Anatomic variation of cranial parasympathetic ganglia

Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve), the pterygopalatine ganglion (located in the pterygopalatine fossa), the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve), and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen). The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia

Masticatory muscle activity evaluation by electromyography in subjects with zygomatic implants

Zygomatic implants are an alternative treatment in the rehabilitation of atrophic maxilla to promote stability in the stomatognathic system. The aim of this study was to compare the electromyographic (EMG) activity of masseter and temporalis muscles in controls and in individuals with complete implant-supported dentures anchored in the zygomatic bone. Fifty-four volunteers of both genders (mean age 52.5 years) were selected and distributed into two groups: Individuals with zygomatic implant (ZIG; n=27) and fully dentate patients (CG; n=27). MyoSystem-BR1 was used to assess masseter and temporalis muscles EMG activity in different mandibular movements: protrusion, clenching, maximal voluntary contraction (MVC) with Parafilm M®, right and left laterality and chewing (peanuts and raisins). Data was processed, normalized (MVC) and analyzed using the SPSS 21.0. Student t-test (P ? 0.05) was used for group comparison. The results were statistically significant (P ? 0.05) for protrusion, clenching, right and left laterality and raisin chewing. For the mandibular posture conditions, the ZIG obtained higher EMG activity patterns when compared to CG. For the masticatory performance during chewing of peanuts and raisins, the ZIG showed higher EMG mean values when compared to CG. The zygomatic implant promoted an active response of the muscle fibers (hyperactivity) during both mandibular posture and chewing conditions, probably due to the absence of periodontal receptors, which play a significant role for preparing a bolus for swallowing

Electromyographic analysis of the masseter and temporalis muscles and bite force in a patient treated by functional maxillary orthopedics: a case report

This case report evaluated electromyographic activity of the masseter and temporalis muscles and molar bite force, before and after with functional orthopedic. A 65 years woman presenting with orofacial pain symptoms, cervical tension, condyle subluxation and osteoarthrosis. The patient was diagnosed with temporomandibular dysfunction and treated with use of a Simões Network 9 modified type functional maxillary orthopedics appliance. The Myosystem BR1 apparatus was used to analyze the electromyographic activity of the masseter and temporalis muscles. The maximum molar bite force was measured with the digital dynamometer (Kratus). This study showed increased EMG activity of the masseter and temporalis muscles in postural conditions of mandible and molar bite force after 12 months of treatment. After twelve months of treatment, the patient had lack of pain symptoms as well as an improvement in the balance of the mastication muscles, as demonstrated by EMG activity and maximum molar bite force

Morphological analysis of dental remains of a human skeleton found in a mountain-shell (Sambaqui) in Ilha Bela Archipelago on the northern coast of São Paulo, state, Brazil

The bioanthropological evaluation on remains of hard tissues can collaborate in identifying physicalcharacteristics of individuals. The teeth are important in the identification of human bodies that have undergone major changes particularly due to its resistance to degradation. The aim of this study is analyzing the dental remains of a human skeleton - dated of 1920 ± 40 years BP and located in a shell mound at the Ilhabela Archipelago, São Paulo State, Brazil - as a source of anatomical analysis for scientific purposes. The remaining teeth were classified according to dental notation and the authors concluded that even in a long time, teeth keep maintain anatomical features which may be helpful in identifying the deceased individual.  A avaliação bioantropológica em remanescentes de tecidos duros pode colaborar na identificação dascaracterísticas físicas dos indivíduos. Os dentes, estrutura dura que também se caracteriza por ser resistente à degradação, são importantes na identificação de corpos que passaram por grandes modificações. O objetivo deste estudo é analisar os remanescentes dentais de uma ossada humana datada de 1920 ± 40 anos AP localizados em sambaqui, no Arquipélago de Ilhabela – SP, Brasil, como fonte de análise anatômica para fins científicos. Os remanescentes dentais foram classificados segundo a notação dental e os autores concluíram que, mesmo com o passar do tempo, os dentes mantém características anatômicas marcantes, podendo ser de grande utilidade na identificação do indivíduo morto.  

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements