Nasosinusal Endoscopic Anatomy and Physiology

The present article focuses on the analysis of the nasal cavity's anatomy succinctly and descriptively. This essay was carried out through a bibliographic review, directed to the detailed anatomy of the nasal cavity, and the structures that form its sinuses. We have identified the need formore studies directed to the related anatomical area so that the improved knowledge of this region ensures a nasoendoscopic treatment with better effectiveness and no complications.

Pterygopalatine Fossa: Microsurgical Anatomy and its Relevance for Skull Base Surgery

Introduction The purpose of this study was to define the anatomical relationships of the pterygopalatine fossa (PPF) and its operative implications in skull base surgical approaches. Methods Ten cadaveric heads were dissected at the Dianne and M Gazi Yasargil Educational Center MicrosurgicaLaboratory, in Little Rock, AK, USA. The PPF was exposed through an extended dissection with mandible and pterygoid plate removal. Results The PPF has the shape of an inverted cone. Its boundaries are the pterygomaxillary fissure; themaxilla, anteriorly; themedial plate of the pterygoid process, and greater wing of the sphenoid process, posteriorly; the palatine bone,medially; and the body of the sphenoid process, superiorly. Its contents are the maxillary division of the trigeminal nerve and its branches; the pterygopalatine ganglion; the pterygopalatine portion of the maxillary artery (MA) and its branches; and the venous network. Differential diagnosis of PPF masses includes perineural tumoral extension along the maxillary nerve, schwannomas, neurofibromas, angiofibromas, hemangiomas, and ectopic salivary gland tissue. Transmaxillary and transpalatal approaches require extensive resection of bony structures and are narrow in the deeper part of the approach, impairing the surgical vision and maneuverability. Endoscopic surgery solves this problem, bringing the light source to the center of the surgical field, allowing proper visualization of the surgical field, extreme close-ups, and different view angles. Conclusion We provide detailed information on the fossa's boundaries, intercommunications with adjacent structures, anatomy of the maxillary artery, and its variations. It is discussed in the context of clinical affections and surgical approaches of this specific region, including pterygomaxillary disjunction and skull base tumors.

The anatomic analysis of the vidian canal and the surrounding structures concerning vidian neurectomy using computed tomography scans / Avaliação anatômica do canal vidiano e estruturas adjacentes por tomografia computadorizada para a neurectomia do vidiano

Abstract Introduction: The type of endoscopic approach chosen for vidian neurectomy can be specified by evaluating the vidian canal and the surrounding sphenoid sinus structures. Objective: The variations and morphometry of the vidian canal were investigated, focusing on the functional correlations between them which are crucial anatomical landmarks for preoperative planning. Methods: This study was performed using paranasal multidetector computed tomography images that were obtained with a section thickening of 0.625 mm of 250 adults. Results: The distributions of 500 vidian canal variants were categorized as follows; Type 1, within the sphenoid corpus (55.6%); Type 2, partially protruding into the sphenoid sinus (34.8%); Type 3, within the sphenoid sinus (9.6%). The pneumatization of the pterygoid process is mostly seen in vidian canal Type 2 (72.4%) and Type 3 (95.8%) (p < 0.001). The mean distances from the vidian canal to the foramen rotundum and the palatovaginal canal were greater in the vidian canal Type 2 and 3 with the pterygoid process pneumatization (p < 0.001). The prevalence of the intrasphenoid septum between the vidian canal and the vomerine crest and lateral attachment which ending on carotid prominence were much higher in vidian canal Type 3 than other types (p < 0.001). The mean angle between the posterior end of the middle turbinate and the lateral margin of the anterior opening of the vidian canal was measured as 33.05 ± 7.71°. Conclusions: Preoperative radiologic analysis of the vidian canal and the surrounding structures will allow surgeons to choose an appropriate endoscopic approach to ensure predictable postoperative outcomes.

Resumo Introdução: O tipo de abordagem endoscópica para a neurectomia do vidiano pode ser definido pela avaliação do canal do vidiano e das estruturas adjacentes aos seios esfenoidais. Objetivo: Investigar as variações e a morfometria do canal vidiano com enfoque nas suas correlações funcionais, pois são parâmetros anatômicos cruciais para o planejamento pré-operatório. Método: Esse estudo foi realizado utilizando-se imagens de tomografia computadorizada multidetectores dos seios paranasais com espessura de corte de 0,625 mm obtidas de 250 indivíduos adultos. Resultados: A distribuição das 500 variantes do canal vidiano foi categorizada da seguinte forma: Tipo 1, dentro do corpo ósseo esfenoidal (55,6%); Tipo 2, protrusão parcial no interior do seio esfenoidal (34,8%); Tipo 3, no interior do seio esfenoidal (9,6%). A pneumatização do processo pterigoide foi observada principalmente no canal vidiano Tipo 2 (72,4%) e Tipo 3 (95,8%) (p < 0,001). As distâncias médias do canal vidiano até o forame redondo e o canal palatovaginal foram maiores no canal vidiano do Tipo 2 e 3, com a pneumatização do processo pterigoide (p < 0,001). A presença do septo intraesfenoidal entre o canal vidiano e a crista vomeriana e a extensão lateral, que termina na proeminência da carótida, foi muito maior no canal vidiano Tipo 3 do que nos outros tipos (p < 0,001). A angulação média entre a cauda da concha média e a margem lateral da abertura anterior do canal vidiano foi de 33,05° ± 7,71°. Conclusões: A análise radiológica pré-operatória do canal do vidiano e das estruturas circunjacentes permitem ao cirurgião escolher uma abordagem endoscópica apropriada e prever resultados pós-operatórios.

Contribución al Estudio Descriptivo del Foramen y Canal Palatino Mayor / Contribution to the Descriptive Study of the Foramen and Greater Palatine Canal

RESUMEN: El foramen y canal palatino mayor (FPM y CPM) comunican boca con fosa pterigopalatina. El conocimiento adecuado de su morfología, permite el abordaje anestésico del nervio maxilar. En el vivo, el FPM está recubierto por una mucosa gruesa, debido a esto los puntos de referencia óseos y dentarios son importantes para ubicar el sitio de punción. Se ha descrito gran variabilidad en cuanto a la etnia, posición, forma, diámetros, longitudes y permeabilidad. Este estudio tuvo como objetivo describir éstas características en cráneos de adultos chilenos. Se utilizaron 31 cráneos de ambos sexos. En los paladares se determinó; forma, largo, profundidad y ancho. En los FPM se consideró su forma, diámetros y localización. En los CPM se registró su permeabilidad y su coincidencia con la forma del FPM. Los registros se realizaron con cámara digital, compás de precisión, caliper digital, compas tridimensional de Korkhaus y sonda metálica. Los resultados muestran un predominio de la forma cuadrada del paladar por sobre las formas triangular y redondeada. Las mediciones de su largo, ancho y profundidad indican diferencias por sexo y por etnia. La forma del FPM no muestra diferencia por sexo, primando la forma ovalada por sobre la fusiforme y la redondeada. La posición de este mismo foramen tampoco muestra diferencias sexuales, primando la posición frente al tercer molar superior, seguida por la posición frente al espacio entre segundo y tercer molar superior y por último frente al 2do molar superior. Las dimensiones del FPM son mayores en individuos masculinos. Los CPM se observaron en su totalidad permeables y los FPM no siempre coincidieron en forma con la sección transversal del CPM. Estos resultados y su comparación con la literatura indican variaciones importantes, lo que impide establecer directrices objetivas a la técnica anestésica que utiliza esta vía anatómica.

ABSTRACT: The greater palatine foramen and canal (GPF and GPC) communicate with the pterygopalatine fossa. The adequate knowledge of its morphology allows the anesthetic approach of the maxillary nerve. In vivo, the GPF is covered by a thick mucosa, therefore, the bone and dental reference points are important to locate the puncture site. Great variability has been described in terms of ethnicity, position, shape, diameters, lengths and permeability. The objective of this study was to describe these characteristics in skulls of Chilean adults. 31 skulls of both sexes were used. In the palates shape, length, depth and width were determined. In the GPF its shape, diameters and location were considered. In the GPC, their permeability and their coincidence with the shape of the GPF were recorded. The records were made with digital camera, precision compass, digital caliper, Korkhaus three-dimensional compass and metallic probe. The results show a predominance of the square shape of the palate over the triangular and rounded forms. The measurements of its length, width and depth indicate differences by sex and ethnicity. The shape of the GPF shows no difference by sex, with the oval shape prevailing over the fusiform and the rounded. The position of this same foramen also shows no sexual differences, with the position prevailing against the upper third molar, followed by the position in front of the space between the upper second and third molars and finally against the upper 2-molar. The dimensions of GPF are greater in male individuals. The GPC were found to be entirely permeable and the GPF did not always coincide in form with the cross section of the GPC. These results and their comparison with the literature indicate important variations, which prevents establishing objective guidelines for the anesthetic technique used in these cases.

Estudio anatómico de la región pterigopalatina en cráneos macerados de brasileños con el objetivo de contribuir al desarrollo de la técnica de disyunción de la sutura esfenomaxilar / Anatomical study of the pterigopalatine region in macerated skulls of brazilians aiming to contribute to the improvement of spheno-maxillary suture disjunction technique

Una de las técnicas utilizadas en cirugía ortognática es la osteotomía Le Fort I en la cual un paso quirúrgico importante es la disyunción de la sutura esfenomaxilar. Durante este procedimiento a veces ocurren complicaciones quirúrgicas, tales como lesiones neurovasculares, debido principalmente a la falta de conocimiento de la anatomía de la región y posicionamiento inadecuado de los cinceles. El objetivo de este estudio fue contribuir para que esta técnica sea más predecible, ofreciendo datos morfométricos de los principales reparos anatómicos de la región pterigopalatina. El valor promedio de la altura de la sutura esfenomaxilar fue 13,22mm en hombres y 12,47mm en mujeres; el valor promedio del ancho de la sutura esfenomaxilar fue 11,40mm en hombres y 11,02mm en mujeres; el valor promedio de la distancia del punto de mayor concavidad de la cresta cigomatoalveolar hasta la sutura esfenomaxilar fue 25,12mm en hombres y 23,80mm en mujeres; el valor promedio de la distancia desde el punto más inferior de la sutura esfenomaxilar hasta la fisura orbitaria inferior fue 31,12mm en hombres y 29,61mm en mujeres. Los valores obtenidos en nuestra investigación pueden ser utilizados como parámetros para la realización de la técnica de disyunción de la sutura esfenomaxilar, haciéndola más predecible y con menor riesgo de complicaciones.

Among the techniques used in orthognathic surgery is the Le Fort I osteotomy in which a important surgical step is the disjunction of the spheno-maxillary suture. During this procedure surgical complications, such as neurovascular injuries sometimes occur, mainly due to lack of knowledge of regional anatomy and poor positioning of chisels. The aim of this work is to contribute for this surgical technique to become more predictable, offering morphometric data of the main anatomical landmarks of the pterygopalatine region. The height of the spheno-maxillary suture was on average 13.22mm in men and 12.47mm in women; the width of the spheno-maxillary suture was on average 11.40mm in men and 11.02mm in women, the distance from the point of greatest concavity of zigomaticoalveolar crest until spheno-maxillary suture was on average 25.12mm in men and 23.80mm in women; the distance between the lowest portion of the spheno-maxillary suture and the inferior orbital fissure was on average 31.12mm in men and 29.61mm in women. The values obtained in our study may be used as a parameter in performing the technique of spheno-maxillary suture disjunction, making it more predictable and with less risk of complications.

Relationship between volume of pterygopalatine fossa and block anesthesia of maxillary nerve: a pilot study / Relación entre el volumen de la fosa pterigopalatina y la anestesia troncular del nervio maxilar: un estudio piloto

Block anesthesia of maxillary nerve 9BAMN) is achieved by depositing anesthesia through greater palatine canal into the pterygopalatine fossa. Authors differ in the amount of anesthesia to be administered and the rate of complications (diplopia and hematomas), Coronado et al., (2008), measured the size of the pterygopalatine fossa finding an average of 1.2 ml, suggesting that amount of anesthesia for BAMN. The aim of this study is to compare the effectiveness of low doses of 1.2 ml (LD)versus traditional dose of 1.8 m. (TD) of anesthesia for BAMN and its adverse effects. A quasi experimental exploratory clinical study was performed involving 82 patients where the anesthetic technique was suitable for tooth extraction procedure; patients were randomized in LD and TD groups, 2 percent lidocaine with 1:50.000 epinephrine was used. Demographic (sex and age), clinical (tooth for extraction and anesthetic dose) as well as anatomical variables (upper facial and cranial index) were recorded. The anesthetic success (AS) was defined as the possibility to perform the tooth extraction with no pain or minimal pain as measured by visual analogue scale (VAS). For statistical analysis chi-square and t test (p <0.05) were used. The results show that the pain and AS were 2.93 and 61.67 percent in LD group and 3.09 and 59.09 percent in TD group respectively, there were 6 cases of diplopia with no significant statistical difference between groups.

El bloqueo troncular del nervio maxilar (BTNM) se logra depositando anestesia vía canal palatino mayor en la fosa pterigopalatina. Los autores difieren en la cantidad de anestesia a depositar y la tasa de complicaciones asociadas (diplopía y hematomas). Coronado et al. (2008) midió el volumen de la fosa pterigopalatina encontrando un promedio de 1,2ml, sugiriendo dicha cantidad de anestesia para el BTNM. El objetivo del presente trabajo es comparar la eficacia de dosis bajas de 1,2ml (DB) versus dosis tradicional de 1,8ml (DT) de anestesia para el BTNM y sus efectos adversos. Se realizó un estudio clínico cuasiexperimental de carácter exploratorio, participaron 82 pacientes donde la técnica anestésica estaba indicada para un procedimiento de exodoncia, los que fueron aleatorizados en los grupos DB y DT, administrándoles lidocaína al 2 por ciento con 1:50.000 de epinefrina. Se registraron variables demográficas (sexo y edad), clínicas (pieza a extraer y dosis administrada) y anatómicas (índices facial superior y craneal). El éxito anestésico (EA) se definió como la posibilidad de realizar la exodoncia con nulo o mínimo dolor, medido con escala visual análoga (EVA). En el análisis estadístico se utilizaron los tests de chi cuadrado y t de student (p<0,05). Los resultados muestran que el dolor y el EA en el grupo DB fueron de 2,93 y 61,67 por ciento y en el DT de 3,09 y 59,09 por ciento respectivamente, hubo 6 casos de diplopía sin diferencias estadísticamente significativas entre ambos grupos.