Assessing the relationship between single nucleotide polymorphisms in Wingless signaling pathway genes and sella turcica morphology.

Sella turcica development involves molecular factors and genes responsible for ossification. It is possible that single nucleotide polymorphisms (SNPs) in key genes are involved in morphological variation of sella turcica. Genes belonging to the WNT signaling pathway are involved in the ossification process and are candidates of sella turcica morphology. This study aimed to evaluate if SNPs in WNT6 (rs6754599) and WNT10A (rs10177996 and rs3806557) genes are associated with the calcification and patterns of the sella turcica. Nonsyndromic individuals were included in the research. Cephalometric radiographs were examined and the sella calcification was evaluated and classified according to the calcification of the interclinoid ligament (no calcification, partial calcification, and incomplete calcification) and sella turcica pattern (normal sella turcica, bridge type A-ribbon-like fusion, bridge type B-extension of the clinoid processes, incomplete bridge, hypertrophic posterior clinoid process, hypotrophic posterior clinoid process, irregularity in the posterior part, pyramidal shape of the dorsum, double contour of the floor, oblique anterior wall, and oblique contour of the floor). DNA samples were used to evaluate SNPs in the WNT genes (rs6754599, rs10177996, and rs3806557) using real-time PCR. Chi-square test or Fisher's exact test were used to compare the allele and genotype distributions according to sella turcica phenotypes. The alpha was set as 5% for all comparisons. A total of 169 individuals were included, 133 (78.7%) present sella turcica partially or completely calcified. Sella turcica anomalies were found in 131 individuals (77.5%). Sella turcica bridge type A (27.8%), posterior hypertrophic clinoid process (17.1%), and sella turcica bridge type B (11.2%) were the most prevalent morphological patterns observed. Individuals carrying the TT genotype in rs10177996 (TT vs. CT + CC) had higher chance to present a partially calcified sella turcica (p = 0.047; Odds ratio = 2.27, Confidence Interval 95% 1.01-5.13). In conclusion, the SNP in WNT10A is associated with the calcification phenotype of the sella turcica, the pleiotropic effect of this gene should be taken into consideration in future studies.

Evaluation of Dimension and Bridging of Sella Turcica and Presence of Ponticulus Posticus in Individuals With and Without Cleft: A Comparative Study.

OBJECTIVE: Sella turcica abnormalities such as sella turcica bridging (STB) have been observed frequently among patients with craniofacial anomalies. Ponticulus posticus (PP) is an important structure and its presence causes complications during surgeries. Due to the importance of these structures, this study aimed to evaluate the prevalence of STB, PP, and dimensions of the sella turcica in individuals with and without cleft. DESIGN: A cross-sectional study. SETTING: Orthodontic and Radiology Departments in a public dental school, Tehran, Iran. PATIENTS: Eighty-three lateral cephalograms of individuals with cleft and ninety-two cephalograms of class I individuals without cleft. MAIN OUTCOME MEASURES: Length, depth, and maximum anterior-posterior diameter (APD) of sella turcica, presence of STB (classified as types 1, 2, and 3), and PP. RESULTS: In the group with cleft, 19.3% of individuals had type I, 65.1%, type II, and 15.7%, type III STB. In the group without cleft, 15.2% had type I, 73.9%, type II, and 10.9%, type III STB. In the group with cleft, 65.1% of individuals had no PP, 24.1%, incomplete, and 10.8%, complete PP while in the group without cleft, 56.5% had no PP, 29 31.5%, incomplete, and 12%, complete PP. CONCLUSION: The sella turcica dimensions, STB, and PP prevalence were not significantly different between individuals with and without cleft. The sella turcica length and prevalence of STB and PP were not affected by age, sex, and cleft type. However, the depth and the APD were affected by age.

Case 299: Sellar Spine.

History Part one of this case appeared 4 months previously and may contain larger images. A 32-year-old woman presented to an ophthalmologist for bilateral blurry vision. She underwent MRI of the brain and orbits, which showed a focal abnormality within the pituitary gland. The patient was referred to an endocrinologist for further evaluation. Review of systems and physical examination by the endocrinologist revealed no symptoms or signs of endocrine dysfunction. Anterior pituitary hormone levels, including growth hormone, prolactin, thyroid stimulating hormone, follicular-stimulating hormone, luteinizing hormone, and adrenocorticotropic hormone, were normal. Dynamic contrast-enhanced MRI of the sella and pituitary gland and subsequent CT of the anterior skull base were performed.

The first evidence of pituitary gland tumor in ground sloth Valgipes bucklandi Lund, 1839.

Bone diseases are commonly found in the fossil record, especially in mammals of the Pleistocene megafauna, which exhibit signs of overload in the articulations. However, pathologies that affect soft tissues are not usually reported, even due to the nature of fossilization that rarely preserves such materials. In paleoneurological research using CT scan and three-dimensional reconstructions of Pleistocene sloths, an anomaly is discovered in the space that houses the pituitary gland, the sella turcica. The tomographic analysis of a Valgipes bucklandi skull revealed a great enlargement at the sella turcica, at the medial region in the body of the basisphenoid bone. The images delimit an enlarged dorsal-ventral projection, measuring approximately 15 mm height, at the tridimensional reconstructed endocranium. Taphonomic processes, such as the action of necrophagous agents, were discarded due to the shape and conditions of the structure, which also showed signs of bone remodeling. Thus, it is possible to affirm that a paleopathological process altered the size of the pituitary gland of the specimen MCT 3993-M, being probably a pituitary tumor.

Is Gadolinium Contrast Necessary for Pituitary MRI in the Evaluation of Pediatric Short Stature and Growth Hormone Deficiency?

INTRODUCTION: Short stature is a common concern that necessitates pediatric endocrinology evaluation. Growth hormone deficiency (GHD) is a commonly considered etiology. Brain and pituitary magnetic resonance imaging (MRI) with gadolinium-based contrast agents (GBCAs) is the most widely used imaging in assessing patients with GHD. Given the significant strides made in MRI technology, the need for contrast material should be reassessed. METHOD: We performed a retrospective review of healthy patients with short stature and/or GHD who underwent brain and pituitary MRI with and without contrast to assess the added value of contrast administration. RESULTS: 227/318 identified patients underwent growth hormone (GH) stimulation testing; 28 (12.3%) with normal GH response and 62 (27.3%) with severe GHD. We found a low incidence of sellar and suprasellar pathologies. When comparing noncontrast and contrast MRI, we found perfect agreement in detecting abnormal posterior pituitary bright spots (kappa:1.0) and substantial agreement in detecting pars intermedia cysts and posterior superior sellar cysts (kappa: 0.74 and 0.71, respectively). Initially, only moderate agreement was found in detecting infundibular abnormalities (kappa: 0.51), although a revised noncontrast MRI protocol with high-resolution 3D images enabled visualization of the infundibulum. CONCLUSION: The MRI evaluation of healthy patients with short stature and/or isolated GHD may be completed without the use of GBCAs. The slight overestimation of pituitary stalk interruption by noncontrast images can be overcome by adding newer high-resolution sequences.

Comparison of cervical vertebral anomalies and sella turcica bridging in different growth stages with various vertical skeletal growth patterns.

PURPOSE: To compare cervical vertebral anomalies and sella turcica bridging (STB) in different growth stages in orthodontic patients with different vertical skeletal growth patterns. METHODS: Lateral cephalometric radiographs (LCR) of 270 patients in the preadolescent, adolescent, or postadolescent periods and having low angle [LA], normal angle [NA], or high-angle [HA] vertical skeletal growth patterns were evaluated retrospectively. STB was visualized using LCRs while evaluating the deficiency of ponticulus posticus (PP) and atlas posterior arch (PAA) associated with the atlas bone. The Pearson chi-square and Fisher's exact tests were used for categorical data and one-way ANOVA for numerical data. RESULTS: The prevalence of fully calcified PP and STB increased from the preadolescent (PP, 10.0%; STB, 11.1%) to the postadolescent period (PP, 24.4; STB, 21.1%); they did not differ from vertical skeletal growth patterns (p > 0.05). The prevalence of PAA deficiency is significantly higher in individuals with LA (46.7%) than with other angles (NA, 27.8%; HA, 26.7%). The vertical skeletal growth pattern was significantly related to STB in the preadolescent period and PAA in the postadolescent period. CONCLUSIONS: Different anomalies during different growth periods correlate with the vertical skeletal growth pattern. It will be useful to evaluate a different anomaly according to the relevant growth period.

Associations among palatal impaction of canine, sella turcica bridging, and ponticulus posticus (atlas arcuate foramen).

INTRODUCTION: The palatal impaction of canine (PIC) can be predicted by some head and neck skeletal anomalies or variants. Since studies on this regard (especially vertebral anomalies) are scarce, this study was conducted. METHODS: This case-control study was done on 46 PIC orthodontic patients (34 females, 12 males) and 46 control orthodontic patients (36 females, 10 males). The diagnosis of PIC was done on lateral cephalographs and panoramic radiographs. On cephalographs, sella turcica bridging (occurrence and severity) and ponticulus posticus (occurrence and severity) were assessed. Associations between PIC, sella bridging, and ponticulus posticus were examined statistically (α = 0.05, ß ≤ 0.2). RESULTS: Cases' and controls' mean ages were 17.7 ± 4.0 and 17.4 ± 3.5, respectively. Of the case subjects, 22, 22, and 2 had respectively types I (normal), II, and III of sella bridging, while these numbers were 34, 12, and 0 in controls (chi-square P = 0.023 for severity, 0.010 for occurrence). Ponticulus posticus was observed in 28 cases (7 completed) and 17 controls (6 completed, P = 0.022 for occurrence, 0.056 for severity). Sella bridging was not associated with ponticulus posticus (Spearman P = 0.150). According to binary logistic regression, sella bridging can increase the odds of palatal canine impaction for OR = 2.8 times, while ponticulus posticus for OR = 2.6. Age and sex did not affect sella bridging or ponticulus posticus. CONCLUSIONS: Both sella bridging and ponticulus posticus can predict an increased rate of PIC for more than 2.5 times.

Sphenoid sinus agenesis and sella turcica hypoplasia: very rare cases of two brothers with Hamamy syndrome.

Hamamy syndrome (HS) is an autosomal recessive syndrome with a genetic origin that is very rarely observed. The syndrome with craniofacial dysmorphisms, including midface prominence, severe telecanthus, sparse lateral eyebrows, protruding ears, fronto-nasal abnormalities, lacrimal-salivary apparatus agenesis, thin upper vermillion border, myopia, mental retardation, sensorineural hearing impairment, congenital heart anomalies with intraventricular conduction delay, hypochromic microcytic anaemia and skeletal abnormalities of the long bones with recurrent fractures. In this paper, we report a case of two brothers diagnosed with HS at the ages of 25 and 18 years, visited out clinic at different times due to dental reasons. In the radiological examinations, it was observed that both brothers have sphenoid sinuses agenesia, and their sella turcica were smaller than normal. HS may be observed very rarely, and it should be kept in mind that, in addition to various symptoms, it may also cause sphenoid sinus agenesis and sella turcica hypoplasia as shown for the first time in this case report.

Physiopathological Aspects of Sellar Epidermoid Cyst Determining Endocrine Disturbances: A Case Report

Epidermoid cysts (ECs) of the central nervous system (CNS) constitute benign circumscribed lesions that aremore common in lateral than in midline sites. Epidermoid cysts of the CNS arise more frequently in the cerebellopontine angle, around the pons, near the sella, within the temporal lobe, in the diploe, and in the spinal canal. Most common tumoral lesion of sellar region is pituitary adenoma, and sellar cystic epithelial masses may be difficult to differentiate based only on clinical and imaging findings. Epidermoid cysts are covered by keratinized squamous epithelium and are usually filled with keratin lamellae. The process is, for the most part, maldevelopmental in origin, presumably arising from trapped surface ectodermal elements in association with the developing CNS during the closure of the neural groove or formation of the secondary cerebral vesicles. In the present study, the authors describe a case of sellar epidermoid cyst producing endocrine alterations and visual disturbance in a 35 years woman, and review the physiopathological and diagnostic criteria of this lesion.

Variaciones anatómicas de la silla turca en radiografías laterales de cráneo. Hospital "Faustino Pérez", 2017-2018 / Anatomic variants of sella turcica in lateral crania radiographies. Hospital “Faustino Pérez¨, 2017-2018

RESUMEN Introducción: diversos autores reflejan que la morfología de la silla turca constituye un factor predisponente para algunas enfermedades. Por ejemplo, se considera que existe correlación entre la morfología de esta estructura anatómica y varias patologías; como el síndrome de la silla turca vacía, síndrome de Williams, paladar hendido, entre otras. Objetivo: describir las variaciones anatómicas de la silla turca que se observan en las radiografías laterales de cráneo del Hospital Universitario "Faustino Pérez" de la ciudad de Matanzas, en el período de enero del 2017 a enero del 2018. Materiales y métodos: el universo fue 140 radiografías laterales de cráneo, de estas 85 pertenecieron al sexo femenino y 55 al masculino. Las variables estudiadas fueron edad, sexo y variaciones anatómicas de la silla turca. Se emplearon métodos teóricos y empíricos. Resultados: se observó un predominio de la variación anatómica de la silla turca en forma de U, en ambos sexos. Seguido de la forma de J, predominando la variación en forma de U en el grupo etario de 41 a 50 años y la forma de J en los pacientes mayores de 60 años. Conclusiones: es imprescindible el conocimiento de la anatomía normal de la silla turca y de sus variaciones anatómicas, tanto para las especialidades quirúrgicas como para las no quirúrgicas. Un análisis exhaustivo de la morfología de esta estructura es necesario para establecer parámetros que excluyan determinadas patologías (AU).

ABSTRACT Introduction: several authors declare that sella turcica morphology is a predisposing factor to several diseases. For example, it is considered that there is a correlation between the morphology of this anatomical structure and several pathologies like empty sella turcica syndrome, Williams syndrome, cleft palate and others. Objective: to describe the anatomical variants of sella turcica observed in side cranial radiographies of the University Hospital ¨Faustino Perez¨ of Matanzas, in the period January 2017-January 2018. Materials and methods: the universe was 140 side cranial radiography: 85 belonged to female patients and 55 to male patients. The studied variables were age, sex and sella turcica anatomical variables. Theoretic and empirical methods were used. Results: it was observed a predominance of the U-shaped sella turcica anatomical variant in both sexes, followed by the J-shaped one. The U-shaped form predominated in the 41-50-years-old age-group and the J-shaped form in patients elder than 60 years. Conclusions: it is essential to know sella turcica normal anatomy and its anatomical variables, both for the surgical specialties and for the non-surgical ones. It is necessary the exhaustive analysis of this structure to establish parameters excluding several pathologies (AU).

Variaciones anatómicas de la silla turca en radiografías laterales de cráneo. Hospital "Faustino Pérez", 2017-2018 / Anatomic variants of sella turcica in lateral crania radiographies. Hospital "Faustino Pérez¨, 2017-2018

RESUMEN Introducción: diversos autores reflejan que la morfología de la silla turca constituye un factor predisponente para algunas enfermedades. Por ejemplo, se considera que existe correlación entre la morfología de esta estructura anatómica y varias patologías; como el síndrome de la silla turca vacía, síndrome de Williams, paladar hendido, entre otras. Objetivo: describir las variaciones anatómicas de la silla turca que se observan en las radiografías laterales de cráneo del Hospital Universitario "Faustino Pérez" de la ciudad de Matanzas, en el período de enero del 2017 a enero del 2018. Materiales y métodos: el universo fue 140 radiografías laterales de cráneo, de estas 85 pertenecieron al sexo femenino y 55 al masculino. Las variables estudiadas fueron edad, sexo y variaciones anatómicas de la silla turca. Se emplearon métodos teóricos y empíricos. Resultados: se observó un predominio de la variación anatómica de la silla turca en forma de U, en ambos sexos. Seguido de la forma de J, predominando la variación en forma de U en el grupo etario de 41 a 50 años y la forma de J en los pacientes mayores de 60 años. Conclusiones: es imprescindible el conocimiento de la anatomía normal de la silla turca y de sus variaciones anatómicas, tanto para las especialidades quirúrgicas como para las no quirúrgicas. Un análisis exhaustivo de la morfología de esta estructura es necesario para establecer parámetros que excluyan determinadas patologías.

ABSTRACT Introduction: several authors declare that sella turcica morphology is a predisposing factor to several diseases. For example, it is considered that there is a correlation between the morphology of this anatomical structure and several pathologies like empty sella turcica syndrome, Williams syndrome, cleft palate and others. Objective: to describe the anatomical variants of sella turcica observed in side cranial radiographies of the University Hospital ¨Faustino Perez¨ of Matanzas, in the period January 2017-January 2018. Materials and methods: the universe was 140 side cranial radiography: 85 belonged to female patients and 55 to male patients. The studied variables were age, sex and sella turcica anatomical variables. Theoretic and empirical methods were used. Results: it was observed a predominance of the U-shaped sella turcica anatomical variant in both sexes, followed by the J-shaped one. The U-shaped form predominated in the 41-50-years-old age-group and the J-shaped form in patients elder than 60 years. Conclusions: it is essential to know sella turcica normal anatomy and its anatomical variables, both for the surgical specialties and for the non-surgical ones. It is necessary the exhaustive analysis of this structure to establish parameters excluding several pathologies.

Aneurysmal Bone Cyst of the Skull Base ­ Case Report

Introduction Aneurysmal bone cysts (ABCs) are pseudotumoral bone lesions of unknown etiology that are also hypervascularized, benign, and locally destructive. They are rare in the base of the skull. The present case report describes a case of aneurysmal bone cyst in the sella turcica. Case Report The present study was developed at the department of neurosurgery of the Hospital Universitário Professor Alberto Antunes of the Universidade Federal de Alagoas (HUPAA-AL, in the Portuguese acronym), Maceió, state of Alagoas, Brazil, and is accompanied by a review of the literature from the PubMed database. A 17-year-old female patient with bitemporal hemianopia and intense left hemicranial headache associated with symptoms from the cranial nerves contained in the cavernous sinus. Neuroimaging evidenced a large lesion in the suprasellar region with calcification foci, sellar erosion, and extension to the cavernous sinus. The patient was submitted to a partial lesion resection and the histopathological analysis showed an aneurysmal bone cyst. Conclusion A rare case of intracranial aneurysmal bone cyst, with the important differential diagnosis from pituitary adenoma.

Physiologic pituitary hyperplasia causing visual disturbance during adolescence.

We report for the first time two cases of physiologic pituitary hyperplasia causing visual disturbance during adolescence. Case 1. A 15-year-old boy visited our department with a pituitary mass lesion on magnetic resonance imaging (MRI) associated with headache and transient bitemporal hemianopsia repeating. A visual field defect became apparent on the bitemporal upper side, and the area of the visual field defect enlarged to hemianopsia. The visual defect usually occurred in relation to exercise and continued for approximately 10 min. MRI showed the mass effect of pituitary hyperplasia to the optic chiasm. At six months later after the initial onset of the symptom, the visual field defect disappeared. Case 2. A 14-year-old girl came to our emergency department with a pituitary mass lesion on MRI associated with acute headache and visual disturbance occurring during exercise. MRI revealed the possibility of pituitary hyperplasia compressing the optic chiasm; however, her clinical course showed pituitary apoplexy. We conducted emergency transsphenoidal surgery to decompress her optic chiasm. The operative findings and histological examinations revealed a normal pituitary gland. Her visual disturbance immediately recovered after the surgery. Physiologic pituitary hyperplasia during adolescence can cause visual disturbance. Surgery should be carefully conducted, given the possibility of physiologic pituitary hyperplasia with visual symptoms.

Association between sella turcica bridging and palatal canine impaction: Evaluation using lateral cephalograms and CBCT.

INTRODUCTION: The purpose of this study was to find a correlation between sella turcica bridging and the presence of a palatal impacted canine, using lateral cephalograms and CBCT. MATERIAL AND METHOD: We selected the lateral cephalograms and CBCTs of 60 patients meeting specific criteria. The radiographs were analysed to study the relationship between sella turca bridging and several factors. The presence or absence of a partial or total bridging was deducted by measuring the dimensions of the sella turcica and by using an accurate scoring system. RESULTS AND CONCLUSION: Our study did not show any statistically significant association between sella turcica bridging as diagnosed on the lateral cephalogram and the CBCT images and the following factors: age, gender, facial type, skeletal class and the presence of an impacted canine. We found a significant difference for the classification of the sella turcica between these two radiographic methods.

Incidence and morphometry of sellar bridges and related foramina in dry skulls: Their significance in middle cranial fossa surgery.

PURPOSE: The current study investigated the incidence, morphology and morphometry of the ossified ligaments expanding between petrous bone and posterior clinoid processes and in between the anterior, middle and posterior clinoid processes. Side symmetry, gender dimorphism and age influence were also studied. MATERIALS AND METHODS: A total of 123 adult Greek dry skulls were observed. RESULTS: A caroticoclinoid bar (CCB) was found in 60.2%. Partial CCBs appeared more commonly (36.6%) than complete (23.6%). The caroticoclinoid foramen (CCF) was symmetrical on both sides and genders. An anterior interclinoid, a posterior petroclinoid and a partial posterior interclinoid bar appeared in 19.5%, 6.5% and 2.4%, respectively. Osseous spurs posterolateral to the posterior clinoid process were present in 5.7%. CONCLUSION: The study highlights important morphometric details about osseous bars of the sella region and the related CCF in Greek skulls. Notable differences in the incidence of these bars in Greek individuals compared with findings from other populations highlight the growing awareness of ethnic differences in skull base landmarks. Variations and surgically oriented measurements provided by this study may benefit clinicians involved in the treatment of the middle cranial fossa pathology, enriching understanding of the complicated regional anatomy. Preoperative sellar area mapping is essential, by using computed tomography images, since modification of the surgical approach may be required in cases of severe ossification.

Sella turcica bridging and ossified carotico-clinoid ligament: Correlation with sex and age.

Aim Sella turcica bridging and ossified carotico-clinoid ligament are two variants of the sella turcica, the origin of which is partially unknown. These variations should be properly recognised, as they may hamper the removal of the anterior clinoid process in surgical procedures. Therefore, our aim was to determine the prevalence of these two anatomical variants and to investigate their prevalence according to patient sex and age in a series of maxilla computed tomography scans. Materials and methods We revised 300 computed tomography scans of the head from northern Italian patients, stratified into three age groups (18-40 years, 41-60 years, >60 years): a logistic regression analysis was used to explore an association of sella turcica bridging with age and sex through Matlab software, also including a test for the extracted model ( P < 0.05). Results The mean prevalence of sella turcica bridging and ossified carotico-clinoid ligament were 0.16 ± 0.06 (48/300, 16.0%) and 0.09 ± 0.03 (26/300, 8.7%), respectively. Statistically significant differences according to sex were found neither for sella turcica bridging ( P = 0.345) nor for ossified carotico-clinoid ligament ( P = 0.412). Only sella turcica bridging showed a correlation with age ( P = 0.007). In addition, the two variants were often associated, as patients without sella turcica bridging usually did not show ossified carotico-clinoid ligament ( P < 0.001). Discussion Our results suggest an association between the two variants, and provide a novel contribution to the debate around their origin.

Double inter-internal carotid artery communication through intercavernous anastomosis and posterior communicating artery associated with multiple intracranial artery segmental agenesis/aplasia.

Segmental internal carotid artery (ICA) and basilar artery (BA) agenesis/aplasia are rare vascular anomalies. We report an extremely rare case of combined ICA, BA, and A1 segmental absence presenting with double inter-ICA collateral communication through the intercavernous anastomosis and posterior communicating arteries. The patient presented with diplopia and transient ischemic attack. The pathogenesis of the anatomic anomalies and clinical symptoms are discussed.

Associations among sella turcica bridging, atlas arcuate foramen (ponticulus posticus) development, atlas posterior arch deficiency, and the occurrence of palatally displaced canine impaction.

INTRODUCTION: Head and neck skeletal anomalies or normal variants might predict the occurrence of palatally displaced impacted maxillary canines. Despite their clinical importance, studies in this regard are rare, especially when it comes to vertebral anomalies. METHODS: This case-control study was performed on cephalographs of 35 orthodontic patients (11 male, 24 female) with palatally displaced canines (PDC) and 75 patients without them (29 male, 46 female). PDC were diagnosed on panoramic and lateral cephalographs and from clinical reports. The occurrence and severity of sella turcica bridge and the atlas ponticulus posticus, and deficiency of the posterior atlas arch were evaluated twice on lateral cephalographs. The associations between the occurrence and level of these skeletal anomalies and variations of PDC occurrence as well as additional correlations were assessed using multivariable and bivariate statistics (α = 0.05; ß ≤0.2). RESULTS: The patients' mean age was 18.4 ± 1.9 years. In the control and patient groups, 23 (30.7%) and 21 subjects (60%) had sella turcica bridging, respectively (chi-square, P = 0.003). Ponticulus posticus was observed in 14 (18.7%) controls and 15 (42.9%) patients (chi-square, P = 0.007). Posterior atlas arch deficiency was observed in 4 (5.3%) controls and 5 (14.3%) patients (chi-square, P = 0.111). The presence of ponticulus posticus and sella turcica bridging might be associated with increased odds of PDC occurrence for about odds ratios of 3.1 and 3.5 times, respectively (binary logistic regression). CONCLUSIONS: PDC is positively associated with the occurrence and severity of sella turcica bridging and ponticulus posticus. The association between PDC and posterior atlas arch deficiency was inconclusive.