A cephalometric morphometric study of the sella turcica

Calcification patterns and morphology of Sella turcica are related to anteroposterior skeletal malocclusions: A cross-sectional study

BACKGROUND

The sphenoid bone is an irregular, unpaired, symmetrical bone located in the middle of the anterior skull and is involved in craniofacial growth and development. Since the morphology of Sella turcica (ST) is associated with different craniofacial patterns, this study aimed to investigate if there is a correlation between ST morphology on the one hand and sagittal craniofacial patterns on the other hand.

METHODS

This study was conducted with a convenience sample that included Brazilian individuals undergoing orthodontic treatment. Lateral cephalograms were used to evaluate the calcification pattern and morphology of ST, as well as skeletal class by analyzing the ANB angle. Pearson's chi-square test with Bonferroni post-hoc test was performed to evaluate the association between ST calcification pattern and morphology, and anteroposterior skeletal malocclusion. The established significance level was 0.05.

RESULTS

The study collective was comprised of 305 orthodontic patients (178 (58.4 %) female, 127 (41.6 %) male), who had a mean age of 23.2 (±10.6) years. 131 participants (42.9 %) presented skeletal class I, 142 (46.6%) skeletal Class II, and 32 (10.5%) had a skeletal class III. The degree of prognathism of the mandible showed a homogenous distribution within the study collective (91 (29.9 %) orthognathic, 100 (32.9 %) retrognathic, 113 (37.2 %) prognathic mandible). Concerning the maxilla, 92 (30.2%) individuals presented an orthognathic upper jaw, whereas 60 (19.7%) showed maxillary retrognathism and 153 (50.2%) maxillary prognathism. Compared to patients with skeletal class I, skeletal class III individuals presented significantly more hypertrophic posterior clinoid process (p<0.007) and pyramidal shape of the dorsum of the ST (p<0.038).

CONCLUSIONS

Our results suggest that the hypertrophic posterior clinoid process and pyramidal shape of the ST dorsum are more prevalent in individuals with skeletal class III malocclusion.

Morphometric Analysis of the Sella Turcica on Cone-Beam Computed Tomography Images

INTRODUCTION

Sella turcica is an important anatomic formation that contains the pituitary gland and is in a close neighborhood with many vital structures. It is important to know the morphometry of the sella turcica, as it is a transition point during surgical interventions such as the endoscopic endonasal transsphenoidal approach to the region. The findings obtained are thought to be useful in the examination of sella turcica and surrounding structures and will contribute to the literature by knowing the morphometry of the region for the surgical method.

METHOD

In this study, cone-beam computed tomography images of 400 individuals, 200 females and 200 males, aged between 18 and 65 years, who did not have craniofacial pathology, who applied to Gaziantep University, Faculty of Dentistry between 2015 and 2020 for any reason, were evaluated retrospectively. In the sagittal section, 8 parameters were examined, 6 of which were transverse.

RESULTS

The length () of the sella turcica in the sagittal plane is 10.19±1.77 mm, the diameter of the sella turcica is 11.6±1.69 mm, the anterior height of the sella turcica is 7.88±1.56 mm, the median height of the sella turcica 8.18±1.42 mm, posterior height of sella turcica 6.98±1.31 mm, width of sella turcica 11.10±1.6 mm. The distance between anterior clinoid processes in the transverse plane was 24.93±2.57 mm, and the distance between posterior clinoid processes was 14.92±2.46 mm.

CONCLUSION

It was determined that there was an increase in many parameters with age, and length of the sella turcica and anterior clinoid processes were statistically significantly higher in males.

Exploring the association between PITX2, third molars agenesis and sella turcica morphology : PITX2, third molars agenesis and sella turcica morphology

OBJECTIVES

PITX2 is required for mammalian development and single nucleotide polymorphisms (SNPs) in this gene could be involved in dental agenesis and sella turcica patterns. Thus, the present study evaluated the association between SNPs in PITX2, third molars agenesis and sella turcica phenotypes.

MATERIALS AND METHODS

The sample consisted of healthy orthodontic German patients with lateral cephalometric radiographs with clearly visualization of the sella turcica, and dental orthopantomograms. The morphological variations of the sella turcica were evaluated using the lateral cephalograms, while third molar agenesis was evaluated using orthopantomograms. DNA isolated from buccal cells was used for genotyping three SNPs in PITX2 (rs3796902, rs1947187, and rs2595110). The analyzes were performed using a significance of 5%. There was no association between third molar agenesis and sella turcica phenotypes (p > 0.05). SNPs in PITX2 were also not associated with third molars agenesis (p > 0.05).

RESULTS

SNPs in PITX2 were associated with sella turcica phenotypes. The rs3796902 was associated with hypertrophic posterior clinoid process (p = 0.013). The rs1947187 and rs2595110 were associated with sella turcica bridge type A (p = 0.013 and p = 0.011, respectively for genotype distribution). Patients that carry the genotypes GG-CC-AG (rs3796902- rs1947187- rs2595110) had 7.2 higher chance to present sella turcica bridge type A (p = 0.002; Odds ratio = 7.2, Confidence interval 95% 2.04-27.04).

CONCLUSIONS

Third molar agenesis was not associated with SNPs in PITX2 and sella turcica phenotypes. SNPs in PITX2 may have an important role in sella turcica pattern.

Sella turcica morphometrics in subjects with down syndrome

OBJECTIVE

Since the number of patients diagnosed with Down syndrome seeking orthodontic treatment is increasing, clinicians could contribute by applying diagnostic modalities used frequently in the orthodontic field for research purposes. Thus, The aim of the present study is to implement morphometric methods to investigate the size and shape of sella turcica in subjects with Down syndrome.

MATERIALS AND METHODS

In this retrospective study, archive records of 24 individuals with Down syndrome were compared to 48 healthy controls matched for age and gender. Parameters such as sella anterior, midpoint, and posterior height were measured, as well as sella width, area, and length were calculated. Independent sample t-tests were applied for the comparison of differences in sella turcica dimensions. Geometric morphometric analysis of the sella was performed with, implementing methods such as Procrustes superimposition and principal component analysis. Statistical significance was set at p<0.05.

RESULTS

Statistically significant differences were found for sella anterior height, sella midpoint height, sella posterior height, sella maximum height, sella length, and sella area. All the aforementioned values were significantly increased in the Down syndrome subjects (p<0.05). Principal component analysis (PCA) depicted a statistically significant difference in sella shape between patients with Down syndrome and healthy controls (p<0.05).

CONCLUSIONS

Subjects with Down syndrome presented significantly increased sella turcica dimensions as well statistically significant differences in shape compared to healthy controls.

A Cephalometric Study of Sella Turcica: Correlation of Its Size with Different Skeletal Malocclusions

Introduction

The present study was done to determine the size of the sella turcica in different skeletal type subjects and to evaluate if any significant difference exists between them, which could be the basis for early diagnosis.

Materials and methods

A total of 60 lateral cephalograms of patients above 15 years of age were selected and distributed according to skeletal malocclusion into class I (n = 20), class II (n = 20), and 20 class III (n = 20). Syndromic patients (physically/mentally/both) or patients with major illnesses were not included. Two linear measurements of the sella turcica, that is, length and depth in mid-sagittal plane, were obtained in accordance with Silverman and Kisling method. Unpaired t-test and one-way analysis of variance (ANOVA) were performed.

Results

The mean length of sella turcica in class I, class II, and class III subjects was 3.81, 3.37, and 3.9, respectively. Similarly, the mean depth of sella turcica in class I, class II, and class III subjects was 7.6, 6.83, and 9.075, respectively.

Conclusion

No significant difference in length of the sella turcica could be found between different skeletal types. Maximum depth of sella turcica was found to be in subjects with class III and minimum with class II skeletal types.

Clinical significance

The linear dimensions of sella turcica can be used to approximate the pituitary gland size. The pedodontist should be familiar with different morphologies of the sella turcica to differentiate normal from abnormal appearance so that treatment can be diagnosed and treated early.

How to cite this article

Grover N, Khan DUZ, Bhagchandani J, et al. A Cephalometric Study of Sella Turcica: Correlation of Its Size with Different Skeletal Malocclusions. Int J Clin Pediatr Dent 2023;16(S-3):S229-S232.

Morphology of the Sella Turcica: A Meta-Analysis Based on the Results of 18,364 Patients

BACKGROUND

This meta-analysis aimed to present data on the sella turcica (ST) morphology and variations. Furthermore, a detailed morphometric analysis of the ST was conducted.

METHODS

Major online databases such as PubMed, Scopus, Embase, Web of Science, and the Cochrane Library were searched through. The overall search process was conducted in three stages.

RESULTS

This meta-analysis was based on the results of 18,364 patients and demonstrates the most up-to-date and relevant data regarding the morphology of the ST in the available literature. Four classification methods of the ST shape can be distinguished, in which the most commonly occurring variants are the normal ST (55.56%), the U-shaped ST (73.58%), the circular type of ST (42.29%), and non-bridging ST (55.64%). The overall midpoint height of the ST was 6.59 mm (SE = 0.13). The overall length of the ST was 9.06 mm (SE = 0.15). The overall volume of the ST was 845.80 mm3 (SE = 288.92). Four main classification methods of ST morphology can be distinguished in the available literature. Various morphometric characteristics of the ST may be applied in clinical practice to evaluate its shape, dimensions, and normal or pathological variants.

Deep learning-based automatic sella turcica segmentation and morphology measurement in X-ray images

BACKGROUND

Although the morphological changes of sella turcica have been drawing increasing attention, the acquirement of linear parameters of sella turcica relies on manual measurement. Manual measurement is laborious, time-consuming, and may introduce subjective bias. This paper aims to develop and evaluate a deep learning-based model for automatic segmentation and measurement of sella turcica in cephalometric radiographs.

METHODS

1129 images were used to develop a deep learning-based segmentation network for automatic sella turcica segmentation. Besides, 50 images were used to test the generalization ability of the model. The performance of the segmented network was evaluated by the dice coefficient. Images in the test datasets were segmented by the trained segmentation network, and the segmentation results were saved in binary images. Then the extremum points and corner points were detected by calling the function in the OpenCV library to obtain the coordinates of the four landmarks of the sella turcica. Finally, the length, diameter, and depth of the sella turcica can be obtained by calculating the distance between the two points and the distance from the point to the straight line. Meanwhile, images were measured manually using Digimizer. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to analyze the consistency between automatic and manual measurements to evaluate the reliability of the proposed methodology.

RESULTS

The dice coefficient of the segmentation network is 92.84%. For the measurement of sella turcica, there is excellent agreement between the automatic measurement and the manual measurement. In Test1, the ICCs of length, diameter and depth are 0.954, 0.953, and 0.912, respectively. In Test2, ICCs of length, diameter and depth are 0.906, 0.921, and 0.915, respectively. In addition, Bland-Altman plots showed the excellent reliability of the automated measurement method, with the majority measurements differences falling within ± 1.96 SDs intervals around the mean difference and no bias was apparent.

CONCLUSIONS

Our experimental results indicated that the proposed methodology could complete the automatic segmentation of the sella turcica efficiently, and reliably predict the length, diameter, and depth of the sella turcica. Moreover, the proposed method has generalization ability according to its excellent performance on Test2.

Radio-Morphometric Analysis of Sella Turcica in Relation to Age and Gender in Sri Ganganagar Population: A Prospective Cephalometric Study

Background Sella turcica (ST) is a crucial structure that is morphologically situated in the median position and is well-utilised in cephalometrics. This saddle-shaped sella constitutes a significant radiographic landmark for various related analyses. Therefore, studying its varying dimensions in different populations is of utmost importance. This paper evaluates and compares the linear dimensions and morphological variations of ST in different facial skeletal classes in relation to age and gender using lateral cephalograms in the Sri Ganganagar population. Methodology The study population was selected through simple random sampling from the accessible population of the Sri Ganganagar district. A total of 180 participants of both genders were selected from patients who visited the outpatient clinic of the Department of Oral Medicine and Radiology of Surendra Dental College and Research Institute in Sri Ganganagar. These samples were equally divided into three age groups. Apart from typical morphology, five possible variations of ST were determined. The area of ST on the lateral cephalogram was also evaluated. The extent of ST was calculated from the tubercle portion to the top of the dorsal side. The relative deepness of the sella was assessed by making a tangent across the innermost point of the sella. SPSS software was utilised for statistical analysis and related inferences. Results In the study sample (n = 180), 50% were men and 50% were women. The sample was divided into three equal groups based on age: Group I (n = 60; 33.33%) consisted of participants aged 15-20; Group II (n = 60; 33.33%) consisted of participants aged 21-25; and Group III (n = 60; 33.33%) consisted of participants aged 26-30. Conclusions The anteroposterior diameter of the sella structure is strongly related to age progression with no significant gender correlation. The most common shape of ST other than the normal one was oblique. Additionally, skeletal relationships showed a significant relationship with the shape of ST in the study population.

Sella turcica dimensions and maxillary growth in patients with unilateral cleft lip and palate

OBJECTIVES

We aimed to investigate associations between sella turcica dimensions and maxillary growth in children with unilateral cleft lip and palate (UCLP).

METHODS

Forty-nine patients with non-syndromic UCLP, prior to secondary alveolar bone-grafting, were included. The outcomes measured were sella turcica and maxillary cephalometric measurements, and scores representing dental arch relationships derived from dental casts. On lateral cephalograms, sella width, height, and area were measured, as well as maxillary length, height, protrusion, and inclination. Dental arch relationships were measured using the modified Huddart/Bodenham (MHB) scoring system, and translated GOSLON yardstick score. Multiple linear regression was used to assess associations between sella turcica measurements and either cephalometric parameters or MHB/GOSLON scores, including age and sex as covariables.

RESULTS

No significant associations were found between sella turcica dimensions and dental arch relationships. For cephalometric measurements, sella height and area were associated with basal maxillary length, alveolar maxillary length, and anterior maxillary height.

CONCLUSIONS

Sella height and area seem to be predictors for both maxillary length and height as assessed cephalometrically, in a sample of patients with non-syndromic UCLP.

Maturation of the sella turcica and parasellar region: Surgical relevance for anterior skull base approaches in pediatric patients

OBJECTIVE

Traditional and extended transnasal transsphenoidal approaches provide direct access to a variety of anterior skull base pathologies. Despite increased utilization of transnasal approaches in children, anatomic studies on pediatric skull base maturation are limited. We herein perform a surgically relevant morphometric analysis of the sella and parasellar regions during pediatric maturation.

METHODS

Measurements of sellar length (SL), sellar depth (SDp), sellar diameter (SDm), interclinoid distance (ID), intercavernous distance (ICD), and the presence of sphenoid sinus pneumatization (SSP), and sphenoid sinus type (SST) were made on thin-cut CT scans from 60 patients (evenly grouped by ages 0-3, 4-7, 8-11 12-15, 16-18, and >18 years) for analysis. Data were analyzed by sex and age groups using t-tests and linear regression.

RESULTS

Sella and parasellar parameters did not differ by sex. SL steadily increased from 8.5 ± 1.2 mm to 11.5 ± 1.6 mm throughout development. SDp and SDm increased from 6.0 ± 0.9 mm to 9.3 ± 1.4 mm and 9.0 ± 1.6 mm to 14.4 ± 1.8 mm during maturation, with significant interval growth from ages 16-18 to adult (p < 0.01). ID displayed significant growth from ages 0-3 to 4-7 (18.0 ± 2.4 mm to 20.7 ± 1.9 mm; p = 0.002) and ICD from ages 0-3 to 8-11 (12.0 ± 1.8 mm to 13.5 ± 2.1 mm; p < 0.001), without further significant interval growth. SSP was not seen in patients < 3, but was 100% by ages 8-11. SSTs progressed from conchal/presellar (60% at ages 4-7) to sellar/postsellar (80% at adulthood).

CONCLUSION

The sella and parasellar regions have varied growth patterns with development. Knowledge of the expected maturation of key anterior skull base structures may augment surgical planning in younger patients.

Is there a relationship between transverse maxillary deficiency and sella turcica: A cephalometric analysis study?

Objectives:

The aim of this study was to investigate the dimensions and morphological variations of sella turcica and to test whether a relationship exists between sella turcica and transverse maxillary deficiency.

Materials and Methods:

The cephalometric radiographs of patients older than 17.99 years, which have been taken before the orthodontic treatment, and patient records were analyzed to investigate sella turcica dimensional and morphological analysis. Linear measurements of sella are as follows sella length, sella width, sellar area, sella height anterior, posterior, and median. The sella turcica morphological shape analysis was performed into six groups (normal sella turcica, oblique anterior wall, sella turcica bridge, double contour of floor, irregularities of the posterior part of the dorsum sella, and pyramidal shape of the dorsum sella). The width of the maxillary arch is measured by the digital caliper. Male participants with a maxillary width of less than 30.8 mm and a maxillary width of less than 31.1 mm in female patients in the first molar region were determined as a transverse maxillary deficiency. The mean dimensions of sella turcica and the relationship between cases with transverse maxillary deficiency and non-skeletal anomaly were compared using independent samples t-tests. The transverse maxillary deficiency and the sellar morphology relationship were compared using Chi-square test. Post hoc multiple comparisons and analyzes were performed at 95% confidence interval by Bonferroni correction.

Results:

The sella length measurements yielded higher values among the patients with transverse maxillary deficiency (P < 0.05). The normal sella morphology had quantitative superiority in patients without skeletal anomaly in comparison with transverse maxillary deficiency cases (P < 0.05). It was observed that the sella turcica bridge had a statistically superiority in patients with transverse maxillary deficiency (P < 0.05).

Conclusion:

The increased sellar measurement and sella turcica bridging, may provide knowledge about possible transverse maxillary deficiency.

The Shapes and Normal Dimensions of the Sella Turcica

OBJECTIVE

The aim of this study was to evaluate the normal dimensions and shape of the sella turcica (ST) in the Turkish population using multidetector computed tomography.

METHODS

This single-center, retrospective study included 188 patients who met the study criteria and had paranasal multidetector computed tomography taken between January 2019 and December 2019. The patients included in the study comprised 77 females and 111 males. The whole patient group was separated into 3 age groups of 18 to 25 years (group 1), 25 to 40 years (group 2), and 40 years and over (group 3). They were also separated according to gender.

RESULTS

The mean length of the ST was determined as 8.52 ± 1.42 mm (min-max 4.61-12.73 mm), mean height as 7.00 ± 1.31 mm (min-max 3.00-10.51 mm), mean aperture as 6.50 ± 2.00 mm (min-max 2.24-12.51 mm), and mean width as 11.01 ± 1.50 mm (min-max 7.78-14.94 mm). No statistically significant difference was determined between the length, height, width, and aperture size values of the ST according to gender and age groups.

CONCLUSION

The results of this study demonstrated no significant difference in ST dimensions according to gender or age groups. It can be considered that the shape and dimensions of the ST can be more accurately evaluated with computed tomography and classification can be more robustly applied.

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).

Morphometric evaluation of cranial base and sella turcica in patients with bilateral agenesis of maxillary lateral incisors

The aim of this paper is to evaluate the dimensions and morphology of cranial base and sella turcica in patients with bilateral agenesis of maxillary lateral incisors (BMLI). This retrospective study was conducted on lateral cephalometric radiographs of 34 female patients with BMLI (17.69 ± 2.96 years) and 34 female patients with complete dentation and skeletal Class 1 relationship serving as a control group (17.22 ± 2.2 years). Basicranial and maxillomandibular variables together with linear dimensions and morphology of sella turcica were evaluated. Differences between groups were analyzed by Student's t test for parametric variables and Mann-Whitney U test for nonparametric variables. Chi-square test followed by post hoc test with Bonferroni correction was used for categoric variables (p < 0.05). When compared to control group, N-S-Se angle was less negative, dimensions between Ba-Se, N-Ba, and N-Ar were larger, and SNA angle was smaller in BMLI group. There were no significant differences between groups regarding the linear dimensions of sella turcica. However, variations in sella turcica morphology were more frequent in BMLI group (n = 17; 50%) when compared to control group (n = 2; 5.8%). The most common morphologic variations in BMLI group were oblique anterior wall (20.6%) and irregularity (notching) in the posterior part of sella turcica (14.7%). The present study showed a statistically significant relationship between the presence of BMLI with some craniofacial parameters and morphological variations of sella turcica. This information may be useful as an additional and early diagnostic tool for BMLI and to highlight the possible links to its development.

Sella Turcica Bridging and Tooth Agenesis in Children With Unilateral Cleft Lip and Palate

AIM

To investigate differences in sella turcica size and bridging in children with unilateral cleft lip and palate (UCLP) with or without concomitant dental anomalies.

PATIENTS AND METHODS

A cross-sectional study was carried out looking at 56 children with nonsyndromic UCLP. Lateral cephalograms, taken before alveolar bone grafting, were used to assess sella turcica height, width, area, and bridging. Panoramic radiographs were used to evaluate the presence of dental anomalies in the cleft area including agenesis, supernumerary, and peg-shaped lateral incisors. Differences between sella turcica measurements in the presence or absence of dental anomalies were assessed using t tests. Differences between the prevalence of dental anomalies and sella turcica bridging were assessed using χ² and Fisher exact tests. Multinomial logistic regression was used to investigate potential associations between sella measurements and dental anomalies.

RESULTS

Twenty-six of the 56 children presented with agenesis of the cleft-side lateral incisor, while 7 had a supernumerary, and 19 had a peg-shaped lateral incisor. With regard to sella turcica bridging, 27 children had no calcification, 25 partial and 4 complete calcification. Children with agenesis of the cleft-side lateral incisor showed a shorter sella maximum height (P = .010) and a smaller area (P = .019). When looking at sella turcica bridging, 100% of children with complete calcification showed agenesis of the cleft-side lateral incisor, compared with 52% and 33% of children with partial calcification and no calcification, respectively (P = .034).

CONCLUSIONS

Children with UCLP and sella turcica bridging are more likely to present with agenesis of the cleft-side maxillary lateral incisor.

Sella Turcica Morphology in Patients With Genetic Syndromes: Protocol for a Systematic Review

Background

The sella turcica is an important anatomical reference used in orthodontics and the evaluation of craniofacial growth. Studies have found an association between variations in sella turcica morphology in patients with certain syndromes affecting the craniofacial complex. It is hypothesized that each related syndrome or pathological condition is associated with a specific pattern of malformation of the sella turcica.

Objective

This study outlines the protocol for a systematic review that aims to determine if genetic syndromes involving the craniofacial complex are associated with abnormal radiographic sella turcica morphology and if there is a pattern of malformation that is consistent with each syndrome.

Methods

An electronic database search was conducted using a planned search strategy to identify relevant studies. We included primary studies evaluating the morphology of the sella turcica based on imaging from a lateral view. Specifically, only studies with postnatal human participants with genetic syndromes involving the craniofacial complex were included in this review. We placed no restrictions on the language or time frame of these studies. Based on the search findings, studies were further screened for relevance and eligibility by two independent reviewers. Data were extracted from the selected studies. We assessed the selected studies for risk of bias and quality by using risk of bias tools from the Joanna Briggs Institute. We will provide a narrative synthesis of our findings and a structured summary based on prespecified themes.

Results

The protocol is registered with PROSPERO (#CRD42019148060) and approved by the University of Western Cape Biomedical Science Research Ethics Committee (BM205/3). The literature search was conducted in September 2019 and updated in July 2020. The study was completed in August 2020, and the findings will be published in an open-access journal.

Conclusions

The results of this systematic review are expected to provide a comprehensive list of morphological variations of the sella turcica, which will aid in the identification of syndromes associated with the craniofacial complex. We also expect to identify patterns of sella turcica morphology that highlight genotype-phenotype correlations, thus adding to the body of evidence relating to genetics and craniofacial malformations.

Trial Registration

PROSPERO International Prospective Register of Systematic Reviews CRD42019148060; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=148060

International Registered Report Identifier (IRRID)

RR1-10.2196/16633

Sella turcica morphology in patients with genetic syndromes: A systematic review

The sella turcica is an important anatomical reference used in orthodontics for the evaluation of craniofacial growth. Studies have found variations in the sella turcica morphology in patients with syndromes affecting the craniofacial complex. This review aims to determine whether genetic syndromes involving the craniofacial complex are associated with abnormal radiographic sella turcica morphology and whether there is a pattern of malformation which is consistent within each syndrome. An electronic database search was conducted to identify relevant studies. We included primary studies describing the morphology of the sella turcica on lateral radiographs in human subjects with genetic syndromes involving the craniofacial complex. No restrictions were placed on language or timeframe. PROSPERO registration CRD42019148060. Thirty-eight studies were included in this review. A 'J'-shaped sella was found in patients with Hutchinson-Gilford-Progeria syndrome and other syndromes. A bulbous dorsum sellae was highly prevalent Cleidocranial dysplasia, and a bulbous dorsum sellae and uneven contours of the clivus was found in Cri du chat syndrome. A steep clivus was described in patients with Axenfeld-Rieger syndrome. An oblique anterior wall was the most frequent malformation found in Down's syndrome. Genetic syndromes affecting the craniofacial complex are associated with abnormal morphology of the radiographic sella turcica. Clinicians should be observant of abnormal sella turcica morphology which can be a sign of undiagnosed or subclinical syndromes. More high-quality studies are needed which use standardized and objective methods of determining the morphology of the sella turcica.

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, β ≤ 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.

Three-dimensional assessment of the sella turcica: comparison between cleft lip and palate patients and skeletal malocclusion classes

PURPOSE

The main aim of the present study was to investigate the dimensions and morphological appearance of the sella turcica in cleft lip and palate patients using cone-beam computed tomography (CBCT) images, compared to non-cleft individuals.

METHODS

CBCT images of 40 (20 females and 20 males) cleft lip and palate patients and 60 (27 males and 33 females) non-cleft individuals were assessed, retrospectively. The linear dimensions (depth, diameter and length) of the sella turcica and inter-clinoid distance were measured. Sella turcica shapes were examined in the cleft lip and palate patients and non-cleft individuals. Non-cleft individuals were divided into skeletal malocclusion classes. All variables were analyzed using the Kruskal-Wallis test, Mann-Whitney U tests and Chi-square test.

RESULTS

No significant difference was observed between individuals with and without cleft in the linear dimensions (depth, diameter and length) of the sella turcica (p > 0.05). However, a significant difference was found in the inter-clinoid distance between patients with cleft and non-cleft individuals (p < 0.05). Comparison of the sella turcica shape between skeletal malocclusion classes and patients with cleft showed significant differences (p < 0.05).

CONCLUSIONS

No significant difference was determined in the depth, diameter, or length of the sella turcica in cleft patients when compared with non-cleft individuals. The inter-clinoid distance was lower in cleft patients than in non-cleft individuals, and this difference was statistically significant.

Sella turcica morphometrics in children with unilateral cleft lip and palate

OBJECTIVE

To use morphometric methods to investigate the size and shape of the sella turcica in children with unilateral cleft lip and palate (UCLP).

SETTING AND SAMPLE POPULATION

Fifty-six healthy children with non-syndromic UCLP, from a major paediatric teaching hospital, with lateral cephalograms taken prior to alveolar bone grafting, were compared with an age- and sex-matched control group of healthy children without orofacial clefts, with lateral cephalograms taken prior to orthodontic treatment.

MATERIALS AND METHODS

In this cross-sectional study, conventional measurements were performed on the sella turcica to measure width, height and area on lateral cephalograms. Sella shape was also analysed using 11 points defining the sella turcica contours, using geometric morphometrics. Procrustes superimposition was used to register all sella contour tracings to calculate average sella shape. Principal component analysis was applied to the residuals of the point coordinates, and principal components (PCs) of shape were extracted.

RESULTS

Statistically significant differences between the UCLP and control groups were found for sella posterior height, midpoint height, maximum height and area, where all of these were smaller in children with UCLP. Principal component analysis revealed that the first two PCs accounted for 84.7% of total shape variance. There was a statistically significant difference in sella shape between children with UCLP and control children.

CONCLUSIONS

In children with UCLP, the sella turcica is shorter and with a smaller surface area when compared to matched non-cleft children. Moreover, sella turcica shape, when disregarding size, seems to differ to that of non-cleft children.

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.

Assessment of the relationship between size, shape and volume of the sella turcica in class II and III patients prior to orthognathic surgery

PURPOSES

The main purpose of this study was to assess the measurements and shape of the sella turcica by using cone beam computed tomography (CBCT) and to associate the data to skeletal class II and class III patients, including correlations with gender, age and measurements of the anterior cranial base.

MATERIAL AND METHODS

A trained examiner specialist in dental radiology selected and evaluated randomly 95 CBCT images of pre-orthognathic surgery patients, 60 (63.2%) being female and 35 (36.8%) male with age between 16 and 57 years. All images were evaluated to determine the size, shape and volume of the sella turcica. The anterior cranial base, represented by the S-N line (sella-nasion), was also measured.

RESULTS

Of these 95 patients, 48 (50.5%) had class III facial skeletal pattern, whereas 47 (49.5%) had class II. No statistically significant differences were found between class II and class III patients in the measurements and shape of the sella turcica (P > 0.05). The diameter and volume of the sella turcica had higher values in female patients, whereas the measurements of the anterior cranial base were higher in males (P < 0.05).

CONCLUSION

Therefore, one can conclude that measurements of the sella turcica are not reliable parameters to evaluate whether a class II or class III patient will or will not need orthognathic surgery.

Morphometric analysis of sella turcica in growing patients: an observational study on shape and dimensions in different sagittal craniofacial patterns

The aim of this study was to evaluate the differences in sella dimensions and shape between growing patients with Class I, Class II, and Class III skeletal malocclusions, evaluated through morphometric analysis. Seventy-eight subjects aged between 9 and 13 years were selected and assigned to either the Class I, Class II, or Class III groups according to the measured ANB angle (the angle between the Nasion, skeletal A-point and skeletal B-point). Six landmarks were digitised to outline the shape of the sella turcica. Linear measurements of the sella length and depth were also performed. Procrustes superimposition, principal component analysis, and canonical variate analysis were used to evaluate the differences in sella shape between the three groups. A one-way MANOVA and Tukey’s or Games-Howell tests were used to evaluate the presence of differences in sella dimensions between the three groups, gender, and age. The canonical variate analysis revealed a statistically significant difference in sella shape between the Class I and the Class II groups, mostly explained by the CV1 axis and related to the posterior clinoidal process and the floor of the sella. No differences were found regarding linear measurements, except between subjects with different age. These differences in sella shape, that are present in the earlier developmental stages, could be used as a predictor of facial growth, but further studies are needed.

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.

Evaluation of the relationship between impacted canines and three-dimensional sella morphology

PURPOSE

The purpose of this study was to assess the three-dimensional morphometric features of the sella turcica using cone beam computed tomography (CBCT) in subjects with unilateral and bilateral maxillary impacted canines and normal controls.

METHODS

In this retrospective study, CBCT images captured with ultra-low dose protocol of 73 subjects (21 males, 52 females; mean age 20.01 ± 6.53 years) with unilateral or bilateral maxillary impacted canines (29 unilateral and 29 bilateral) and 15 controls were evaluated. Nineteen different measurements of the pituitary fossa were made on CBCT images. To evaluate the normality, the Kolmogorov-Smirnov test was used. The nonparametric statistical Kruskal-Wallis and Mann-Whitney U tests were applied to analyze the significant differences among and between the groups. Statistical significance was set at 5%.

RESULTS

No measurement differed significantly among the groups (all p > 0.05) other than the right sella length, which differed between the unilateral and bilateral test groups and the unilateral test group and controls (both p < 0.05). The bilateral test group and control group did not differ significantly, but both exhibited greater right sella length than did the unilateral test group (p > 0.05).

CONCLUSIONS

Other than the right sella length, there were no among-group differences in the mean pituitary fossa measurements of subjects with impacted unilateral and bilateral canines and normally erupted canines. The right sella length was lower in subjects with impacted unilateral canines than in those with bilateral impacted canines and normal controls.

Morphometric Analysis of Sella Turcica Using Cone-Beam Computed Tomography in Patients With Cleft Lip and Palate

OBJECTIVE

The purpose of this study is to evaluate morphometric analysis of sella turcica using cone-beam computed tomography (CBCT) in patients with cleft lip and palate (CLP) and healthy controls.

METHODS

Cone-beam computed tomography images of 68 patients (36 males, 32 females, age range 7-20 years) with CLP and 68 healthy individuals (36 males, 32 females, age range 8-19 years) were examined retrospectively. Sella turcica shapes were analyzed by 2 different methods in CLP and control groups. Length, depth, and diameter of sella turcica were measured in both groups. The data were statistically assessed by age, gender using Independent t-test and one-way analysis.

RESULTS

Diameter of sella turcica was smaller in CLP group compared to healthy individuals (P < .05). Length and depth of sella turcica were lower than in control group, but not statistically significant (P > .05). Sella turcica shape significantly differed between groups (P < .05). The most common sella turcica types were flattened and irregular shapes in CLP group, whereas round and normal shapes were in control group. There was no significant difference between groups in any dimension of sella turcica by gender (P > .05). Sella turcica depth was significantly higher at age of 15 years and above in CLP group.

CONCLUSION

This study showed that flattened and irregular shapes of sella turcica were the most common types in CLP group. Smaller sella turcica was detected in CLP group compared to healthy individuals. Cone-beam computed tomography can be useful for evaluation of sella turcica.

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.

Association of sella turcica bridging with palatal canine impaction in skeletal Class I and Class II

Purpose

Based on the evidence of the embryonic origin of the sella turcica and the teeth, this retrospective study evaluated the association between sella turcica bridging and palatal canine impaction in skeletal Class I and Class II orthodontic patients.

Methods

Sixty-two orthodontic patients with palatally impacted canines and 54 controls with erupted canines (aged 12–25 years) were classified into skeletal Class I and Class II (according to ANB angle and Wits analysis). The length, depth, and diameter of the sella turcica were measured, and the shape was described. The difference in linear dimensions between the study and control groups was calculated using two-way analysis of variance and Student’s t-test. The interrelationship of the variables, subject groups, skeletal type, and age, with the linear dimensions of sella turcica, was tested using regression analyses. The association between sella turcica, bridging and palatally impacted canines was determined in skeletal type using a chi-square test.

Results

Highly significant differences were found in the length, diameter, and depth of the sella turcica between the study sample and the control (P<0.001, P=0.015, P<0.0001, respectively). There was a highly significant frequency of bridging in cases with palatally impacted canines (P<0.0001). An increasing incidence of bridging was found in subjects with palatally impacted canines and skeletal Class I (P<0.0001) and Class II (P=0.044) relationships. Regression analysis showed that the age was significantly related to a change in length (P=0.025), diameter (P<0.0001), and depth (P<0.0001). The normal sella turcica morphology was present in most subjects (56.4%), and no significant association was found in subjects with palatally impacted canines in terms of the shape of the sella turcica.

Conclusion

Sella turcica bridging is frequently seen in patients with impacted canines. The findings suggest that careful monitoring of canine eruption is required in patients diagnosed with sella turcica bridging at an early age.

The morphology and bridging of the sella turcica in adult orthodontic patients

Background

The purpose of this study was to determine and compare the shapes, sizes, and bridging of the sella turcica in patients with different skeletal patterns and genders.

Methods

It was a cross-sectional comparative study. The samples were divided into three groups according to the skeletal pattern viz. Class I, Class II and Class III, and each group consisted of 40 samples (20 males and 20 females). The lateral cephalograms were traced and the sella turcica was assessed for its size, shape, and bridging.

Results

The mean length, anteroposterior diameter and depth of sella turcica were 8.13 ± 2.03 mm, 9.60 ± 1.43 mm and 6.40 ± 1.21 mm respectively. The mean length of sella turcica was 7.91 ± 1.52 mm in Class I, 7.32 ± 1.62 mm in Class II and 9.16 ± .2.42 in Class III skeletal pattern; anteroposterior diameter was 9.30 ± 1.02 mm in Class I, 9.15 ± 1.28 mm in Class II and 10.35 ± 1.64 mm in Class III skeletal pattern; and the depth was 6.40 ± 0.92 mm in Class I, 6.07 ± 1.01 mm in Class II and 6.74 ± .1.54 mm in Class III skeletal pattern. There were significant differences in length and anteroposterior diameter and sella turcica between Class I, Class II and Class III skeletal patterns (p = 0.01), (p = 0.01) respectively. There was no significant difference in size of sella turcica between different genders and age groups. Sixty percent of the patients studied had normal Sella morphology. Partial Sella turcica bridging and Sella turcica bridging was seen in this study in 23.33% and 11.67% of patients respectively.

Conclusion

Sixty percent of the patients had normal sella turcica. There were significant differences in lengths and anteroposterior diameters among Class I, Class II and Class III patients. The larger size was present in skeletal Class III patients.

Morphometric Analysis of Sella Turcica Using Cone Beam Computed Tomography

OBJECTIVE

The purpose of this study was to assess morphological shape and morphometric analysis of the sella turcica using cone beam computed tomography (CBCT) in different planes of section (coronal and sagittal).

MATERIALS AND METHODS

CBCT images of 177 subjects of which 51 males and 126 females in the age group of 11 to 73 years were included in the study population. Linear dimensions which include the length, depth, diameter, and interclinoid distance were measured and the shape of sella turcica was analyzed.

RESULTS

Sella turcica had circular morphology in 69.5% of the subjects while flattened shape of sella turcica was observed in 16.4%, oval shape of sella turcica in 14%. There was no significant difference in the all measurements of sella turcica between males and females (P > 0.05). Diameter (P < 0.01), depth (P < 0.001), length (P < 0.05), and interclinoid distance (P < 0.05) of the sella turcica differed significantly with age.

CONCLUSIONS

The anatomical structure of sella turcica can be studied effectively in CBCT images. Linear dimensions and shape of sella turcica in the current study can be used as reference standards for further investigations.

A cone beam computed tomographic evaluation of the size of the sella turcica in patients with cleft lip and palate

OBJECTIVE

Changes in the size of the sella turcica are frequently related to pathologies and syndromes. The aim of this was to compare the sella turcica dimensions in patients with unilateral and bilateral cleft lip and palate and non-cleft subjects.

METHODS

Cone beam computed tomography (CBCT) images of three groups consisted of 20 patients with unilateral cleft lip and palate; 20 patients with bilateral cleft lip and palate and a control group consisting of 20 non-cleft subjects were the research population in this pilot study. The sella turcica linear dimensions in terms of length, depth and diameter were measured for all subjects. One-way ANOVA test was used to determine any significant differences among the three groups for the measured parameters.

RESULTS

The length, depth and diameter of sella turcica were found to be significantly smaller in the unilateral and bilateral groups compared with the normal age and gender matched group. No significant differences were found in the measured variables between the unilateral and bilateral cleft patients.

CONCLUSION

CBCT images showed a greater likelihood of abnormal sella turcica dimensions in patients with unilateral and bilateral cleft lip and palate. Therefore, the sella turcica dimensions may have an intrinsic relationship to the cleft condition.

Anthropometric Parameters for Access to Sella Turcica Through the Nostril

The pituitary gland is located in the sella turcica. Pituitary tumors constitute approximately 15% of intracranial benign tumors. "Endo nasal endoscopic trans-sphenoidal" method is an appropriate surgical technique to remove this tumor. In this operation an endoscope enters the nasal cavity through the nostril to reach the floor of the sella turcica. The aim of this study was an anthropometric evaluation of the route of endoscope in this surgery. Two hundred twenty-seven patients (116 women, 111 men) were divided into ≥30, 31 to 61, and ≥61-year age groups. Lateral scanograms of skull were used to measure 3 linear distances and 1 angle. While the mean of the linear variables was significantly higher in men (P <0.001), this difference was not significant in angular measurement between sexes. More detail evaluation of the age groups showed age- and sex-specific differences in measurements. The authors concluded that it needs to consider the anthropometrical indexes in pituitary surgery.

Sella turcica measurements on lateral cephalograms of patients with neurofibromatosis type 1

The aim of this study was to measure line segments and areas of sella turcica on lateral cephalograms with respect to the clinical diagnosis of facial phenotype of patients with neurofibromatosis type 1 (NF1). Special attention was given to correlate the measured values with certain tumour types that are typical for this disease.

Material and methods: Lateral cephalograms of 194 individuals were investigated. Patients with NF1 were further divided according to the detection and topography of facial plexiform neurofibromas (PNF) taking into account the distribution pattern of the trigeminal nerve. All patients with PNF showed unilateral tumour localisation. Patients without any facial PNF constituted a separate group. Healthy volunteers with ideal occlusion and no history of any intervention in the maxillofacial region served as a control group. The following items were determined on the radiographs: sella entrance, sella width, sella depths, sella diagonal, and sella area.

Results: Patients with PNF of the first and second trigeminal nerve branch or affected in all branches showed highly statistically significant enlarged sella tucica measurement values. On the other hand, patients with PNF restricted to one branch only or simultaneously in the second and third branches showed measurement values that were not different to those obtained in NF1 patients devoid of facial PNF. The latter group also showed no difference of sella turcica parameters obtained in the control group.

Conclusion: This study provides evidence for the association of a certain NF1 phenotype with distinct skeletal alterations of the skull base, shown here using the example of the representation of the sella turcica in the lateral radiograph. These findings are also relevant in the discussion of NF1 as a disease of bones and in the assessment of brain development in NF1. Both items are discussed in relationship to a facial plexiform neurofibroma. Furthermore, the knowledge of this association of findings provides the clinician with relevant information in the planning of skull base procedures in these patients.

Reproducibility of three-dimensional posterior cranial base angles using low-dose computed tomography

OBJECTIVES

One of the key aspects of three-dimensional (3D) craniofacial cephalometry is the measurement of posterior cranial base angle as this area is deeply involved in craniofacial development. The purpose of our retrospective study was to define the best reproducible 3D posterior cranial base angles among five 3D angles transposed from 2D cephalometry (Cousin, BL1 of Ross and Ravosa, Bjork, Delaire, CBA4 of Liberman) and seven 3D angles based on physical anthropology studies and on new concepts (R1 to R7). The null hypothesis was that all 3D posterior cranial base angles were equally reproducible.

MATERIAL AND METHODS

We used a preoperative low-dose computed tomography (CT) data from 20 adult patients undergoing orthognathic surgery after approval by local ethical committee. Two independent observers performed two series of 23 3D landmark identifications on 3D CT surface rendering of each patient using Maxilim software. Then, the same observers performed twice 3D cephalometric analyses (23 landmarks, 4 midpoints, 19 planes) that provided the automatic measurement of 12 posterior cranial base angles.

RESULTS

Inter-observer correlation coefficient varied from 0.545 (Cousin) to 0.695 (CBA4 of Liberman) and from -0.177 (R2) to 0.827 (R4).

CONCLUSIONS

The null hypothesis was rejected. The most reproducible angle was 3D angle R4 based on "basion," "superior optic" (right, left), and "crista galli inferior" landmarks.

CLINICAL RELEVANCE

R4 angle might be used as reference 3D posterior cranial base angle in further clinical studies involving 3D cephalometry as a diagnostic tool for orthodontics and for orthognathic surgery.

Radiographic Comparison of Vertical Skeletal and Dental Parameters in Skeletal Open Bite

Objective: The purpose of our randomized study was to compare the skeletal and dental values in open bite cases using lateral cephalometric analysis and panoramic X-rays analysis and to evaluate if PR is a reliable diagnostic method in skeletal malocclusions.

Methods: 21 (6 boys, 15 girls) patient with skeletal open bite were selected and both radiological examinations were performed. “Modified cephalometric analysis” on panoramic X-rays and Steiner’s cephalometric analysis was performed using AudaxCeph software. Statistical analysis was performed using the Pearson correlation method and SPSS statistical software for comparison.

Results: Skeletal values like anterior facial height (AFH), angles between Frankfort horizontal and mandibular/palatal plane (ML/H and NL/H) showed no statistical significance, mandibular plane/ramus tangent angle (goniac angle) and mandibular plane/palatal plane angle (ML/RL, ML/NL) showed high or moderate (posterior facial height - PFH) significant statistical interrelation (r=0.46-0.80). Almost all dental parameters were statistically significant, from moderate to high (r=0.56-0.79). The only statistically insignificant dental parameter was the mesial cusp tip of the upper first molar/palatal plane (ms-NL) distance (r=0.32). Vertical skeletal and dental parameters on panoramic X-rays can moderately approximate lateral cephalomteric values. This means that mostly in skeletal malocclusions, panoramic X-rays cannot be used for quantitative determination of the parameters.

Sella size and jaw bases - Is there a correlation???

INTRODUCTION

Sella turcica is an important cephalometric structure and attempts have been made in the past to correlate its dimensions to the malocclusion. However, no study has so far compared the size of sella to the jaw bases that determine the type of malocclusion. The present study was undertaken to find out any such correlation if it exists.

MATERIALS AND METHODS

Lateral cephalograms of 110 adults consisting of 40 Class I, 40 Class II, and 30 Class III patients were assessed for the measurement of sella length, width, height, and area. The maxillary length, mandibular ramus height, and body length were also measured. The sella dimensions were compared among three malocclusion types by one-way ANOVA. Pearson correlation was calculated between the jaw size and sella dimensions. Furthermore, the ratio of jaw base lengths and sella area were calculated.

RESULTS AND CONCLUSION

Mean sella length, width and area were found to be greatest in Class III, followed by Class I and least in Class II though the results were not statistically significant. 3 out of 4 measured dimensions of sella, correlated significantly with mandibular ramus and body length each. However, only one dimension of sella showed significant correlation with maxilla. The mandibular ramus and body length show a nearly constant ratio to sella area (0.83-0.85, 0.64-0.65, respectively) in all the three malocclusions. Thus, mandible has a definite and better correlation to the size of sella turcica.

Two coexisting heterozygous frameshift mutations in PROP1 are responsible for a different phenotype of combined pituitary hormone deficiency

The role of genetic background in childhood-onset combined pituitary hormone deficiency (CPHD) has been extensively studied. The major contributors are the PROP1, POU1F1, LHX3, LHX4 and HESX1 genes coding transcription factors implicated in pituitary organogenesis. The clinical consequences of mutations encompass impaired synthesis of a growth hormone (GH) and one or more concurrent pituitary hormones (i.e. LH, FSH, TSH, PRL). Manifestation of the disorder may vary due to various mutation impacts on the final gene products or an influence of environmental factors during pituitary organogenesis. We describe the clinical and molecular characteristics of two brothers aged 47 and 39 years presenting an uncommon manifestation of congenital hypopituitarism. Sequencing of the PROP1, POU1F1, LHX3, LHX4 and HESX1 genes was performed to confirm the genetic origin of the disorder. A compound heterozygosity in the PROP1 gene has been identified for both probands. The first change represents a mutational hot spot (c.150delA, p.R53fsX164), whereas the second is a novel alteration (p.R112X) that leads to protein disruption. Based on precise genetic diagnosis, an in silico prediction of a p.R112X mutation on protein architecture was performed. The resulting clinical phenotype was surprisingly distinct compared to most patients with genetic alterations in PROP1 reported in the current literature. This may be caused by a residual activity of a newly identified p.R112X protein that preserves over 70 % of the homeodomain structure. This examination may confirm a key role of a DNA-binding homeodomain in maintaining PROP1 functionality and suggests a conceivable explanation of an unusual phenotype.

Bridging the Gap: Sella Turcica in Unilateral Cleft Lip and Palate Patients

Objectives

The aims of this study were to analyze the prevalence of sella turcica bridging and to measure the size of the sella turcica on profile cephalograms in a homogenous group of surgically repaired unilateral cleft lip and palate (UCLP) patients.

Setting

Tertiary care center.

Design

Retrospective cross-sectional study.

Patients

Preorthodontic lateral cephalometric radiographs of 64 UCLP individuals between the ages of 16 and 29 years along with an equal number of age- and sex-matched skeletal Class I controls.

Main Outcome Measures

The extent of calcification of the interclinoid ligament was quantified (completely calcified, partially calcified, no calcification) and mean values compared. Length, depth, and diameter of the sella turcica were also measured. The results were statistically analyzed using paired t test and Wilcoxon signed ranks test.

Results

Complete sella bridging of both type A (4.6%) and type B (21.7%) was significantly higher in UCLP patients. This has not been reported previously. Partial sella bridging was also higher in cleft patients as evaluated by two methods (42.18%, 39.06%). This study demonstrated a statistically significant decrease in all dimensions of sella turcica in UCLP patients.

Conclusions

The UCLP patients apparently had higher predilection for sella turcica bridging. The dimensions of sella turcica were also seen to be significantly smaller than the control group. Defective proliferation and deviated pathways of neural crest cell migration as well as premature rupture of contact between neuroepithelium and oral ectoderm as postulated causes are discussed.

Sella turcica: an anatomical, endocrinological, and historical perspective

INTRODUCTION

The sphenoid bone has a superior depression called the sella turcica, Latin for "Turkish saddle," where the pituitary gland is found. The availability of modern radiological imaging techniques has replaced plain radiography of the sella turcica in the investigation of hypothalamo-pituitary abnormalities. However, the size of the sella turcica, and smaller sella turcica size in particular, may cause pituitary dysfunction because of the changes in the structure of pituitary gland or may be associated with some genetic or acquired endocrine disorders. The name "sella turcica" is one of the most commonly used terms in everyday endocrine practice.

METHODS

In this review, after a brief explanation of the anatomical and endocrinological features of the sella turcica had been given, a historical perspective of sella turcica nomenclature was presented for the first time.

FINDINGS AND CONCLUSIONS

After Andreas Vesalius's description of it as a suitable cavity for the gland that receives the "phlegm of the brain" in De Humani Corporis Fabrica (1543), medical scholars began to use seat/saddle-related terms such as the ephippium, pars sellaris, sella equina, sella ossis, and sella sphenoidalis. The real designation of the sella turcica, however, was introduced to the anatomical nomenclature by the anatomist Adrianus Spigelius (1578-1625) in his famous work De Corpora Humanis Fabrica (1627).

Correlation of Shape and Size of Sella Turcica With the Type of Facial Skeletal Class in an Iranian Group

Background:

In orthodontic science, diagnosis of facial skeletal type (class I, II, and III) is essential to make the correct treatment plan that is usually expensive and complicated. Sometimes results from analysis of lateral cephalometry radiographies are not enough to discriminate facial skeletal types. In this situation, knowledge about the relationship between the shape and size of the sella turcica and the type of facial skeletal class can help to make a more definitive decision for treatment plan.

Objectives:

The present study was designed to investigate this relationship in patients referred to a dental school in Iran.

Patients and Methods:

In this descriptive-analytical study, cephalometric radiographies of 90 candidates for orthodontic treatment (44 females and 46 males) with an age range of 14 - 26 years and equal distribution in terms of class I, class II, and class III facial skeletal classification were selected. The shape, length, diameter, and depth of the sella turcica were determined on the radiographs. Linear dimensions were assessed by one-way analysis of variance while the correlation between the dimensions and age was investigated using Pearson’s correlation coefficient.

Results:

Sella turcica had normal morphology in 24.4% of the patients while irregularity (notching) in the posterior part of the dorsum sella was observed in 15.6%, double contour of sellar floor in 5.6%, sella turcica bridge in 23.3%, oblique anterior wall in 20% and pyramidal shape of the dorsum sella in 11.1% of the subjects. In total, 46.7% of class I patients had a normal shape of sella turcica, 23.3% of class II patients had an oblique anterior wall and a pyramidal shape of the dorsum sella, and 43.3% of class III individuals had sella turcica bridge (the greatest values). Sella turcica length was significantly greater in class III patients compared to class II and class I (P < 0.0001). However, depth and diameter of sella turcica were similar in class I, class II, and class III patients. Furthermore, age was significantly correlated to the diameter of sella turcica as greater diameters were observed in older ages (P < 0.04).

Conclusion:

A significant relationship exists between the type of facial skeletal classification and the shape of the sella turcica; as in class III patients, sella turcica bridge was reported with a higher frequency. Also, sella turcica had a significantly higher length in these patients than in those with class I and class II facial skeletal types.

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.

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.