A Study of the Mechanical Characteristics of a Mandibular Parasymphyseal Fracture with Internal Fixation Device Subject to Variable Bite Forces: Finite Element Analysis

In recent times, research into mandibular fracture has gained momentum from advances in scanning techniques, software/algorithm developments and improvements, and numerical structural modeling using the finite-element method (FEM). In this work, the FEM is used to model a mandibular fracture (using an inhomogeneous and orthotropic jaw model) simulating the effect of different bite tasks/forces on the stability of the fixated fracture. Specifically, bilateral and unilateral clenches (using muscle data) were studied using a low-profile 3D 4 × 2 hole mini-plate deployed for fracture fixation. Here, the mandible bone was treated as orthotropic and spatially inhomogeneous. Although the results of stress and displacement analyses, for this fixation hardware, indicate sufficient fixation under normal biting conditions, the results show that the unilateral and ipsilateral bites develop, in general, the highest stresses or displacements. Such results can guide post-surgery recommendation on bite behavior.

Bite force and masticatory efficiency in individuals with different oral rehabilitations

Objective: This study was analyzed adult individuals rehabilitated with different types of dentures, with the purpose of verifying the effect that different types of denture rehabilitation have on maximal bite force and masticatory efficiency. The aim of this study is to facilitate diagnosis and prognosis, bringing contributions to the quality and stability of treatments Materials and Methods: Fifty individuals were divided into five groups: one control group with ten dentate individuals and another four groups formed according to the type of rehabilitation treatment. Maximal bite force was recorded on the first molar regions, and masticatory efficiency rates were recorded on the right, left and habitual sides. Results: Data related to the maximal bite force recordings were statistically significant across the analyzed groups [ANOVA for p ≤ 0.01]. The data related to masticatory efficiency rates also showed statistical significance across all groups [ANOVA for p ≤ 0.05] in the three tested conditions [mastication on the right, left and habitual sides]. Conclusion: The group of individuals rehabilitated with implants and single crowns showed greater bite force values and masticatory efficiency rates compared to the other groups, and the treatment with implantsupported mandibular overdenture improved the function compared to conventional complete dentures, thus evincing that the stomatognathic system has different functional behaviors depending on the type of oral rehabilitation.

The scaling of bite force and constriction pressure in kingsnakes(Lampropeltis getula):Proximate determinants and correlated performance

Across the diversity of vertebrates,bite force has been studied and suggested to have important ecological and evolutionary consequences.However,there is a notable lineage of vertebrates that use this performance trait yet are missing from the bite-force literature:the snakes.Snakes often rely on biting during prey subjugation and handling.Many snakes bite and hold prey while a constriction coil is formed or while venom is being delivered,or both.Others use biting exclusively without employing any additional prey-handling behaviors.In addition to biting,constriction is an important predation mechanism.Here,I quantify bite force and constriction pressure in kingsnakes(Lampropeltis getula).Furthermore,I explore the proximate determinants of bite force as well as the relationship between biting and constriction performance.Bite force increased linearly with all head and body measures.Of these,head height was the best predictor of bite force.Bite force in kingsnakes was within the range of values reported for lizards,but their relative performance was lower for their head size compared to lizards.Peak constriction pressure also increased with all body measures.Biting and constricting use 2 different parts of the musculoskeletal system and are positively and significantly correlated with one another.Future work targeting a greater diversity of snakes that rely more heavily on biting may reveal a greater range of bite performance in this diverse and successful vertebrate group.

Biting force and tongue muscle strength as useful indicators for eating and swallowing capability assessment among elderly patients

Weakened capability of eating and swallowing is common among elderly population,affecting negatively on their health and well-being.This work measured occlusal force and tongue muscle strength of elderly patients and then assessed whether correlations existed between oral physiological properties and the eating and swallowing capability.A total of 26 elderly patients with potential swallow disorder were recruited in this work.Participants’denture status and daily diet texture were determined by a pre-questionnaire analysis.Their swallowing capability was assessed and rated by water drinking test.Maximum tongue pressure,incisor occlusal force and hand gripping force were measured for each subject.It was observed that participating subjects have on average a significantly lower biting force and maximum tongue pressure than that of normal adults.The swallowing grades assessed by water drinking test showed significant correlations with both the biting force(r=−0.498,P<0.05)and the tongue muscle strength(r=−0.544,P<0.05).The biting force of dysphagia participants correlates significantly with dental conditions(P<0.05).The observed correlation between tongue pressure and diet texture indicates that tongue muscle strength could be used as a reliable indicator of the eating and swallowing capability for elderly people.

Effect of Different Splint Thicknesses on Occlusal Function and Temporomandibular Joint Sounds:A Clinical Report

Background: Occlusal splint therapy, which is a conservative approach to treat temporomandibular disorders (TMDs) and bruxism, can change the occlusal contact of dentition. However, little is known about the variation in bite force and temporomandibular joint (TMJ) sounds. The objective of this case report is to compare the effects of different splint thicknesses constructed by vacuum lamination technology on occlusal function and TMJ sounds. Clinical Presentation: This study presents a 24-year-old male with bruxism. Four splints of different thicknesses (0.6 mm, 1 mm, 2.5 mm and 3 mm) were fabricated and tested. Then, an array of occlusal data were recorded and analyzed by the T-Scan?III system and joint vibration analysis (JVA). Conclusion: The results reveal that splints of different thicknesses manufactured by the vacuum hot-lamination apparatus may cause a change in occlusal force.

Case report involving temporomandibular dysfunction,eagle’s syndrome and torus mandibularis—Multidisciplinary approaches

The prevalence of torus mandibularis, Eagle’s syndrome and parafunctional activity was reported to be higher in patients with temporomandibular joint dysfunction and might be useful as an indicator of increased risk of temporomandibular disorders. This study case report was to evaluate a 62-year-old female patient, with limited mandibular and cervical movements, articular and muscular pain, ear fullness, irritation of the lingual mucosa, discomfort associated with movement of her tongue, involving temporomandibular dysfunction, torus mandibularis and Eagle’s syndrome. The treatment comprehended the collection of data of Helkimo’s Clinical Dysfunction Index, electromyographic activity of the masseter and temporalis muscles in rest position and bite force, masticatory efficiency, speech evaluation and oclusal splint, after the excision of the stylohyoid process and mandibularis torus. The authors found a decrease in electromyographic activity of masticatory muscles, a reduction of painful symptoms throughout the region muscular and joint pains, an increase in the amplitude of mandibular movements, an improvement in masticatory efficiency and an increase in bite force.