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Bite force

David J Daegling, Kristian J Carlson, Paul Tafforeau, Darryl J de Ruiter, Lee R Berger
Fossils attributed to Australopithecus sediba are described as having phylogenetic affinities with early Homo to the exclusion of other South African australopiths. With respect to functional anatomy of mastication, one implication of this hypothesis is that A. sediba mandibles should exhibit absolutely and relatively reduced stiffness and strength in comparison to Australopithecus africanus and Paranthropus robustus jaws. Examination of cortical bone distribution in the MH 1 and MH 2 mandibles of A. sediba (evaluated against samples of Pan, early and modern Homo as well as A...
November 2016: Journal of Human Evolution
Xing Zhou Qu, Ming Yi Wang, Hui Shan Ong, Chen Ping Zhang
OBJECTIVES: This study aimed to evaluate the stability of prostheses supported by zygoma implants and remaining teeth for subjects who had undergone hemi-maxillectomy. METHODS: Ten patients were included in the study. Oral rehabilitation was performed using a temporary prosthesis that was supported by remaining teeth for the first three months. Then, a zygoma implant was placed to provide support for a final prosthesis in addition to the remaining teeth. Each prosthesis was tailor-made according to biomechanical three-dimensional finite element analysis results...
October 1, 2016: Clinics
Narges Shayesteh Moghaddam, Ahmadreza Jahadakbar, Amirhesam Amerinatanzi, Mohammad Elahinia, Michael Miller, David Dean
: The aim of this study is to investigate the behavior of the healthy mandible under maximum molar bite force to demonstrate the problems associated with the current standard of care procedures for mandibular segmental defect reconstruction (ie, use of Ti-6Al-4V hardware and either a single- or double-barrel fibular graft). With current Ti-6Al-4V mandibular reconstruction hardware, there is a significant stiffness mismatch among the hardware, graft, and the remaining host anatomy. How the distribution of mechanical forces through the mandible is altered after a segmental bone loss and reconstruction is incompletely understood...
September 2016: Plastic and Reconstructive Surgery. Global Open
Suguru Kimoto, Yasuhiko Kawai, Atsuko Gunji, Hisatomo Kondo, Taro Nomura, Tomohiko Murakami, Akito Tsuboi, Guang Hong, Shunsuke Minakuchi, Yusuke Sato, Gaku Ohwada, Tetsuya Suzuki, Katsuhiko Kimoto, Noriyuki Hoshi, Makiko Saita, Yoshikazu Yoneyama, Yohei Sato, Masakazu Morokuma, Joji Okazaki, Takeshi Maeda, Kenichiro Nakai, Tetsuo Ichikawa, Kan Nagao, Keiko Fujimoto, Hiroshi Murata, Tadafumi Kurogi, Kazuhiro Yoshida, Masahiro Nishimura, Yasuhiro Nishi, Mamoru Murakami, Toshio Hosoi, Taizo Hamada
BACKGROUND: Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. However, many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. The aim of this study is to verify the efficacy of denture adhesives to establish guidelines for Japanese users...
October 18, 2016: Trials
Sho Kayumi, Yoshiyuki Takayama, Atsuro Yokoyama, Nana Ueda
BACKGROUND: The purpose of this study was to investigate the influence of occlusal forces (the contractile force of masticatory muscles) exerted during occlusal adjustment on the distribution of the forces among teeth, implants, and temporomandibular joints (TMJs) in intercuspal clenching in cases with bilateral missing molars and premolars by using finite element analysis. METHODS: A three-dimensional finite element model of the mandible with eight implants in the premolar and molar regions was constructed...
December 2015: Int J Implant Dent
Shunichi Suzuki, Eduardo Enrique Castrillon-Watanabe, Taro Arima, Yoshimasa Kitagawa, Peter Svensson
BACKGROUND: Myofascial pain associated with temporomandibular disorders has often been linked to pathological muscle hyperactivity. As a result, localized disturbances of intramuscular blood flow could lead to a lower level of oxygen distribution, hypoxia and microcirculatory changes. AIM: To assess hemodynamic changes in the masseter muscle during sustained elevated muscle activity (SEMA). MATERIALS AND METHODS: Sixteen healthy participants performed thirty 1-minute bouts of SEMA with intervals of 1-minute "rest" periods between the bouts on a bite force transducer device...
October 15, 2016: Journal of Oral Rehabilitation
Sina David, Johannes Funken, Wolfgang Potthast, Alexander Blanke
Insects show a remarkable diversity of muscle configurations, yet the factors leading to this functional diversity are poorly understood. Here, we use musculoskeletal modelling to understand the spatio-temporal activity of an insect muscle in several dragonfly species and to reveal potential mechanical factors leading to a particular muscle configuration. Bite characteristics potentially show systematic signal, but absolute bite force is not correlated with size. Muscle configuration and inverse dynamics show that the wider relative area of muscle attachment and the higher activity of subapical muscle groups are responsible for this high bite force...
October 2016: Journal of the Royal Society, Interface
Miguel A Roque, German O Gallucci, Sang J Lee
PURPOSE: To describe the occlusal pressure redistribution in dental arches following placement of single posterior implant-supported restorations in occlusion with natural dentitions. MATERIALS AND METHODS: Fifteen patients who presented for successfully osseointegrated single posterior implant restorations participated in the study. Cement-retained, all-ceramic implant crowns were fabricated and delivered after adjustment for interproximal contacts, fit, and uniform occlusal contacts...
October 5, 2016: Journal of Prosthodontics: Official Journal of the American College of Prosthodontists
Flávia Zardo Trindade, Luiz Felipe Valandro, Niek de Jager, Marco Antônio Bottino, Cornelis Johannes Kleverlaan
PURPOSE: To determine the elastic properties of five ceramic systems with different compositions (lithium disilicate vs. feldspathic ceramics) and processing methods and compare the stress distribution in premolars in the interface with inlays made with these systems loaded with the maximum normal bite force (665 N) using 3D finite element analysis (FEA). MATERIALS AND METHODS: The elastic properties of five ceramic restoration materials (IPS e.max Press, IPS e...
October 3, 2016: Journal of Prosthodontics: Official Journal of the American College of Prosthodontists
Ana Cláudia M Melo, Ingrid M Ledra, Rogéria A Vieira, Edivaldo R Coró, Ivete Aparecida de M Sartori
PURPOSE: (1) To evaluate patients' long-term maximum bite force (MBF) after rehabilitation with mandibular implant-supported prosthesis, (2) to assess the influence of facial pattern in MBF, and (3) to evaluate the relation between the dominant chewing side and MBF. MATERIALS AND METHODS: Twenty-nine patients were selected. Pre- (T0) and immediate post-rehabilitation (T1) data of MBF were collected. In a follow-up visit 3 to 5 years after rehabilitation (T2), 24 patients participated...
September 30, 2016: Journal of Prosthodontics: Official Journal of the American College of Prosthodontists
Mei Xin Chong, Chong Dee Khoo, Kai Hoe Goh, Farhana Rahman, Yoshinobu Shoji
This study compared bite force in adults older than 60 years with that of young adults. The participants were 20 healthy adults (9 men) older than 60 years (median age, 66 years) and 44 healthy young adults (22 men; age range, 18-25 years; median age, 22 years) at the International Medical University, Malaysia. All participants had at least 20 teeth, and bite force was measured and evaluated using the Dental Prescale system. Average (SD) bite force was 420.5 (242.0) N for the older adults and 541.4 (296.3) N for the young adults...
2016: Journal of Oral Science
Atsushi Nanami
Parrotfishes (family Labridae: Scarini) are regarded to have important roles for maintaining the ecosystem balance in coral reefs due to their removal of organic matter and calcic substrates by grazing. The purpose of the present study was to clarify the interspecific differences in grazing ability of five parrotfish species (Chlorurus sordidus, C. bowersi, Scarus rivulatus, S. niger and S. forsteni) in relation to interspecific differences in jaw-lever mechanics and the relative weight of the adductor mandibulae (muscles operating jaw closing)...
2016: PeerJ
François Therrien, Annie Quinney, Kohei Tanaka, Darla K Zelenitsky
Mandibular force profiles apply the principles of beam theory to identify mandibular biomechanical properties that reflect the bite force and feeding strategies of extant and extinct predators. While this method uses external dimensions of the mandibular corpus to determine its biomechanical properties, more accurate results could potentially be obtained by quantifying its internal cortical bone distribution. To test this possibility, mandibular force profiles were calculated using both external mandibular dimensions ('solid mandible model') and quantification of internal bone distribution of the mandibular corpus obtained from CT scans ('hollow mandible model') for five carnivorans (Canis lupus, Crocuta crocuta, Panthera leo, Neofelis nebulosa, and the extinct Canis dirus)...
September 15, 2016: Journal of Experimental Biology
Stephan Lautenschlager, Florian Witzmann, Ingmar Werneburg
Temnospondyls were the morphologically and taxonomically most diverse group of early tetrapods with a near-global distribution during the Palaeozoic and Mesozoic. Members of this group occupied a range of different habitats (aquatic, amphibious, terrestrial), reflected by large morphological disparity of the cranium throughout their evolutionary history. A diagnostic feature of temnospondyls is the presence of an open palate with large interpterygoid vacuities, in contrast to the closed palate of most other early tetrapods and their fish-like relatives...
October 2016: Die Naturwissenschaften
Chris J Law, Colleen Young, Rita S Mehta
Sexual dimorphism attributed to niche divergence is often linked to differentiation between the sexes in both dietary resources and characters related to feeding and resource procurement. Although recent studies have indicated that southern sea otters (Enhydra lutris nereis) exhibit differences in dietary preferences as well as sexual dimorphism in skull size and shape, whether these intersexual differences translate to differentiation in feeding performances between the sexes remains to be investigated. To test the hypothesis that scaling patterns of bite force, a metric of feeding performance, differ between the sexes, we calculated theoretical bite forces for 55 naturally deceased male and female southern sea otters spanning the size ranges encountered over ontogeny...
September 2016: Physiological and Biochemical Zoology: PBZ
Mariana Vilela Sônego, Marcelo Coelho Goiato, Daniela Micheline Dos Santos
OBJECTIVES: The aim of this study was to investigate the outcomes of the installation of two implant-supported overdentures until such treatment is complete. Although this treatment is well established in the literature, there are no studies comparing what happens to muscles and the quality of life (QoL) of patients during the treatment. METHODS: We selected 13 completely edentulous patients, according to inclusion and exclusion criteria, to rehabilitate with mandibular overdentures retained by two dental implants and a complete denture as antagonists...
September 11, 2016: Clinical Oral Implants Research
Wendy J Binder, Kassaundra S Cervantes, Julie A Meachen
The late Pleistocene megafaunal extinction of approximately 12,000 years ago, included the demise of Smilodon fatalis, a hypercarnivore from the Rancho La Brea deposits, which has been studied across time by looking at different deposits or pits to determine morphological size and shape changes and trends during this time. To better understand functional aspects of these changes, this study focused on a measure of jaw strength over time, which can give an indication of morphological changes within the jaw that cannot be seen using surface morphometrics...
2016: PloS One
Dennis Flanagan
A fractured abutment screw of a crown supported by an endosseous implant is a complication. The fragment in the fixture can be retrieved with a festooned #557 latch burr set in reverse torque and subsequent clockwise turning #33 1/3 burr touched to the fragment side. The cemented abutment and crown can be salvaged by heating the crown/coronal screw fragment to 1000 degrees C for 20 minutes. Upon cooling, the crown and abutment can be then separated. A new abutment screw can then be used. The patient's diet, occlusal scheme and maximal bite force should be assessed...
September 6, 2016: Journal of Oral Implantology
Aline Pedroni-Pereira, Darlle Santos Araujo, Kelly Guedes de Oliveira Scudine, Daniela Galvão de Almeida Prado, Débora Alves Nunes Leite Lima, Paula Midori Castelo
Physiological and behavioral aspects of masticatory function may have an impact on nutritional status, which has been little studied. The aim was to perform a comprehensive evaluation of objective, subjective and behavioral aspects of masticatory function in 231 adolescents, aged 14-17 years and compare these parameters between normal-weight (n = 115) and adolescents with overweight/obesity (n = 116). Objective aspects were examined by the Oro-facial Myofunctional Evaluation-expanded protocol (OMES-e), determining the masticatory type, chewing time/frequency, abnormal movements, and other; masticatory performance (color changeable chewing gum) and bite force were also explored...
September 2, 2016: Appetite
Chaitanya C Khanapure, Salika Ayesha, George Sam, V J Anil Kumar, C Deepika, Haseena Ahmed
AIM: The present study was aimed to evaluate the resistance to deformation or fracture of brackets of various materials (ceramic, ceramic reinforced with metal slot, and stainless steel brackets) with archwires during application of torque. MATERIALS AND METHODS: The sample size included 30 brackets of maxillary right central incisor with slot dimension of 0.022 × 0.028" and made of three materials (10 of each type): (1) Ceramic brackets (cer), (2) ceramic brackets reinforced with stainless steel slot (cer/ss), and (3) stainless steel brackets (metal)...
2016: Journal of Contemporary Dental Practice
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