Incidence of basilar invagination in patients with tonsillar herniation ? a case control craniometrical study / Incidência da invaginação basilar com heriação tonsilar ? estudo da craniometria do tipo caso-controle

A retrospective case-control study based on craniometrical evaluation was performed to evaluate the incidence of basilar invagination (BI). Patients with symptomatic tonsillar herniation treated surgically had craniometrical parameters evaluated based on CT scan reconstructions before surgery. BI was diagnosed when the tip of the odontoid trespassed the Chamberlain’s line in three different thresholds found in the literature: 2, 5 or 6.6 mm. In the surgical group (SU), the mean distance of the tip of the odontoid process above the Chamberlain’s line was 12 mm versus 1.2 mm in the control (CO) group (p<0.0001). The number of patients with BI according to the threshold used (2, 5 or 6.6 mm) in the SU group was respectively 19 (95%), 16 (80%) and 15 (75%) and in the CO group it was 15 (37%), 4 (10%) and 2 (5%).

Realizamos estudo retrospectivo tipo caso-controle baseado na avaliação craniométrica para avaliar a incidência da Invaginação Basilar (IB). Pacientes com herniação tonsilar sintomática tratada cirurgicamente foram avaliados quanto a parâmetros craniométricos obtidos em reconstrução de TC antes da cirurgia. IB foi diagnosticada quando a ponta do odontóide passava acima da linha de Chamberlain em 2, 5 ou 6,6 mm. No grupo cirúrgico (CI), a distância média da ponta do odontóide acima da linha de Chamberlain foi de 12 mm versus 1,2 mm no grupo controle (CO) (p<0.0001). O número de pacientes com IB conforme o critério diagnóstico usado (2, 5 ou 6,6 mm) foi de 19 (95%), 16 (80%) e 15 (75%) no grupo CI, respectivamente, contra 15 (37%), 4 (10%) e 2 (5%) no grupo CO. Pacientes com herniação tonsilar tinham maior incidência de IB comparados ao grupo controle.

Cervical vertebral anomalies in skeletal malocclusions: A cross-sectional study on orthodontic patients at the Aga Khan University Hospital, Pakistan.

Introduction: Morphological deviations of the cervical vertebral column have been described in relation to craniofacial aberrations and syndromes. Furthermore, it has recently been shown that abnormal morphology of upper cervical vertebrae is associated with malformation of the jaws and occlusion. Accordingly, it is relevant to focus on similar associations in patients with skeletal malocclusions. Therefore, the objectives of this study are to: • Identify the anomalies of the cervical column in patients with skeletal malocclusions • Determine the association between cervical vertebral anomalies and skeletal malocclusions. Materials and Methods: This cross‑sectional study was conducted on a total of 90 subjects at the Aga Khan University Hospital, Pakistan. The inclusion criteria were: (1) Pakistani origin; (2) standardized pretreatment profile radiograph with first six cervical vertebrae visible; and (3) accessibility of the second‑profile radiograph (mid‑ or posttreatment). The exclusion criteria were: (1) A prior history of orthodontic treatment; (2) any craniofacial anomaly; and (3) systemic muscle or joint disorder. Lateral cephalograms of all subjects (n = 90) were traced by the principal investigator and sagittal jaw relationship was assessed. A total of 30 subjects each with skeletal Class I, Class II, and Class III malocclusions were selected and the cervical vertebral anomalies were observed on their cephalometric radiographs. The frequencies of cervical vertebral anomalies according to skeletal malocclusion categories and gender were analyzed with the Chi‑square test, whereas association of cervical vertebral anomalies with skeletal malocclusions was assessed with logistic regression analysis. The level of significance (P ≤ 0.05) was used for the statistical tests. Results: Most common anomaly observed in the three groups was fusion between C2 and C3 (P = 0.006). This anomaly was found in 20% of subjects with skeletal Class I, 50% of subjects with skeletal Class II and 53.3% with skeletal Class III malocclusions. The highest frequencies of partial cleft at the level of C1 and occipitalization were observed in subjects with skeletal Class II and III malocclusions, respectively. However, none of the subjects showed fusion between C1 and C2 or dehiscence. No statistically significant gender difference was found in the occurrence of morphological deviations of the cervical column. The association of cervical vertebral anomaly was found to be the highest with skeletal Class III and lowest with skeletal Class I malocclusions. Conclusion: Fusion between C2 and C3 seems to be the most commonly occurring anomaly. This anomaly seems to be more often associated with skeletal Class III than skeletal Class I or Class II malocclusions.

Atlanto-occipital fusion and its neurological complications: a case report

During routine activities in the Laboratory of Human Anatomy at the University of Santa Cruz do Sul – Brazil, an atlanto-occipital fusion was observed in a Caucasian cadaver skull. The skull used in our study had complete fusion of the occipital bone with the atlas vertebra, except in traffic areas of the vertebral arteries. Some important neurological disorders seem to be related with atlanto-occipital fusion. The presence of other anatomical variations was not verified. Thus, the present study shall be important for health sciences and those who keep some interest in pathologies associated with brain.

An unusual anatomic variation of the jugular foramen with doubled posterior condylar canal / Una variación anatómica inusual del foramen yugular con canal condilar posterior duplicado

A case of unusual anatomical variation of the jugular foramen (JF) with doubled posterior condylar canal (PCC) is reported. According to the presence of bridging, the JF can be defined as Type I (one septation, two compartments) on the right side and Type IV (three septations, four compartments) on the left side. The dome of the jugular fossa is present on the right, absent on the left. The jugular foramen shows a canal-like structure with an external and an internal opening. The lengths of the longest and widest axes of the JFs are measured as 21.93 x 16.56 mm on the right and 16.75 x 15.14 mm on the left side. The right JF is larger. The PCC is doubled on the right side and there is only one on the left side. It is essential not only to know compartments per se but also to know the structures passing through the compartments, in order to achieve desired surgical outcomes and avoid complications.

Es reportado el caso de una inusual variación anatómica del foramen yugular (FY), con el canal condilar posterior duplicado (CCP). De acuerdo con la presencia de los puentes, el FY se puede definir como Tipo I (una tabicación, dos compartimientos) en el lado derecho y Tipo IV (tres tabiques, cuatro compartimientos) en el lado izquierdo. El domo de la fosa yugular está presente en el lado derecho, y ausente en el izquierdo. El foramen yugular mostró una estructura igual a un canal con una apertura externa y otra interna. Las longitudes de los ejes más largos y anchos de la FY fueron 21,93x16,56mm al lado derecho y 16,75x15,14mm al lado izquierdo. El FY derecho fue más grande. El CCP se observó duplicado en el lado derecho y único en el lado izquierdo. Es esencial no sólo conocer los compartimientos en sí, sino también las estructuras que pasan a través de los compartimientos con el fin de lograr los resultados deseados y evitar las complicaciones quirúrgicas.

Analysis of bone variations of the occipital bone in man / Análisis de las variaciones del hueso occipital en el hombre

Inadequate ossification of the interparietal region induces the appearance of interparietal and wormian bones, also associated with genetic factors. The formation of the interparietal bone depends on the separation of the intermediate segment from the lateral plate by the transverse occipital suture, which means that this bone is formed by the medial and lateral plates. Wormian interparietal bones or epactal bones are located within the interparietal region, being single or multiple, and are located in the upper central region of the interparietal region, the sutural bones, however, are formed from additional ossification centers that can occur in near sutures. The aim of this work was to macroscopically evaluated the presence of changes in the structure of the adult human occipital bone in cadavers found in the human anatomy laboratory of the Goißs Federal University in order to determine the frequency of supernumerary bones associated with occipital and parietal bones and relate it to literature, as well as to provide images and data for ethnic studies in the Brazilian population and data that could help medical practices such as fetal position and radiographs. Our data have indicated that the frequency of the interparietal bone of 1.92 percent is among those seen in countries such as Japan, Bulgaria, Nigeria, India and Turkey, but lower than values found in pre-Hispanics Chileans; however, for the sutural bones, the frequency of this study was higher than other data obtained from Spanish and other Brazilians.

La osificación inadecuada de la región interparietal induce a la aparición de los huesos interparietal y wormiano, asociado también con factores genéticos. La formación del hueso interparietal depende de la separación del segmento intermedio desde la placa lateral por la sutura occipital transversal, lo que significa que este hueso se forma por las placas medial y lateral. Los huesos interparietales wormianos o hueso epactal se encuentram dentro de la región interparietal, siendo únicos o múltiples, y se localizan en la región central superior de la zona interparietal. Los huesos suturales, sin embargo, se forman de centros de osificación adicionales que pueden aparece cerca de estas suturas. El objetivo de este trabajo, fue evaluar macroscópicamente la presencia de variaciones en la estructura del hueso occipital en cadáveres humanos, adultos encontrados en el Laboratorio de Anatomía Humana de la Universidad Federal de Goiás, con la finalidad de determinar la frecuencia de los huesos supernumerarios asociados con los huesos parietal y occipital. Además, comparamos estos datos con los descritos enla literatura y, aportamos imágenes y datos para estudios étnicos en la población Brasileña. Estos datos pueden ayudar en las prácticas médicas como la posición fetal y radiografías. Nuestros datos indicaron que la frecuencia del hueso interparietal fue de 1,92 por ciento y se encuentra en países como Japón, Bulgaria, Nigeria, India y Turquía, pero inferior a los valores encontrados en chilenos prehispánicos. Sin embargo, para los huesos suturales, la frecuencia de este estudio fue superior a otros datos obtenidos de españoles y otros estudios realizados en individuos brasileños.

Unusual occipital condyles of the skull: an osteological study with clinical implications

CONTEXT: The occipital condyles of the skull articulate with the superior articular facets of the atlas vertebra and form an important junction between the cranium and the vertebral column. The morphological features of occipital condyles are relevant in biomechanical, anatomical and clinical studies. OBJECTIVE: To describe the anatomical profile of unusual occipital condyles detected in a bone specimen. CASE REPORT: The present osteological study provides a detailed morphological description of unusual occipital condyles showing uneven and serrated surfaces and also displaying longitudinal and transverse grooves on the left and right sides respectively. The case study also discusses the clinical importance of such anomalies. Precise anatomical knowledge of the occipital condyles is important for any craniovertebral operative procedures such as resection of the occipital condyles.

CONTEXTO: Os côndilos occipitais do crânio se articulam com as facetas superiores da vértebra atlas e formam uma importante junção entre o crânio e a coluna vertebral. As características morfológicas dos côndilos occipitais são relevantes em estudos biomecânicos, anatômicos e clínicos. OBJETIVO: Descrever o perfil anatômico de côndilos occipitais incomuns observados em uma amostra óssea cadavérica. RELATO DE CASO: O estudo osteológico aqui apresentado mostra a detalhada descrição morfológica de côndilos occipitais incomuns com superfícies desproporcionais e serradas, e também com sulcos longitudinais e transversais à esquerda e à direita, respectivamente. O estudo do caso também discute a importância clínica dessas anomalias. O conhecimento anatômico preciso dos côndilos occipitais é importante para qualquer procedimento cirúrgico como, por exemplo, a ressecção de côndilos occipitais.

Tripartite Os Inca: an embryological and morphological study

Inca bone [Os Inca] or os interparietale is an interesting developmental cranial variation. It is the portion of the squamous part of the occipital bone that lies superior to the highest nuchal line when this portion remains separate throughout life. In one hundred and ten human adult skulls examined in this study an Inca bone was found in only one specimen; it was tripartite. In this presentation the embryological background and morphological features of this anomaly are discussed

Paracondylar foramen--a new anomalous aperture of the occipital bone.

A new anomalous apperture has been identified by the author in association with the occipital bone. It was situated in the interval between the jugular fossa and the occipital condyles. Out of 118 skull bases examined four instances of this anomalous apperture were found (2 complete and 2 incomplete). The author speculates that they may transmitting the posterior condylar emissary vein in the absence of the condylar canal or in its abrrent course to the jugular foramen. In view of its topographical location the author proposes the name--'Paracondylar foramen' to this anomalous apperture.

Mri in basilar invagination

Basilar Invagination has been described in association with many medical conditions which could be either congenital or acquired. Previously, this condition was diagnosed using plain X-ray of the skull utilising difficult-to-apply criteria. Brain CT-scan was also used with some difficulties and limitations. In this paper we describe four different cases of basilar invagination. The role of MRl in its diagnosis is discussed