Calcification of the interclinoid and petroclinoid ligaments of sella turcica: a radiographic study of the prevalence

[Frequency of Ponticulus posticus and Ponticulus lateralis in patients admitted to hospital with traumatic brain injur]

OBJECTIVE

To determine the frequency of Ponticulus posticus and Ponticulus lateralis among patients admitted to a24-hour emergency hospital.

MATERIAL AND METHODS

The study included 2887 patients with a traumatic history who were admitted to the hospital for emergency reasons. This principle of sampling allowed us to exclude a high concentration of studies of patients with chronic neurological diseases, the cause of which could be symptomatic Kimmerle's anomaly (KA). During the period 01.01.20 to 31.12.20, primary CT was performed on an emergency basis in 7348 patients. Of these, CT scans of the brain and cervical spine were performed in 2965 patients. Some patients (78 people) were excluded from the study due to the presence of cervical vertebral fractures and metal artifacts in the craniovertebral region.

RESULTS

The Ponticulus posticus was detected in 1162 (40.2%) patients, among them class 3 and 4 was detected in 27.7%, and class 2 ossification in 12.5%. This Ponticulus posticus was significantly more common (χ2 test, p=0.0005) in men. The Ponticulus lateralis was identified in 231 patients (8%), among them 94 patients (3.3%) had complete ponticulus on both sides, 29 patients (1%) - on one side, and 108 patients (3.7%) - two-sided incomplete ponticulus. In patients with class 2-3-4, Ponticulus lateralis were detected significantly more often (χ2 test, p<0.0001).

CONCLUSION

The cumulative incidence of KA was 42%, 17% of patients are carriers of a complete KA bridge, which is significantly higher than in the European or Asian regions. The data suggest that KA is not the result of ossification of the posterior atlanto-occipital membrane, since different classes of KA occur equally often at different ages. Further studies of KA are needed, including its occurrence in patients of the neurological department and its correlation with individual neurological syndromes to determine the need for surgical treatment in the population.

Association between sella turcica bridging and the impaction severity of palatally displaced canines: A retrospective study

INTRODUCTION

This retrospective study aimed to investigate the association between the extent of the bridging and dimensions of sella turcica and the impaction severity of palatally displaced canines. Secondarily, any possible association between skeletal age and gender was evaluated.

METHODS

Panoramic and cephalometric radiographs of 94 patients (63 female, 31 male; 19 pre-peak, 75 post-peak) with palatally displaced canines were evaluated. Sector classification and α angle were used to determine the impaction severity of palatally displaced canines on panoramic radiographs. The distance from the cusp tip of the palatally displaced canines to the occlusal plane (d) and the extent of the bridging and dimensions of the sella turcica were evaluated on cephalometric radiographs.

RESULTS

Sella turcica bridging and dimensions did not vary regarding the impaction severity of palatally displaced canines, but a significant association was found between sella turcica bridging and skeletal age (P = 0.038). Class II (33.3%) and Class III (12.0%) bridging was higher in postpubertal patients. No differences between females and males were detected for the extent of bridging and dimensions of the sella turcica.

CONCLUSIONS

These findings indicate no association between sella turcica bridging and dimensions and the impaction severity of palatally displaced canines. Sella turcica bridging is more frequent in the postpubertal period, whereas gender does not influence sella turcica bridging. More studies are needed to evaluate if the extent of sella turcica bridging may be indicative of severely impacted palatal canines, which in turn would allow for careful monitoring of patients from an early age and for the clinician to take preventive measures.

Investigating the Relationship between the Dimensions and Morphology of Sella Turcica with the Long-Face Growth Pattern and the Vertical Growth Pattern

Introduction

The sella turcica is one of the important landmarks of lateral cephalometry, which is used in orthodontics for the diagnosis, treatment plan, and evaluation of skeletal development and maturity. The purpose of the present study is to investigate the relationship between the dimensions and morphology of sella turcica with the long-face growth pattern and people with an open bite. This study also examines the relationship between sella turcica bridging (STB) and the vertical growth pattern.

Methods

As many as 153 radiographs were analyzed using the Romexis software, considering the basal, gonial, and FMA angles to determine the vertical growth pattern of the face. The basal angle was also used to check for an open bite. Of these patients, 80 had a long vertical face growth pattern, and 73 had a normal face growth pattern. The four landmarks of tuberculum sellae, dorsum sellae, sellae floor, and posterior clinoid were determined on the cephalograms to measure the length, depth, and anteroposterior diameter of the sella turcica.

Results

In this study, it was found that the chance of developing a long face in people with partial and complete bridging is 8.37 and 1.92, respectively. An increase in the length of the sella turcica for one unit decreases the chance of a long face, and as the depth of the sella turcica increases, the chance of a long face increases.

Conclusions

STB is frequently seen in people with long faces. However, this finding should be considered in relation to other diagnostic parameters. The shorter the length and higher the depth of sella turcica, the higher the chance of developing a long face.

Morphological Variations and Anomalies of the Sella Turcica on Lateral Cephalograms of Cleft-Palate-Only (CPO) Patients

Sella turcica abnormalities were reported in malocclusions and clefts. No studies were found on sella turcica abnormalities in CPO patients. This study aimed to compare the prevalence of sella turcica abnormalities on cephalometric radiographs in CPO versus non-cleft orthodontic patients. Cephalograms of CPO patients (n = 89) and controls (n = 89) were analyzed for normal sella turcicae and sella turcica abnormalities. Then, cephalometric analysis was performed using specialized software. Statistical analysis was performed using the Rv.4.1.1 package. No variation in or anomaly of the sella turcica was more frequent in CPO compared to non-cleft individuals. Patients with hypertrophic posterior clinoid process had higher interincisal and 1+:Nasion-A angles. Subjects with hypertrophic posterior clinoid process and double contour of the floor had higher Sella-Nasion-A, Sella-Nasion-B and Sella-Nasion-Pogonion and lower ANB. A pyramidal shape of the dorsum sellae was more prevalent in males, as was double contour of the floor in females. Subjects with an oblique anterior wall had lower SNB, GntgoAr and NLA. Subjects with a normal sella had higher SNPg, ML-NSL and 1+:NAmm. A normal sella was more prevalent in younger patients. CPO is not associated with sella turcica abnormalities compared to non-cleft orthodontic patients.

Osseous Bridges of the Sphenoid Bone: Frequency, Bilateral and Sex Distribution

Sellar (caroticoclinoid and interclinoid), pterygospinous and pterygoalar bridges are osseous bars of the sphenoid bone, which enclose additional foramina in the skull base and could cause entrapment of nerves, occlusion of vessels and obstruction of surgical corridors. This study aimed to investigate the frequency of sphenoid bone bridges in Bulgarians and to assess the bilateral and sex differences in their distribution. This study was performed on head CT scans of 315 Bulgarians, 148 males and 167 females. The sellar bridges were the most common type of sphenoid bridging; particularly the caroticoclinoid bridge. The pterygospinous bridge was a relatively common finding and the pterygoalar bridge was the most infrequent type of bridging. The total frequency of sellar bridges did not differ significantly between both sides and sexes. The pterygospinous bridge did not indicate significant bilateral differences but showed considerable sex differences concerning the left-side occurrence, which was significantly higher in the male series. There were no considerable bilateral and sex differences in the distribution of the pterygoalar bridging. There were no significant correlations between the different types of sphenoid bone bridges, but each type of bridging showed significant positive correlations between the right and left side co-occurrence in males and females.

A CBCT Investigation of the Sella Turcica Dimension and Sella Turcica Bridging in Different Vertical Growth Patterns

This study aimed to compare the sella turcica dimensions and sella turcica bridging (STB) via cone-beam computed tomography in different vertical patterns and then analyze the link between the sella turcica and vertical growth patterns. The CBCT images of 120 skeletal Class I subjects (an equal proportion of females and males; mean age of 21.46 years) were divided into three vertical growth skeletal groups. Student's t tests and Mann-Whitney U tests were used to assess the possible diversity in genders. The link between sella turcica dimensions and different vertical patterns was explored by one-way analysis of variance, as well as Pearson and Spearman correlation tests. The prevalence of STB was compared using the chi-square test. Sella turcica shapes were not linked to gender, but statistical differences were observed among different vertical patterns. In the low-angle group, a larger posterior clinoid distance and smaller posterior clinoid height, tuberculum sellae height, and dorsum sellae height were determined, and the incidence of STB was higher (p < 0.01). Sella turcica shapes were linked to vertical growth patterns, mainly involving the posterior clinoid process and STB, which could be used as an index to assess vertical growth trends.

Microanatomical study of arachnoid granulations and meningeal architecture around Meckel's cave

Although the microanatomy of Meckel's cave (MC) has been well studied, there are still controversies regarding the meningeal architecture of the space. Moreover, there are only general mentions of the arachnoid granulations near MC in just a few sources. This study is aimed at determining the frequency, location, and anatomical variability of the main clusters of arachnoid granulations around MC. The dissection involved 26 isolated specimens of MC fixed in formalin (neutral buffered, 10%). This number included five freshly harvested specimens examined histologically. Additional paraffin block with MC horizontal section was taken from our neuroanatomical collection. Carefully selected anatomical and histological techniques were applied to assess the complex relationships between the arachnoid granulations and adjacent structures. Arachnoid granulations were found around MC in all specimens with different anatomical variations. The main clusters of arachnoid granulations were close to the trigeminal ganglion and its divisions. The dorsolateral wall of MC was a thick layer formed by interweaving bundles of collagen fibers arranged in various directions. The entire MC was surrounded by a dural sleeve (envelope). This sleeve separated MC from the lateral sellar compartment. At its anterior (rostral) end, it formed a cribriform area pierced by individual fascicles of the trigeminal nerve's primary divisions. The connective tissue forming the sleeve was not only continuous with the epineurium but also shifted to the perineuria surrounding individual nerve fascicles. The meningeal architecture around MC has a complex and multilayer arrangement with a collagenous sleeve closely related to the trigeminal ganglion. Arachnoid granulations are typically found around MC.

Physiologic intracranial calcifications incidentally detected on cone beam computed tomography

OBJECTIVES

This study aims to determine the incidence of physiologic intracranial calcifications on cone beam computed tomography (CBCT) and to contribute to the differentiation between physiologic and pathologic intracranial calcifications by sharing their characteristic appearances, with the largest number of patients in the literature and many different types of physiologic calcifications.

STUDY DESIGN

CBCT images of 996 patients admitted to the clinic between 2018 and 2019 were scanned retrospectively. Petroclinoid (PCL) and interclinoid ligaments (ICL), pineal gland, coronoid plexus, falx cerebri, tentorium cerebelli, and other dural calcifications were evaluated in each radiograph.

RESULTS

Physiologic calcification was present in 49.4% of the cases, and pineal gland calcification was the most common (47.6%) type. PCL calcification was detected in 22.1%, and it was mostly bilateral partial. There were complete ICL in 1.2%, coronoid plexus in 11.3%, falx cerebri in 6.3%, tentorium cerebelli in 1.1%, and other dural calcifications in 3.6%. Only PCL calcifications differed between sexes and were more common in males. PCL, pineal gland, and coronoid plexus calcifications were most detected in the third decade of the cases.

CONCLUSIONS

Intracranial calcifications are detected incidentally in CBCT examinations. Some calcifications may indicate pathologic conditions, and patients may need to be referred for further evaluation.

Review of the Petroclinoid Ligament

An ossified left petroclinoid ligament was found during routine dissection of the skull base in an adult male cadaver. The petroclinoid ligament is clinically and surgically important given its anatomical relationships to cranial nerves III, V, and VI, so its ossification is a risk factor for injuries due to trauma, increased intracranial pressure, and vascular and tumor compression resulting in abducens and oculomotor palsies. The causes of petroclinoid ligament ossification are yet to be completely elucidated although several reports have associated them with age-related and physiological processes. Assessing the integrity of the petroclinoid ligament is important during skull base surgical interventions to avoid postoperative complications. Therefore, this paper reviews the petroclinoid ligament and its variation, the ossified petroclinoid ligament.

Sella turcica bridging: a systematic review

PURPOSE

Sella turcica bridging (STB) has significant implications during neurosurgery, since it alters regional anatomy; however, no studies have investigated the global prevalence of STB. Our systematic review aimed to establish the global prevalence of STB, in specimens/individuals with and without comorbidities, in males and females, and of partial, complete, unilateral, and bilateral bridging.

METHODS

A literature search was conducted in MEDLINE/PubMed, ScienceDirect, and Google Scholar with various key words relating to Sella turcica bridging. Quantitative data were extracted and statistically analysed.

RESULTS

Eighty-two studies satisfied our inclusion criteria. The mean prevalence of STB was 26.54%, and most prevalent in Europe. STB was detected more frequently using radiological investigations. STB was less prevalent in healthy individuals (21.12%) when compared to individuals with comorbidities (33.31%). Partial STB was found to be the more prevalent in both individuals with (41.06%) and without (21.55%) comorbidities. The prevalence of unilateral and bilateral STB was only studied in healthy individuals, with unilateral bridging being the more prevalent (6.26% vs 3.84%).

CONCLUSION

The global overall prevalence of Sella turcica bridging in the general population was found to be higher than previously thought. Anatomical and embryological textbooks should consider including information on STB in their texts, due to its considerable prevalence and effects to the regional anatomy.

Sella Turcica Abnormalities, Dental Age and Dental Abnormalities in Polish Children

The frequency of some sella turcica abnormalities on cephalometric radiographs is age related. Chronological age might not overlap with growth; however, no studies could be found on the association between sellar morphology and dental age. Although an association exists between sella turcica bridging and dental abnormalities, no studies have been found correlating sellar abnormalities other than bridging with dental abnormalities. The aim of this study was to find any correlations between sella turcica abnormalities and dental age or dental abnormalities. Methods: Lateral cephalograms and panoramic radiographs of 206 children aged 6–15 years were analyzed for sela turcica abnormalities, Demirijan dental age, and dental abnormalities. Results: The prevalence of dental abnormalities in patients with sela turcica abnormalities was 16.98%, while in those with normal sella, it was 3%. The differences between dental and chronological age were higher in patients with sella turcica abnormalities (p = 0.002). Dental abnormalities were more prevalent (p = 0.001) in patients with sellar abnormalities other than sellar bridging than in those with sellar bridging or normal sella. Conclusions: Sella turcica abnormalities are correlated with delayed dental age. Dental abnormalities are more frequent in patients with sellar abnormalities. Dental abnormalities are less frequent in subjects with sellar bridges compared to those with other sellar abnormalities.

Physiologic and Pathologic Calcifications of Head and Neck Significant to the Dentist

This article aims to help the practitioner identify structures found in routine three-dimensional imaging studies of the head and neck region and understand their significance and possible need for intervention. The prevalence of advanced imaging in dental practice, especially cone beam computed tomography, highlights the need to recognize and identify various high-density structures that are, in fact, soft tissue calcifications or alterations of normal bony anatomy. The wide range of these findings includes both benign and malignant pathologic entities as well as age-related calcifications and remodeling of normal anatomic structures and dystrophic calcifications.

Diagnostic accuracy of lateral cephalograms and cone-beam computed tomography for the assessment of sella turcica bridging

INTRODUCTION

The purpose of this research was to assess the diagnostic accuracy of sella turcica bridging on lateral cephalograms when compared with true sella turcica bridging determined via cone-beam computed tomography (CBCT).

METHODS

A cross-sectional study was conducted using CBCT images from which lateral cephalograms were generated. The study included 185 subjects (118 females and 67 males; age range, 10-30 years; mean age, 16.63 ± 4.20 years). Sella turcica landmarks and related measurements were calculated for both diagnostic modalities and analyzed by 1 examiner. Subjects were classified into 1 of 3 outcome groups: no bridging, partial bridging, and complete bridging. Diagnostic accuracy was evaluated using sensitivity, specificity, positive and negative predictive values, and receiver operator characteristic curves.

RESULTS

Ten patients were diagnosed as complete bridging on CBCT, whereas 31 patients were diagnosed as complete bridging on lateral cephalogram. Although the lateral cephalogram detected all subjects with complete bridging, it incorrectly classified 12% of subjects. The percent agreement between both diagnostic methods was 55.68%, with a kappa statistic of 0.22 on the right sella turcica and 0.20 on the left sella turcica, indicating fair but statistically significant agreement. The overall accuracy of lateral cephalograms as a diagnostic modality in discriminating between no bridging and partial bridging was good as determined with the area under the curve values of 0.86 and 0.85 for right and left sides, respectively.

CONCLUSIONS

Although lateral cephalograms overestimate patients with complete bridging compared to CBCTs, they are a suitable screening modality for accurately suggesting complete sella turcica bridging and differentiating between patients with no bridging and partial bridging.

Microsurgical Anatomy of the Inferomedial Paraclival Triangle: Contents, Topographical Relationships and Anatomical Variations

The inferomedial triangle is one of the two surgical triangles in the paraclival subregion of the skull base. It is delineated by the posterior clinoid process, the dural entrance of the trochlear nerve and the dural entrance of the abducens nerve. The aim of the present article is to describe the anatomical variations within the inferomedial triangle. Measurements of the triangle’s borders and area were supplemented by detailed observations of the topographical anatomy and various arrangements of its contents. Nine adult cadaveric heads (18 sides) and 28 sagittal head sections were studied. The mean area of the inferomedial triangle was estimated to be 60.7 mm². The mean lengths of its medial, lateral and superior borders were 16.1 mm, 11.9 mm and 10.4 mm, respectively. The dorsal meningeal artery was identified within the inferomedial triangle in 37 out of 46 sides (80.4%). A well-developed petrosphenoidal ligament of Grüber was identified within the triangle on 36 sides (78.3%). Although some structures were variable, the constant contents of the inferomedial triangle were the posterior petroclinoid dural fold, the upper end of the petroclival suture, the gulfar segment of the abducens nerve and the posterior genu of the intracavernous internal carotid artery.

Sella Turcica Morphology on Cephalometric Radiographs and Dental Abnormalities-Is There Any Association?-Systematic Review

Background: The sella turcica is a saddle-like structure in the middle cranial fossa on the intracranial surface of the sphenoid bone, visible on lateral cephalograms routinely conducted for orthodontic diagnosis. The development of facial structures follows similar traits to the sella turcica: glandular anomalies may be associated with functional disorders, e.g., altered hormonal levels, thus influencing dental development. The aim of this study is to find out if there is any association between the morphology of the sella turcica on cephalometric radiographs and the presence of dental abnormalities. (2) Methods: The search was conducted on 27 January 2021 in four search engines: Medline (PubMed Central), Scopus, Web of Science, Embase. The keywords used in the search strategy were as follows: “sella turcica” AND (“dental abnormalities” OR “dental anomalies” OR “malocclusion”). Since all the studies finally included were retrospective case–control studies, the Newcastle–Ottawa Quality Assessment Form for Case–Control Studies was applied. (3) Results: The search strategy identified 465 articles: 289 from PubMed, 121 from Scopus, 32 from Web of Science and 23 from Embase. Finally, 10 full-text papers were included into qualitative analysis. (4) Conclusions: Sella turcica bridging is very frequent among orthodontic patients. A clear association exists between dental abnormalities and sella turcica bridging.

Morphology of Sella Turcica and Bridging Prevalence Correlated with Sex and Craniofacial Skeletal Pattern in Eastern Asia Population: CBCT Study

Purpose

Sella turcica bridging (STB) refers to a rare anatomical variation formed by the ossification of the ligament between the anterior and posterior clinoid processes. The presence of the STB was significantly correlated with craniofacial skeleton classification and a higher prevalence rate in skeletal Class III. The current study is aimed at investigating the dimensions of sella turcica and the prevalence of STB in different sexes and on the three craniofacial skeletal patterns using cone beam computed tomography (CBCT).

Materials and Methods

A total of 159 adults (66 males and 93 females), including 3 different craniofacial skeletal patterns (skeletal Classes I, II, and III), were included in the study. The sella turcica dimensions and the prevalence of STB were calculated. An independent t-test and generalized linear model were used to compare the differences in the sella turcica dimensions and the skeletal relations. The Spearman rank correlation coefficient was used to analyze the correlations between sella turcica dimensions and skeletal relation.

Results

The sella length (SL) was 11.05 ± 1.80 mm for males and 10.77 ± 1.56 mm for females. The anterior clinoid distance (ACD) which was measured for the anterior width of sella turcica showed 25.83 ± 2.04 mm and 24.04 ± 2.28 mm for males and females, respectively (p < 0.0001). The overall percentage of complete bridging and partial bridging was 6.6% and 56.9%, respectively. Complete bridges were more common in males (males: 9.1%, females: 4.8%), and partial bridges were more frequent in females (males: 49.2%, females: 62.4%). Both sexes differed with respect to sella turcica dimensions. Moreover, males had a significantly larger ACD, posterior clinoid distance (PCD), and diameter of sella turcica (DST), on both sides, relative to females.

Conclusion

The prevalence rate of complete STB in the Taiwanese population was 6.6%. Significant differences between sexes were found in sella turcica dimensions. The prevalence rates of STB as well as the sella turcica dimensions did not significantly differ between different craniofacial skeletal patterns (skeletal Classes I, II, and III).

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.

Size and bridging of the sella turcica in Japanese orthodontic patients with tooth agenesis

The purpose of this study was to investigate the association between the size and bridging of the sella turcica and tooth agenesis, and whether the likelihood of second premolar agenesis can be predicted from the sella turcica size and bridging in Japanese orthodontic patients. Patients were divided into four groups of 32: groups 1 and 2 consisted of patients with agenesis of the maxillary and mandibular second premolars, respectively; group 3, patients with severe tooth agenesis; and group 4, patients without tooth agenesis. Each group was divided into two subgroups of 16 each based on the patient's age: patients under 14 years of age (groups 1A through 4A, group A) and patients 14 years of age or older (groups 1B through 4B, group B). Lateral cephalograms were used to evaluate the size and bridging of the sella turcica. The interclinoidal distance (ID) was significantly shorter in groups 1 and 3 than in group 4, and in group 3 than in group 2. Group B exhibited significantly greater depth, diameter, area, and perimeter of the sella turcica than group A. Groups 3 and 1B had a significantly higher prevalence of sella turcica bridging than groups 4 and 4B, respectively. Maxillary second premolar agenesis and severe tooth agenesis were associated with a reduced ID irrespective of age and increased occurrence of sella turcica bridging. The early emergence in life of a short ID might be a predictor of possible second premolar agenesis in later life.

Morphology, Incidence of Bridging, Dimensions of Sella Turcica, and Cephalometric Standards in Three Different Racial Groups

This study aims to assess the morphological appearance, incidence of bridging, linear dimensions of sella turcica and establish cephalometric standards in Bosnian, Chinese and Nepalese subjects. This retrospective study examined digital standardized lateral cephalograms of 540 subjects, which consisted of 116 females and 64 males with an age range of 8 to 28 years. The sella morphology, bridging, and size were analyzed on the lateral cephalograms. Steiner's and Rickett's analyses were performed on 270 subjects. Sella turcica presented a normal morphology in most Bosnian (86.7%), and Nepalese (90%) subjects whereas flat-shaped morphology was highly prevalent among Chinese subjects (36.7%). The frequency of full bridging was 7.2%, 2.8%, and 11.7% for Bosnian, Chinese, and Nepalese subjects, respectively. A significant correlation was detected between the length of sella turcica and gender of Bosnian subjects, whereas the size of sella turcica and gender of Chinese and Nepalese subjects were not affected. A direct correlation existed between age and size of sella turcica of Bosnian subjects. A significant correlation was detected between length and diameter of sella turcica and age in Chinese and Nepalese subjects. A statistically significant difference was found in length (P < 0.001), depth (P < 0.01) and diameter (P < 0.001) of sella turcica with race. The diameter of sella turcica was the only parameter significantly associated with race, gender and age. Significant differences were found between cephalometric norms in different racial groups. These findings assist orthodontists, neurosurgeons, and forensic medical investigatiors during orthodontic treatment planning, diagnosis of pathology of the pituitary gland, and age determination.

Association between sella turcica bridging and congenitally missing maxillary lateral incisors

Background/purpose

Sella turcica bridging (STB) and its association with dental anomalies has been investigated and reported in literature. This is the first study that exclusively compared STB among the orthodontic patients with congenital missing maxillary lateral incisors (CMMLI) and individuals with complete dentition.

Materials and methods

The retrospective study has recruited 49 patients with CMMLI (13 males and 36 females aged between 12 and 43 years) and 49 patients with complete dentition. Sella dimensions and association of STB with CMMLI were evaluated and the results were analysed using descriptive and inferential statistics.

Results

The comparison of mean diameter, length, and depth of sella between groups showed reduction in length among the CMMLI (p = 0.04). CMMLI group has shown a significant higher (p < 0.05) number of subjects (69.4%) with calcification when compared to control group (46.9%). The odds of having sella's bridging in patients with CMMLI were 2.5 times greater than patients with full set of teeth. Age showed a significant (p < 0.001) positive correlation with sella's width only in CMMLI.

Conclusion

Patients with CMMLI tend to have an increased frequency of STB, and decreased sella turcica length.

Association between sella turcica bridging and altered direction of dental eruption: A case-control study

Background

Calcification between the anterior and posterior clinoid processes, also the so-called sella turcica bridging, has been associated in some studies with skeletal anomalies as well as with dental and eruption disturbances. It was hypothesized that sella turcica bridging was associated with an altered direction of dental eruption. The aim of the study was to assess whether there was a relationship between the degree of calcification and the presence or absence of an alteration in the tooth eruption direction.

Material and Methods

A case-control multicenter study was conducted. The study population consisted of 150 subjects (age 10-50 years), 30 of which presented some type of alteration of the direction canine eruption (impactation or transposition) (cases) and 120 selected at random who did not present altered direction of dental eruption (controls). Cases and controls were matched by age, sex, and approximate date of starting orthodontic treatment. Lateral cephalometric radiographies were obtained and the extent of the sella turcica bridging was measured using a Vernier caliper and scored as no calcification, partially calcified, and completely calcified.

Results

The frequency of a partially or completely calcified sella turcica bridge was significantly higher among cases with altered direction of dental eruption as compared with controls. There was a trend towards a shorter length of sella turcica in subjects with two or more canine eruption alterations. Sella turcica bridging was unrelated to sex, but it was significantly influenced by age.

Conclusions

Sella turcica bridging is frequently detected in subjects with altered direction of dental eruption of canines. Key words:Dental eruption, sella turcica bridging, anterior clinoid process calcification, posterior clinoid process calcification, cephalometric radiographs.

Cone Beam Computed Tomographic Evaluation of Intracranial Physiologic Calcifications

OBJECTIVE

The aim of the present study was to evaluate the incidence of physiologic intracranial calcifications detected in cone beam computed tomography (CBCT) images of a Turkish subpopulation.

METHODS

The CBCT image of the full head of 573 patients taken between 2015 and 2018 was evaluated retrospectively. The prevalence of habenular calcification, petroclinoid ligament, coroid plexus, interclinoid ligament (ICL), and carotico-clinoid ligament (CCL) calcifications was investigated. The age and gender of the patients were recorded.

RESULTS

Intracranial calcification was found in 190 (33.1%) of 573 cases. The frequency of physiological calcifications is respectively; 19.2% were found as habenular, 4.88% as ICL, 3.83% as CCL, 2.7% as petroclinoid ligament, and 2.4% as choroid plexus. 38.2% of the women and 29.3% of the men had intracranial calcification. In 4 patients, both ICL and CCL ossification were detected. No statistically significant relationship was found between age, gender, and calcifications.

CONCLUSION

Cone beam computed tomography is a widely used imaging technique for dental diagnosis and treatment. Intracranial physiological calcifications may be a common incidental finding of CBCT scans.

The Petroclinoid Ligament: Its Morphometrics, Relationships, Variations, and Suggestion for New Terminology

The anatomy and definition of the petroclinoid ligament (PCL) and its relationship with the abducens nerve are variably described. The goal of this study was to clarify the anatomy of the PCL and better elucidate its relationship with the abducens nerve. Thirty-six sides from 18 fresh-frozen adult cadaveric heads were used in this study. Specimens were all Caucasian and derived from 10 males and 8 females. The mean age at death was 79 years. Dissection of the PCL and abducens nerve was performed using a surgical microscope. The anterior and posterior attachments of the PCL, and position of the abducens nerve were noted. Subsequently, the width, thickness, and length of the ligament, and diameter of the abducens nerve were measured. Thirty-one sides (86.1%) were found to have a PCL, on two sides (5.6%), the PCL was ossified, and on three sides (8.3%), the PCL was absent. The width, thickness, and length of the PCL ranged from 0.54 to 3.39, 0.07 to 0.49, and 3.27 to 17.85 mm, respectively. No PCL had an anterior attachment onto the posterior clinoid process but rather, the clivus. Therefore, based on our findings, the PCL would be better described as the petroclival ligament.

Skull base ligamentous mineralisation: evaluation using computed tomography and a review of the clinical relevance

Objectives

To determine the frequency, morphologic and demographic characteristics, and clinical relevance of the mineralisation of six skull base ligaments (interclinoid, caroticoclinoid, petrosphenoid, posterior petroclinoid, pterygospinous, and pterygoalar).

Methods

This is a retrospective review of 240 CT scans of the paranasal sinuses (ages 6–80 years). A limited systematic review was performed primarily using Embase and Medline databases.

Results

Ligamentous mineralisation was well delineated on CT and occurred at ≥ 1 location in 58.3% of patients. There was a nonsignificant trend towards a greater incidence with advancing age. The interclinoid and posterior petroclinoid ligaments were most commonly mineralised (22.1% and 18.3%, respectively); the petrosphenoid and pterygoalar ligaments were least frequently mineralised (10.8% and 6.3%, respectively). The mean age of patients with posterior petroclinoid mineralisation was significantly greater than those with interclinoid and petrosphenoid mineralisation and was not seen in patients aged 6–20 years. The literature review highlighted the clinically relevant potential for mineralised ligaments to cause barriers to surgical access (e.g. to the foramen ovale), increase the risk of neurovascular injury during surgery at the skull base (e.g. during anterior clinoidectomy), and predispose to neural impingement.

Conclusions

Skull base ligamentous mineralisation is commonly encountered on CT imaging. Given the potentially significant clinical implications, an understanding of the morphological appearances is of importance to those planning interventions at the skull base. To the authors’ knowledge, this study is the first to comprehensively evaluate such a wide range of skull base ligaments using CT. For some ligaments, the incidence on CT has not been previously described.

Morphology, incidence of bridging, and dimensions of sella turcica in different racial groups

OBJECTIVES

This study was performed to assess the morphological appearance, incidence of bridging, and linear dimensions of the sella turcica (ST) in Bosnian and Iraqi subjects, and to identify associations of sex, age, and racial group with the size of the ST.

METHODS

The digital standardised lateral cephalograms of 360 Bosnian and Iraqi patients (116 female, 64 male; age range 8-28 years) were retrospectively analysed. The following ST-related parameters were analysed on the lateral cephalograms: sella morphology, sella bridging, and sella size. The data were correlated with sex, age, and race.

RESULTS

The ST exhibited a normal morphology in most subjects of both races (86.7%). The frequency of partial bridging was found in 38.9 and 37.2% of Bosnian and Iraqi subjects, respectively. A significant correlation was detected between the length of the ST and sex in both the Bosnian and Iraqi subjects (p < 0.05). A direct correlation was present between patient age and the size of the ST in both races at the 0.01 and 0.001 levels for depth, length, and diameter. When race was compared with sella size, a significant difference was found in the length and depth of the ST (p <  0.001).

CONCLUSIONS

Similarities were found between Bosnian and Iraqi subjects in the morphology, incidence of bridging, and linear dimensions of the ST. Length was the only parameter significantly associated with sex, age, and racial group. These findings could be used as reference standards for studying the ST in both races.

Relationship between sella turcica bridging and cephalometric parameters in adolescents and young adults

OBJECTIVES

Sella turcica bridging occurs with fusion or calcification of the anterior and posterior clinoid processes in the middle cranial region. This study aimed to compare the cephalometric parameters among normal shape, partial bridge, and total bridge of the sella turcica in adolescent and young adult subjects.

METHODS

This retrospective study was performed on the lateral cephalometric radiographs of 410 Turkish adolescent and young adult subjects. The subjects were divided into three groups: normal sella turcica shape (128 females, 32 males; mean age: 17.7 ± 1.54 years), partial sella turcica bridge (129 females, 32 males; mean age: 17.8 ± 2.15 years), and total sella turcica bridge (66 females, 23 males; mean age: 18.2 ± 1.82 years). Thirteen angular and eight linear cephalometric measurements were performed using a cephalometric software program. The data were analyzed by one-way analysis of variance, and the Kruskal-Wallis test with the Bonferroni correction.

RESULTS

Significant differences were found for Nperp-A distance, Nperp-Pg distance, and palatal plane-to-anterior cranial base angle among the groups (p < 0.016). There were no significant differences in the cephalometric parameters between the partial and total sella turcica bridging groups (p > 0.05).

CONCLUSIONS

This study evaluated a large amount of data for cephalometric measurements focusing on the degree of calcification of the sella turcica in adolescent and young adult subjects. The maxilla and mandible were located in a sagittally retrusive position in the partial and total sella turcica bridge subjects compared with the normal sella turcica shape subjects.

Relationship between bridging and dimensions of sella turcica with classification of craniofacial skeleton

PURPOSE

In orthodontics, it is essential to determine the craniofacial skeleton pattern (class I, II, III) for planning treatment. Sella turcica bridging that is seen on lateral cephalometric radiographs is considered as a normal finding. This study aimed to compare sella turcica bridging and its dimensions in patients with various craniofacial patterns.

MATERIAL AND METHODS

A total of 105 lateral cephalometric radiographs (53 men and 52 women), aged 14-26 years, were randomly and equally assigned to three groups of class I, II, and III, respectively. The length, diameter, and depth of the sella turcica as well as sella turcica bridging were determined on radiographs. The chi-squared test was used for assessing the relationship between sella turcica bridging and craniofacial skeleton classification. ANOVA was used for assessing the relationship between the dimensions of the sella turcica and craniofacial skeleton classification. The Pearson's correlation coefficient was used for assessing the relationship between age and the dimensions of the sella turcica.

RESULTS

The sella turcica had a normal shape in 64.76% of patients, whereas 35.33% of patients had sella turcica bridging. In total, 11.42% of patients belonged to class I, 34.28% to class II, and 66.62% to class III. The diameter of the sella turcica had a significant relationship with age; the diameter of the sella turcica increased with age (p < 0.001).

CONCLUSIONS

There is a significant relationship between craniofacial skeleton patterns and sella turcica bridging, i.e., the incidence of sella turcica bridging is higher in class III patients. The sella turcica had a greater diameter in older patients.

A CBCT Investigation of the Association between Sella-Turcica Bridging and Maxillary Palatal Canine Impaction

Objectives

To investigate the association between unilateral/bilateral maxillary canine impaction and sella-turcica bridging using CBCT imaging.

Methods

This retrospective comparative study analyzed 76 CBCT images of the craniofacial complex including sella-turcica. The impacted cuspid group consisted of thirty-eight subjects (7 males, 31 females; mean age, 14.6 ± 3.2 years) diagnosed with unilateral (left n = 14, right n = 11) or bilateral (n = 13) palatal canine impaction. The control group included thirty-eight subjects matched by sex (7 males, 31 females; mean age, 19.5 ± 3.6 years) with no impaction. Multinomial logistic regression analysis was used to determine the association between unilateral/bilateral canine impaction and right and left sella-turcica bridging.

Results

The prevalence of sella-turcica bridging was 59.3% and 50% in the impacted canine and control groups, respectively. Although the odds for unilateral canine impaction were increased in the right and left sella-turcica bridging groups compared to the controls, the difference was not statistically significant. The risk of bilateral impaction was different between the two sides of sella-turcica bridging, but, again, the findings were not statistically significant.

Conclusion

Contrary to previous 2D studies, there is no statistically significant association between unilateral/bilateral palatal canine impaction and sella-turcica bridging when using 3D CBCT.

Sella turcica bridging and dental anomalies: is there an association?

BACKGROUND

Sella turcica bridging (STB), or calcification of the interclinoid ligament of sella turcica, has been reported to be associated with some dental anomalies (palatal canine impaction and transposition).

HYPOTHESIS OR AIM

The aim of the study was to find any association between canine impaction, hyperdontia or hypodontia and sellar dimensions or bridging.

DESIGN

Lateral cephalometric radiographs from 78 patients with impacted canines, 68 with dental agenesis and 17 with hyperdontia were collected. Linear dimensions of sella turcica were calculated and compared to those of a control group (47 individuals). A standardize scoring scale was used to quantify the extent of STB from each radiographs.

RESULTS

The frequency of partial and complete calcifications of sella in patients with dental anomalies is increased when compared to controls. STB can influence the interclinoid distance but does not affect other linear dimensions of sella. No statistically significant difference has been found in sellar dimensions and STB expression when evaluating radiographs at different ages.

CONCLUSIONS

STB is frequently found in patients with dental abnormalities.

Reproducibility of the sella turcica landmark in three dimensions using a sella turcica-specific reference system

Purpose

This study was performed to assess the reproducibility of identifying the sella turcica landmark in a three-dimensional (3D) model by using a new sella-specific landmark reference system.

Materials and Methods

Thirty-two cone-beam computed tomographic scans (3D Accuitomo® 170, J. Morita, Kyoto, Japan) were retrospectively collected. The 3D data were exported into the Digital Imaging and Communications in Medicine standard and then imported into the Maxilim® software (Medicim NV, Sint-Niklaas, Belgium) to create 3D surface models. Five observers identified four osseous landmarks in order to create the reference frame and then identified two sella landmarks. The x, y, and z coordinates of each landmark were exported. The observations were repeated after four weeks. Statistical analysis was performed using the multiple paired t-test with Bonferroni correction (intraobserver precision: p<0.005, interobserver precision: p<0.0011).

Results

The intraobserver mean precision of all landmarks was <1 mm. Significant differences were found when comparing the intraobserver precision of each observer (p<0.005). For the sella landmarks, the intraobserver mean precision ranged from 0.43±0.34 mm to 0.51±0.46 mm. The intraobserver reproducibility was generally good. The overall interobserver mean precision was <1 mm. Significant differences between each pair of observers for all anatomical landmarks were found (p<0.0011). The interobserver reproducibility of sella landmarks was good, with >50% precision in locating the landmark within 1 mm.

Conclusion

A newly developed reference system offers high precision and reproducibility for sella turcica identification in a 3D model without being based on two-dimensional images derived from 3D data.

Isolated unilateral oculomotor nerve neuropraxia following a trivial fall in a patient with calcified posterior petroclinoid ligament

Isolated traumatic oculomotor nerve palsy caused by a trivial fall is extremely rare. We report a case of this condition. A 49-year-old woman had distal radius fracture and ptosis on the same side after having a trivial domestic fall. She did not show any clinical or radiological signs of head injury. Computerized tomography revealed a calcified posterior petroclinoid ligament which has direct anatomical and pathological relation with the oculomotor nerve.

Ossification of the Posterior Petroclinoid Dural Fold: A Cadaveric Study with Neurosurgical Significance

Objectives The roof of the porus trigeminus, composed of the posterior petroclinoid dural fold, is an important landmark to the skull base surgeon. Ossification of the posterior petroclinoid dural fold is an anatomical variation rarely mentioned in the literature. Such ossification results in the trigeminal nerve traversing a bony foramen as it enters Meckel cave. The authors performed this study to better elucidate this anatomical variation. Design Fifteen adult cadaveric head halves were subjected to dissection of the middle cranial fossa. Microdissection techniques were used to examine the posterior petroclinoid dural folds. Skull base osteology was also studied in 71 dry human skulls with attention paid to the attachment point of the posterior petroclinoid dural folds at the trigeminal protuberances. Setting Cadaver laboratory Main Outcome Measures Measurements were made using a microcaliper. Digital images were made of the dissections. Results Completely ossified posterior petroclinoid folds were present in 20% of the specimens. Of the 142 dry skull sides examined, 9% had large trigeminal protuberances. Conclusions Based on this study, the posterior petroclinoid dural fold may completely ossify in adults that may lead to narrowing of the porus trigeminus and potential compression of the trigeminal nerve at the entrance to Meckel cave.

Dimensions and morphologic variations of sella turcica in type 1 diabetic patients

INTRODUCTION

Some chronic diseases are associated with changes in the morphology of sella turcica, and type 1 diabetes is the most common chronic disease in children and adolescents. Therefore, the aim of this study was to evaluate the size and morphology of sella turcica in patients with type 1 diabetes compared with a healthy control group.

METHODS

The study included 76 type 1 diabetic patients (38 boys, 38 girls; ages, 14.16 ± 2.46 years) and 76 controls (38 boys, 38 girls; ages, 14 ± 2.08 years). The groups were categorized as pubertal and postpubertal according to bone age. The length, height, and diameter of sella turcica were measured. Then the morphology of sella turcica was analyzed and categorized as normal, oblique anterior wall, bridging, double contour of the floor, irregularity in the posterior part of dorsum sellae, or pyramidal shape of the dorsum sellae. All measurements were made on tracings of cephalometric radiographs. Differences between the groups were tested with the Mann-Whitney U test. Categorical data were evaluated with the Fisher exact test, and the Bonferroni correction was made. The significance level was assigned as P <0.05.

RESULTS

There was no statistically significant difference in the dimensions of sella between the diabetic patients (diameter, 12.20 ± 1.49 mm; length, 10.49 ± 1.55 mm; height, 8.07 ± 1.25 mm) and the controls (diameter, 12.45 ± 1.43 mm; length, 10.90 ± 1.73 mm; height, 8.29 ± 1.66 mm). However, diameter and length increased with age in the overall assessment. Length was greater in the postpubertal controls (11.39 ± 1.69 mm) compared with the pubertal controls (10.41 ± 1.64 mm). Diameter was greater in the postpubertal diabetic patients (1.283 ± 1.55 mm) than in the pubertal diabetic patients (11.56 ± 1.12 mm) and was specifically higher in postpubertal boys. Normal sella morphology was less common in general in the diabetic patients, particularly in the diabetic boys and diabetic pubertal boys (P <0.05).

CONCLUSIONS

The measurements concerning sella were similar in the type 1 diabetic and control subjects, but dysmorphologic types were more common in diabetic patients.

Incidence of osseous interclinoid bars in Indian population

PURPOSE

Parasellar interclinoid bars are significant in surgical management while dealing with the vascular, neoplastic or traumatic lesions of the central skull base and can also compress the surrounding structures giving rise to various clinical symptoms. The literature cites several case reports but systematic study of these bars has not been done. Therefore this study was carried out to see the incidence of osseous interclinoid bars in Indian population.

METHOD

Two hundred and fifty adult dried human skulls were studied.

RESULTS

It was observed that the bony bars between the three clinoid processes can be divided into four types (Types I, II, III, IV). Due to the presence of these bars three types of interclinoid foramina were formed. A total incidence of 22% of various types of interclinoid bars was observed, out of which 12% were Type I, 5.6% Type II, 4% type III and only 0.4% were of type IV variety.

Bridging of the sella turcica in skeletal Class III subjects

Several investigations have analysed the frequency of sella turcica anomalies in patients with severe craniofacial deviations. Until now, there have been no studies concerning the prevalence of sella turcica bridging in homogenous groups of patients. Therefore, the aims of this controlled study were to analyse the prevalence of sella turcica bridging and measure the size of the sella turcica in two well-defined groups of Caucasian individuals. In a multicentre retrospective study, 400 pre-treatment lateral cephalograms of adult patients (over 17 years of age) with a skeletal Class III (n = 250, 132 females and 118 males) or a skeletal Class I (n = 150, 94 females and 56 males) malocclusion were analysed. The morphology, length, depth, and diameter of the sella turcica were investigated. For statistical analysis, chi-square and t-tests were used. Skeletal Class III patients presented a significantly higher rate of sella turcica bridging, 16.8 per cent (P = 0.031), in comparison with skeletal Class I patients, whose rate was 9.4 per cent. No differences between females and males were detected for the length, depth, and diameter of the sella turcica. Bridging of the sella turcica could be seen radiographically in skeletal Class III subjects.

Skeletal Anomalies and Normal Variants in Patients with Palatally Displaced Canines

Objective: To test the null hypothesis that there is no increased prevalence of skeletal anomalies and/or normal variants as evidenced by the cephalometric radiographs of patients with palatally displaced canines (PDC).

Materials and Methods: The treatment records of 38 white subjects between 14 and 20 years old with PDC were collected and evaluated retrospectively. Inclusion criteria for the study required that the case records include good-quality panoramic radiographs and lateral cephalometric radiographs with the first four cervical vertebrae clearly visible. The anomalies recorded for each case included sella bridge, atlanto-occipital ligament calcification or ponticulus posticus, and posterior arch atlas deficiency. A control group consisted of 70 consecutively treated subjects who had no other dental anomalies and whose maxillary canines had erupted normally. Fisher's exact test and Pearson's chi-square test were used to determine possible statistically significant differences in the incidence of skeletal anomalies and/or normal variants between the group of patients with PDC and the control group.

Results: The prevalence of skull anomalies and normal variants seen in cephalometric radiographs was increased in patients with PDC. Because of the presence of ponticulus posticus (Pearson's chi-square, P &lt; .050; Fisher's exact test, P &lt; .052), sella bridge (Pearson's chi-square, P &lt; .042; Fisher's exact test, P &lt; .042), and posterior arch deficiency (Pearson's chi-square, P &lt; .047; Fisher's exact test, P &lt; .039), statistically significant differences were observed between subjects with PDC and the control group.

Conclusions: The null hypothesis was rejected. There is an increased prevalence of skull skeletal anomalies and/or normal variants in patients with PDC.