Relação anatômica da Bola de Bichat com ramos terminais do nervo facial / Anatomical Correlation among Bichat's fat pad with the Facial Nerve Terminal Branches

Introdução: A cirurgia de Bichectomia está sendo muito procurada por pessoas que visam diminuir o volume facial. O corpo adiposo da bochecha, ou bola de Bichat, possui uma complexa relação anatômica com estruturas faciais. Uma das complicações que o procedimento pode causar é a paralisia facial temporária ou permanente, em decorrência de injúrias causadas aos ramos terminais do nervo facial, devido à proximidade dessas duas estruturas anatômicas. Metodologia: O objetivo do presente artigo é enfatizar a relação anatômica da bola de Bichat com alguns ramos terminais do nervo facial através da dissecação de cadáveres. Foram feitas dissecações em três hemifaces de cadáveres humanos para a exposição do corpo adiposo da bochecha e dos ramos extracranianos do nervo facial. Resultados: A anatomia dos ramos terminais zigomáticos e bucais do nervo facial se mostrou variável em cada hemiface dissecada, mas sempre intimamente relacionados a bola de Bichat. Conclusões: O profissional que realiza a Bichectomia deve ter pleno conhecimento não só da técnica cirúrgica, mas também da variabilidade anatômica da região... (AU)

Introduction: The Buccal Fat Extraction surgery has been sought by people who aim to reduce facial volume. The Buccal fat pad has a complex anatomical correlation among the facial structures. The facial nerve paralysis is one of Bichat's fat extraction complications which might be temporary or permanent, due to the proximity of those anatomical structures. Methodology: The present article aims to emphasize the anatomical correlation between the Buccal fat pad and a few terminal branches of the facial nerve through the human cadaveric dissection. The dissection was performed on three human cadaveric hemifacial to expose the buccal fat pad body and the facial nerve extracranial branches. Results: The zygomatic and buccal terminal branches anatomy of the facial nerve has shown variables in each dissected hemifacial part. However, it has always presented closely related to Bichat's fat pad. Conclusions: The professional that performs the Buccal Fat Removal surgery must have to have the full knowledge not only about the surgical technique but the anatomical variability of the region, as well... (AU)

Immunohistochemistry and ultrastructural characteristics of nerve endings in the oral mucosa of rat.

The sensory nerve endings of the rat tongue, cheek and palate were studied using immunohistochemical staining and transmission electron microscopy analysis. The specimens were fixed in modified Karnovsky solution and embedded in Spurr resin. Substance P, calcitonin gene-related peptide (CGRP)- and protein gene product 9.5 (PGP b9.5)-containing nerve fibers in the rat tongue, cheek and palate were examined by electronic microscopical analysis and immunohistochemical localization. These fibers run very close to the basal lamina of the epithelium and extend into the filliform and fungiform papillae. Numerous plexiform fibers immunoreactive for substance P, CGRP and PGP 9.5 were found in the connective tissue of mucosa. Electron microscopic observations showed clearly immunostained nerve fibers, which are located very close to the basal lamina of epithelial cells. Some electron-dense granules may be observed in the axoplasms of both substance P and CGRP immunoreactive fibers. Several lamellar corpuscles into the subepithelial connective tissue papillae, Merkel corpuscles and numerous thin unmyelinated and myelinated axons were observed. The terminal axons revealed numerous mitochondria, neurofilaments, microtubules and clear vesicles in the base of axoplasmic protrusions. The lamellar cells showed caveolae and interlamelar spaces filled by amorphous substance. Between the lamellar cells and axoplasmic membrane, and in the adjacent lamellae region, desmosome-type junctions were observed. The quantitative and morphometric analysis showed nerve endings with an average area of 4.83 ± 3.4 µm(2) and 19.4 internal mitochondria in this site and the organized corpuscles with an average area of 79.24 ± 27.24 µm(2) and 24.23 internal mitochondria in this place. All the structures observed are involved in the transmission of pain and mechanoreceptors stimulus of these oral mucosae.

Comparison of hemodynamic effects of lidocaine, prilocaine and mepivacaine solutions without vasoconstrictor in hypertensive patients.

OBJECTIVE: Local anesthetic solutions with vasoconstrictors are not contraindicated in hypertensive patients, but due to their hemodynamic effects, local anesthetics without vasoconstrictors are mainly preferred by the clinicians. The aim of this study was to compare hemodynamic effects of three different local anesthetics without vasoconstrictors during tooth extraction in hypertensive patients. MATERIAL AND METHODS: Sixty-five mandibular molars and premolars were extracted in 60 hypertensive patients (29 females and 31 males; mean age: 66.95 ± 10.87 years; range: 38 to 86 years old). Inferior alveolar and buccal nerve blocks were performed with 2% lidocaine hydrochloride (HCl), 2% prilocaine HCl or 3% mepivacaine HCl without vasoconstrictor. Hemodynamic parameters namely systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), saturation rate (SR), rate pressure product (RPP) and pressure rate quotient (PRQ) were investigated before and at different intervals after anesthetic injection. RESULTS: The hemodynamic effects of the three agents were similar to each other, although some significance was observed for DBP, MAP, RPP and PRQ values in the lidocaine, prilocaine and mepivacaine groups. CONCLUSION: Lidocaine, prilocaine and mepivacaine solutions without vasoconstrictor can be safely used in hypertensive patients. It is advisable that dental practitioners select anesthetic solutions for hypertensive patients considering their cardiovascular effects in order to provide patient comfort and safety.

Comparison of hemodynamic effects of lidocaine, prilocaine and mepivacaine solutions without vasoconstrictor in hypertensive patients

OBJECTIVE: Local anesthetic solutions with vasoconstrictors are not contraindicated in hypertensive patients, but due to their hemodynamic effects, local anesthetics without vasoconstrictors are mainly preferred by the clinicians. The aim of this study was to compare hemodynamic effects of three different local anesthetics without vasoconstrictors during tooth extraction in hypertensive patients. MATERIAL AND METHODS: Sixty-five mandibular molars and premolars were extracted in 60 hypertensive patients (29 females and 31 males; mean age: 66.95 ± 10.87 years; range: 38 to 86 years old). Inferior alveolar and buccal nerve blocks were performed with 2 percent lidocaine hydrochloride (HCl), 2 percent prilocaine HCl or 3 percent mepivacaine HCl without vasoconstrictor. Hemodynamic parameters namely systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), saturation rate (SR), rate pressure product (RPP) and pressure rate quotient (PRQ) were investigated before and at different intervals after anesthetic injection. RESULTS: The hemodynamic effects of the three agents were similar to each other, although some significance was observed for DBP, MAP, RPP and PRQ values in the lidocaine, prilocaine and mepivacaine groups. CONCLUSION: Lidocaine, prilocaine and mepivacaine solutions without vasoconstrictor can be safely used in hypertensive patients. It is advisable that dental practitioners select anesthetic solutions for hypertensive patients considering their cardiovascular effects in order to provide patient comfort and safety.

Endogenous motor neuron properties contribute to a program-specific phase of activity in the multifunctional feeding central pattern generator of Aplysia.

Multifunctional central pattern generators (CPGs) are circuits of neurons that can generate manifold actions from a single effector system. This study examined a bilateral pair of pharyngeal motor neurons, designated B67, that participate in the multifunctional feeding network of Aplysia californica. Fictive buccal motor programs (BMPs) were elicited with four distinct stimulus paradigms to assess the activity of B67 during ingestive versus egestive patterns. In both classes of programs, B67 fired during the phase of radula protraction and received a potent inhibitory postsynaptic potential (IPSP) during fictive radula retraction. When programs were ingestive, the retraction phase IPSP exhibited a depolarizing sag and was followed by a postinhibitory rebound (PIR) that could generate a postretraction phase of impulse activity. When programs were egestive, the depolarizing sag potential and PIR were both diminished or were not present. Examination of the membrane properties of B67 disclosed a cesium-sensitive depolarizing sag, a corresponding I(h)-like current, and PIR in its responses to hyperpolarizing pulses. Direct IPSPs originating from the influential CPG retraction phase interneuron B64 were also found to activate the sag potential and PIR of B67. Dopamine, a modulator that can promote ingestive behavior in this system, enhanced the sag potential, I(h)-like current, and PIR of B67. Finally, a pharyngeal muscle contraction followed the radula retraction phase of ingestive, but not egestive motor patterns. It is proposed that regulation of the intrinsic properties of this motor neuron can contribute to generating a program-specific phase of motor activity.

Predictive factors in infraorbital sensitivity disturbances following zygomaticomaxillary fractures.

The aim of this study was to define if the alterations in sensory modalities could be a predictive factor in the prognostic recovery of the ION. Ten patients that had suffered facial trauma, associated with sensitivity alterations of the ION were evaluated prospectively. Touch detection thresholds (TD) were measured using Von Frey's filaments aesthesiometer. A warm/cold discrimination (W/C) was also done to the patients, on the same areas. The patients were examined in both sides of the face, using the non-traumatized side as control. The tests were done before surgery and several times postoperatively. For statistical analysis of the results, the two-sample t test was used. A significant difference (P < 0.0001) in the mean tactile recovery time between the areas without thermal sensitivity before surgery and those with normal thermal sensitivity before surgery was observed. Therefore, we propose that during the preoperative examination, the surgeon examines the thermal discrimination in order to establish prognosis and approximate recovery times.

A population of pedal-buccal projection neurons associated with appetitive components of Aplysia feeding behavior.

Backfills of the cerebral-buccal connective (CBC) of Aplysia californica revealed a cluster of five to seven pedal-buccal projection neurons in the anterolateral quadrant of the ventral surface of each pedal ganglion. Intra- and extracellular recordings showed that the pedal-buccal projection neurons shared common electrophysiological properties and synaptic inputs. However, they exhibited considerable heterogeneity with respect to their projection patterns. All pedal-buccal projection neurons that were tested received a slow excitatory postsynaptic potential from the ipsi- and contralateral cerebral-pedal regulator (C-PR) neuron, a cell that is thought to play a key role in the generation of a food-induced arousal state. Tests were conducted to identify potential synaptic follower neurons of the pedal-buccal projection neurons in the cerebral and buccal ganglia, but none were detected. Finally, nerve recordings revealed projections from the pedal-buccal projection neurons in the nerves associated with the buccal ganglion. In tests designed to determine the functional properties of these peripheral projections, no evidence was obtained supporting a mechanosensory or proprioceptive role and no movements were observed when they were fired. It is proposed that peripheral elements utilized in consummatory phases of Aplysia feeding may be directly influenced by a neuronal pathway that is activated during the food-induced arousal state.