Ossification around intercavernous sinus: An osteological finding that can complicate trans - sphenoidal surgery

The aim of the study was to document an anatomical variation around the sella turcica which was unique and lacked any reference in the literature. A low lying osseous bar connecting the right middle clinoid process to the midpoint of the right lateral border of the dorsum sella was observed in a human skull specimen. The osseous bar was forming a foramen close to the floor of the sella, and the structure in association with this part of sella is the inferior intercavernous sinus. Measurements of the sella turcica bridge (STB), carotico-clinoid foramen (CCF), interclinoid foramen (ICF) on both sides and that of the ossified bar and foramen formed by itself were taken with the help of ImageJ software. The values observed for the measurements of different parameters of STB and its components, for CCF and ICF were bilaterally different. While the values for the osseous bar and foramen formed by it cannot be compared because of its unilateral occurrence. The presence of foramen around the inferior intercavernous sinus may lead to difficulty in performing procedures like transsphenoidal surgery (TSS) or extended TSS (eTSS) while extracting intradural lesions, thus increasing the chances of haemorrhage.

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.

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.

Anatomical analysis on the lateral bone window of the sella turcica: a study on 530 adult dry skull base specimens

OBJECTIVE

To investigate the morphometric characteristics of the lateral bone window (LBW) of the sella turica.

METHODS

A descriptive anatomical study of LBW was performed in 530 cases of dry skull base specimens with relatively complete sella turcica. Detailed morphometric characteristics such as dimensions and classification of the LBW was studied. All data analysis was performed using SPSS 17.0 statistical software.

RESULTS

LBW is located in the lateral bony structures of sella turcica. The mean area sizes of the LBW were 75.99 ± 25.81 mm(2) (left) and 76.00 ± 25.53 mm(2) (right). There was no significant difference and there was a ​​good positive correlation between bilateral areas of the LBWs. The area size of the LBWs is graded as follows: Grade A (< 60 mm(2)), B (60~90 mm(2)) and C (> 90 mm(2)). LBW morphology was typed as follows: Type I, II, III, IV. And Tpye III includes Type IIIa and IIIb; Type IV includes Type IVa, IVb, IVc, IVd.

CONCLUSIONS

The lateral bone window of sella turcica is an important structure located between pituiary fossa and parasellar region. The morphological measurements and variations of LBW in this study will provide preliminary data for further anatomical study of sella turcica. Moreover, knowing detailed anatomy of this region is essential for neurosurgeons who make surgery on cranial base or for teaching about the sella turcica in the neuroanatomy lab.

Prevalence and Dimensions of Complete Sella Turcica Bridges and Its Clinical Significance

The ossification of ligamentous structures in various part of the body may result in clinical problems. The complete sella turcica bridge corresponds to the complete ossification of the interclinoid ligaments. Fifty dry adult skull bones were studied for presence of ossified interclinoid ligaments. Three skull bones show sella turcica bridge, of which one shows bilateral and two show unilateral. The ligamentous or bony interclinoid connections have important neuronal and vascular relations and are both clinically and surgically important. The knowledge of detailed anatomy of the interclinoid ligament can increase the success of diagnostic evaluation and surgical approaches to the region. The existence of a bony caroticoclinoid foramen may cause compression, tightening, or stretching of the internal carotid artery. Further, removing the anterior clinoid process is an important step in regional surgery; the presence of a bony caroticoclinoid foramen may have high risk.