Objectives: Sensory information provided by the periodontal mechanoreceptors (PMRs) is used by the nervous system to optimize the positioning of food, force levels, and force vectors involved in biting. The aim of this study was to describe motor performance during a novel manipulation-and-split task and to assess the extent to which control of this performance involves information from the PMRs.
Materials And Methods: A total of 10 subjects with natural teeth, 10 with bimaxillary tooth-supported fixed prostheses (TSP) and 10 with bimaxillary implant-supported fixed prostheses (ISP) (61-83 [mean 69] years of age) were asked to perform an intraoral manipulation-and-split task that involved positioning a spherical chocolate dragée between the front teeth and then splitting it into two parts of equal size. The vertical jaw movement, sound of food cracking and masseter muscle activity were monitored during this task and the accuracy of the split was evaluated.
Results: The group with natural teeth was significantly better than the other groups at splitting the candy with high precision. The jaw movements were similar between groups, but the contact phase prior to the split was significantly longer for those with natural dentition.
Conclusions: The present findings support the conclusion that the nervous system collects rich information about contact between the teeth and food from the PMRs prior to powerful jaw action. Impairment (TSP) or absence (ISP) of this information alters motor behavior and impairs performance during the natural biting task employed here.
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http://dx.doi.org/10.1111/j.1600-0501.2011.02418.x | DOI Listing |
Arch Orthop Trauma Surg
January 2025
Division of Orthopaedics and Traumatology, Cantonal Hospital Winterthur, Winterthur, Switzerland.
Total hip arthroplasty (THA) is a very successful operation. Once the problem of implant fixation was solved with the use of bone cement, the next development steps focused on improving the bearing. Weber, a Swiss surgeon, introduced the first modular heads in THA.
View Article and Find Full Text PDFZhongguo Gu Shang
January 2025
Ningbo Beilun People's Hospital, Ningbo 315800, Zhejiang, China.
Objective: To investigate the effects of bone density, plate bending degree and proximal screw type on the stress fracture of clavicle hook.
Methods: Three sows weighing between 45 and 50 kg were selected, from which a total of 40 rivs were collected. The 15 ribs of sows were divided into 3 groups according to bone density and bone hardness with 5 rivs in each group.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
January 2025
Department of Orthopaedics, Zhongda Hospital Southeast University, Nanjing Jiangsu, 210009, P. R. China.
Objective: To compare the short-term effectiveness between Gamma 3 intramedullary nails and Gamma 3 U-Blade system in the treatment of osteoporotic intertrochanteric fractures in the elderly.
Methods: A retrospective analysis was conducted on the clinical data of 124 elderly patients with osteoporotic intertrochanteric fractures, who were admitted between February 2020 and February 2023 and met the selection criteria. The fractures were fixed with Gamma 3 intramedullary nails in 65 patients (control group) and Gamma 3 U-Blade systems in 59 patients (UB group).
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
January 2025
Department of Sports Medicine, the First Affiliated Hospital of Kunming Medical University, Kunming Yunnan, 650032, P. R. China.
Objective: To investigate the effectiveness of modified single patellar tunnel medial patella femoral ligament (MPFL) reconstruction in the treatment of recurrent patellar dislocation.
Methods: Between January 2023 and June 2023, a total of 61 patients with recurrent patellar dislocation who underwent MPFL reconstruction with autologous semitendinosus were enrolled and divided into 2 groups using random number table method. In the patellar anchor group, 31 patients were treated with MPFL reconstruction with double medial patellar anchors, and 30 patients in the patellar tunnel group were treated with MPFL reconstruction with single patellar tunnel.
J Biol Methods
September 2024
Department of Prosthodontics, SRM Dental College, Bharathi Salai, Ramapuram, Chennai, Tamil Nadu, India.
Background: Worn dentition is a common problem encountered by most people in the last decade. Rehabilitation of a full mouth needs individual attention and proper treatment planning, which is very challenging for partial edentulous cases where bilateral teeth are missing and collapsed vertical dimension leaves inadequate restorative space. Treatment of these cases is complex and needs to apply standard principles while designing and fabricating prostheses.
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