper and lower vertical regions and the zygomatic end in the zygomaticomaxillary region provide optimal screw placement sites. Bone thickness differences by gender and age suggest occlusal force and age-related bone resorption as influencing factors.

Evaluation of microtensile bond strength and marginal adaptation of fiber-reinforced composites

Background: Long-term durability of a restoration relies on the marginal integrity and its ability to withstand the occlusal forces. Fiber-reinforced composites (FRCs) exhibited superior properties in terms of fracture toughness, flexural strength, and wear resistance. Aim: The aim of this study was to assess and compare marginal adaptation and microtensile bond strength (µTBS) of posterior FRCs comparing with a condensable composite. Materials and Methods: Standardized mesio- and disto-occlusal cavities were prepared on 60 maxillary molars with 3.5 mm pulpal floor depth, 3 mm buccolingual width, and 1.5 mm axial depth. The mesial cavities were restored with everX Posterior and Build-It FRCs, while distal cavities of all teeth were restored with Alert composite and were thermomechanically aged. Half of the specimens from each group (n = 15) were evaluated for marginal adaptation under scanning electron microscope (SEM), and the other half were sectioned for μTBS testing with Instron testing machine. Bond failure mode was examined under SEM. Results: Marginal microgaps were significantly high for the Alert group than FRC groups. Gingival surface showed more gaps. Mean µTBS values were significantly high for FRCs. Cohesive failures are more among FRCs, and adhesive failures are more in condensable composite. Conclusion: The short FRCs showed superior marginal adaptation and better bond strength than condensable composite.

Oral Antacid Use Is Negatively Associated with Serum Prealbumin Levels in Japanese Individuals Undergoing Health Checkups.

The aim of this study is to investigate the association between physical and chemical digestion and nutrition markers (serum albumin (ALB), prealbumin (PAB), and vitamin B12 (B12) levels). During a detailed checkup at Fujita Health University, we examined the associations of physical (occlusal force, masticatory performance, and swallowing ability (via the 10-item Eating Assessment Tool, EAT-10)) and chemical (Helicobacter pylori (HP) eradication history, HP antibody levels, and oral antacid (proton pump inhibitors) use) digestion parameters with serum ALB, PAB, and B12 levels in 92 individuals (M:67, F:25). Forty-eight percent of the participants were older than 65 years of age, 19% had decreased occlusal force, 3.2% had decreased masticatory strength, 3.2% had decreased swallowing function, 24% had a history of HP eradication, 23% were HP antibody positive, and 16% were taking oral antacid medication. Additionally, 14% and 11% of the patients had low serum ALB and PAB levels, respectively, and 14% of the patients had B12 deficiency. Multivariate analysis adjusted for age, sex, body mass index, and C-reactive protein levels revealed that there were no significant associations between the physical digestion parameters and the serum PAB, ALB, or B12 levels. On the other hand, there was a significant association between oral antacid use and PAB levels (β = -3.3, p = 0.04). Independent of physical or chemical digestion parameters, serum PAB and B12 levels were significantly associated with protein and B12 intake, respectively. Oral antacid use may decrease serum PAB levels, indicating protein synthesis.

Relationship Between Oral Motor and Cognitive Function in Community-Dwelling Korean Older Adults: A Cross-Sectional, Observational Study.

Background: The present study analyzed the relationship between oral motor and cognitive functions in community-dwelling older Korean adults. Methods: Study participants included 113 community-dwelling older adults with a mean age of 73.84 years. Subjects' cognition was assessed using the Korean version of the Montreal Cognitive Assessment, and tongue, cheek, and lip pressures were assessed using the Iowa Oral Performance Instrument. Tongue and masseter thicknesses were measured using an ultrasound device (Sonon, Healcerion, Roseville, CA, USA). The occlusal force was measured using a specialized device (Innobyte, Kube Innovation, Montreal, QC, Canada), and the number of lost teeth was directly verified by a dental hygienist. Results: Results of analysis of cognitive function according to demographic characteristics of older community-dwelling adults revealed a significant difference in cognitive function according to education level and employment status. Cognitive function demonstrated a positive correlation with oral motor function, including pressure on the cheek, lips, and tongue, thickness of the masseter and tongue, occlusal force, number of lost teeth, and age. Hierarchical regression analysis revealed that demographic characteristics and cheek, lip, tongue, and masseter functions did not affect cognition, whereas occlusal force and number of lost teeth significantly affected cognition. In this study, oral motor function, excluding occlusal force and number of lost teeth, did not affect cognition. Conclusions: Future studies, however, are required to analyze the relationship between oral motor function and cognition in older adults with a wider range of such functions.

Dimensions of Posterior Implant Restorations Related to Intra-Coronal Cantilever and Occlusal Forces: An In Vitro Study.

The aim of the present study was to investigate the relation of the implant position to the implant crown and analyze the location and magnitude of bite force. The dimensions of 49 posterior implant-supported restorations were recorded in terms of: 1. implant diameter, 2. crown length, 3. crown width, 4. crown height, 5. occlusal surface of the restoration. The crown/implant height was measured and the distance between the implant center and the restoration center revealed the size of intra-coronal cantilevers. The occlusal force analysis determined the point and magnitude of loading. Correlation coefficient r was used for the statistical process and statistical control was carried out with the aid of t-test with minimum level of significance p < 0.05. - The mean crown-to-implant ratio was 0.9 and in short implants (< 10mm) the ratio was 1.28. - Intra-coronal cantilever extensions ranged from 2.1 mm to 6.35 mm depending on crown size. - Occlusal loading was identified in cantilever areas of the crown. - Implant center deviates from crown center in 71%-82% of the cases depending on site location. - Implants with non-ideal position may support a functionally occluding crown. Intra-coronal cantilevers are a critical factor to avoid clinical complications and should be taken under consideration both in the planning and fabrication phase of implant restorations.

Predicting cognitive function changes from oral health status: a longitudinal cohort study

Recent studies indicate a potential link between oral health and cognitive function; however, long-term associations remain unclear. This study aimed to identify oral health factors that predict changes in cognitive function among older adults over time. The study included 583 independent older adults (201 male, 382 female) with a mean age of 72.7 years. Cognitive function was assessed using Mini-Mental State Examination (MMSE) at baseline and follow-up over two years, with relative change in MMSE (rMMSE) calculated. Baseline oral health variables included number of remaining teeth, masticatory performance, occlusal force, oral diadochokinesis and tongue pressure. Physical performance and confounding factors were also considered. The relationship between rMMSE and the variables was analyzed using Pearson’s correlation, Mann-Whitney U test, and multiple linear regression analysis. Cognitive function declined in 196 subjects, with rMMSE significantly correlated with oral diadochokinesis. Regression analysis revealed significant associations between cognitive changes and oral diadochokinesis (p = 0.020) and knee extension strength as a physical performance (p = 0.047). Our findings suggest that cognitive decline may be indicated by declines in both physical and oral motor performance. Incorporating oral diadochokinesis testing into health screenings could aid early detection of cognitive decline, improving outcomes and reducing healthcare burdens.

Pain Catastrophizing and Functional Activation During Occlusion in TMD Patients-An Interventional Study.

In temporomandibular disorder (TMD), the effects of standard interventions such as using an occlusal splint and its impact on pain relief and pain catastrophizing are poorly understood. Earlier work pointed to a crucial role of insula activation with changes in pain relief by occlusal splint treatment. We performed a functional imaging study using specially developed splint systems to allow for a placebo-controlled longitudinal design. Using functional MRI we examined 20 TMD patients during repetitive occlusal movements at baseline and over the course of splint therapy and also collected self-reported pain catastrophizing. For balancing performance between baseline and after intervention we used occlusion force measures in an individualized fMRI-splint system. Splint therapy lasted for approximately 7 weeks with one group selected by randomization wearing a palatine placebo splint over the first 3 weeks (delayed start; 11 individuals). As expected, fMRI activation in areas involved in pain processing (insula, primary and secondary somatosensory cortex) decreased with intervention. At baseline a positive correlation between activation of the left anterior insula and pain catastrophizing was present. Both parameters decreased over intervention while associations were primarily observable for patients with rather mild TMD.

The Association of Walking Ability with Oral Function and Masticatory Behaviors in Community-Dwelling Older People: A Cross-Sectional Study.

Background/Objectives: An association between oral function and physical fitness, including walking capacity, has been reported. However, the association between masticatory behaviors and walking ability-both of which represent patterns of movement in daily life-has not been clarified. This study aimed to investigate the association between masticatory behaviors, oral function, and walking capacity in older people. Methods: One hundred community-dwelling older people (31 men, 69 women, mean age 75.7 ± 6.3 years) were selected to participate in this study. Age, sex, masticatory behaviors, oral functions (tongue pressure, tongue-lips motor function, occlusal force, and masticatory performance), and walking capacity were assessed. Masticatory behaviors were assessed during the consumption of one rice ball (100 g) using a wearable chewing counter, and the number of chews, chewing rate, the number of chews per bite, and meal time were recorded. Walking capacity was assessed using the timed up and go test (TUG). Spearman's rank correlation coefficients were calculated to assess the strength and direction of the association. Results: Moderate negative correlations were observed between TUG time and tongue pressure and between TUG time and tongue-lips motor function (/ta/ and /ka/) (rs = -0.33, -0.21, -0.28, respectively). In addition, moderate negative correlations between TUG time and chewing rate (rs = -0.22) and between TUG time and meal time (rs = 0.33) were observed, suggesting that lower walking capacity was associated with slower chewing rate and longer meal times. Conclusions: In community-dwelling older people, declines in mastication speed and dexterity and tongue strength are associated with lower walking capacity.

A Case-Control Split-Mouth Study of Comparison of Maximum Occlusal Forces in Endodontically Treated Teeth and Vital Counterparts.

To compare the maximum occlusal force in endodontically treated teeth and their vital contralateral counterparts and to evaluate the intraoral factors affecting them. Thirty adult participants presented with an endodontically treated tooth and its vital contralateral counterpart were recruited, with 15 males and females in each group. Maximum occlusal forces were measured using a wireless sensor network occlusal force recorder, and the mean maximum occlusal force of endodontically treated teeth was compared with that of their vital contralateral counterparts. Multiple-factor ANOVA was used to examine the association between various clinical factors and maximum occlusal force. The mean maximum occlusal force for endodontically treated teeth was significantly higher than their vital counterparts (215.44 ± 74.11N and 202.40 ± 70.67N, respectively) (P < 0.001). Among the clinical factors, the maximum occlusal forces were significantly influenced by the location of teeth (P < 0.01) and the crown root ratio (P = 0.01). Upon further analysis of endodontically treated teeth and control groups, the location of teeth was identified as a sole factor associated with maximum occlusal force, with P < 0.05. The maximum occlusal forces for endodontically treated teeth were statistically significantly higher than those of their corresponding vital contralateral teeth.