Automatic segmentation and classification of frontal sinuses for sex determination from CBCT scans using a two-stage anatomy-guided attention network.

Sex determination is essential for identifying unidentified individuals, particularly in forensic contexts. Traditional methods for sex determination involve manual measurements of skeletal features on CBCT scans. However, these manual measurements are labor-intensive, time-consuming, and error-prone. The purpose of this study was to automatically and accurately determine sex on a CBCT scan using a two-stage anatomy-guided attention network (SDetNet). SDetNet consisted of a 2D frontal sinus segmentation network (FSNet) and a 3D anatomy-guided attention network (SDNet). FSNet segmented frontal sinus regions in the CBCT images and extracted regions of interest (ROIs) near them. Then, the ROIs were fed into SDNet to predict sex accurately. To improve sex determination performance, we proposed multi-channel inputs (MSIs) and an anatomy-guided attention module (AGAM), which encouraged SDetNet to learn differences in the anatomical context of the frontal sinus between males and females. SDetNet showed superior sex determination performance in the area under the receiver operating characteristic curve, accuracy, Brier score, and specificity compared with the other 3D CNNs. Moreover, the results of ablation studies showed a notable improvement in sex determination with the embedding of both MSI and AGAM. Consequently, SDetNet demonstrated automatic and accurate sex determination by learning the anatomical context information of the frontal sinus on CBCT scans.

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.

Variaciones anatómicas de los senos frontales en radiografías de cráneo de pacientes con cráneos braquicéfalos / Anatomical variations of frontal sinuses in skull radiographs of patients with brachycephalic skulls

Introducción: La anatomía ósea de las cavidades paranasales presenta múltiples variantes, que pueden ser causa o factor predisponente de enfermedad rinosinusal, entre las que se encuentran las asimetrías y las agenesias. Éstas pueden ser reparos de gran importancia en la cirugía endoscópica nasal y demandan atención médica con frecuencia. Objetivo: Determinar las variaciones anatómicas de los senos frontales en los pacientes con cráneos braquicéfalos y que no presentaron diagnóstico de enfermedad rinosinusal. Métodos: Se realizó un estudio observacional, descriptivo y transversal, donde fueron estudiados los diámetros transversales y longitudinales de los senos frontales a través de radiografías de cráneo AP en 28 pacientes con cráneos braquicéfalos, en el servicio de imagenología del Hospital Juan Bruno Zayas Alfonso en los meses de enero y febrero de 2019. Resultado: Se identificaron las principales variaciones de los senos frontales a través de radiografías de cráneo y su comportamiento según variables epidemiológicas. Conclusiones: Predominó los enfermos (9) en el rango etáreo de 19-29 años, lo que representa un 32,1 por ciento, hubo un ligero predominio de los hombres con respecto a las mujeres, 10 (35,7 por ciento) pacientes presentaron agenesia bilateral y 3 (10,7 por ciento) agenesia unilateral izquierda. Las magnitudes de las cavidades derechas fueron mayores que las izquierdas y los senos frontales estudiados son asimétricos por su tamaño y posición(AU)

Introduction: The bone anatomy of paranasal cavities presents a large number of variants which may be the cause of or predisposing factor for rhinosinus disease, among which are asymmetry and agenesis. These may be very important hurdles in nasal endoscopic surgery and often require medical care. Objective: Determine the anatomical variations in the frontal sinuses of patients with brachycephalic skulls not diagnosed with rhinosinus disease. Methods: A cross-sectional observational descriptive study was conducted of frontal sinus longitudinal and transverse diameters of frontal sinuses based on AP skull radiographs of 28 patients with brachycephalic skulls attending the imaging service of Juan Bruno Zayas Alfonso Hospital from January to February 2019. Result: Identification was made of the main frontal sinus variations in skull radiographs and their behavior according to epidemiological variables. Conclusions: The 19-29 years age group prevailed, with 9 patients (32.1 percent). There was a slight predominance of men versus women. Ten (35.7 percent) patients had bilateral agenesis and 3 (10.7 percent) had unilateral left agenesis. The magnitudes for right cavities were greater than those for left cavities. The frontal sinuses studied were asymmetrical in terms of size and position(AU)

Cuerpo esqueletizado identificado por análisis morfológico del seno frontal y características del material de osteosíntesis - relato de caso pericial / Skeletonized body identified by analysis of frontal sinus morphology and characteristics of osteosynthesis material: a forensic case report

La odontología legal resulta fundamental para la identificación de víctimas en descomposición avanzada, carbonizadas o esqueletizadas. Este trabajo relata un caso de identificación humana, por medio de análisis morfológico del seno frontal y material de osteosíntesis. Un cuerpo esqueletizado fue sometido a examen antropológico, evidenciándose la existencia de tres placas de osteosíntesis en ambas regiones periorbitarias. Parientes de la supuesta víctima aportaron radiografías ante-mortem, en las que se aprecia una sola placa de osteosíntesis. Empero, tras la realización de exámenes imagenológicos del esqueleto, con la misma incidencia de los efectuados ante-mortem, se constató una clara semejanza morfológica del seno frontal y de la única placa de osteosíntesis presente en las imágenes ante-mortem y post-mortem. Así, fue posible identificar positivamente a la víctima, allanando el camino a la investigación criminal y realzando el rol de las imágenes radiográficas y caracteres anatómicos en el proceso de identificación humana.

Forensic dentistry is essential for the identification of highly decomposed and charred bodies, as well as skeletal remains. This study reports a case of human identification by analyzing the morphology of the frontal sinuses and osteosynthesis material. In the anthropological assessment of skeletal remains a surgical plate used for osteosynthesis was detected in the periorbital regions. Relatives of the potential victim provided ante-mortem (AM) radiographs which revealed the presence of an osteosynthesis plate. Post-mortem (PM) imaging exams were performed to reproduce the AM data. Similarities were observed between the AM and PM radiographs, especially regarding the morphology of the frontal sinuses and the position and outline of the surgical plate used for osteosynthesis. The comparison of AM and PM images made it possible to identify the victim and to aid the criminal investigation. It also highlighted the role of radiographs and anatomical characteristics in the process of human identification.

Frontal sinus ontogeny and covariation with bone structures in a modern human population.

In humans, the frontal sinus (FS) is located in the medial part of the supraorbital region, sometimes expanded throughout the frontal squama. It exhibits high morphological variability, but its general form appears to be constrained by surrounding structures. The goal of this study is to analyze FS growth and test for covariation between FS volume and the glabellar region, upper nasal region, bone thickness and endocranial size in a human sample from Argentina. The sample comprises 149 reconstructions derived from computed tomography images of individuals aged 0-31 years. Volume of the FS and measurements of the surrounding structures were recorded. The FS growth trajectory was assessed by parametric and nonparametric methods, and covariation was determined using correlations and partial correlations. The FS volume could be measured at an age of about 6 years and older; adults had no aplasia but hyperplasia was found in some cases. Since the most conspicuous characteristic found was variation among individuals, the nonparametric smoothing spline produced very poor fitting. The modified logistic function was the only parametric method providing significant parameters. Sexes differed in the age at which FS growth began and ended, with FS developing earlier but at a slower rate in females than in males. The FS volume did not correlate with either upper nasal width or endocranial volume, but it correlated with bone thickness measurements (mainly from the glabellar region), even when age was held constant. Expansion of the FS at the frontal poles also correlated with frontal bone thickness. Despite the difficulty in modeling and predicting the trajectory and morphology of FS, our results suggest that it is affected by its surrounding bony environment.

The Frontal Sinus Cavity Exhibits Sexual Dimorphism in 3D Cone-beam CT Images and can be Used for Sex Determination.

Few studies have assessed the use of the frontal sinus cavities for sex differentiation. In this study, a new methodology was used to assess the reliability of CBCT images of the frontal sinus cavity for determining sex based on the sexual dimorphism found in this anatomical structure. The survey sample consisted of 130 scans that were reconstructed three-dimensionally. 3D images of the cavity volume in the frontal, lateral, and basal views were exported in TIFF. The following variables were measured in a second program: area, perimeter, bounding rectangle, ellipse fit, circularity, aspect ratio, roundness, solidity, and Feret's diameter. The methodology demonstrated the existence of sexual dimorphism with an accuracy of 80.0% in the logistic regression model. The basal view had the greatest explanatory power in the final model. This methodology may be used as an alternative way of determining a reliable biological profile during the analysis of skeletal remains.

The possible effects of altitude and climate on the development of the frontal sinus in adults / Los posibles efectos de la altitud y el clima sobre el desarrollo del seno frontal en adultos

Climatic and altitude features of living region may affect human body. Many changes in several tissues and organs and several health problems due to climatic and altitude effects were defined in the literature. However, there were limited number of studies which evaluated correlation between development of frontal sinus and climatic/altitude effect. In this study, widths, heights, AP lengths and volumes of frontal sinus were compared by Paranasal CT scans in populations living in Van which has colder climate and higher altitude and Manisa which has milder climate and lower altitude. It was found that widths, antero-posterior lengths and volumes of frontal sinus were higher in populations living in colder climate and higher altitude according to populations living in milder climate and lower altitude. Heights of frontal sinuses were on the contrary of this. These results were found appropriate to increasing of cephalic index in cold climate according to Allen's Rule. We suggest that larger population study should be made with peoples having the same or similar race and genetic structure in different climate and altitude regions and the proportional comparison of frontal sinus measurements with cephalic index should be considered in future studies.

Las características climáticas y de altitud de una región pueden afectar al cuerpo humano. En la literatura se han identificado muchos cambios en varios tejidos y órganos, como así también numerosos problemas de salud debido a los efectos climáticos y de altitud. Sin embargo, existe un número limitado de estudios que han evaluado la correlación entre el desarrollo del seno frontal y el efecto climático / altitud. En este estudio, los anchos, alturas, longitudes antero-posteriores y volúmenes de seno frontal se compararon mediante tomografía computarizada paranasal en poblaciones que viven en Van, que tiene un clima más frío y mayor altitud, y Manisa, que tiene un clima más suave y menor altitud. Se encontró que los anchos, las longitudes antero-posteriores y los volúmenes de los senos frontales eran mayores en poblaciones que vivían en un clima más frío y de mayor altitud respecto a poblaciones que vivían en clima más suave y con menor altitud. En relación a la altura de los senos frontales, se dio la situación contraria a lo anterior. Estos resultados se encontraron adecuados con el aumento del índice cefálico en la región de clima frío, de acuerdo con la Regla de Allen. Sugerimos que se realice un estudio poblacional más amplio con poblaciones de raza y estructura genética iguales o similares en diferentes regiones climáticas y de altitud. La comparación proporcional de las mediciones de los senos frontales con índice cefálico debería considerarse en futuros estudios.

Tratamento cir£rgico de seio frontal atrav‚s da cranializa‡Æo e utiliza‡Æo do acesso bicoronal – relato de caso / Surgical treatment of frontal sinus through cranialization using bicoronal access – case report

O trauma maxilofacial ‚ um dos grandes desafios para os servi‡os de sa£de e representa um dos problemas mais importantes devido … elevada taxa de incidˆncia e alto custo financeiro. A frequente associa‡Æo entre trauma craniofacial e maxilofacial exige abordagens e tratamento multiprofissional e sÆo cada vez mais complexos, com tempo de interna‡Æo mais longo e altos custos para o sistema p£blico de sa£de. Este estudo apresenta um relato de caso cl¡nico de um paciente admitido no servi‡o de emergˆncia do Hospital Municipal Salgado Filho (HMSF) – RJ, v¡tima de agressÆo f¡sica por pedra no ter‡o superior de face e submetido ao tratamento cir£rgico por equipe multiprofissinal (neurocirurgiÆo e cirurgiÆo bucomaxilofacial), com cranializa‡Æo do seio frontal e reparo do defeito ¢sseo com tela de titƒnio de reconstru‡Æo. Conclui-se neste trabalho que a proposta cir£rgica, que consistiu na cranializa‡Æo do seio frontal pelo acesso bicoronal, como tratamento proposto para o paciente, apresentou- -se satisfat¢ria, segundo as referˆncias liter rias consultadas. Sugere-se acompanhamento p¢s-operat¢rio cl¡nico e radiogr fico do paciente, uma vez que neste relato foi mencionado apenas o tratamento cir£rgico do caso.

TMaxillofacial trauma is a major challenge for health services and represents a serious problem due to its high incidence and high costs. The frequent association between craniofacial and maxillofacial trauma requires multidisciplinary approaches and treatment, and it i salso very complex, with longer hospitalization time and high costs to the public health system. This study presents a case report of a patient assisted in the emergency department of the Salgado Filho Municipal Hospital (HMSF) – RJ, victim of physical assault by stone in the upper third of the face, who underwent surgery conducted by multiprofissinal team (neurosurgeons and maxillofacial surgeon) with cranialization of the frontal sinus and repair of bone defect reconstruction with titanium screen. It was concluded that the surgical approach, which consisted of the frontal sinus cranialization using bicoronal access was satisfactory as treatment according to the researched literature. It is suggested post-operative clinical and radiographic follow-up of the patient since in this report only the surgical treatment of the case was approached.

Analysis of the Agger nasi cell and frontal sinus ostium sizes using computed tomography of the paranasal sinuses.

UNLABELLED: The Agger nasi cell (ANC) and the frontal sinus ostium (FO) are important structures that can influence the anatomy and physiology of the frontal recess. The aim of this study was to evaluate the presence and size of ANC and the FO and correlate them according to gender, race and among themselves. METHOD: A prospective study with 40 patients who underwent CT of the paranasal sinuses with sagittal reconstruction. MEASUREMENTS: ANC (APAN) anteroposterior diameter, ANC (CCAN) craniocaudal diameter, ANC (LLAN) side-to-side diameter, anteroposterior diameter of the FO (APFO) and side-to-side diameter of the FO (LLFO). RESULTS: Twenty-two patients were male and 18 females, mean age 33.7 years. Most patients were white (45%), followed by browns (32.5%), blacks (20%) and asians (2.5%). The ANC was present in 98.7% of patients. There was statistical difference for APAN on females and LLAN on females and on the total sample. There were no differences for all measurements regarding gender, as well as the race. ANC and FO measurements showed positive correlation, but poor or very poor. CONCLUSION: The prevalence of ANC in our sample was high and did not show a statistically significant difference for most measurements. The correlation between measurements of ANC and the FO was poor or very poor.

Análise das dimensões da célula do Agger nasi e do óstio do seio frontal utilizando tomografia computadorizada de seios paranasais / Analysis of the Agger nasi cell and frontal sinus ostium sizes using computed tomography of the paranasal sinuses

A célula do Agger nasi (CAN) e o óstio do seio frontal (OF) são estruturas importantes que podem influenciar a anatomofisiologia do recesso frontal. OBJETIVO: O objetivo deste trabalho foi avaliar a presença e as dimensões da CAN e do OF e correlacioná-las de acordo com o sexo, raça e entre si. MÉTODO: Estudo prospectivo com 40 pacientes submetidos à tomografia computadorizada de seios paranasais com reconstrução sagital. Foram realizadas as medidas: diâmetro ântero-posterior da CAN (AGAP), diâmetro crânio-caudal da CAN (AGCC), diâmetro látero-lateral da CAN (AGLL), diâmetro ântero-posterior do OF (OFAP) e diâmetro látero-lateral do OF (OFLL). RESULTADOS: Vinte e dois pacientes eram do sexo masculino e 18, do feminino; média de idade de 33,7 anos. A maioria dos pacientes era da raça branca (45%), seguidos pelos da raça parda (32,5%), da raça negra (20%) e da raça amarela. A CAN esteve presente em 98,7% das fossas nasais. Houve diferença estatística para AGAP no sexo feminino e AGLL no sexo feminino e na amostra total. Não houve diferenças para as medidas tanto quanto ao sexo como quanto à raça. As medidas da CAN e do OF apresentaram correlação, mas de maneira ruim ou péssima. CONCLUSÃO: A prevalência da CAN em nossa amostra foi alta e não houve diferença estatisticamente significante para a maioria das medidas realizadas. A correlação das medidas da CAN e do OF foi ruim ou péssima.

The Agger nasi cell (ANC) and the frontal sinus ostium (FO) are important structures that can influence the anatomy and physiology of the frontal recess. The aim of this study was to evaluate the presence and size of ANC and the FO and correlate them according to gender, race and among themselves. METHOD: A prospective study with 40 patients who underwent CT of the paranasal sinuses with sagittal reconstruction. Measurements: ANC (APAN) anteroposterior diameter, ANC (CCAN) craniocaudal diameter, ANC (LLAN) side-to-side diameter, anteroposterior diameter of the FO (APFO) and side-to-side diameter of the FO (LLFO). RESULTS: Twenty-two patients were male and 18 females, mean age 33.7 years. Most patients were white (45%), followed by browns (32.5%), blacks (20%) and asians (2.5%). The ANC was present in 98.7% of patients. There was statistical difference for APAN on females and LLAN on females and on the total sample. There were no differences for all measurements regarding gender, as well as the race. ANC and FO measurements showed positive correlation, but poor or very poor. CONCLUSION: The prevalence of ANC in our sample was high and did not show a statistically significant difference for most measurements. The correlation between measurements of ANC and the FO was poor or very poor.

Anatomic variations of paranasal sinuses-clinical case report.

This article describes the clinical case of an 86-year-old female patient with an asymptomatic clinical condition, without presenting a history of previous traumatisms. When routine radiographic exam-panoramic radiograph-was performed, the following extensions of the paranasal sinuses were found: maxillary sinus (palate), sphenoid sinus (pterygoid process, major wing, and anterior clinoid process), and supraorbital portion of the frontal sinus. Thus computerized tomography was performed to confirm the diagnosis.

Management of frontal sinus fractures.

The traditional treatment of frontal sinus fractures is undergoing a review by many clinicians. This review will undoubtedly contribute to the existing controversy surrounding the management of patients with this condition. This article seeks to further the review and suggest the authors' perspective on a more appropriate approach to the care of patients with frontal sinus injuries.

Pharyngeal airway space and frontal and sphenoid sinus changes after maxillomandibular advancement with counterclockwise rotation for Class II anterior open bite malocclusions.

OBJECTIVES: The purpose of this study was to cephalometrically evaluate the pharyngeal airway space and frontal and sphenoid sinus changes after maxillomandibular advancement counterclockwise rotation for class II anterior open bite malocclusion. METHODS: The study included 49 patients (98 lateral teleradiographs; 36 females and 13 males) who were analysed in the pre-operative (1 week before surgery) and post-operative (6 months after surgery) periods. In each lateral teleradiography, the dimensions of the inferior and superior pharyngeal airway space, TB-PhW1 [the point between the posterior aspect of the tongue to the dorsal pharyngeal wall (oropharynx) (TB) and the point on the dorsal pharyngeal wall closest to TB (PhW1)] and UP-PhW2 [and the point between the posterior aspect of the soft palate to the dorsal pharyngeal wall (nasopharynx) (UP) (PhW2)] measurements were evaluated, as well as the dimensions of the frontal and sphenoid sinuses. The differences between the two operative times were evaluated by Student's t-test. RESULTS: All measurements showed excellent reproducibility for the intraclass correlation coefficient (ICC > 0.9; p < 0.0001). There was an increase in the measurements TB-PhW1 and UP-PhW2 and a decrease in the dimensions of the frontal and sphenoid sinuses after orthognathic surgery. CONCLUSIONS: The morphology of the superior and inferior pharyngeal airway space and frontal and sphenoid sinuses changes after 6 months of maxillomandibular advancement counterclockwise rotation for class II anterior open bite malocclusion.

Frontal sinus size on facial plain radiographs

Introduction: Plain radiographs are still routinely used for diagnosis in dentistry. They allow the assessmentof anatomical structures and their variations, and the detection of abnormalities in the region assessed. Theaim of this research was to determine the width and height distances of the frontal sinus on posteroanteriorskull view of Brazilian subjects. Materials and methods: The sample was composed of 158 posteroanteriorfacial radiographs (Caldwell projection). It was measured the height and width of the frontal sinus, both sides,under a standardized protocol, using rules and a viewer box. The relationship between frontal sinus size andside of the face, and size and age were evaluated. Results: Thirteen radiographs were excluded (six of unilateralfrontal sinus, two agenesies, and five showing totally individualized chambers). The final sample studied was of145 subjects. The mean values obtained were a 68 mm for latero-lateral and 39 mm for superoinferior distances.In 39.3% cases both sides were approximately equal or had the left chamber larger than the right one. Therewas a significant correlation between width and height of frontal sinus (Spearman coefficient), however therewas no significant difference among the age groups studied (Kruskal-Wallis, p > 0,05). Conclusion: There is agreat anatomical variety of frontal sinus in this population. The left cavity of frontal sinus is larger or equal tothe right one and the age group differences was not significant regarding the size of the frontal sinus.

Anatomical variations of the frontal sinus

An anatomical study of the frontal sinus in 100 macerated skulls. The study introduces an innovation on the literature by means of the measurement of the sinus's volume. All the found information in the literature attained to other aspects including the diameters of the sinus and the geometric area of the same. Objective: Evaluation of the measures of the frontal sinus frequently involved in cranial base surgeries and supraorbital craniotomies in order to help the surgical approaches that cross this anatomical route Methods: The measurement included: sagital, transverse and antero-posterior diameter acquired with a paquimeter and the volume obtained after filling the sinus with sand. Results: They are in accordance with the literature that shows the male's predominance in all measurements done.

Se presenta un estudio anatómico del seno frontal que fue realizado en 100 cráneos. El estudio introduce una novedad en la literatura, que es la medida volumétrica del seno frontal. Toda la literatura se refiere a otros aspectos, incluyendo los diámetros de los senos y su área geométrica. El objetivo del estudio fue estimar las medidas del seno frontal que con frecuencia hacen parte en las cirugías de la base del cráneo y en las craneotomías supraorbitarias, con la finalidad de facilitar las vías de acceso quirúrgico por estas regiones. Las medidas realizadas fueron: diámetro sagital, transversal y antero-posterior con un caliper, y el volumen fue obtenido llenando el seno con arena fina. Los resultados están de acuerdo con la literatura que demuestra un mayor predominio del sexo masculino en todas las medidas efectuadas.

Frontal recess anatomy study by endoscopic dissection in cadavers.

INTRODUCTION AND AIMS: The frontal sinus ostium is frequently difficult to recognize because of anatomical structures that hide it. The objective of the present study was to identify and describe the frontal recess anatomy that impairs the endoscopic recognition of the frontal sinus ostium. STUDY DESIGN AND METHODS: A prospective study was conducted by consecutive endoscopic dissections of 32 cadavers (59 sides), 10 (31.25%) females and 22 (68.75%) males. After resection of the lower portion of the uncinate process, with preservation of its upper insertion, we evaluated which anatomical structures needed to be removed for complete visualization of the frontal sinus ostium. RESULTS AND CONCLUSIONS: Visualization of the frontal sinus ostium after resection of the lower portion of the uncinate process was possible in only 11 (18.64%) nasal cavities. The uncinate process (terminal recess) was the main anatomical structure that impaired the recognition of the frontal sinus ostium, present in 45 (76.27%) nasal cavities, followed by the ethmoid bulla (16.95%) and agger nasi cells (6.78%).

Estudo da anatomia do recesso frontal por meio de dissecção endoscópica em cadáveres / Frontal recess anatomy study by endoscopic dissection in cadavers

INTRODUÇÃO E OBJETIVO: O óstio do seio frontal freqüentemente apresenta difícil reconhecimento devido a estruturas anatômicas que encobrem sua visibilização. O objetivo principal desse estudo foi identificar e descrever as estruturas anatômicas do recesso frontal que dificultam o reconhecimento do óstio do seio frontal. CASUíSTICA E MÉTODOS: Foi realizado um estudo prospectivo por meio de dissecção endoscópica consecutiva de 32 cadáveres (59 fossas nasais), 10 (31,25 por cento) do sexo feminino e 22 (68,75 por cento) do sexo masculino. Após exérese endoscópica da porção inferior do processo uncinado, com a preservação da sua inserção superior, avaliamos quais estruturas anatômicas necessitavam ser removidas até a completa visibilização endonasal do óstio do seio frontal. RESULTADOS E CONCLUSÃO: A visibilização do óstio do seio frontal após a exérese da porção inferior do processo uncinado foi possível em apenas 11 (18,64 por cento) fossas nasais. O processo uncinado (recesso terminal) representou a principal estrutura anatômica que dificultou o reconhecimento endonasal do óstio do seio frontal, ocorrendo em 45 (76,27 por cento) fossas nasais, seguido pela bolha etmoidal (16,95 por cento) e a célula agger nasi (6,78 por cento).

INTRODUCTION AND AIMS: The frontal sinus ostium is frequently difficult to recognize because of anatomical structures that hide it. The objective of the present study was to identify and describe the frontal recess anatomy that impairs the endoscopic recognition of the frontal sinus ostium. STUDY DESIGN AND METHODS: A prospective study was conducted by consecutive endoscopic dissections of 32 cadavers (59 sides), 10 (31.25 percent) females and 22 (68.75 percent) males. After resection of the lower portion of the uncinate process, with preservation of its upper insertion, we evaluated which anatomical structures needed to be removed for complete visualization of the frontal sinus ostium. RESULTS AND CONCLUSIONS: Visualization of the frontal sinus ostium after resection of the lower portion of the uncinate process was possible in only 11 (18.64 percent) nasal cavities. The uncinate process (terminal recess) was the main anatomical structure that impaired the recognition of the frontal sinus ostium, present in 45 (76.27 percent) nasal cavities, followed by the ethmoid bulla (16.95 percent) and agger nasi cells (6.78 percent).

Is there a reason for performing frontal sinus trephination at 1 cm from midline? A tomographic study.

UNLABELLED: The complex anatomy of the frontoethmoidal recess, as well as its anatomical relationship with the vital adjacent structures in the region explain the reason for considerable surgical care to protect these structures and minimize complications related to healing. Trephination is an accepted procedure to access the frontal sinus. AIM: Discuss the best location for performing frontal sinus trephination. METHODS: Measuring sinus frontal depth at 3 points equidistant to the midline (crista galli) through the axial tomographic sections. RESULTS: We measured 138 frontal sinus (69 patients). Frontal sinus depth at 0,5 cm was statistically larger than 1 cm and 1.5 cm, as well as the 1 cm trephine point was significantly larger than 1.5 cm (12.22+/-4.25 vs 11.78+/-4.65 p<0,05; 12.22+/-4.25 vs 10.78+/-5.98 p<0.001; 11.78+/-4.65 vs 10.78+/-5.98 p<0.05). The trephine set used (maximum depth of penetration of 0.7 cm) is safe to be applied in approximately 80% of the patients. CONCLUSION: Analyzing the results, the trephination may be performed at variable points of the frontal sinus, but the distance of 1 cm from midline appears to be safer and shows better aesthetic results.

A Trefinação do Seio Frontal deve ser sempre realizada a 1cm da linha média? Um estudo tomográfico / Is there a reason for performing frontal sinus trephination at 1 cm from midline? A tomographic study

A complexa anatomia do recesso frontoetmoidal, bem como sua relação anatômica com estruturas vitais, explicam a razão do considerável cuidado que se tem durante a cirurgia para preservar estas estruturas e minimizar complicações relacionadas ao processo de cicatrização. A trefinação é um procedimento amplamente aceito para acesso ao seio frontal. OBJETIVO: Avaliar o melhor ponto para se realizar a trefinação do seio frontal. MÉTODOS: Mensuração da profundidade do seio frontal em 3 pontos eqüidistantes da linha média (crista galli) em cortes tomográficos axiais. RESULTADOS: Foram medidos 138 seios frontais (69 pacientes). A profundidade do seio frontal medida a 0,5cm da linha média foi significativamente maior do que a 1,0 e 1,5cm, assim como a medida a 1,0cm foi significativamente maior do que a 1,5cm (12,22±4,25 vs 11,78±4,65 p<0,05; 12,22±4,25 vs 10,78±5,98 p<0,001; 11,78±4,65 vs 10,78±5,98 p<0,05). O trefinador usado (penetração máxima de 0,7cm) é seguro de ser usado em cerca de 80 por cento dos pacientes. CONCLUSÃO: A trefinação pode ser realizada em pontos variáveis do seio frontal, mas a distância de 1cm da linha média parece ser mais segura e apresentar resultados estéticos melhores.

The complex anatomy of the frontoethmoidal recess, as well as its anatomical relationship with the vital adjacent structures in the region explain the reason for considerable surgical care to protect these structures and minimize complications related to healing. Trephination is an accepted procedure to access the frontal sinus. AIM: Discuss the best location for performing frontal sinus trephination. METHODS: Measuring sinus frontal depth at 3 points equidistant to the midline (crista galli) through the axial tomographic sections. RESULTS: We measured 138 frontal sinus (69 patients). Frontal sinus depth at 0,5 cm was statistically larger than 1 cm and 1,5 cm, as well as the 1 cm trephine point was significantly larger than 1,5 cm (12,22±4,25 vs 11,78±4,65 p<0,05; 12,22±4,25 vs 10,78±5,98 p<0,001; 11,78±4,65 vs 10,78±5,98 p<0,05). The trephine set used (maximum depth of penetration of 0,7 cm) is safe to be applied in approximately 80 percent of the patients. CONCLUSION: Analizing the results, the trephination may be performed at variable points of the frontalsinus, but the distance of 1 cm from midline appears to be safer and shows better aestethic results.

The frontal sinus morphology in radiographs of Brazilian subjects: its forensic importance

The determination of gender of unknown persons is of vital importance in forensic investigations, such as anthropologic,medical and dental forensic studies, mainly in cases where only fragments of the skull remain and there is no possibility of identification based on the dental arch. The aim of the present study was to develop a mathematical method based on logistic regression analysis capable of determining the gender of individuals using measurements of the frontal sinus. The right and left areas and the maximum height and width of the frontal sinus were determined in 100 radiographs taken by the Caldwell technique of 50 women and 50 men between 20 and 30 years old, with the help of the prog ram SIARCS 3.0 (EMBRAPA). The mean values of the frontal sinus were greater in males and the left area was larger than the right area, based on Student’s t-test at the 5% level of significance. The mathematical model based on logistic regression analysis gave a concordanceindex for gender of 79.7% in the cases studied. The areas of the frontal sinus and the logistic regression technique proved to be useful in the determination of gender. (Logit = 1.6905 – 0.5383* left area).