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.

Study of Incidence of Ponticulus Posterior In Dry Human Atlas Vertebra and Its Clinical Significance

Background: Atlas is the first cervical vertebra. The vertebral artery lies in the groove on posterior arch of the atlas. The vertebral artery groove may sometimes get converted into a foramen. This is commonly known as ponticulus posterior (ponticulus posticus) or arcuate foramen of the atlas. These foramina may be complete or incomplete. This can lead to compression of the vertebral artery and produce symptoms like headache, syncope, altered consciousness etc. It can also complicate manipulations of the cervical spine by reducing the blood flow during extreme rotations of head and neck. It is also associated with vertebrobasilar artery stroke So, neurosurgeons or orthopaedic surgeons who operate in this area should have a detailed knowledge of variations of groove for the vertebral artery. Materials and Methods: The present study was conducted on 50 dried and fully ossified adult human atlas of unknown age and sex collected from the department of Anatomy, Government Medical college, Nagpur. Each atlas vertebra was carefully observed for the presence or absence of complete or incomplete ponticuli on superior surface of posterior arch of atlas. Results: Out of the 50 vertebra studied 7(14%) showed the presence of Ponticuli. Ponticuli were incomplete in all 7 atlas vertebras. Complete ring was not observed in any of the atlas vertebra .Out of the 7 ponticuli 6(12%) were found to be unilateral and in only 1 (2%) case it was found to be bilateral. Out of the 6 ponticuli 4(8%) were noticed on the Left side and 2(4%) were present on the right side. Conclusion: Presence of incomplete ponticulus posterior might cause cervical pain and even cerebrovascular disorders due to pressure on third part of vertebral artery present in the vertebral artery groove. This anatomical knowledge is important for neurosurgeons, orthopaedic surgeons, radiologists and clinicians while dealing with this region.

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

Evaluación del ponticulus posticus según la relación esquelética en radiografías laterales estrictas / Evaluation of ponticulus posticus according to the skeletal relationship found in strict lateral radiographs

RESUMEN Objetivo: Evaluar el ponticulus posticus según la relación esquelética encontrada en radiografías laterales estrictas en la Centro Dental Docente de la Universidad Peruana Cayetano Heredia durante el período 2015-2017, utilizando la clasificación de acuerdo al grado de mineralización descrita por Selby y la clasificación de la relación esquelética de Steiner. Material y Métodos: Se realizó en radiografías laterales estrictas digitales usando una pantalla de 20 pulgadas utilizando el programa SIDEXIS XG, observando el grado de mineralización del ponticulus posticus: sin evidencia de la espícula ósea sobre la arteria vertebral = puente ausente, cuando se notaba o evidenciaba la formación de la espícula y/o calcificación en medio del puente o en forma incompleta = puente parcial, cuando el arco óseo estaba evidente terminado visualizándose = puente completo y la clasificación de la relación esquelética midiendo el ángulo ANB: Clase I = 0-4°; Clase II = >4° y Clase III = <0°: el análisis estadístico se hizo con el programa SPSS V.22.0 para Windows mediante las pruebas de Chi2. Resultados : De las 925 radiografías laterales estrictas digitales evaluadas se encontró que 283 radiografías presentaron ponticulus posticus y la mayor frecuencia se encontró en el tipo ausente (69,4%), el tipo parcial (17,1%) y el tipo completa (13.5%). El ponticulus posticus se presentó en 25.1% del sexo femenino y en 38.4% en el sexo masculino. La relación esquelética asociada al ponticulus posticus se presentó en la Clase II (19.1%), Clase I (10,4%) y Clase III (1.1%), Conclusiones : El ponticulus posticus es una variante anatómica que se presenta en el 30,6% de los casos. No se encontró diferencia estadísticamente significativa entre la presencia de ponticulus posticus y la relación esquelética o sexo.

SUMMARY Objective: To evaluate the posticus ponticulus according to the skeletal relationship found in strict lateral radiographs at the Teaching Dental Center of the Cayetano Heredia Peruvian University during the period 2015-2017, using the classification according to the degree of mineralization described by Selby and the classification of the Steiner's skeletal relationship. Material and Methods: It was performed on strict digital lateral radiographs using a 20-inch screen using the SIDEXIS XG program, observing the degree of mineralization of ponticulus posticus: no evidence of the bone spicule on the vertebral artery = absent bridge, when it was noted or evidenced the formation of the spicule and / or calcification in the middle of the bridge or in incomplete form = partial bridge, when the bone arch was clearly finished visualizing = full bridge and the classification of the skeletal relationship by measuring the ANB angle: Class I = 0- 4th; Class II => 4th and Class III = <0 °: the statistical analysis was done with the SPSS V.22.0 program for Windows using the Chi2 tests. Results: Of the 925 digital strict lateral radiographs evaluated, it was found that 283 radiographs presented ponticulus posticus and the highest frequency was found in the absent type (69.4%), the partial type (17.1%) and the complete type (13.5 %). Ponticulus posticus occurred in 25.1% of the female sex and in 38.4% of the male sex. The skeletal relationship associated with ponticulus posticus was presented in Class II (19.1%), Class I (10.4%) and Class III (1.1%). Conclusions: Ponticulus posticus is an anatomical variant that occurs in 30.6% of the cases. No statistically significant difference was found between the presence of ponticulus posticus and the skeletal relationship or sex.

Endoscopic evaluation of middle ear anatomic variations in autopsy series: analyses of 204 ears / Avaliação endoscópica das variações anatômicas da orelha média em uma série de autópsias: análise de 204 orelhas

Abstract Introduction Microsurgery of the ear requires complete evaluation of middle ear surgical anatomy, especially the posterior tympanic cavity anatomy. Preoperative assessment of the middle ear cavity is limited by the permeability of eardrum and temporal bone density. Therefore, middle ear exploration is an extremely useful method to identify structural abnormalities and anatomical variations. Objective The aim of this study is to determine anatomic variations of the middle ear in an autopsy series. Methods All evaluations were performed in the Forensic Medicine Institute Morgue Department. The cases over 18 years of age, with no temporal bone trauma and history of otologic surgery included in this study. Results One hundred and two cadavers were included in the study. The mean age was 49.08 ± 17.76 years. Anterior wall prominence of the external auditory canal was present in 27 of all cadavers (26.4%). The tympanic membrane was normal in 192 ears (94%) while several eardrum pathologies were detected in 12 ears (6%). Agenesis of the pyramidal eminence and stapedial tendon was found in 3 ears. While the ponticulus was bony ridge-shaped in 156 of 204 ears (76.4%), it was bridge-shaped in 25 ears (12.3%). The ponticulus was absent in 23 ears (11.3%). While complete subiculum was present in 136 of all ears (66.7%), incomplete subiculum was present in 21 ears (10.3%). Subiculum was absent in 47 ears (23%). Facial dehiscence was found in 32 ears and the round window niche was covered by a pseudomembrane in 85 ears (41.6%). A fixed footplate was present in 7.4% of all ears, and no persistent stapedial artery was seen in any cases. Conclusion The pseudomembrane frequency covering the round window niche was found different from reports in the literature. In addition, the frequency of the external auditory canal wall prominence has been reported for the first time.

Resumo Introdução A otomicrocirurgia requer avaliação completa da anatomia cirúrgica da orelha média, especialmente da anatomia da cavidade timpânica posterior. A avaliação pré-operatória da cavidade timpânica é limitada pela permeabilidade do tímpano e densidade do osso temporal. Portanto, a exploração da orelha média é um método extremamente útil para identificar anormalidades estruturais e variações anatômicas. Objetivo Determinar as variações anatômicas da orelha média em uma série de autópsias. Método Todas as avaliações foram realizadas no necrotério do Instituto Médico-Legal. Os casos com mais de 18 anos, sem trauma do osso temporal e história de cirurgia otológica foram incluídos neste estudo. Resultados Cento e dois cadáveres foram incluídos no estudo. A média de idade foi de 49,08 ± 17,76 anos. A proeminência da parede anterior do conduto auditivo externo estava presente em 27 de todos os cadáveres (26,4%). A membrana timpânica era normal em 192 orelhas (94%), enquanto várias alterações do tímpano foram detectadas em 12 orelhas (6%). Agenesia da eminência piramidal e do tendão do estapédio foi encontrada em 3 orelhas. Enquanto o pontículo tinha formato de crista óssea em 156 das 204 orelhas (76,4%), tinha o formato de ponte em 25 orelhas (12,3%). O pontículo estava ausente em 23 orelhas (11,3%). Enquanto o subículo completo estava presente em 136 de todas as orelhas (66,7%), encontrava-se incompleto em 21 orelhas (10,3%). O subículo estava ausente em 47 orelhas (23%). Deiscência facial foi encontrada em 32 orelhas e o nicho da janela redonda estava coberto por uma pseudomembrana em 85 orelhas (41,6%). A platina fixa foi observada em 7,4% de todas as orelhas e a artéria estapediana persistente não foi vista. Conclusão A frequência da pseudomembrana que cobre o nicho da janela redonda foi diferente daquela encontrada na literatura. Além disso, a frequência da proeminência da parede do canal auditivo externo foi relatada pela primeira vez.

Morphological Study Of Ponticuli In Adult Human Atlas Vertebrae

Introduction: The atlas, the first cervical vertebra, supports the head. It is unique in that it fails to incorporate acentrum. Because it supports the skull, it was named after Atlas who, according to Greek mythology, supportedthe earth on his shoulders. Frequently bony spurs arise from the anterior and posterior margins of the groove forthe vertebral artery. These are sometimes referred to as Ponticles, and they occasionally convert the groove intoa foramen. More often the foramen is incomplete superiorly. Arcuate foramen also known as ponticulus posticus(Latin for “little posterior bridge”).Aims and Objectives: To study the proportion and various types of ponticuli.Materials and methods: Present study was conducted on 100 adult human atlas vertebrae, collected from thedepartment of Anatomy, Mysore Medical College and Research Institute, Mysuru.Observations and Results: Out of 100 atlas vertebrae examined, 20 atlas vertebrae showed ponticuli of varioustypes. 27 Ponticuli was observed in twenty (20) atlas vertebra as follows: a) Ponticulus posticus -15. b) Ponticuluslateralis -07. c) Ponticulus posterolateral -05. d) Complete Ponticulus -11. e) Incomplete Ponticulus -16.e) Bilateral Ponticulus -07. f) Unilateral Ponticulus -13. g) Right side -17 and Left side -10.Conclusion: Proper identification of this anomaly on preoperative lateral radiographs should alert the surgeonto avoid using the ponticulus as a starting point for a lateral mass screw in order to not injure the vertebralartery. It is also useful to surgeons who face regularly the patients complaining about the symptoms ofvertebrobasilar insufficiency like headache, vertigo, migraine.

The C2 Pedicle Width, Pars Length, and Laminar Thickness in Concurrent Ipsilateral Ponticulus Posticus and High-Riding Vertebral Artery: A Radiological Computed Tomography Scan-Based Study

STUDY DESIGN: Retrospective radiological study. PURPOSE: We aimed to determine the prevalence of ponticulus posticus (PP) and high-riding vertebral artery (HRVA) occurring simultaneously on the same side (PP+HRVA) and in cases of PP+HRVA, to assess C2 radio-anatomical measurements for C2 pars length, pedicle width, and laminar thickness. OVERVIEW OF LITERATURE: PP and HRVA predispose individuals to vertebral artery injuries during atlantoaxial fixation. In cases of PP+HRVA, the construct options thus become limited. METHODS: Consecutive computed tomography scans (n=210) were reviewed for PP and HRVA (defined as an internal height of <2 mm and an isthmus height of <5 mm). In scans with PP+HRVA, we measured the ipsilateral pedicle width, pars length, and laminar thickness and compared them with controls (those without PP or HRVA). RESULTS: PP was present in 14.76% and HRVA in 20% of scans. Of the 420 sides in 210 scans, PP+HRVA was present on 13 sides (seven right and six left). In scans with PP+HRVA, the C2 pars length was shorter compared with controls (13.69 mm in PP+HRVA vs. 20.65 mm in controls, p<0.001). The mean C2 pedicle width was 2.53 mm in scans with PP+HRVA vs. 5.83 mm in controls (p<0.001). The mean laminar thickness was 4.92 and 5.48 mm in scans with PP+HRVA and controls, respectively (p=0.209). CONCLUSIONS: The prevalence of PP+HRVA was approximately 3% in the present study. Our data suggest that, in such situations, C2 pedicle width and pars length create important safety limitations for a proposed screw, whereas the translaminar thickness appears safe for a proposed screw.

Associação entre ponticulus, cefaleia primária e disfunção temporomandibular / Association among pontículos posticus, primary headches and temporomandibular dysfunction

Na primeira vértebra cervical (atlas) pode existir uma alteração anatômica caracterizada por um arco ósseo e diagnosticada por imagens radiográficas, chamada de Ponticulus Posticus (PP) e pode estar relacionada a cefaleias primárias e outras dores orofaciais. Objetivo: O objetivo deste estudo foi avaliar a associação entre PP, cefaleias primárias, disfunções temporomandibulares (DTMs) e maloclusão. Métodos: Todos pacientes foram voluntários e já possuíam documentação ortodôntica com telerradiografia odontológica e passaram antes das manutenções ortodônticas pelos questionários de Diagnóstico das Desordens Temporomandibulares (RDC/DTM) na versão em português, questionário clínico baseado nos critérios da CIC-2 (Classificação Internacional de Cefaleias) e exame clínico para avaliação das maloclusões. Todos os dados utilizados neste estudo foram coletados a partir destes documentos. As variáveis incluídas neste estudo foram: idade, tempo de tratamento, prevalência da maloclusão (quantitativas); gênero, tipo de disfunção temporomandibular (DTM), cefaleia primária e PP (qualitativas). Os dados foram organizados em uma planilha do programa SPSS 15.0, a relação entre as variáveis foram analisadas por meio de um modelo de regressão binária e foi calculado o odds ratio. As variávies gênero, tempo de tratamento ortodôntico, tipo de maloclusão e idade foram verificadas pelo teste qui-quadrado. Resultados: Mostraram não terem associação em relação à presença de PP, cefaleias primárias e DTM. Foi constatado que a presença de PP aumentou a chance do paciente em ter cefaleia primária e DTM tanto isoladamente como concomitantemente. Conclusão: Diante destes resultados, é importante que o diagnóstico por imagem dessa alteração torne-se uma prática comum entre os profissionais da saúde.

In the first cervical spine (Atlas) there may be an anatomical alteration characterized by a bone arch and diagnosed by radiographic images, called Ponticulus Posticus (PP) and may be related to primary headaches and other orofacial pains. Goal: The goal of this paper was to evaluate the association among PP, primary headaches, temporomandibular dysfunctions (TMDs) and malocclusion. Methods: All patients were voluntary and have already had the orthodontic documentation with the orthodontic tele radiography and went through orthodontic maintenance by Temporomandibular Disorder Diagnosis questionnaires (RDC/TMD) in the Portuguese version, clinical questionnaire based on some criteria of CIH-2 (international classification oh headaches) and clinical exam to evaluate the malocclusions. All the dada that were used in this research were collected from these documents. The variables included in this study were: age, time of treatment, prevalence of malocclusion (quantitative), sex, type of temporomandibular dysfunction (TMD), primary headache and PP (qualitative). The data were organized in a spreadsheet of SPSS 15.0 program and the relation among variables were analysed through the binary regression model, and the odds ration was calculated. The variables sex, time of the orthodontic treatment, type of malocclusion and age were checked by the chi-square test and the results obtained showed no association with the presence of PP, primary headache and TMD. Results: It was found that the presence of PP increased the patient's chance of having primary headache and TMD both individually and concomitantly. Conclusion: Considering these results, it is important that the diagnosis by image of this alteration becomes a common practice among health professional.

Ponticuli In Atlas Vertebrae And Its Clinical Aspect

Background: Atlas, the first cervical vertebra, has an oblique ligament which bridges the groove for vertebralartery. This ligament may ossify sometimes converting groove into foramen. These foramina are called asponticulus posterior or arcuate foramen of the atlas. The ponticuli can distort vertebral artery. They havetendency to cause vertebra basic insufficiency. During any manipulation of cervical spine, these variations ofatlas should be kept in mind.Objectives: To study the presence of ponticuli, their other features like whether complete or incomplete, unilateralor bilateral, sidedness- right or left.Material and Methods: A total of 50 fully dried adult human atlas were collected from the Department ofAnatomy, Government Medical College, Jammu and from the students of the first year MBBS, Government MedicalCollege, Jammu. Bones were intact and free from osteophytes. The superior surface of posterior arch was observedcarefully in each atlas for presence of ponticulus.Results: In the present study, 50 human atlas vertebrae were observed out of which 4 atlas (8%) had ponticuli. Itwas incomplete in 2 vertebrae (4%) and was complete in 2 atlas vertebrae (4%). It was unilateral in 3 atlasvertebrae (6%) and bilateral in 1 atlas vertebra (2%). 2 ponticuli were on the right side, 1 on left side and 2 werefound on both sides. All were ponticuli posterior except one which was lateral ponticulus.Conclusion: The presence of ponticuli can cause cervical pain and pressurize vertebral artery leading tocerebrovascular accidents. Detailed knowledge about the variations in the cervical region is very helpful toneurosurgeons, orthopaedicians and otolaryngologists to avoid any mishap. Spinal surgeons must be fullyaware about these ponticulus to prevent any complications during surgeries

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.

A Morphological Study of Ponticuli of the Human Atlas Vertebrae and its Clinical Significance.

BACKGROUND: The first cervical vertebra, atlas plays a vital role in the movement of skull & neck. The anatomy of atlas is complex due to its three dimensional structure. There is a groove on superior surface of posterior arch of atlas for passage of 3rd part of vertebral artery and first cervical spinal nerve (suboccipital nerve). Sometimes the oblique ligament of atlas which is present at the lower border of posterior atlanto-occipital membrane may ossify and convert this groove into a foramen. This foramen may be complete or incomplete, In some cases a bony bridge also extends from lateral masses of atlas to the posterior root of transverse process and form an additional foramen through which vertebral artery travels. The vertebral artery is prone to compression in its entire course between foramen transversarium and foramen magnum during extreme rotation movement of head & neck. This condition may be aggravated by the presence of these ponticuli & results in compromised blood flow and causes vertebrobasilar insufficiency presenting with dizziness, fainting, vertigo, transient diplopia & various neurological disturbances. MATERIALS & METHODS: The present study was carried out on 118 (Male-62, Female-56) dried fully ossified adult human atlas of known sex for the presence of complete or incomplete ring for vertebral artery i.e. different ponticuli on the superior surface of the atlas vertebra. RESULTS: We observed 21.17% cases of ponticulus posterior in which 7.62% specimens had complete ring while 13.55% specimens had incomplete ring & ponticulus lateralis was reported only in 5.93% cases (unilateral: 2.54% & bilateral: 3.39%). Incidence of ponticulus posterior as well as lateralis were more common in male as compared to female. Complete ponticulus posterior was more common in right side, while incomplete ponticulus posterior as well as ponticulus lateralis were more commonly bilaterally. CONCLUSION: As indicated by our study, ponticulus posterior as well as lateralis are not so rare anomaly in the population of Bihar. So, the detail knowledge about these variations is very helpful to the neurophysicians, neurosurgeons, orthopedicians & otolaryngologists who faces regularly the patients complaining about the symptoms of vertebrobasilar insufficiency. These informations are also important for the spine surgeons to prevent vascular complications during spinal surgeries especially in those patients who required screw placements in the lateral mass of atlas.

MSCT VRT observation and analysis in the ponticulus of atlas / 实用放射学杂志

Objective To expand MSCT obseration and cognition in the ponticulus of atlas,and to improve the diagnosis for it. Methods 263 cases were collected among the patients undergone the examine of MSCT angiography in intracranial and cervical and volume rendering technique(VRT)with unenhance images,and observation and analysis was focused on the posterior arch of atlas. Results 69 cases(97 sides)were detected ponticulus in this group,including unilateral in 41 cases,bilateral in 28 cases.The simple type ponticulus were 82 sides,including the ponticulus posterior (PP)were 60 sides,the ponticulus lateralis (PL)were 1 5 sides,the ponticulus borderland (PB)were 5 sides,The ponticulus middle (PM)were 2 sides.According to the shape of the ponticulus:simple root in 43 sides,opposite beaked in 21 sides,complete type in 18 sides.The ponticulus compound (PC)were 1 5 sides.Conclusion The images of MSCT VRT can showed accurately the ponticulus of atlas,and it can provide reliable imaging evidence on its diagnosis and classification,and it can be used as an unearthly method for its examination.

Ponticulus posticus incidence in Brazilian Atlas vertebrae: a cadaveric study

The suboccipital segment of the vertebral artery (VA) passes around the lateral mass of atlas (C1). It is located in a groove on the superior surface of the arch of C1, the so-called vertebral artery sulcus (VAS). Occasionally, a small bony arch is found to connect the retroglenoid tubercle with the posterior arch of C1. This anatomical structure is known as ponticulus posticus (PP). The partial or total incidence of PP reported in the literature ranges from 5.14 percent to 51 percent. The clinical implication of PP includes the cervicogenic migraine, vertigo, and the Barre-Lieou syndrome. The scope of this paper is to determine the incidence of PP in isolated cadaveric vertebrae in the Brazilian population. The cervical vertebrae C1 from thirty not identified adult cadavers were examined at the Laboratory of Anatomy of the Federal University of Sergipe, Brazil. PP was present in 40 percent of evaluated C1 and it involved a complete bony arch in 42 percent of the cases. In 58 percent of the cases, PP was observed bilaterally. In the cases where the presence of PP was unilateral, this structure was situated exclusively on the right, even though a bigger incidence on the left side has been described for the majority of right-handed people. PP was a frequent finding in our study and its presence always must be suspected while setting the diagnosis of cervicogenic chronic headache and cervical pain without radiation to upper limbs.

Ponticulus posticus on the posterior arch of atlas, prevalence analysis in asymptomatic patients / Ponticulus posticus en el arco posterior del atlas, análisis de su prevalencia en pacientes asintomáticos

The Ponticulus posticus is a bony bridge located in the posterior arch of the atlas in relation to the passage of the vertebral artery. Its presence has been associated with development of cervical pain and cerebrovascular disorders. The purpose of this study was to assess its prevalence in asymptomatic patients. We examined 436 digital teleradiographs of patients aged from 5 to 70 years (mean of 18.44 years, SD. 9.59) of both sexes (173 men, 263 women). In 80.7 percent (n = 352) of cases, no radiographic evidence of ossification was found; 19.3 percent showed some degree of ossification, of which 10.1 percent had partial ossification and 9.2 percent complete ossification. The prevalence of complete ossification was slightly higher in women than in men and occurs in all the age groups analyzed. Our results suggest that the Ponticulus posticus is an anatomic condition with a protective function.

El Ponticulus posticus es un puente óseo ubicado en el arco posterior de atlas en relación al paso de la arteria vertebral. Su presencia se ha asociado al desarrollo de cervicalgias y trastornos vasculares encefálicos. El propósito de este estudio fue analizar su prevalencia en pacientes asintomáticos, para ello fueron examinadas 436 teleradiografías digitales de pacientes de entre 5 y 70 años (Media 18,44 años; DS 9,59), de ambos sexos (173 hombres; 263 mujeres). En el 80,7 por ciento (n=352) no se encontraron signos radiograficos de osificación, el 19,3 por ciento de los casos se pudo apreciar algún grado de osificación, de los cuales el 10,1 por ciento presento una osificación parcial y el 9,2 por ciento completa. La prevalencia de osificación completa fue levemente mayor en mujeres y se presentó en todos los grupos etáreos analizados. Nuestros resultados sugieren que el Ponticulus posticus es una condición anatómica destinada a proteger el paso de la arteria verebral y no debe considerarse una calcificación con significado patológico.

Radiological Analysis of Ponticulus Posticus in Koreans

PURPOSE: Since there has been little reporting on the prevalence or morphologic characteristics of ponticulus posticus in Asians, we retrospectively reviewed cervical 3-dimensional CT scan images and plain radiographs which had been ordered by neurosurgeons or orthopaedic surgeons for evaluation of cervical spine problems to investigate the prevalence and morphologic features of the ponticulus posticus in Koreans. PATIENTS AND METHODS: The presence and types of ponticulus posticus were investigated on 200 consecutive cervical 3-D CT scans. RESULTS: Thirty-one patients, 48 ponticulus posticus, complete or partial, bilateral or unilateral, were identified on the 200 cervical 3-D CT scans; therefore, the prevalence was 15.5% in our patient population. In plain radiographs analysis, the prevalence was 6.95%. CONCLUSION: The ponticulus posticus is a relatively common anomaly in Koreans. Therefore, proper identification of this anomaly on preoperative lateral radiographs should alert surgeons to avoid using the ponticulus posticus as a starting point for a lateral mass screw. Because of its size and shape have wide variation, 3-D CT scanning should be considered before lateral mass screw placement into the posterior arch if its presence is suspected or confirmed on radiographs.

Prevalence and Morphologic Features of Ponticulus Posticus in Koreans: Analysis of 312 Radiographs and 225 Three-dimensional CT Scans

STUDY DESIGN: A retrospective review of three-dimensional CT scan images and radiographs. PURPOSE: To investigate the prevalence and morphologic features of ponticulus posticus in Koreans. OVERVIEW OF LITERATURE: There has been little reported on the prevalence or morphologic characteristics of ponticulus posticus in Asians, predisposing them to vertebral artery injury during screw placement in the lateral mass of the atlas. METHODS: The presence and types of ponticulus posticus were investigated on 225 consecutive cervical three-dimensional CT scans and 312 consecutive digital lateral cephalometric head radiographs. RESULTS: Various spectra of ponticulus posticus were found in 26% of the CT scans and 14% of the radiographs. CONCLUSIONS: Ponticulus posticus is a relatively common anomaly in Koreans. Therefore, the presence of this anomaly should be carefully examined for on radiographs before lateral mass screw placement. If ponticulus posticus is suspected or confirmed on radiographs, three-dimensional CT scanning should be considered before placement of lateral mass screws into the posterior arch, especially given its wide variation of size and shape.