Maximum Bite Force Research Articles

The Effects of Wearing a Removable-Partial-Denture on the Bite Forces: A Cross-Sectional Study.

Background: Removable partial dentures are a frequently used prosthetic treatment in the elderly population, but different types or RPDs might guarantee different chewing capabilities. In many studies, the relationship between chewing and aging has been reported and it has been shown that efficient chewing can improve the overall quality of life. Objectives: In the present study, the relationship between maximum bite force (MBF) and RPDs was studied. A relationship between the body mass index (BMI) and the type of prosthesis was also analyzed. Methods: 240 elderly patients, 120 males and 120 females, with bilateral posterior edentulism (class 1 of Kennedy classification) who had been wearing an RPD for at least a year, were recruited. Patients were divided into two groups: Group 1: male (n = 60) and female (n = 60) patients with bilateral edentulous areas located posterior to the remaining natural teeth and natural teeth in the opposite dental arch. Group 2: male (n = 60) and female (n = 60) patients with maxillary and mandibular bilateral edentulous areas located posterior to the remaining natural teeth. Their Body Mass Index (BMI) and Maximum bite force (MBF) were measured and compared according to the material and design of their RPD. Results: In both Groups, patients wearing cobalt-chrome alloy RPDs (Co-Cr-RPD) (Group 1: 20.25 ± 6.7 MBF, p < 0.001; Group 2: 16.0 ± 5.7 MBF, p < 0.001) had an increased MBF when compared to polymethylmethacrylate RPD (PMMA-RPD) (Group 1: 12.9 ± 3.36 MBF; Group 2: 10.4 + 2.8 MBF), and Valplast RPD (V-RPD) (Group 1: 14.3 ± 4.7 MBF; Group 2: 11.3 ± 3.4 MBF) users. There were no significant differences in bite force between patients wearing PMMA-RPD and V- RPD in both Groups. Patients in Group 2 showed a lower MBF than those in Group 1 (Group 1: 16.05 ± 6.13 MBF; Group 2: 12.6 ± 4.84 MBF; p < 0.001). Conclusions: A reduction in chewing force can lead to choosing softer foods for nutrition, which can lead to an increase in BMI. Our results show that only CoCr-RPD wearers were able to chew consistent food, whereas PMMA- RPD and V-RPD, due to the properties of the materials, their instability, and the possibility of causing pain during mastication, determined a limitation in the choice of food for many of the participants.

Patient-Centered Treatment Outcomes with Full-Arch PEEK Rehabilitation Supported on Four Immediate or Conventionally Loaded Implants. A Randomized Clinical Trial.

This study aims to assess the treatment outcomes (functional and subjective) of full-arch fixed hybrid rehabilitations made of PEEK (poly-ether-ether-ketone) with milled crowns of nano-filled composite (NFC) supported on four to six implants. In this randomized clinical trial, 34 edentate patients in the upper and/or the lower jaws were treated with the fixed hybrid dentures. In 16 patients (47.1% of the sample), the implants were loaded immediately (IL) by means of a provisional fixed rehabilitation made of PMMA (polymethylmethacrylate) screwed on Multi-Unit (MU) abutments connected after emplacement of the implant; however, in the counterparts (n = 18) these MU abutments were covered by healing caps and were left unloaded during two months (conventional loading protocol—CL), when all patients received a fixed hybrid PEEK-NFC rehabilitation on the upper and/or the lower jaw. Treatment outcomes were assessed 12 months after prostheses delivery. Functional outcomes were calculated according to masticatory performance, estimated by mixing ability tests of two colored chewing gums after ten chewing strokes, by the occlusal force/area recorded by pressure-sensitive sheets, and by electromyography of masseters and temporal muscles at maximum biteforce. The subjective outcomes of the treatment were assessed using both the oral satisfaction scale (visual analog scale) and the Spanish version of the Oral Health Impact Profile (OHIP-20). The findings of the present study showed that treatment with fixed PEEK-NFC hybrid prostheses significantly improved the masticatory performance, bite force, occlusal pattern, quality of life, and satisfaction, with the IL group being those with significantly higher occlusal bite forces and greater satisfaction in comparison with CL group. It should be concluded that PEEK-NFC hybrid prostheses can improve several patient-centered outcomes and that loading protocol significantly affects the patient’s self-rated satisfaction.

Masticatory Ability and Oral Health Related Quality of Life in Partially Edentulous Patients Involving Posterior Teeth after Rehabilitation with Tooth-Supported Fixed Dental Prosthesis

Background: Loss of teeth affects the masticatory ability and overall health of the patient especially posterior teeth as they contribute more to mastication as compared to anteriors. Loss of teeth can lead to undesirable consequences and early rehabilitation with any type of prosthesis can lead to desirable changes and thus missing teeth should be replaced as soon as possible.&#x0D; Aims and Objectives: To determine the change in masticatory ability and quality of life (QoL) after replacement of missing posterior teeth by fixed dental prosthesis.&#x0D; Methodology: Maximum bite force was recorded before and after treatment. Also a self-perceived questionnaire was filled by the patient to assess the change in QoL. Patients with missing posterior teeth were included. Patients with acute infections or systemic diseases were excluded.&#x0D; Results: Significant change (p=0.0001) in both masticatory ability and QoL of the patient was seen. The co-relation of both was clinically significant while statistically non-significant (p=0.77). Results were significant for both the studied parameters but co-relation between them was no significant. It is because of the patients perceived satisfaction of the overall treatment.&#x0D; Conclusion: Rehabilitation of posterior teeth improves mastication and also overall oral health related QoL.

Biting Force and chewing efficiency of Conventional and CAD/CAM complete dentures. A Cross-over Study

Background: Many studies reported using CAD/CAM technology in implant-supported prostheses. However, few studies reported its use in complete dentures. The aim of this study is to compare the Maximum Biting Force (MBF) and chewing efficiency of complete dentures fabricated by conventional, rapid prototyping and milling techniques. Materials and Methods: This is a clinical study with a cross-over design where 27 completely edentulous participants were divided in a random order into 3 equal groups as 1. received conventional complete denture 2. received 3D printed complete dentures 3. received milled complete dentures. Assessment of MBF was performed after denture insertion at 1 week, 1 month and 3 months, using Flexiforce A 301® force sensor. Mixing ability test was used to assess chewing efficiency 3 months after denture insertion. Repeated measure ANOVA test and Paired sample t-test were used with P ≤ 0.05 level of significance. Results: Regarding the MBF, there was a statistically significant increase (p < 0.001) in the MBF at 1w, 1m and 3m follow-up periods in all three groups. There was a statistically significant difference in chewing efficiency between 5, 10, 20, 30 and 50 strokes and between the three groups (p < 0.001). MBF and chewing efficiency increased significantly (p < 0.001) in Printed CAD/CAM and Milled CAD/CAM groups when compared to conventional complete dentures. Milled group showed a statistically significant improvement (p < 0.001) in MBF and chewing efficiency when compared to Printed group. Conclusion: The CAD/CAM fabricated dentures showed better results in terms of MBF and chewing efficiency compared to conventional complete denture.

Comparison of stud and telescopic crown attachments for mini-implant retained mandibular complete overdentures

Objectives: Is to make a radiographic and bite force comparison between stud and double telescopic crowns as two different attachment systems for two interforaminal mini implants retaining mandibular complete overdenture. Subjects and materials: Randomized, controlled, clinical study was done on 20 completely edentulous patients that divided into 2 equal groups, in The first group (study group), patients were treated by two mini-implants (with ball abutments) of 2.4mm diameters and 13mm lengths (in the canine regions) retaining mandibular overdentures and by conventional maxillary complete dentures, in The second group (control group), patients were treated by two mini-implants (with square head abutments) of 2.4mm diameters and 13mm lengths (in the canine regions) retaining mandibular overdentures and by conventional maxillary complete dentures. Results: At the end of the 12 months, a total loss of 0.69 mm for group I (with ball abutments), and 1.64 mm for group II (with square head abutments) was detected. For Maximum Bite Force, there was no significant difference between the two groups at all follow-up periods. Conclusion: Mandibular overdentures retained by two mini implants considered an acceptable treatment modality over the one-year observation period. Ball attachments are more favorable than telescopic attachments, in regard to the reduction of the peri-implant bone loss, while, the type of the attachment has less effect on the maximum bite force.

Occlusal contact of primary dentition at intercuspal position in children with individual normal occlusion

Objective: To record occlusal contact of primary dentition at maximal intercuspal position in children with individual normal occlusion. Methods: A total of 57 children were recruited from patients of the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology. Inclusion criteria were that the subjects were 3-5 years old with no visually detectable caries or pupal and periapical diseases, had complete primary dentition, had individual normal occlusion, had normal function of craniofacial system, were medically healthy, could cooperate with sampling and had obtained written informed consent from the parents or guardians. Finally, forty-seven children aged 3 to 5 years old were enrolled, including 24 males and 23 females. The age, height and weight of all subjects were (4.1±0.7) years old (ranging 3.0-5.8 years old), (103.7±7.2) cm (ranging 90-120 cm) and (17.1±2.5) kg (ranging 12.5-22.5 kg), respectively. Occlusal abilities such as occlusal contact area, average bite pressure, maximum bite pressure, maximum bite force and occlusal balance were measured with Dental Prescale Ⅱ system. Results: Maximum bite force and occlusal contact area at intercuspal position in children with primary dentition were (567.40±223.84) N (ranging 226.7-1 154.6 N) and (18.56±6.54) mm2 (ranging 8.4-41.2 mm2), respectively. There was a significantly strong correlation between maximum bite force and occlusal contact area (r=0.954, P<0.01). Height and weight of children were also positively correlated with their maximum bite force (r=0.397, P=0.022 and r=0.453, P=0.008, respectively). Maximum occlusal bite force and contact occlusal area of boys [(651.80±224.34) N and (20.77±6.97) mm2] were significantly higher and larger than those of girls [(479.34±190.45) N and (16.25±5.27) mm2] (P<0.05). Thirty-two of all 47 children had one occlusal contact point with maximum bite pressure, mostly locating within the primary molar region. Bite forces of anterior and posterior teeth of primary dentition were (124.12±56.99) N and (450.11±205.09) N, respectively, about (21.82±11.40)% and (71.80±21.35)% of maximum bite force of the whole primary dentition. All of the occlusal balance points located in posterior teeth regions. Occlusal contacts were observed at both anterior and posterior teeth of primary dentition with individual normal occlusion. Conclusions: There was a great variation of maximum bite forces of primary dentitions at intercuspal position of children with individual normal occlusion. Maximum bite force of primary dentition was significantly correlated with occlusal contact area, height and weight of children. Occlusal contact points with maximum bite pressure and occlusal bite balance points of primary dentitions mostly located in primary molar regions.

Morphology of the limb, shell and head explain the variation in performance and ecology across 14 turtle taxa (12 species)

Abstract Given that morphology directly influences the ability of an organism to utilize its habitat and dietary resources, it also influences fitness. Comparing the relationship between morphology, performance and ecology is fundamental to understand how organisms evolve to occupy a wide range of habitats and diets. In turtles, studies have documented important relationships between morphology, performance and ecology, but none was field based or considered limb, shell and head morphology simultaneously. We compared the morphology, performance and ecology of 14 turtle taxa (12 species) in Mexico that range in their affinity to water and in their diet. We took linear measurements of limb, shell and head variables. We measured maximum swimming speed, maximum bite force and how often turtles were encountered on land, and we used stable isotopes to assess trophic position. We used these data to test the following three hypotheses: (1) morphology, performance and ecology covary; (2) limb and shell variables, like hand length, are correlated with swimming speed and the percentage of time spent on land; and (3) head variables, such as head width, are correlated with bite force and stable isotopes. We find support for these hypotheses and provide the first evidence that morphology influences performance and ecology in turtles in the field.

The Influence of Customized Mouthguards on the Muscular Activity of the Masticatory Muscles at Maximum Bite and Motor Performance During Static and Dynamic Exercises

BackgroundSome studies have suggested that a mouthguard is a performance-enhancing device due to a remote voluntary contraction. The extent to which a mouthguard can induce this phenomenon, e.g., by potentially increasing biting, has not been clarified. This study’s aim was to investigate the muscular activity of the maxillary and peripheral musculature and motor performance during a rest and exercise test.MethodsOur study comprised 12 active, male, professional young handball players (age 18.83 ± 0.39 years). Their performance, electromyographic (EMG) muscle activity (Σ), and lateral deviation (Δ) of the masticatory and peripheral musculature were measured during rest in a maximum bite force measurement, one-legged stand, a kettlebell swing exercise and a jump test while wearing a customized mouthguard (CMG) or not wearing one (Co).ResultsMaximum bite force measurements did not differ significantly in their mean values of muscle activity (Σ) for the masseter and temporalis muscles (Co 647.6 ± 212.8 µV vs. CMG 724.3 ± 257.1 µV p = 0.08) (Co 457.2 ± 135.5 µV vs. CMG 426.6 ± 169.3 µV p = 0.38) with versus without CMG. We found no differences in the mean activation values during a one-legged stand, the kettlebell swing, and jump test (Σ) in any of the muscles tested. Lateral deviations (Δ) wearing a CMG were significantly less in the erector spinae during the kettlebell swing (Co 5.33 ± 3.4 µV vs. CMG 2.53 ± 1.8 µV p = 0.01) and countermovement jump (Co 37.90 ± 30.6 µV vs. CMG 17.83 ± 22.3 µV p = 0.03) compared to the performance without a CMG. Jump height, rotation moment, and balance were unchanged with versus without CMG.ConclusionOur results at rest and during specific motor stress show no differences with or without a CMG. The improved peripheral muscular balance while wearing a CMG indicates improved muscular stabilization.

Effects of ultrasound-assisted botulinum neurotoxin-A injection in patients with bruxism and masseter hypertrophy.

Objectives This study aims to explore effects of ultrasound-assisted injection of the botulinum neurotoxin-A (BoNT-A) on muscle thickness (MT) in patients with masseter hypertrophy. Patients and methods Between December 2018 and December 2019, a total of 20 patients (3 males, 17 females; mean age: 28±6.9 years; range, 18 to 42 years) with bruxism who underwent BoNT-A injections were reviewed retrospectively. The patients were treated using individualized injection dosages and sites. Assessment methods included length between the tragus and the angle of the mouth, maximal bite force, and MT of the masseter muscle. Follow-up data were collected from the hospital electronic database. Results There were 26 masseter muscles with masseter hypertrophy in 20 patients. There was a significant difference in ultrasonographic measurements of the relaxed and contracted masseter muscles between the baseline and two weeks, one month and three months after the treatment (p<0.05). In the ultrasonographic measurement of the relaxed masseter muscle, post-treatment third month values significantly differed from the second week values. The differences in the measurement of the line between the tragus and the angle of the mouth between the baseline and two weeks, one month and three months after the treatment were statistically significant (p<0.05). In the maximal bite force measurements, no significant difference was observed between the baseline and post-intervention measurements (p>0.05). Conclusion The MT decreases after a single dose of BoNT-A injection in patients with masseter muscle hypertrophy and ultrasonography is a convenient imaging modality for BoNT-A injection to the masseter.

The influence of jaw-muscle fibre-type phenotypes on estimating maximum muscle and bite forces in primates.

Numerous anthropological studies have been aimed at estimating jaw-adductor muscle forces, which, in turn, are used to estimate bite force. While primate jaw adductors show considerable intra- and intermuscular heterogeneity in fibre types, studies generally model jaw-muscle forces by treating the jaw adductors as either homogeneously slow or homogeneously fast muscles. Here, we provide a novel extension of such studies by integrating fibre architecture, fibre types and fibre-specific tensions to estimate maximum muscle forces in the masseter and temporalis of five anthropoid primates: Sapajus apella (N = 3), Cercocebus atys (N = 4), Macaca fascicularis (N = 3), Gorilla gorilla (N = 1) and Pan troglodytes (N = 2). We calculated maximum muscle forces by proportionally adjusting muscle physiological cross-sectional areas by their fibre types and associated specific tensions. Our results show that the jaw adductors of our sample ubiquitously express MHC α-cardiac, which has low specific tension, and hybrid fibres. We find that treating the jaw adductors as either homogeneously slow or fast muscles potentially overestimates average maximum muscle forces by as much as approximately 44%. Including fibre types and their specific tensions is thus likely to improve jaw-muscle and bite force estimates in primates.

The cranial biomechanics and feeding performance of Homo floresiensis.

Homo floresiensis is a small-bodied hominin from Flores, Indonesia, that exhibits plesiomorphic dentognathic features, including large premolars and a robust mandible, aspects of which have been considered australopith-like. However, relative to australopith species, H. floresiensis exhibits reduced molar size and a cranium with diminutive midfacial dimensions similar to those of later Homo, suggesting a reduction in the frequency of forceful biting behaviours. Our study uses finite-element analysis to examine the feeding biomechanics of the H. floresiensis cranium. We simulate premolar (P3) and molar (M2) biting in a finite-element model (FEM) of the H. floresiensis holotype cranium (LB1) and compare the mechanical results with FEMs of chimpanzees, modern humans and a sample of australopiths (MH1, Sts 5, OH5). With few exceptions, strain magnitudes in LB1 resemble elevated levels observed in modern Homo. Our analysis of LB1 suggests that H. floresiensis could produce bite forces with high mechanical efficiency, but was subject to tensile jaw joint reaction forces during molar biting, which perhaps constrained maximum postcanine bite force production. The inferred feeding biomechanics of H. floresiensis closely resemble modern humans, suggesting that this pattern may have been present in the last common ancestor of Homo sapiens and H. floresiensis.

Longitudinal Assessment of Strength, Functional Capacity, Oropharyngeal Function, and Quality of Life in Oculopharyngeal Muscular Dystrophy.

Background and ObjectivesOculopharyngeal muscular dystrophy (OPMD) is a late-onset, progressive muscle disease. Disease progression is known to be slow, but details on the natural history remain unknown. We aimed to examine the natural history of OPMD in a large nationwide cohort to determine clinical outcome measures that capture disease progression and can be used in future clinical trials.MethodsPatients invited by their treating physicians or identified from the national neuromuscular database and invited family members were examined twice 20 months apart with fixed dynamometry; Medical Research Council (MRC) grading; maximum bite force and isometric tongue strength; Motor Function Measure (MFM); 10-step stair test; maximum swallowing, chewing, and speech tasks; and quality of life assessments.ResultsDisease progression was captured by 8 of 18 measures over 20 months in 43 patients with genetically confirmed OPMD. The largest deterioration was seen in deltoid muscle strength (−27% [range −17% to −37%]), followed by the quadriceps (−14% [range −6 to −23%]), iliopsoas (−12.2%), tongue (−9.9%), and MRC sum score (−2.5%). The 10-step stair test (−12.5%), MFM part D1 (−7.1%), and maximum repetition rate of /pa/ (−5.3%) showed a significant decrease as well (all p < 0.05). The Physical Functioning domain of the Short Form-36 Health Survey significantly deteriorated (p = 0.044). No relationship was found between disease progression and genotype or disease duration (p > 0.05).DiscussionDespite the slow disease progression of OPMD, this study showed that several outcome measures detected progression within 20 months. Deltoid muscle strength, measured by fixed dynamometry, showed the greatest decline. These longitudinal data provide clinical outcome measures that can be used as biomarkers in future clinical trials.

Analysis of maximum bite force and chewing efficiency in unilateral temporomandibular joint ankylosis cases treated with buccal fat pad interpositional arthroplasty

There is limited knowledge about masticatory function after the release of temporomandibular joint (TMJ) ankylosis. In this study, masticatory function was evaluated by measuring maximum voluntary bite force (MVBF) and chewing efficiency in 30 unilateral TMJ ankylosis patients who were treated with buccal fat pad (BFP) interpositional arthroplasty. Eighteen subjects over 12 years of age were included in study Group A and 12 subjects below 12 years of age in study Group B. Patients in the study groups had completed a minimum follow up of one year after surgery. Control groups C (over 12 years of age, n = 18) and D (under 12 years of age, n = 12) consisted of age, sex, and weight-matched normal subjects. The mean MVBF was measured between occluding molar teeth with a strain gauge transducer. Chewing efficiency was measured with two different coloured chewing gum strips. These were chewed for 5, 10, 20, 30, and 50 strokes. Compared with normal subjects, the study groups (A and B) could generate 64.7% (p = 0.004*) and 89.8% (p = 0.121) of MVBF, respectively. Overall chewing efficiency was 88.7% in Group A and 92.9% in Group B (p = 0.014* and p = 0.138, respectively) when compared with normal subjects. The study has shown that BFP interpositional arthroplasty effectively restores masticatory function.

Relationship between mandibular dimensions and bite force: an exploratory study

ABSTRACT Purpose: This study aims to explore the possible relationship between mandibular dimensions and bite force. Subjects and Methods: Forty-one subjects (mean age 22.4 ± 1.6 years) were recruited from a pool of dental students and patients seeking dental treatment at the outpatient clinics, College of Dentistry, Taibah University. Digital panoramic radiographs were used and five angular and eleven linear measurements were taken. Comparisons were drawn between right and left sides and eating and non-eating sides using the Mann–Whitney test. Pearson correlation and multiple regression tests were used to assess the existence of any relationship between the bite force and mandibular dimensions. Results: No significant variations were detected in the bite force measurements between the right and left sides or between the eating and non-eating sides. Significant correlations were found between average and maximum posterior bite force and the inclinations of the lower first molar and the lower canine. Conclusion: No relationship exists between the mandibular dimensions and bite force except that the posterior bite force positively correlated with the inclinations of molars and canines.

Locator vs telescopic crown attachments for maxillary implant overdenture. A within-subject study of chewing efficiency and maximum bite force

Aim: This within-subject study report to investigate masticatory efficiency and maximum bite force of Locator and telescopic crown attachments used to retain maxillary implant overdentures. Materials and methods: Six edentulous patients (3 males and 3 females) received 4 implants in the anterior maxillary region between the maxillary sinuses using a standardized 2 stage surgical approach. Six months after osseointegration, the implants were loaded either by Locator or telescopic maxillary overdentures in a cross-over study design. Masticatory efficiency was performed using the 2-colored gum mixing ability test. The gum was chewed for 5, 10, 20, 30, and 50 cycles, and the images of the chewed gum were analyzed using a Photoshop program to calculate the unmixed fraction (UF). Also, maximum bite force was evaluated using a bite-force transducer. Chewing efficiency and maximum bite forces were evaluated 3 months after wearing each overdenture. Results: The success rate was 100% in both groups. There was a trend for a decrease in UF (ie improved masticatory efficiency) with the increase in the number of masticatory cycles. Telescopic maxillary overdentures showed significantly lower UF (ie higher masticatory efficiency) and higher maximum bite force than Locator maxillary overdentures Conclusion: Telescopic attachments are recommended for maxillary implant overdentures as it had improved masticatory efficiency and maximum bite force than Locator attachments

Cantilevered Versus non-cantilevered resilient bar attachment for 2-implant retained mandibular overdentures. A short term crossover study of chewing efficiency and bite force.

Aim of the study: This study compared chewing efficiency and maximum bite force between cantilevered and non-cantilevered resilient bar attachment used for 2-implant retained mandibular overdentures. Materials and methods: Eight completely edentulous participants (4 men, 4 women) with atrophied mandibular ridges receive 2 implants in the canine region. After 3 months, each patient received Hader bar with 7mm distal cantilevers and mandibular overdenture with 3 clips (CHB group). After another 3 months, distal cantilevers were sectioned and patients received Hader bar without cantilevers and mandibular overdentures with one clip (HB). Chewing efficiency (using unmixed fraction (UF) in a colored gum) and bite force were measured 3 months after using conventional dentures CD, CHB, and HB. Results: The highest unmixed fraction (UF) was noted with 5 cycles and the lowest number was noted with 50 cycles. UF decreased with the increase of number of chewing strokes. For all chewing strokes, the highest the UF was noted with CD, followed by HB, and the lowest UF was noted with CHB. At 30 and 50 strokes, there was a significant difference between each 2 groups, and HB showed significant higher UF than CHB. The highest maximum bite force was noted with CHB, followed by HB, and the lowest was noted with CD. Conclusion: it could be concluded that both cantilevered and non-cantilevered bar attachments for 2 implant overdentures achieved higher chewing efficiency and maximum bite force than conventional dentures in patients with atrophied mandibular ridges.

Change in Bite Force of Completely Edentulous Patients After Placement of Single Implant-Retained Mandibular Overdentures

Purpose: This study aimed to assess the change in the maximum bite force of completely edentulous patients rehabilitated with thermoplastic acrylic complete denture after placement of single implant-retained mandibular overdentures. Materials and Methods: Sixteen completely edentulous patients with age ranged from 50-60 years were selected from removable prosthodontic clinics, faculty of dental medicine, Al-Azhar University. Each patient received a thermoplastic acrylic complete denture. Three months after a new denture placement, bite force was evaluated using an occlusal force meter (GM10, Nagano Keiki, Japan). Each patient received a mid-symphyseal single dental implant, 10 mm length and 3.7mm diameter (Dentis, Dalseo-gu, Daegu , Korea) placed at the midline of the mandibular alveolar ridge. Two weeks after overdenture placement, bite force was evaluated to assess the changes in bite force after a single implant placement. Results: Bite force was increased considerably after single implant placement. It was significantly higher than the bite force recorded with a conventional thermoplastic complete denture. Conclusion: It was concluded that using immediate loading single implant-retained mandibular overdentures resulted in considerable improvement of bite force in completely edentulous patients.

Oral function in patients with myasthenia gravis.

Myasthenia Gravis (MG) is characterised by muscle weakness and increased fatigability. The aim of this pilot study was to investigate if patients with MG demonstrate different functional chewing patterns and report more complaints related to mastication as compared with healthy controls. Twelve patients (median 60 years Q1–Q3: 46–70) with generalised MG and nine healthy controls (median 57 years Q1–Q3: 55–63) participated. All participants underwent dental and oral examination and were asked to fill in a questionnaire concerning oral health. Static maximum bite force was measured with a bite force transducer, electromyography in the masseter, temporalis, and suprahyoid muscles were recorded, and jaw movement was tracked, during a 5-minute gum chewing test. The patients had more oral complaints (oral health impact profile total score 22.6 vs 7.5 P < 0.01) and had lower peak bite force than controls (18.8kgf (11.1;26.4) (95% CI) vs 29.5 kgf (21.6; 37.4) (P = 0.04)). In contrast, fatigability of the masticatory muscles, as defined by number of chewing cycles during the gum-chewing test, did not differ between patients and controls (P = 0.10). In conclusion, patients had more oral complaints and lower bite force than controls, but did not show significantly different functional chewing patterns. Future studies should aim at integrating measurement of peak force into functional tests. Attention should be given to oral complaints of patients with MG.

Single implant overdenture reinforced with a metallic framework: A 2-year clinical follow-up.

To prevent single-implant overdenture (SIO) fracture, the inclusion of a framework in the overdenture has been suggested. However, no investigations verified their benefits. To evaluate prosthetic maintenance events, patient satisfaction, and mastication of SIO reinforced by metallic framework users. Fifteen volunteers had a new set of complete dentures converted into an SIO containing a framework. Maintenance events were recorded, while patient satisfaction was assessed using a visual analog scale. Masticatory performance (MP) was evaluated using the sieving method, maximum bite force (MBF) by pressure sensors, and masseter thickness by ultrasound. Measurements were performed 2, 12, and 24months after SIO use. Repeated-measures ANOVA and paired Student's t-tests (p<0.05) were applied. Matrix exchange was the most prevalent maintenance event (83.6%), and no SIO was fractured during the entire follow-up. Satisfaction with the SIO stability decreased (p<0.01) after 12months. MP did not change between evaluations (p>0.05). Conversely, MBF and masseter thickness improved after 12 and 24months of SIO use (p<0.05). Reinforced SIO did not fracture during 2 years but requires maintenance. It improves bite force and muscle thickness, maintaining MP values. Satisfaction with SIO stability decreased in the first year of use.

Maximum bite force in children with juvenile idiopathic arthritis with and without clinical established temporomandibular joint involvement and in healthy children: a cross-sectional study.

BackgroundIn children with juvenile idiopathic arthritis (JIA), the temporomandibular joint (TMJ) can be involved, resulting in dysfunction of the masticatory system. Bite force is one of the variables that reflects the function of the masticatory system. The aim of this study was to compare maximum bite force in children with JIA, with and without TMJ involvement and with healthy children.MethodsChildren with JIA and healthy children between the ages 6 and 18 were included in this cross‐sectional study. The clinical examination consisted of measuring the anterior maximum voluntary bite force (AMVBF), assessment of the TMJ screening protocol items and TMJ, masseter and temporal muscle palpation pain. Unadjusted linear regression analyses were performed to evaluate the explanatory factors for AMVBF. Two adjusted models were constructed with corrections for age and gender differences: model 1 to compare children with JIA and healthy children and model 2 to compare children with JIA with and without TMJ involvement.ResultsIn this cross‐sectional study, 298 children with JIA and 169 healthy children participated. AMVBF was 24 Newton (N) lower in children with JIA, when compared with healthy children (95%CI: −35.5–−12.4, p = .000). When children with JIA also had clinically established TMJ involvement, AMVBF was reduced 42 N (component JIA:−16.78, 95% CI −28.96–−4.59, p = .007 and component TMJ involvement:−25.36, 95% CI −40.08–−10.63, p = .001). Age and male gender increased AMVBF.ConclusionChildren with JIA had a reduction in the AMVBF compared with healthy children. In children with JIA and clinically established TMJ involvement, AMVBF was more reduced.