RESUMEN
PURPOSE: The internal auditory canal (IAC) plays a key role in lateral skull base surgery. Although several approaches to the IAC have been proposed, endoscope-assisted transcanal corridors to the IAC have rarely been studied. We sought to provide a step-by-step description of the transcanal transpromontorial approach to the IAC and analyze anatomic relationships that might enhance predictability and safety of this approach. METHODS: Ten cadaveric specimens were dissected and the extended transcanal transpromontorial approach to the IAC was established. Various morphometric measurements and anatomic landmarks were reviewed and analyzed. RESULTS: The proposed technique proved feasible and safe in all specimens. There was no inadvertent injury to the jugular bulb or internal carotid artery. The chorda tympani, a key landmark for the mastoid segment of the facial nerve, was identified in all dissections. The spherical recess of the vestibule and middle turn of cochlea are important landmarks for identification of the labyrinthine segment of the facial nerve. Identification of all boundaries of the working area is also essential for safe access. Among various morphometric measurements, the modiolus-IAC angle (≈ 150°) proved particularly consistent; given its ease of use and low variability, we believe it could serve as a landmark for identification and subsequent dissection of the IAC. CONCLUSIONS: The extended transcanal transpromontorial approach to the IAC is feasible and safe. Relying on anatomic landmarks to ensure preservation of the involved neurovascular structures is essential for a successful approach. The modiolus-IAC angle is a consistent, reproducible landmark for IAC identification and dissection.
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Cadáver , Oído Interno , Endoscopía , Humanos , Oído Interno/anatomía & histología , Oído Interno/cirugía , Endoscopía/métodos , Puntos Anatómicos de Referencia , Disección/métodos , Base del Cráneo/anatomía & histología , Base del Cráneo/cirugíaRESUMEN
OBJECTIVE: To analyze variability in the distance between the Anterior Ethmoidal Artery (AEA) and the anterior Skull Base (SB), as well as the frequency of lateral asymmetry in a Latin American population using computed tomography. METHODS: A total of 250 computed tomography scans of paranasal sinuses in coronal reconstruction (500 AEAs) were analyzed. After determining the image with the best anatomical view of the artery, the distance between its midpoint and the ethmoidal roof was measured, and the images were independently interpreted by 2 physicians. RESULTS: Of the 500 AEAs, 279 (55.8%) adhered to or passed through the SB at a distance of 0mm. A total of 221 AEAs (44.2%) were at some distance from the SB, of which 107 (48.4%) were on the right side, ranging from 1.18 to 6.75mm, and 114 (51.5%) were on the left side, ranging from 1.15 to 6.04mm. The overall mean distance between the AEA and SB was 1.22 (SD=1.57) mm, increasing to 2.77 (SD=1.14) when the arteries adhered to the SB were excluded. Seventy-six individuals (30.4%) had a lateral distance variation > 1mm. CONCLUSION: Our study includes the largest sample of AEA analyzed with computed tomography scans of paranasal sinuses. There was some distance between the AEA and SB in almost half the patients, and we found a high rate of lateral variability >1mm. LEVEL OF EVIDENCE: Level 3.
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Senos Etmoidales , Base del Cráneo , Tomografía Computarizada por Rayos X , Humanos , Femenino , Masculino , Base del Cráneo/diagnóstico por imagen , Base del Cráneo/anatomía & histología , Base del Cráneo/irrigación sanguínea , Persona de Mediana Edad , Adulto , Anciano , Senos Etmoidales/diagnóstico por imagen , Senos Etmoidales/irrigación sanguínea , Senos Etmoidales/anatomía & histología , Adulto Joven , Adolescente , Anciano de 80 o más Años , Arterias/anatomía & histología , Arterias/diagnóstico por imagenRESUMEN
INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: This approach is intended for tumors centered in the jugular foramen with extensions between intracranial and extracranial spaces, possible spread to the middle ear, and variable bony destruction. 1,2. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: Jugular foramen paragangliomas are complex lesions that usually invade and fill related venous structures. They present complex relationships with skull base neurovascular structures as internal carotid artery, lower cranial nerves (CNs), middle ear, and mastoid segment of facial nerve. In this way, it is essential to perform an adequate preoperative vascular study to evaluate sinus patency and the tumor blood supply, besides a computed tomography scan to depict bone erosion. ESSENTIAL STEPS OF THE PROCEDURE: Mastoidectomy through an infralabyrinthine route up to open the lateral border of jugular foramen, allowing exposure from the sigmoid sinus to internal jugular vein. Skeletonization of facial canal without exposure of facial nerve is performed and opening of facial recess to give access to the middle ear in way of a fallopian bridge technique. 2-10. PITFALLS/AVOIDANCE OF COMPLICATIONS: If there is preoperative preservation of lower CN function, it is important to not remove the anteromedial wall of the internal jugular vein and jugular bulb. In addition, facial nerve should be exposed just in case of preoperative facial palsy to decompress or reconstruct the nerve. VARIANTS AND INDICATIONS FOR THEIR USE: Variations are related mainly with temporal bone drilling depending on the extensions of the lesion, its source of blood supply, and preoperative preservation of CN function.Informed consent was obtained from the patient for the procedure and publication of his image.Anatomy images were used with permission from:⢠Ceccato GHW, Candido DNC, and Borba LAB. Infratemporal fossa approach to the jugular foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.⢠Ceccato GHW, Candido DNC, de Oliveira JG, and Borba LAB. Microsurgical Anatomy of the Jugular Foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.
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Tumor del Glomo Yugular , Foramina Yugular , Humanos , Foramina Yugular/diagnóstico por imagen , Foramina Yugular/cirugía , Base del Cráneo/diagnóstico por imagen , Base del Cráneo/cirugía , Base del Cráneo/anatomía & histología , Tumor del Glomo Yugular/cirugía , Hueso Temporal/diagnóstico por imagen , Hueso Temporal/cirugía , Nervios CranealesRESUMEN
The nasopharynx is an important anatomical structure involved in respiration. Its bony boundaries, including the basicranium and upper cervical vertebrae, may be subject to selective pressures and constraints related to respiratory function. Here, we investigate phenotypic integration, or covariation, between the face, the basicranial boundaries of the nasopharynx, and the atlas and axis to understand constraints affecting these structures. We collected three-dimensional coordinate data from a sample of 80 humans and 44 chimpanzees, and used two-block partial least squares to assess RV (a multivariate generalization of Pearson's r2 ), rPLS , the covariance ratio, and effect size for integration among structures. We find that integration is significant among some of these structures, and that integration between the basicranial nasopharynx and vertebrae and between the face and vertebrae is likely independent. We also find divergences in the pattern of integration between humans and chimpanzees suggesting greater constraints among the human face and nasopharynx, which we suggest are linked to divergent developmental trajectories in the two taxa. Evolutionary changes in human basicranial anatomy, coupled with human-like developmental trajectories, may have required that the face grow to compensate any variation in nasopharyngeal structure. However, we were unable to determine whether the nasopharynx or the face is more strongly integrated with the vertebrae, and therefore whether respiration or biomechanical considerations related to positional behavior may be more strongly tied to vertebral evolution. Future work should focus on greater sample sizes, soft tissue structures, and more diverse taxa to further clarify these findings.
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Evolución Biológica , Base del Cráneo , Animales , Vértebras Cervicales/diagnóstico por imagen , Humanos , Nasofaringe , Pan troglodytes/anatomía & histología , Base del Cráneo/anatomía & histologíaRESUMEN
Introdução. Retorno venoso extracraniano anormal é um importante fator relacionado às craniossinostoses complexas, sendo responsável por alta morbimortalidade. Associa-se a essa circulação, a estenose ou atresia do forame jugular, existindo dúvida na literatura se a presença de circulação colateral venosa é causa da estenose de forame, gerando hipertensão venosa; se o desenvolvimento da circulação venosa acontece como consequência da hipertensão intracraniana ou se existem componentes intrínsecos levando à formação de veias anômalas. Objetivo. Analisar o retorno venoso completo (intra e extracraniano) pré-operatório de pacientes com craniossinostoses complexas e sindrômicas e avaliar a sua relação com a: morfologia da base do crânio, funcionalidade dos forames e seios durais, hipertensão intracraniana e diagnostico sindrômico e molecular. Método. Estudo Retrospectivo e prospectivo de pacientes com craniossinostose complexa ou sindrômica submetidos à angiotomografia com fase venosa no Instituto Fernandes Figueira a partir de 2014. Para avaliação da gravidade do retorno venoso extracraniano foi elaborada uma classificação vascular, categorizando os pacientes em leves, moderados e graves. Essa classificação consistiu em uma pontuação em cada região de circulação colateral estudada, variando de 0 a 3. Desta forma, sendo 9 regiões de interesse (frontais, parietais, mastoides, condilares esquerda e direita e circulação transoccipital), a classificação variou entre 0 quando ausência completa de circulação colateral até 27, considerado a possibilidade mais grave apresentada. De acordo com o Cluster Hierárquico, os pacientes foram classificados em 3 categorias de circulação venosa extracraniana: Leve pontuação vascular entre 0 e 9; Moderada pontuação vascular entre 10 e 18; Grave pontuação vascular entre 19 e 27. Os 3 grupos Moderada pontuação vascular entre 10 e 18; Grave pontuação vascular entre 19 e 27. Os 3 grupos foram comparados quanto à morfologia da base do crânio (áreas, medidas anteroposteriores e volumes do forame jugular, forame magno e fossa posterior), quanto ao retorno venoso intracraniano (seios venosos durais, funcionalidade do forame jugular), quanto à hipertensão intracraniana (número de suturas acometidas, presença de malformação de Chiari I, hidrocefalia, ventriculomegalia) e quanto às síndromes apresentadas (manifestações fenotípicas e estudo molecular). Resultados. Dentre o total de 45 pacientes, 44,4% (n= 20) pertenciam ao grupo leve, 37,8% (n= 17) ao grupo moderado e 17,8% (n= 8) ao grupo grave. A circulação venosa extracraniana não se correlacionou com as medidas anteroposteriores, transversas, de área e de volume dos forames jugulares, forame magno ou da fossa posterior, com o número de suturas acometidas, com a classificação dos seios venosos intracranianos e da fossa posterior, com a hidrocefalia ou ventriculomegalia. A malformação de Chiari I é mais frequente em pacientes mais graves (p valor <0,001). As mutações identificadas se correlacionaram com a gravidade da circulação venosa extracraniana (pvalor <0,001). Conclusões. A estratificação de pacientes em uma classificação vascular permite a avaliação mais adequada dos fatores que historicamente são relacionados à circulação venosa colateral em Craniossinostoses complexas e sindrômicas. As alterações venosas extracranianas não se correlacionaram diretamente com as alterações morfológicas da base do crânio, com a funcionalidade dos seios durais ou com sinais de hipertensão intracraniana. Essas alterações parecem ser resultado de manifestações intrínsecas relacionadas ao genótipo, sendo as mutações no gene FGFR2 mais gravemente relacionadas à circulação venosa extracraniana. Pacientes com síndrome de Pfeiffer apresentaram a classificação venosa extracraniana mais grave, seguido pelas síndromes de Crouzon, Apert, Jackson-Weiss, Saerthre-Chotzen e craniossinostoses complexas negativas. As veias emissárias mais frequentemente encontradas foram as condilares e mastóides, seguidas da circulação transóssea occipital. Atresia funcional do forame jugular se correlaciona com a gravidade da circulação venosa extracraniana e pode ser consequência da atividade molecular intrínseca no endotélio durante a formação do sistema venoso.
Introduction. Abnormal extracranial venous outflow is an important factor related to complex craniosynostosis, that can lead to high morbidity and mortality. It has been associated with stenosis or atresia of the jugular foramen. In fact, there is doubt in the literature if the collateral venous circulation is caused by Jugular foramen stenosis, generating venous hypertension or if the development of the venous circulation happens as a consequence of intracranial hypertension or whether if there are intrinsic components leading to the formation of anomalous veins. Objective. To analyze the preoperative complete venous outflow (intra and extracranial) of patients with complex and syndromic craniosynostosis and to evaluate its relationship with: morphology of the skull base, functionality of the jugular foramina and dural sinuses, intracranial hypertension and syndromic and molecular diagnosis. Method. A retrospective and prospective study of patients with complex or syndromic craniosynostosis on CT angiography with venous phase at Instituto Fernandes Figueira from 2014 to 2022. To assess the severity of extracranial venous drainage, a vascular classification was developed, categorizing patients into mild, moderate and severe. The classification consisted of a score in each region of collateral circulation studied, ranging from 0 to 3. Thus, with 9 regions of interest (frontal, parietal, mastoid, left and right condylar and transoccipital circulation), the classification ranged from 0 when absence collateral circulation up to 27, considered the most serious possibility presented. According to the Hierarchical Cluster, patients were in 3 extracranial circulation categories: Mild vascular assessment between 0 and 9; Moderate vascular assessment between 10 and 18; Severe vascular assessment between 19 and 27. The 3 groups were compared regarding skull base morphology (areas, measurements of jugular foramen and foramen magnum, and posterior fossa volumes), intracranial venous outflow (dural venous sinuses, jugular foramen functionality), and intracranial hypertension (number of affected sutures, presence of Chiari I malformation, hydrocephalus, ventriculomegaly) and the syndromes presented (phenotypic manifestations and molecular study). Results. Among the 45 patients, 44.4% (n=20) belonged to the mild group, 37.8% (n=17) to the moderate group and 17.8% (n=8) to the severe group. The extracranial venous circulation does not correlate with the anteroposterior, transverse, area and volume measurements of the jugular foramen, foramen magnum or posterior fossa, with the number of affected sutures, with the intracranial venous sinuses and the posterior fossa, with the hydrocephalus or ventriculomegaly. Chiari I malformation correlates with the most severe patients (p value <0.001). The mutations identified correlate with the severity of the extracranial venous circulation (p-value <0.001). Conclusions. The stratification of patients in a vascular classification allows a more adequate evaluation of the factors that are historically related to the collateral venous circulation in complex and syndromic craniosynostosis. Extracranial venous changes did not directly correlate with morphological changes in the skull base, functionality of the dural sinuses, or with signs of intracranial hypertension. These alterations seem to be the result of intrinsic manifestations related to the genotype, with mutations in the FGFR2 gene most severely related to extracranial venous circulation. Patients with Pfeiffer syndrome had the most severe extracranial venous classification, followed by Crouzon, Apert, Jackson-Weiss, Saerthre-Chotzen and complex negative craniosynostosis. The emissary veins most frequently found were the condylar and mastoid veins, followed by the occipital transosseous circulation. Functional atresia of the jugular foramen correlates with the severity of extracranial venous circulation and may be a consequence of intrinsic molecular activity in the endothelium during formation of the venous system.
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Pacientes , Circulación Colateral , Base del Cráneo/anatomía & histología , Craneosinostosis/fisiopatología , Foramina Yugular , BrasilRESUMEN
SUMMARY: Surgical operations regarding to skull base are challenging and reliable anatomical landmarks are required. There is a lack of knowledge on anatomical variations in this region. The aim of this study was to determine the safe extracranial landmarks for surgical approach to the skull base. In this study, 23 adult dry skulls were evaluated: the age and sex of the specimens were unknown. All measurements were taken from external surface of inferior aspect of the skull by using digital calipers accurate to 0.01 mm. In right and left sides; the distances between the external acoustic meatus (EAM) and the following anatomical landmarks were measured: articular tubercle (AT); anterior margin of squamous suture (ASS); superior margin of squamous suture (SSS); posterior margin of squamous suture (PSS); end point of styloid process (SP); midpoints of pterygomaxillary fissure (PMF); foramen ovale (FO); foramen spinosum (FS); and of carotid canal (CC).The distances of the external acoustic meatus to the anatomical structures on the right and left sides were: EAM-SP; 24.24±3.19 mm, 23.16±3.17 mm; EAM-PMF; 46.56±4.51mm, 46.25±3.96 mm; EAM-FO; 27.57±2.87 mm, 28.70±2.85 mm; EAM-FS; 22.53±3.19 mm, 22.72±3.47 mm; EAM-CC; 17.35±3.56 mm, 17.19±3.39 mm; EAM-AT; 19.31±3.79 mm, 18.95±3.42 mm; EAM-ASS; 43.14±4.80 mm, 46.82±4.61 mm; EAM-SSS; 49.17±4.74 mm, 48.83±3.34 mm and EAM-PSS; 36.15±4.24 mm, 35.39±4.25 mm, respectively. We think that the findings obtained from this study related to external acoustic meatus can be an important reference for surgical anatomy and surgical procedures in skull base.
RESUMEN: Las cirugías relacionadas con la base del cráneo son un desafío, las cuales requieren puntos de referencia anatómicos confiables. Existe una falta de conocimiento sobre las variaciones anatómicas en esta región. El objetivo de este estudio fue determinar los puntos de referencia extracraneales seguros para el abordaje quirúrgico de la base del cráneo. En este estudio se evaluaron 23 cráneos secos adultos: se desconocía la edad y el sexo de los ejemplares. Las medidas se tomaron de la superficie externa de la cara inferior del cráneo utilizando calibradores digitales con una precisión de 0,01 mm. En lados derecho e izquierdo se midieron las distancias entre el meato acústico externo (MAE) y los siguientes puntos de referencia anatómicos: tubérculo articular (TA); margen anterior de la sutura escamosa (MASE); margen superior de sutura escamosa (MSSE); margen posterior de sutura escamosa (MPSE); punto final del proceso estiloides (PFPE); puntos medios de la fisura pterigomaxilar (PMFP); foramen oval (FO); foramen espinoso (FE); y del canal carotídeo (CC). Las distancias del meato acústico externo a las estructuras anatómicas de los lados derecho e izquierdo fue- ron: MAE-PFPE; 24,24 ± 3,19 mm, 23,16 ± 3,17 mm; MAE-PMFP; 46,56 ± 4,51 mm, 46,25 ± 3,96 mm; MAE-FO; 27,57 ± 2,87 mm, 28,70 ± 2,85 mm; MAE-FE; 22,53 ± 3,19 mm, 22,72 ± 3,47 mm; MAE-CC; 17,35 ± 3,56 mm, 17,19 ± 3,39 mm; MAE-TA; 19,31 ± 3,79 mm, 18,95 ± 3,42 mm; MAE-MASE; 43,14 ± 4,80 mm, 46,82 ± 4,61 mm; MAE-MSSE; 49,17 ± 4,74 mm, 48,83 ± 3,34 mm y MAE-MPSE; 36,15 ± 4,24 mm, 35,39 ± 4,25 mm, respectivamente. Creemos que los hallazgos obtenidos de este estudio relacionados con el meato acústico externo pueden ser una referencia importante para la anatomía quirúrgica y los procedimientos quirúrgicos en la base del cráneo.
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Humanos , Adulto , Base del Cráneo/anatomía & histología , Conducto Auditivo Externo/anatomía & histología , Puntos Anatómicos de ReferenciaRESUMEN
O objetivo deste estudo foi comparar o volume condilar em indivíduos com diferentes maloclusões esqueléticas. Também foram realizadas análises das semelhanças morfológicas entre o côndilo mandibular e outras estruturas da mandíbula e base do crânio, por meio de medidas lineares e volumétricas. Essas análises foram realizadas usando Tomografia Computadorizada de Feixe Cônico (TCFC), modelos tridimensionais de côndilos mandibulares e sínfise mandibular de 58 indivíduos foram construídos, e os volumes e áreas foram mensurados. A amostra foi dividida nos seguintes grupos: Classe I (0 ≤ ANB ≥ 4,5°) (n=18), Classe II (ANB > 4,5°) (n=21) e Classe III (ANB < 0°) (n=19). Dezesseis pontos de referência do tecido duro na mandíbula e base do crânio foram identificados por um operador treinado e calibrado. Foram obtidas as distâncias 3D entre os pontos e as projeções nos três planos do espaco (x, y e z). A comparação do volume condilar entre os lados direito e esquerdo foi realizada pelo teste de Wilcoxon (Classe I) e Test t pareado (Classe II e III) e a comparação inter-grupos foi realizada com o teste ANOVA/Tukey (a=0,05). Análises de correlação de Pearson e regressão linear foram realizadas para avaliar a relação entre o volume dos côndilos e a sínfise mandibular, e o volume dos côndilos e as medidas lineares realizadas na mandíbula e base do crânio. Não foi observada diferença estatisticamente significativa entre os volumes condilares dos lados direito e esquerdo em diferentes maloclusões esqueléticas (Classe I: p=0,728; Classe II: p=0,741 e Classe III: p=0,155). Indivíduos de classe III apresentaram maior volume condilar (Classe III: 1990,85 ± 559,42) em comparação aos indivíduos de classe I e II (Classe I: 1835,22 ± 552,15; Classe II: 1725,47 ± 394,64), embora a diferença não tenha sido estatisticamente significativa (p=0,214). Houve uma correlação significativa, mas moderada, entre os volumes condilares e as medidas lineares da sínfise mandibular (p <0,01). Conclui-se que os volumes condilares não variam significativamente em diferentes padrões esqueléticos sagitais e, entre os lados direito e esquerdo. A relação entre o volume condilar e a sínfise mandibular foi moderada e equações de regressão foram desenvolvidas para estimar o volume condilar. (AU)
The aim of this study was to compare the condylar volume in individuals with different skeletal classes. Analyzes of the morphological similarities between the mandibular condyle and other structures of the mandible and cranial base were also performed, using linear and volumetric measurements. These analyzes were performed using Cone Beam Computed Tomography (CBCT), three-dimensional models of mandibular condyles and mandibular symphysis of 58 individuals were constructed, and volumes and areas were measured. The sample was divided into the following groups: Class I (0 ≤ ANB ≥ 4.5 °) (n = 18), Class II (ANB> 4.5°) (n = 21) and Class III (ANB <0 °) (n = 19). Sixteen hard tissue reference points in the mandible and cranial base were identified by a trained and calibrated operator. 3D distances were obtained between the points and the projections in the three planes of the space (x, y and z). The comparison of the condylar volume between the right and left sides was performed by the Wilcoxon test (Class I) and the paired t-test (Class II and III) and the inter-group comparison was performed with the ANOVA / Tukey test (a = 0, 05). Pearson's correlation analyzes and linear regression were performed to assess the relationship between condylar volume and mandibular symphysis, and condylar volume and linear measurements. There was no statistically significant difference between condylar volumes on the right and left sides in different skeletal malocclusions (Class I: p = 0.728; Class II: p = 0.741 and Class III: p = 0.155). Class III individuals had a higher condylar volume (Class III: 1990.85 ± 559.42) compared to Class I and II individuals (Class I: 1835.22 ± 552.15; Class II: 1725.47 ± 394, 64), although the difference was not statistically significant (p = 0.214). There was a significant, but moderate, correlation between condylar volumes and linear measurements of the mandibular symphysis (p <0.01). It is concluded that the condylar volumes do not vary significantly in different sagittal skeletal patterns and, between the right and left sides. The relationship between the condylar volume and the mandibular symphysis was moderate and regression equations were developed to estimate the condylar volume. (AU)
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Humanos , Masculino , Femenino , Base del Cráneo/anatomía & histología , Mandíbula/anatomía & histología , Cóndilo Mandibular/anatomía & histologíaRESUMEN
SUMMARY: Since the asymmetry is generally accepted entity which can be detected on human skulls, the goal of this study was to evaluate the presence and degree of skull base asymmetry and analyze it in relation to sex. The study included 60 skulls. Gender identification was estimated according to the external occipital protuberance, mastoid process, supraorbital margin and glabella. The asymmetry was assessed by analyzing the distance from the bilateral foramina (foramen ovale, foramen spinosum, carotid canal, foramen stylomastoideum) to the pharyngeal tubercle. Digital data were processed in the ImageJ software. The skull base asymmetry was found in all samples. Significant difference between the sides was found for the foramen ovale (p=.01). There was no significant difference in the skull base asymmetry with respect to sex. The highest index of asymmetry (7.38 %) was found in carotid canal and the lowest (5.22%) was detected in relation to the foramen stylomastoideum. By comparing the index of asymmetry between the genders significant difference occurs for the carotid canal (p=.02). Skull base asymmetry was confirmed in our study. Oval foramen showed a significant degree of asymmetry. Knowledge of the variability of the skull base is the basis for an clinical and radiological evaluation of its changes.
RESUMEN: Debido a que la asimetría detectada en cráneos humanos es aceptada generalmente, el objetivo de este estudio fue evaluar la presencia y el grado de asimetría de la base del cráneo y analizarla en relación con el sexo. En este estudio fueron incluidos 60 cráneos. El sexo fue determinado de acuerdo con la protuberancia occipital externa, el proceso mastoideo, el margen supraorbital y la glabela. La asimetría se evaluó analizando la distancia desde los forámenes bilaterales (foramen oval, foramen espinoso, canal carotídeo, foramen estilomastoideo) hasta el tubérculo faríngeo. Los datos digitales fueron procesados en software ImageJ. La asimetría de la base de cráneo se observó en todas las muestras. Se encontró una diferencia significativa entre los lados para el foramen oval (p = ,01). No hubo diferencias significativas en la asimetría de la base de cráneo con respecto al sexo. El índice más alto de asimetría (7,38%) se encontró en el canal carotídeo y el más bajo (5,22 %) se detectó en relación con el foramen estilomastoideo. Al comparar el índice de asimetría entre los sexos, se produce una diferencia significativa en el canal carotídeo (p = 0,02). La asimetría de la base de cráneo se confirmó en nuestro estudio. El foramen oval mostró un grado significativo de asimetría. El conocimiento de la variabilidad de la base del cráneo es importante durante la evaluación clínica y radiológica.
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Humanos , Masculino , Femenino , Base del Cráneo/anatomía & histología , Asimetría Facial , Cadáver , Factores Sexuales , Caracteres Sexuales , Foramen OvalRESUMEN
The modern human has the most flexed cranial base among all living animals. The flexure allowed a larger cranial volume to accommodate a greater brain. Spheno-occipitalis synchondrosis (SOS) has been largely responsible for cranial base flexion, between the sphenoid and the Pars basilaris of the occipital bone. The objective of this work is to evaluate the real place of skull base flexure. Analysis based on 50 magnetic resonance imaging from normal adult subjects were used to evaluate normal place for cranial base angulation (CBA). The vertex of the cranial base angle in all individuals occurred intrinsically in the sphenoid bone. In humans, cranial base flexure had a specific pre-chordal origin, rather than in the transition between pre-chordal and chordal plates and occurred in the inner sphenoidal bone.
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Hueso Occipital/anatomía & histología , Base del Cráneo/anatomía & histología , Hueso Esfenoides/anatomía & histología , Adolescente , Adulto , Anciano , Niño , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Hueso Occipital/diagnóstico por imagen , Hueso Occipital/embriología , Base del Cráneo/diagnóstico por imagen , Base del Cráneo/embriología , Hueso Esfenoides/diagnóstico por imagen , Hueso Esfenoides/embriología , Adulto JovenRESUMEN
Abstract Introduction The clinical relevance of the anatomy and variations of the anterior ethmoidal artery (AEA) is outstanding, considering its role as a landmark in endoscopic surgery, its importance in the therapy of epistaxis, and the high risks related to iatrogenic injuries. Objective To provide an anatomical description of the course and relationships of the AEA, based on direct computed-tomography (CT)-based 3D volume rendering. Methods Direct volume rendering was performed on 18 subjects who underwent (CT) with contrast medium for suspected cerebral aneurism. Results The topographical location of 36 AEAs was assessed as shown: 10 dehiscent (27.8%), 20 intracanal (55.5%), 6 incomplete canals (16.7%). Distances from important topographic landmarks are reported. Conclusion This work demonstrates that direct 3D volume rendering is a valid imaging technique for a detailed description of the anterior ethmoidal artery thus representing a useful tool for head pre-operatory assessments.
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Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Arterias/anatomía & histología , Arterias/diagnóstico por imagen , Senos Etmoidales/irrigación sanguínea , Senos Etmoidales/diagnóstico por imagen , Tomografía Computarizada Multidetector/métodos , Tomografía Computarizada por Rayos X/métodos , Aneurisma Intracraneal/diagnóstico por imagen , Estudios Retrospectivos , Base del Cráneo/anatomía & histología , Base del Cráneo/irrigación sanguínea , Base del Cráneo/diagnóstico por imagen , Medios de Contraste , Imagenología TridimensionalRESUMEN
OBJECTIVE: This study aimed to compare cranial base linear and angular measurements between individuals with skeletal open bite and different sagittal skeletal relationships. MATERIALS AND METHODS: This observational and cross-sectional study included 101 lateral radiographs of young Latin-American individuals with skeletal open bite that met the inclusion criteria and were collected from a private radiological centre. Three groups were formed. Groups 1, 2 and 3 included individuals with skeletal open bite (negative overbite and FMA>30°) and Class I (n=31), II (n=35) and III (n=35) sagittal skeletal relationship, respectively. The anterior and posterior cranial bases (SN and SBa), and cranial base angles (BaSN and ArSN) were measured. Groups were compared with one-way analysis of variance and post-hoc Scheffé tests. The influence of predictor variables on the cranial base were evaluated with linear regressions (α=0.05). RESULTS: The cranial base angles were significantly smaller (approximately 3° to 5°) in the skeletal open bite Class III group (BaSN=127.97°± 5.86°, ArSN=120.19°±6.12°) when compared with the other groups. BaSN angle, Class I versus Class III (p<0.001) and Class II versus Class III (p<0.001). ArSN angle, Class I versus Class III (p=0.005) and Class II versus Class III (p=0.026). Multiple linear regressions showed that sex had a significant influence on both cranial base dimensions with men showing larger values than women. CONCLUSIONS: Skeletal open bite Class III individuals show a smaller cranial base angle than Skeletal open bite Class I or II individuals.
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Maloclusión/patología , Mordida Abierta/patología , Base del Cráneo/anatomía & histología , Análisis de Varianza , Cefalometría , Estudios Transversales , Femenino , Humanos , Modelos Lineales , MasculinoRESUMEN
The cranium is an anatomically complex structure. One source of its complexity is due to its modular organization. Cranial modules are distinct and partially independent units that interact substantially during ontogeny thus generating morphological integration. Artificial Cranial Deformation (ACD) occurs when the human skull is intentionally deformed, through the use of different deforming devices applied to the head while it is developing. Hence, ACD provides an interesting example to assess the degree to which biomechanical perturbations of the developing neurocranium impact on the degree of morphological integration in the skull as a whole. The main objective of this study was to assess how ACD affects the morphological integration of the skull. This was accomplished by comparing a sample of non-deformed crania and two sets of deformed crania (i.e. antero-posterior and oblique). Both developmental and static modularity and integration were assessed through Generalized Procrustes Analysis by considering the symmetric and asymmetric components of variation in adults, using 3D landmark coordinates as raw data. The presence of two developmental modules (i.e. viscero and neurocranium) in the skull was tested. Then, in order to understand how ACD affects morphological integration, the covariation pattern between the neuro and viscerocranium was examined in antero-posterior, oblique and non-deformed cranial categories using Partial Least-Squares. The main objective of this study was to assess how ACD affects the morphological integration of the skull. This was accomplished by comparing a sample of deformed (i.e. antero-posterior and oblique) and non-deformed crania. Hence, differences in integration patterns were compared between groups. The obtained results support the modular organization of the human skull in the two analyzed modules. The integration analyses show that the oblique ACD style differentially affects the static morphological integration of the skull by increasing the covariance between neuro and viscerocranium in a more constrained way than in antero-posterior and non-deformed skulls. In addition, the antero-posterior ACD style seems to affect the developmental integration of the skull by directing the covariation pattern in a more defined manner as compared to the other cranial categories.
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Huesos Faciales/anatomía & histología , Base del Cráneo/anatomía & histología , Arqueología , Evolución Biológica , Chile , HumanosRESUMEN
PURPOSES: The main purpose of this study was to assess the measurements and shape of the sella turcica by using cone beam computed tomography (CBCT) and to associate the data to skeletal class II and class III patients, including correlations with gender, age and measurements of the anterior cranial base. MATERIAL AND METHODS: A trained examiner specialist in dental radiology selected and evaluated randomly 95 CBCT images of pre-orthognathic surgery patients, 60 (63.2%) being female and 35 (36.8%) male with age between 16 and 57 years. All images were evaluated to determine the size, shape and volume of the sella turcica. The anterior cranial base, represented by the S-N line (sella-nasion), was also measured. RESULTS: Of these 95 patients, 48 (50.5%) had class III facial skeletal pattern, whereas 47 (49.5%) had class II. No statistically significant differences were found between class II and class III patients in the measurements and shape of the sella turcica (P > 0.05). The diameter and volume of the sella turcica had higher values in female patients, whereas the measurements of the anterior cranial base were higher in males (P < 0.05). CONCLUSION: Therefore, one can conclude that measurements of the sella turcica are not reliable parameters to evaluate whether a class II or class III patient will or will not need orthognathic surgery.
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Toma de Decisiones Clínicas/métodos , Maloclusión de Angle Clase III/cirugía , Maloclusión Clase II de Angle/cirugía , Cirugía Ortognática/métodos , Silla Turca/anatomía & histología , Adolescente , Adulto , Factores de Edad , Cefalometría/métodos , Tomografía Computarizada de Haz Cónico , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios/métodos , Estudios Prospectivos , Reproducibilidad de los Resultados , Silla Turca/diagnóstico por imagen , Factores Sexuales , Base del Cráneo/anatomía & histología , Base del Cráneo/diagnóstico por imagen , Adulto JovenRESUMEN
Although the sphenoidal emissary foramen (SEF) and its content are anatomically and clinically relevant, accurate description of them in the modern literature is lacking. This study aimed to examine and describe the SEF and its content (the sphenoidal emissary vein [SEV]). We analyzed 1,000 computed tomography (CT) images, 170 dry skulls, 50 formalin-fixed specimens, and three specimens (heads) following guidelines proposed by Dr. Albert L. Rhoton Jr. MD for latex injection. SEV morphology was determined by histological staining and electron microscopy. The SEF was observed in 46.8% of the CTs studied (25.4% bilateral and 21.4% unilateral), and 45.2% of the dry skulls (18.8% bilateral and 26.4% unilateral). In 9.5% of CTs and 21.1% of dry skulls there was a blind channel in the external surface of the cranial base; since there was no communication with the cranial cavity, it was not considered as the SEF. During the dissections, the SEF was found in seven individuals. In three of them, the SEV was an alternative route for venous drainage of the venous plexus of the foramen ovale. Its walls were composed of collagen fibers and its endothelium contained rhomboid cells resembling those commonly found in the superior sagittal sinus. The presence of the SEF and SEV can anatomically explain the spread of certain cranial base pathologies from or toward Meckel's cave or the cavernous sinus, and should be taken into account during procedures in the middle cranial fossa, percutaneous approaches, odontological procedures, and treatment of dural arteriovenous fistulas. Clin. Anat., 33:767-781, 2020. © 2019 Wiley Periodicals, Inc.
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Senos Craneales/anatomía & histología , Senos Craneales/diagnóstico por imagen , Base del Cráneo/anatomía & histología , Base del Cráneo/diagnóstico por imagen , Hueso Esfenoides/anatomía & histología , Hueso Esfenoides/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Cadáver , Disección , Humanos , Persona de Mediana Edad , Tomografía Computarizada por Rayos XRESUMEN
Background: Growth hormone plays a significant role in determining craniofacial morphology. Mutations of its receptor gene might be associated with mandibular prognathism (MP). Purpose: The aim of the current study was to evaluate growth hormone receptor (GHR) gene polymorphisms in relation to facial dimensions. Material and Method: The study enrolled 65 participants with class III profile in MP group and 60 orthognathic control participants. Genomic DNA was extracted from a blood sample from the patients and the P561T and C422F polymorphisms of GHR gene were screened by PCR-RFLP method followed by Sanger sequencing of randomly selected samples to validate the genotyping results. Chi square was used to compare distribution of polymorphism in MP and control groups (p<0.05). Results: Heterozygous P561T mutation was found in 10.77% and 8.33% of MP and control groups, respectively (p=0.644) while none of the subjects had the C422F mutation. Sanger sequencing confirmed the genotyping results from the PCR-RFLP method. P561T polymorphism was significantly associated with ramus and lower facial height in MP patients and with ramus height in orthognathic patients (p<0.05). Conclusion: The results indicate that the P561T polymorphism of the GHR gene is associated with the vertical dimension of the mandible in an Iranian population.
Antecedentes: La hormona del crecimiento desempeña un papel importante en la determinación de la morfología craneofacial. Las mutaciones de su gen receptor podrían estar asociadas con el prognatismo mandibular (PM). Propósito: El objetivo del presente estudio fue evaluar dos polimorfismos del gen del receptor de la hormona del crecimiento (RHC) en relación con las dimensiones faciales. Materiales y Métodos: El estudio incluyó a 65 participantes con perfil de clase III en el grupo MP y 60 participantes de control ortognático. El ADN genómico se extrajo de una muestra de sangre de los pacientes y los polimorfismos P561T y C422F del gen RHC se seleccionaron mediante el método PCR-RFLP seguido de la secuenciación por Sanger de muestras seleccionadas al azar para validar los resultados del genotipo por RFLP. El test chi cuadrado se utilizó para comparar la distribución del polimorfismo en el grupo MP y grupo control (p<0.05). Resultados: Se encontró mutación heterocigota P561T en 10.77% y 8.33% de los grupos PM y control, respectivamente (p=0.644) mientras que ninguno de los sujetos tenía la mutación C422F. La secuenciación de Sanger confirmó los resultados de genotipado por el método PCR-RFLP. El polimorfismo P561T se asoció significativamente con la rama y la altura facial más baja en pacientes con PM y con la altura de la rama en pacientes ortognáticos (p<0.05). Conclusión: Los resultados indican que el polimorfismo P561T del gen RHC está asociado con la dimensión vertical de la mandíbula en una población iraní.
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Humanos , Masculino , Femenino , Cefalometría/métodos , Polimorfismo de Nucleótido Simple/genética , Mandíbula/anatomía & histología , Prognatismo , Hormona del Crecimiento , Distribución de Chi-Cuadrado , Prevalencia , Base del Cráneo/anatomía & histología , Genotipo , Irán/etnología , Maloclusión , Maloclusión de Angle Clase III/genéticaRESUMEN
The aim is to study the sexual dimorphism of the base of the skull in radiographs of a bone collection of contemporary Colombian adults, with the intention of formulating discriminant functions capable of classifying sex in this population. The sample consisted of 115 skull base radiographs, (44 females and 71 males), which originated from the Colombian Human Skeletals Collection. Radiographs with good contrast were selected. Images of skulls with asymmetries and fractures were excluded. Five measures: Maximum cranial base length, Foramen magnum length, Maximum cranial breadth, Bizygomatic breadth, Foramen magnum breadth length, were preformed using ImageJ5 software ®; an intra-observer error was determined using paired t-test. Statistical analysis showed a sexual dimorphism for all variables (pâ¯<â¯0.05). The step-by-step procedure of the discriminant function selected 2 variables from the 5 (Foramen magnum length and Bizygomatic breadth) and the precision was between 86.4% and 88.6% in the determination of sex. However cross-validation showed an accuracy of 85.7% to male and 87.2% to female. The skull base is highly dimorphic. The established discriminant functions can be used to estimate sex in the Colombian population.
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Determinación del Sexo por el Esqueleto/métodos , Base del Cráneo/diagnóstico por imagen , Adolescente , Adulto , Puntos Anatómicos de Referencia , Colombia , Análisis Discriminante , Femenino , Antropología Forense , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Base del Cráneo/anatomía & histología , Adulto JovenRESUMEN
Introdução: O objetivo desse estudo foi avaliar quantitativamente a anatomia 3D da Base do Crânio em pacientes com padrão esquelético Classe I, II e III. Material e Método: Um estudo retrospetivo, foi realizado com as imagens de TCFC de 75 pacientes. A amostra foi dividida em três grupos de acordo com o padrão esquelético de cada individuo: Classe I, II e III. As Imagens de TCFC foram reorientadas e foi realizada a segmentação dos arquivos. Foram posicionados pontos de referência em Base do Crânio, Maxila e Mandíbula. Posteriormente, foram construídos modelos volumétricos 3D da Base do Crânio, Maxila e Mandibula. Foram realizadas medidas angulares e lineares utilizando os pontos de referência. As medidas foram utilizadas para avaliar a morfologia da base do crânio e as suas correlações em diferentes padrões esqueléticos. Analise Estatística: As diferenças entre os grupos foram testadas usando o teste de ANOVA, e as correlações foram medidas utilizando o teste de correlação de Pearson. Resultados: Ainda sem muitas diferenças estatisticamente significativas entre os grupos, foram observadas algumas diferenças menores, onde a Classe II e III se comportam como extremos e a Classe I se comporta como intermediário. Foram observadas diferenças estatisticamente significativas para a posição 3D da Fossa Mandibular (p <0.05) e o Comprimento Mandibular (p <0.05). Foram verificadas correlações entre comprimento Mandibular, comprimento Maxilar e o posicionamento mandibular com uma serie de estruturas na Base do Crânio. Conclusões: Nossos resultados sugerem que o comprimento mandibular e o posicionamento da fossa mandibular podem estar relacionados com o padrão esquelético do individuo. (AU)
Introduction: The aim of this study was to quantitatively assess 3D anatomy of CB in patients with Class I, II and II skeletal patterns. Material and Methods: This retrospective study sample was composed by CBCT scans of 75 patients. The sample was divided into three groups according to the skeletal pattern: Class I, II and III. The CBCT scans were re-oriented and segmentation was performed. Landmarks were positioned in CB, Mx and Md. 3D models of CB, Mx, and Md were constructed, and linear and angular measurements was performed. Measurements were used to evaluate the CB morphology and correlations on different skeletal patterns. Statistical Analysis: The differences among groups were tested by ANOVA test and correlation was performed by Pearson correlation test. Results: Even without many significant differences between groups, were observed some differences between groups in most of the measure, where Class II and III have a greater distance between them and Class I behaves as an intermediary. Statistically significant differences were observed for 3D position of MF (p 0.05) and mandibular length (p 0.05). Correlation between MD length, Mx and Md positioning with some structures was verified. Conclusions: Our results suggested that de Md length and MF positioning can be related with de patient skeletal pattern. (AU)
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Humanos , Masculino , Femenino , Adulto , Base del Cráneo/anatomía & histología , Tomografía Computarizada de Haz Cónico/normas , Maloclusión , Mandíbula/anatomía & histología , Maxilar/anatomía & histologíaRESUMEN
SUMMARY: The size of intracranial cavity (IC) and posterior cranial fossa (PCF) plays an important role in the pathophysiology of various disorders. In this study, we aimed at establishing normal volume data of the IC and PCF in Turkish population according to age and sex by using stereological method. This study was carried out retrospectively on 339 individuals (168 females and 171 males) between 0 and 18 years old with no medical or neurological disorders that affected the skeletal morphology of the cranial cavity. Volumetric estimations were determined on computed tomography (CT) images using point-counting approach of stereological methods. Intracranial volume (ICV) and posterior cranial fossa volume (PCFV) were increased with age in both sexes. They reached adult dimensions at 5 years of age during the teenage years. According to sex; the mean ICV and PCFV were 1594.51±245.57cm3 and 244.89±53.86 cm3 in males, 1456.34±241.85 cm3 and 228.24±41.38 cm3 in females, respectively. Generally, significant differences were determined in ICV and PCFV according to sex after they reached maximum growth period. According to age the volume ratios of PCF to IC was ranged from 13.03 to 17.48 in males and 12.06 to 18.54 in females. This study demonstrated that these volume ratios could help the physician for both patient selections for surgery, and for the assessment of any surgical technique used to treatment of PCF malformations. However current study revealed that point counting method can produce accurate volume estimations and is effective in determining volume estimation of IC and PCF.
RESUMEN: El tamaño de la cavidad intracraneal (CI) y la fosa craneal posterior (FCP) desempeñan un papel importante en la fisiopatología de diversos trastornos. En este estudio, se pretende establecer los datos de volumen normal de la CI y FCP en la población turca, de acuerdo a la edad y el sexo, mediante el uso de métodos estereológicos. Este estudio se realizó retrospectivamente en 339 individuos (168 mujeres y 171 hombres) entre 0 y 18 años sin trastornos médicos o neurológicos que afectaron la morfología esquelética de la cavidad craneal. Las estimaciones volumétricas se determinaron en imágenes de tomografía computarizada (TC) utilizando el conteo de puntos de los métodos estereológicos. El volumen intracraneal (VIC) y el volumen posterior de la fosa craneal (VFCP) aumentaron con la edad en ambos sexos. Alcanzaron dimensiones adultas a los 5 años de edad durante la adolescencia. Según el sexo, el promedio de VIC y VFCP fue de 1594,51 ± 245,57 cm3 y de 244,89 ± 53,86 cm3 en los hombres, 1456,34 ± 241,85 cm3 y 228,24 ± 41,38 cm3 en las mujeres, respectivamente. En general, se determinaron diferencias significativas en VIC y VFCP de acuerdo con el sexo después de alcanzar el período de crecimiento máximo. Según la edad, las proporciones de volumen de FCP a CI oscilaban entre 13,03 a 17,48 en los hombres y 12,06 a 18,54 en las mujeres. Este estudio demostró que estas proporciones de volumen podrían ayudar al médico tanto en la selección de pacientes para la cirugía, como para la evaluación de cualquier técnica quirúrgica utilizada en el tratamiento de malformaciones de FCP. Además, el estudio actual reveló que el método de conteo de puntos puede producir estimaciones precisas de volumen siendo eficaz para determinar la estimación de volumen de IC y FCP.
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Humanos , Masculino , Femenino , Recién Nacido , Lactante , Preescolar , Niño , Adolescente , Fosa Craneal Posterior/anatomía & histología , Fosa Craneal Posterior/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Distribución por Edad y Sexo , Imagenología Tridimensional , Base del Cráneo/anatomía & histología , Base del Cráneo/diagnóstico por imagen , TurquíaRESUMEN
Perineural spread adenoid cystic carcinoma can alter the dimension of foramina and canals of the skull base. The objective of this study was to determine the range of normal variation of the foramina and canals of both hemicranium. We analyzed 200 individuals with no alterations of the skull base in a retrospective manner using high-resolution computed tomography. We measured the short and long axis diameters of the foramen rotundum (FR), foramen ovale (FO), stylomastoid foramen (SMF), pterygoid canal (PTC), internal auditory canal (IAC), and the facial nerve canal in its labyrinthine portion (LPFC) to calculate the area in each hemicranium, compare them and obtain the normal range of asymmetry. Parametric and non-parametric comparison tests were realized. The structures that had the lowest range of asymmetry were the LPFC (0.00-0.79 mm2) and the FR (0.00-2.12 mm2). The one that had the highest asymmetry range was the FO (0.00-9.16 mm2). Significant differences were found in the FO (p = 0.01) and the IAC (p = 0.00) in the gender comparison. We determined a normal asymmetry range of the susceptible foramina and canals of the skull base. This study reports a useful and objective measure to differentiate anatomical from pathological variations of the foramina and canals of the skull base by age and gender. Our results establish a basis for future studies that evaluate this range as a diagnostic tool of metastasis in the skull base as a complement of other imaging techniques.
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Carcinoma Adenoide Quístico , Nervios Craneales/patología , Neoplasias de la Base del Cráneo , Base del Cráneo , Adulto , Factores de Edad , Carcinoma Adenoide Quístico/diagnóstico , Carcinoma Adenoide Quístico/patología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Estadificación de Neoplasias , Valores de Referencia , Factores Sexuales , Base del Cráneo/anatomía & histología , Base del Cráneo/diagnóstico por imagen , Base del Cráneo/patología , Neoplasias de la Base del Cráneo/diagnóstico , Neoplasias de la Base del Cráneo/patología , Tomografía Computarizada por Rayos X/métodosRESUMEN
Background: Diseases of the orbit represent a surgical challenge, particularly those compromising the orbital apex. Optimal surgical access should provide the best possible exposure, allowing to identify certain key anatomical structures, called landmarks. Objective: Describe the endoscopic anatomy of the structural unit formed by the Inferior Orbital Fissure (IOF) and the Müller's muscle (MM) at the orbital apex (OA), thus generating a new endoscopic anatomical landmark. Materials and methods: A bone-descriptive analysis of the IOF in dry craniums, was followed by dissection and endoscopic study of six heads (twelve sides), colored and fixed in formaldehyde. In ten dry craniums (twenty sides), distances and angles of OA foramina were measured (optic foramen [OF] and foramen rotundum [FR]). Statistical analysis was performed with SPSS 17.0 statistical software (SPSS, Inc. Chicago, IL). Results: The structural unit IOF-MM was identified in all endoscopic dissections, verifying its intimate relationship with the OA. From the morpho-metric standpoint, OF and FR were found at an average distance of 65.19 mm and 60.16 mm, respectively. The average angle of the OF was 13.32 degrees, whereas the one for FR was 19.31 degrees. We found a significant correlation between OF and FR only on the left side (left hemi-crane) (Kendall Tau b 0.69, p=0.006). There were no anatomical or morphological differences between both sides. Conclusion: The unit IOF-MM is a constant anatomical landmark, useful and safe under endoscopic technique, which allows the recognition of the OA and its contiguous areas.
Antecedentes: Las enfermedades que afectan la órbita representan un desafío quirúrgico, en particular las que comprometen el ápex orbitario. Una vía óptima de acceso quirúrgico proporciona la mejor exposición permitiendo identificar ciertas estructuras anatómicas claves llamadas reparos anatómicos Objetivo: Describir la anatomía endoscópica de la unidad estructural Fisura Orbitaria Inferior / Músculo de Müller a nivel del ápex orbitario generando así un nuevo reparo anatómico endoscópico. Material y método: Análisis descriptivo óseo de la fisura orbitaria inferior (FOI) en cráneos secos, disección y estudio bajo técnica endoscópica de 6 cabezas fijadas en formol y coloreadas; finalmente se tomaron distancias y ángulos a forámenes relacionados con el ápex orbitario a 10 cráneos secos. El análisis estadístico se realizó con el programa estadístico SPSS 17,0 (SPSS, Inc., Chicago, IL). Resultado: En todas las disecciones endoscópicas se pudo identificar la unidad fisura orbitaria inferior-músculo de Müller y también verificar su íntima relación con el ápex orbitario. Morfométricamente el foramen óptico y el foramen redondo mayor están a una distancia promedio de 65.19mm y 60.16mm respectivamente. Los ángulos promedio del FO fue de 13.32 grados y del FRM de19.31 grados. Hallamos correlación significativa entre CO. y el FRM sólo en el hemicráneo izquierdo, (Tau b de Kendall 0.69, P=0.006). No se encontraron diferencias anatómicas (o morfológicas) significativas entre lados. Conclusión: bajo técnica endoscópica la unidad Fisura Orbitaria Inferior-Músculo de Müller (FOI-MM) es un reparo anatómico constante, útil y seguro que permite el reconocimiento del ápex orbitario y sus áreas contiguas.