Análisis de la Distancia entre Hueso Occipital y Atlas en Telerradiografía Lateral de Cráneo / Analysis of the Distance Between the Occipital Bone and Atlas in Lateral Cephalograms

El conocimiento del espacio suboccipital (OA) es esencial para el clínico debido a que su disminución se asocia a posible causa de cefaleas. El objetivo de este estudio fue determinar las diferencias entre la longitud del espacio suboccipital en telerradiografías laterales entre hombres y mujeres de distintos rangos etarios. En este estudio transversal se analizaron un total de 371 telerradiografías laterales de cráneo. Se realizó estadística descriptiva y la aplicación de prueba T-Student y ANOVA para evaluar la asociación entre el espacio suboccipital con el género y la edad. La distancia media del espacio suboccipital fue de 5.62 ± 2.7 mm, siendo mayor en hombres que en mujeres (6.49 ± 2.8 mm y 5.09 ± 2.5 mm respectivamente, p<0.001). Con respecto a la edad, la distancia del espacio suboccipital no presentó variaciones significativas. La longitud del OA entre los hombres y mujeres de distintos grupos tampoco mostró diferencias significativas. Existe una gran variabilidad en la distancia del espacio suboccipital, el cual se observa más disminuido en mujeres, por lo que se sugiere un análisis individual mediante telerradiografía lateral frente a pacientes con cefaleas.

SUMMARY: Knowledge of the suboccipital space (OA) is essential for clinicians because its decrease is associated with headache. The aim of this study was to determine the differences in the length of the suboccipital space in lateral cephalograms of men and women of different age ranges. In this cross-sectional study, a total of 371 lateral cephalograms were analyzed. Descriptive statistics and the application of Student's t-test and ANOVA were performed to evaluate the association between the suboccipital space with sex and age. The mean distance of the suboccipital space was of 5.62 ± 2.7 mm, being higher in men than women (6.49 ± 2.8 mm and 5.09 ± 2.5 mm respectively, p < 0.001). Regarding age, the distance of the suboccipital space did not show significant variations. The length of the OA between men and women of different age groups also showed no significant differences. There is a great variability in the distance of the suboccipital space, which is observed to be more decreased in women; therefore, an individual analysis by lateral cephalograms is suggested in patients with chronic headaches.

Frecuencia de Ponticulus posticus en Telerradiografías Laterales de Cráneo / Frequency of Ponticulus posticus in Digital Lateral Cephalograms

En el arco posterior del atlas se describe una variación de tejido óseo denominada Ponticulus posticus (PP), la cual se ha relacionado con el desarrollo de dolor cervical. El objetivo de este estudio fue determinar la frecuencia de PP en telerradiografías laterales digitales. Este estudio correspondió a un estudio observacional descriptivo, donde se analizaron 450 telerradiografías laterales digitales obtenidas de la base de datos del Servicio de Imagenología Oral y Maxilofacial de la Facultad de Odontología de la Universidad Andrés Bello, Viña del Mar, Chile. Se analizó la presencia de PP en cada cefalograma, y se utilizó la clasificación de Cederberg y Stubbs para determinar los grados de osificación. Se aplicó la prueba de Chi-cuadrado para establecer una asociación entre la presencia de PP con el sexo y la edad. De las 450 telerradiografías laterales el 42,4 % presenta PP, con una mayor prevalencia entre el rango de 21-40 años. En cuanto al grado de osificación, el grado 2 fue el tipo más prevalente (25 %), seguido del grado 4 (9,5 %), el grado 3 (8 %). No se encontró asociación entre la presencia de PP con edad y género (P > 0,05). La PP es frecuente en la población y se observa a diferentes edades sin predilección por sexo.

SUMMARY: A bony tissue variation called Ponticulus posticus (PP) is described in the posterior arch of the atlas, which has been associated with the development of cervical pain. The aim of this study was to determine the frequency of PP in digital lateral cephalograms. This study was an observational descriptive study, in which 450 digital lateral cephalograms obtained from the database of the Oral and Maxillofacial Imaging Service of the Faculty of Dentistry of the Andrés Bello University, Viña del Mar, Chile, were analyzed. The presence of PP was analyzed in each cephalogram, and the Cederberg and Stubbs classification was used to determine the degrees of ossification. The Chi-square test was applied to establish an association between the presence of PP with gender and age. Of the 450 lateral cephalograms, 42.4 % presented PP, with a higher prevalence in the 21-40 year range. In terms of the degree of ossification, grade 2 was the most prevalent type (25 %), followed by grade 4 (9.5 %), and grade 3 (8 %). No association was found between the presence of PP with age and gender (P > 0.05). PP is common in the population and is observed at different ages without a sex preference.

Estudio morfológico de pontículus pósticus en telerradiografías laterales / Morphological study of pontículus pósticus in lateral teleradiographies

OBJETIVO establecer la prevalencia de Pontículus Pósticus (PP) en pacientes atendidos en el Servicio de Imagenología de la Universidad Finis Terrae en el periodo 2015-2020. METODOLOGÍA estudio de tipo transversal descriptivo, donde se analizaron 334 telerradiografías laterales (TL) obtenidas del Servicio de Imagenología de la Universidad Finis Terrae entre los años 2015 y 2019 adquiridas mediante el equipo marca SIRONA modelo Orthophos XG, seleccionándolas según criterios de inclusión y exclusión. Se analizó la primera vértebra cervical buscando la presencia de PP consignando: sexo, edad y tipo de osificación según clasificación de Cederberg y Stubbs, asignándoles valores numéricos para posteriormente realizar el análisis estadístico de tipo descriptivo uni y bivariado. RESULTADOS se seleccionaron 320 TL. La prevalencia de PP fue del 31,9% de las TL incluidas, de los cuales el 68,1% correspondió al tipo 1 de la clasificación de Cederberg y Stubbs, el 14,1% al tipo 2, 10,3% al tipo 4 y el 7,5% al tipo 3. La edad media en pacientes con PP presente correspondió a 30,63 años +/­ 15,888 D.E con un mínimo de 12 años y un máximo de 78. En cuanto a la presencia de PP y la variable sexo, el 53,9% correspondió al sexo femenino y el 46,1% al sexo masculino, en donde no se encontró una predilección estadísticamente significativa (p = 0,08). CONCLUSIONES el PP es una variante anatómica de prevalencia variada, siendo levemente mayor en esta población chilena en comparación con otros países. Además, su evidencia es escasa y no existe un consenso sobre su prevalencia y diversas variables como el género y la edad, difiriendo en varios estudios. Es importante conocer e investigar más sobre la epidemiología de esta anomalía y su relación con distintos desórdenes neurológicos

OBJETIVE to establish the prevalence of Ponticulus Posticus (PP) in patients attended in Radiology Service of Finis Terrae University between the years 2015 and 2020. METHODOLOGY descriptive cross-sectional study, 334 lateral cephalograms were analyzed obtained from the Radiology Service of Finis Terrae University between the years 2015 and 2020 acquired from SIRONA system model Orthophos XG, selecting them following the inclusion and exclusion criteria. The first cervical vertebrae were analyzed searching for the presence of PP, consigning: Type of ossification by Cederberg and Stubbs classification, Age and Sex, assigning them numerical values to subsequently perform the descriptive statistical analysis uni and bivariate. RESULTS the prevalence of PP found was 31,9% of the 320 included TL, of which 68,1% corresponded to Type 0 of Cederberg and Stubbs classification, 14,1% to Type 1, 10,3% to Type 3 and the 7,5% al Type 2. The average age of present PP patient's was 30,63 years +­ 15,888 S.D with a minimum of 12 years and a maximum de 78. As for the presence of PP and sex variable, 53,9% corresponded to female sex and 46,1% to males, where no statistically significant predilection was found (p = 0,08). CONCLUSIONS PP is an anatomical variant with varied prevalence worldwide, being slightly higher in Chile, compared to other countries. In addition, their evidence is scarce and there is no consensus on its prevalence and various variables such as gender and age, differing in several studies. It is important to know and research more about the epidemiology of this anomaly and its relationship with different neurological disorder

Symptomatic Atlas Hypoplasia in a Latin-American Patient: Case Report and Literature Review.

BACKGROUND: Atlas hypoplasia is an infrequent cause of upper cervical stenosis. Only 24 cases in nonsyndromic adult population have been published. We are not aware of previous reports describing isolated fully formed atlas hypoplasia in a Latin-American patient. The purpose of this work was to report a case of an 80-year-old Argentinian woman with cervical myelopathy because of atlas hypoplasia and a literature review about this subject. METHODS: A clinical case and an extended review of the literature are presented. We assessed from each case: age, sex, posterior atlanto-dens interval, surgical treatment, outcomes, and follow-up period. RESULTS: Neurologic symptoms markedly improved after posterior decompression from severe to moderate in the Japanese Orthopaedic Association Scoring System and from four to three on the Nurick scale. Twenty-five patients were analyzed (mean 58.4 years, 32% female). The mean posterior atlanto-dens interval was 8.8 mm. Twenty-three patients underwent decompression alone, and two needed posterior fusion. All patients reported clinical improvement at an average follow-up of 13 months. CONCLUSION: Cervical myelopathy caused by fully formed atlas hypoplasia is not an exclusive pathology of far east population, and it may present in nonsyndromic patients. Surgical treatment by C1 laminectomy improved neurologic impairment. STUDY DESIGN: Case report and literature review.

Rare anatomic variation on a 10,000-year-old South American skeleton: the case of Iuzu, Toca dos Coqueiros, Piauí State, Brazil.

PURPOSE: A skeleton named Iuzu has been unearthed from an exceptional middle Holocene burial in Toca dos Coqueiros site, in Serra da Capivara National Park (UNESCO World Heritage Site, Piauí State, Brazil). During a bioarchaeological analysis of its remains, we discovered that Iuzu was suffering from rare vertebral malformations. A double foramen transversaria, the agenesis of a foramen on the atlas and the hypoplasia of the transverse process of the axis have been highlighted. We aimed to deduce the clinical consequences of the malformation on the patient's health. METHODS: We proceeded to macroscopic observation and radiography of the bones, then we search for other examples of such a pathology in archaeological litterature. RESULT: The malformation caused vascular insufficiency that may have led to neurological lesions leading to various pains and troubles. The very rare malformations Iuzu presented have not been found on a paleoindian skeleton from South America so far. CONCLUSION: This case allowed us to examine the conditions of selection of individuals buried in southern Piauí during the Middle Holocene, during which time this rite does not seem to predominate.

A micro-CT study of different regions of the atlas / Un estudio de micro-CT de diferentes regiones del atlas

This study aimed to examine the differences in bone microarchitecture between different regions of the atlas in 28 dry atlas specimens using micro-CT, in order to explain the mechanism of the predilection sites of atlas fractures from the morphological point of view. A total of 28 dry specimens of intact adult atlas were randomly selected, scanned by micro-CT, and divided into a region from the anterior arch midpoint (AAM) to the lateral masses (LM), a LM region, and a region from the LM to the posterior arch midpoint (PAM). Trabecular thickness, separation, number, connectivity, and structure model index were measured for each of the three regions using the built-in software of the CT scanner. Trabecular thickness was all measured to be 0.11 ± 0.00 mm for AAM to LM, LM, and LM to PAM. Trabecular separation: AAM to LM > LM to PAM > LM. Trabecular number: LM > LM to PAM > AAM to LM. Connectivity: LM > LM to PAM > AAM to LM. Structure model index: LM > LM to PAM > AAM to LM. A lower trabecular number and connectivity and higher trabecular separation were seen in the anterior and posterior arches of the atlas, in which higher fracture rates were reported. By contrast, a higher trabecular number and connectivity and lower trabecular separation were seen in the lateral masses, in which lower fracture rates were reported.

Este estudio tuvo como objetivo examinar las diferencias en la microarquitectura ósea entre diferentes regiones del atlas en 28 muestras de atlas secas utilizando micro-CT, con el fin de informar el área de mayor frecuencia en las fracturas de atlas, desde el punto de vista morfológico. Se seleccionaron al azar un total de 28 muestras secas de atlas adultos intactas las que se escanearon por micro-CT y se dividieron en una región desde el punto medio del arco anterior (MAA) hasta las masas laterales (ML), una región ML y una región desde el ML hasta el punto medio del arco posterior (MAP). Se midió el grosor trabecular, la separación, el número, la conectividad y el índice del modelo de estructura para cada una de las tres regiones utilizando el software incorporado del escáner CT. El grosor trabecular se midió en 0,11 ± 0,00 mm para MAA a ML, ML y ML a MAP. Separación trabecular: MAA a ML> ML a MAP> ML. Número trabecular: ML> ML a MAP> MAA a ML. Conectividad: ML> ML a MAP> MAA a ML. Índice del modelo de estructura: ML> ML a MAP> MAA a ML. Se observó un menor número de estructuras trabeculares y conectividad y una mayor separación trabecular en los arcos anterior y posterior del atlas, en los que se informaron tasas de fracturas más altas. Por el contrario, se observó un mayor número de estructuras trabeculares y conectividad, y una menor separación trabecular en las masas laterales, en las que se observó un número menor de fracturas.

Cervical posture analysis in dental students and its correlation with temporomandibular disorder.

OBJECTIVE: To evaluate the relationship between temporomandibular disorders (TMD) and craniocervical posture in the sagittal plane measured from lateral radiographs of the head. METHODS: The sample was comprised of 80 randomly selected students of dentistry at the Federal University of Rio Grande do Norte. Research Diagnostic Criteria for TMD (RDC/TMD) was used to evaluate the signs and symptoms of TMD. Lateral radiographs of each individual were used to measure the position of the hyoid bone, the craniocervical angle, and the occiput-atlas distance. A chi-square test was used to evaluate the relationships between craniocervical posture measures and TMD. RESULTS: No relationship was found between TMD and the craniocervical posture measured by the positioning of the hyoid bone, head rotation, and the extension/flexion of the head (p > 0.05). CONCLUSION: It can be concluded, therefore, that no relationship exists between cervical posture in the sagittal plane and TMD.

Investigation of the relationship between "sella turcica bridge" and "ponticulus posticus": a lateral cephalometric study / Investigación sobre la relación entre "puente silla turca" y "ponticulus posticus": un estudio cefalométrico lateral

The ponticulus posticus (PP) is a bridge of bone sometimes found on the atlas vertebra surrounding the vertebral artery and the first cervical nerve root. Sella turcica bridging (STB) is the fusion of anterior and posterior clinoid processes. The objective of this study was to find out the association between STB and PP. For the study, 752 digital lateral cephalograms were retrieved from the archived records of Necmettin Erbakan University, Faculty of Dentistry, Konya, Turkey. There was a significant relationship between the presence of STB and PP (p=0.000, p<0.001). This study indicates that there is a significant correlation between the presence of STB and PP.

El Ponticulus Posticus (PP) es un puente de hueso que se encuentra, a veces, en el atlas y rodea la arteria vertebral y la primera raíz del nervio cervical. El puente de la silla turca (PST) es la fusión de los procesos clinoides anteriores y posteriores. El objetivo de este estudio fue conocer la asociación entre PST y PP. Para el estudio, fueron utilizados 752 cefalogramas digitales laterales, obtenidos de los registros archivados de la Facultad de Odontología de la Universidad Necmettin Erbakan, Konya, Turquía. Hubo una relación significativa entre la presencia de PST y PP (p = 0,000, p <0,001). Este estudio indica que existe una correlación significativa entre la presencia de PST y PP.

Arterial variations around the atlas: a comprehensive review for avoiding neurosurgical complications.

INTRODUCTION: Neurosurgical approaches often involve the atlas. Therefore, the arterial relationships and anatomical variations are of paramount importance to the neurosurgeon. METHODS: Using standard search engines, a literature review of arterial variants near the first cervical vertebra was performed. CONCLUSIONS: Arterial variations around the atlas are surgically significant. Awareness of their existence and course may provide better pre-operative planning and surgical intervention, potentially leading to better clinical outcomes. Three-dimensional computed tomography angiography (3D CTA) is an important tool for identifying and diagnosing such abnormalities and should be used when such vascular anomalies are suspected.

Atlas Assimilation Patterns in Different Types of Adult Craniocervical Junction Malformations.

STUDY DESIGN: This is a cross-sectional analysis of resonance magnetic images of 111 patients with craniocervical malformations and those of normal subjects. OBJECTIVE: To test the hypothesis that atlas assimilation is associated with basilar invagination (BI) and atlas's anterior arch assimilation is associated with craniocervical instability and type I BI. SUMMARY OF BACKGROUND DATA: Atlas assimilation is the most common malformation in the craniocervical junction. This condition has been associated with craniocervical instability and BI in isolated cases. METHODS: We evaluated midline Magnetic Resonance Images (MRIs) (and/or CT scans) from patients with craniocervical junction malformation and normal subjects. The patients were separated into 3 groups: Chiari type I malformation, BI type I, and type II. The atlas assimilations were classified according to their embryological origins as follows: posterior, anterior, and both arches assimilation. RESULTS: We studied the craniometric values of 111 subjects, 78 with craniocervical junction malformation and 33 without malformations. Of the 78 malformations, 51 patients had Chiari type I and 27 had BI, of whom 10 presented with type I and 17 with type II BI. In the Chiari group, 41 showed no assimilation of the atlas. In the type I BI group, all patients presented with anterior arch assimilation, either in isolation or associated with assimilation of the posterior arch. 63% of the patients with type II BI presented with posterior arch assimilation, either in isolation or associated with anterior arch assimilation. In the control group, no patients had atlas assimilation. CONCLUSION: Anterior atlas assimilation leads to type I BI. Posterior atlas assimilation more frequently leads to type II BI. Separation in terms of anterior versus posterior atlas assimilation reflects a more accurate understanding of the clinical and embryological differences in craniocervical junction malformations. LEVEL OF EVIDENCE: N/A.

Lateral mass screw fixation of the atlas: surgical technique and anatomy.

The use of lateral mass atlas screws is an important technique to achieve fusion and stability at the craniocervical region affected by different pathologies (degenerative, traumatic, inflammatory, neoplastic, or congenital). This paper describes the anatomy and techniques necessary for proper insertion of posterior C1 lateral mass screws, using anatomic dissection and intraoperative pictures. Knowledge of the anatomy and the surgical technique of insertion of C1 lateral mass screws are of paramount importance to have good surgical results.

Agenesis of the posterior arch of the atlas.

PURPOSE: To illustrate the radiological findings and review the current literature concerning a rare congenital abnormality of the posterior arch of the atlas. CASE REPORT: An adult female without neurological symptoms presented with an absent posterior arch of the atlas, examined with plain films and helical computerized tomography. Complete agenesis of the posterior arch of the atlas is a rare entity that can be easily identified by means of plain films. Although it is generally asymptomatic, atlantoaxial instability and neurological deficits may occur because of structural instability. Computerized tomography provides a means of assessing the extent of this abnormality and can help evaluate the integrity of neural structures. Although considered to be rare entities, defects of the posterior arch of the atlas may be discovered as incidental asymptomatic findings in routine cervical radiographs. Familiarity with this abnormality may aid medical professionals in the correct management of these cases.