Anatomical variations of the frontal sinus and its relationship with the orbital cavity

The Zagreb Skull Collection-The unique identified collection of human skulls from fetuses to centenarians

Skull anatomy and development have been extensively studied due to their significance in evolutionary biology, forensic anthropology, and clinical medicine. Bone collections are an indispensable resource for conducting such anthropological and anatomical studies. However, worldwide there are only few skull collections containing specimens covering the entire fetal and postnatal period. Herein we describe the Zagreb Skull Collection, an identified collection comprising more than 1100 skulls and skull bone sets from the early fetal period to centenarians. The Zagreb Skull Collection consists of two main parts: the unique Collection of Skull Bones containing 386 sets of separated skull bones from the early fetal period to adulthood and the Collection of Skulls containing 742 skulls (age range 4-101 years). The collection was the core source for numerous anatomical studies on the development, postnatal changes, and anatomical variations of the skull. However, the Zagreb Skull Collection is still an underexploited resource for anthropological, forensic, and anatomical studies with translatability to contemporary clinical practice.

Anatomical variations of the frontal sinus: A computed tomography-based study

Background: The pneumatization of the frontal sinus is variable between individuals, including monozygotic twins. The volumetric anatomic variants of the frontal sinus are classified into aplasia, hypoplasia, medium-sized, and hyperplasia. We aimed to study the frontal sinus morphology in Omani patients using computed tomography (CT) evaluations. Methods: Retrospectively, 1220 frontal sinus CT scans from 610 patients investigated at Sultan Qaboos University Hospital, Oman, from January 2019 to December 2020 were reviewed. The frontal sinus morphology was classified according to the classification proposed by Guerram et al. The Chi-square test was used to determine the influence of sex. Results: With regard to the unilateral occurrence, the most prevalent frontal sinus category observed was medium-sized (13.3%), followed by hyperplasia (7.9%), hypoplasia (5.4%), and aplasia (2%) categories. Similarly, in bilateral occurrence, the most common frontal sinus category observed was medium-sized (53%), followed by hyperplasia (13.1%), hypoplasia (3.4%) and aplasia (2%) categories. Right and left frontal sinus aplasia were observed in 2.1% and 1.8% of cases, respectively. In terms of sex influence, the left unilateral ( p<0.01) and the bilateral hypoplasia ( p<0.05) were significantly higher in females. On the other hand, the left unilateral ( p<0.01) and the bilateral hyperplasia ( p<0.05) were higher in males. Conclusions: The baseline data of frontal sinus category frequencies reported in the present study is helpful in the diagnostic evaluation of sinusitis in the clinical setting. The preoperative recognition of frontal sinus types, particularly frontal sinus aplasia in multiplanar CT scans, is crucial to avoid unexpected complications while performing endoscopic sinus surgery.

[Frontal sinus anatomical scanographic study of transgender patients for feminization frontoorbitoplasty surgery]

INTRODUCTION

Little is known about the anatomical elements that allow safe and predictable performance of fronto orbital surgery for facial feminization. The primary objective of this study was to analyze the characteristics (dimensions, pneumatization rate, and anterior wall thickness) of the frontal sinus in MtF transgender patients. The secondary objective was to establish reproducible criteria for CT measurements that could guide preoperative planning of frontal impaction in feminization frontoplasty (FF).

MATERIALS

Fifty preoperative facial mass scans of FF surgery patients were included. The mean age of the operated patients was 34 years. The F line represented the ideal forehead tilt in the absence of a frontal hump.

RESULTS

The height, width, depth, and thickness of the anterior sinus wall were 26.6mm (±5.7), 49.5mm (±11.3), 10.9mm (±3.3), and 3mm (±0.7), respectively. The mean sinus width to skull width ratio was 0.73 (±0.12). Six percent of patients had bilateral frontal sinus agenesis. An osteotomy of the anterior wall of the frontal sinus was performed in the 64% of patients with frontal sinus projection anterior to the F-line. The emergence of the supraorbital nerves from the frontal bone was through a bony notch in 73.8% of cases.

CONCLUSIONS

Knowledge of the anatomy of the frontal sinus and preoperative study of the scans of the facial mass is essential for planning the FF. These characteristics guide the surgical technique of bone remodeling as well as the procedure for releasing the supraorbital nerves.

The Management of Orbital Roof Fractures and Defects: A Review

PURPOSE

To explore the anatomy, etiopathogenesis, diagnosis and classification, current evidence on intervention and the surgical management of orbital roof fractures and defects (ORFD) for oculoplastic surgeons presented with such cases.

METHODS

A review of the current literature through the MEDLINE database using the following search terms: "orbital roof fracture (+treatment/management)," "orbital roof defect (+treatment/management)," "orbital roof erosion (+treatment/management)," "orbital roof repair," "orbital roof," "orbital fracture," "pediatric orbital roof (defect/fracture/erosion)," "orbital anatomy," and "orbital roof anatomy" was conducted. As relatively little has been published on this topic, inclusion criteria were broad and peer-reviewed articles judged to be of clinical importance, relevant to the aims of this review, were included. Non-English abstracts were also included if relevant. Year of publication was not a strict exclusion criterion, and older articles were judged for their suitability based on clinical importance and relevance to current practice. Additional references were obtained from citations in key articles and recommendations from the coauthors based on their areas of expertise.

RESULTS

The etiopathogenesis of ORFD varies. Classification systems have been formulated to guide management decisions and can range from conservative management to complex neurosurgery. Eyelid approaches have also been described. This review provides a summary of the evidence for each and a management framework oculoplastic surgeons can use when presented with ORFD.

CONCLUSION

Oculoplastic surgeons can be involved, either alone or as part of a multidisciplinary team, in the management of ORFD, and for some, conduct orbital approach reconstructive surgery.

Frontal Bone is Thicker in Women and Frontal Sinus is Larger in Men: A Morphometric Analysis

ABSTRACT

Cranial bone thickness and frontal sinus size are important parameters to be known before cranial procedures. Deep-learning systems have become popular for making bulk analyses to diagnose diseases/disorders and plan treatment algorithms in diverse fields of medicine. Deep-learning systems would be valuable assets also for cranial procedures. Deep-learning systems need normative values and variances of the population on which they are used. In the present study, the authors aimed to find out the normative values for skull bone thickness at 4 anatomical locations, and frontal sinus size. the authors also analyzed whether gender affected these values. Consecutive adult female and male patients that had presented to our outpatient and emergency clinics between December 2019 and April 2020 were evaluated. We included 174 patients (98 female and 76 male) into the final analysis. Skull bone thickness was measured in 4 anatomical compartments, and vertical dimension of the left and right frontal sinuses were measured. The mean thickness of frontal, parietal, temporal, and occipital bones was 7.9 mm, 9.7 mm, 6 mm, and 10.1 mm for men; 8.7 mm, 10.2 mm, 6.1 mm, and 10.1 mm for women, respectively. Women had significantly thicker frontal bone when compared to men (P = 0.009). Men had significantly larger frontal sinuses compared to women (16.1 mm versus 13.7 mm for right frontal sinus, P = 0.031; 16.4 mm versus 13.9 mm for left frontal sinus, P = 0.023). Women and men had thicker frontal bone, and larger frontal sinuses, respectively.

Frontal sinus: is it a predictor for vertical malocclusions?

The aim of the present study was to evaluate 3D frontal sinus morphology in consideration with different vertical facial developments. The study was conducted with the pre-treatment CBCT images of 87 patients, who were divided into 3 groups according to the sum of the posterior angle. The frontal sinus measurements were performed on the axial, sagittal, and coronal sections of the CBCT images. Craniofacial measurements were performed on the lateral cephalograms, obtained from the CBCT scans. Normal distribution of the data was confirmed by the Kolmogorov-Smirnov test. ANOVA, followed by post hoc Duncan tests, was used to compare the differences among the three groups. The relationships between sinus dimensions and craniofacial parameters were assessed by the Pearson's correlation coefficient (P < 0.05). The maximum anterior-posterior dimension of the frontal sinuses (0.017), the width of the right (0.020) and left (0.041) frontal sinuses, and the anterior-posterior dimension of the left (0.038) frontal sinus were significantly smaller in the hyperdivergent group compared to hypodivergent group. There was no significant difference between groups in terms of the height of the frontal sinuses. Significant correlation was noted between the maximum anterior-posterior dimension of the frontal sinus and SN-PP, N-Me, N-ANS, SN-GoGn, Post. sum, and Jarabak's ratio. No significant correlation between the height of the frontal sinuses and the craniofacial measurements was found. Individuals with vertical growth pattern presented decreased anterior-posterior dimension of the frontal sinuses, revealing significant correlations with vertical craniofacial parameters.

Biological relationships and frontal sinus similarity in skeletal remains with known genealogical data

Frontal sinus analysis has potential utility for detecting biologically related individuals. However, the methodological approach to its evaluation, as well as its informative value, have been questioned. The aim of this work is to introduce a new approach to evaluating the frontal sinus using the 'external supraorbital line' (ESOL) and to determine whether there are sex differences within families in frontal sinus measurements and whether frontal sinus similarity reflects known genetic relationships in both measurements and morphology. We examined the skeletal remains of 41 adult individuals (25 males, 16 females), all members of one family over four generations (19th to 20th centuries), including individuals with very close consanguinity. CT images of skulls were acquired, and both the dimensions and morphology of the frontal sinuses were analyzed using their portions above the ESOL. No significant sex differences were found within families based on frontal sinus dimensions. Significant relationships were found between biological distance and the maximum height and morphology of the frontal sinuses. The greatest degree of similarity was found among closely related individuals. Additionally, in several cases, there was a greater degree of similarity between first cousins or grandparents and their grandchildren than among siblings or parents and their children. Total surface, volume and width are not significant indicators of relatedness. Known genetic relationships are also supported by individual morphological features. Variability within families with very close consanguineous relationships was lower than within families with common degrees of consanguinity, although differences are significant only for some variables.

The earliest known case of frontal sinus osteoma in man

Frontal sinus osteoma is a relatively common finding in the modern clinical setting. Although, its paleopathological record is not in dispute, its presence in Ancient Egypt has never been clarified. The aim of this article is to contribute to the debate. An Egyptian mummy head from the Musée d'Éthnographie de Neuchâtel (Switzerland) was studied radiologically and the obtained evidence was contextualized in the wider frame of multidisciplinary paleopathology. A 128-slice CT scanner was used for further investigation; datasets were processed with OsiriX-64 bit (version 5.8.5), and multiplanar (MPR) and volumetric reconstructions were performed. A small hyperdense and well-defined structure, most likely an osteoma, was identified in the right frontal sinus. Frontal sinus osteoma definitely existed in Ancient Egypt. Finally, this represents the oldest case in anatomically modern humans so far reported. Clin. Anat.32:105-109, 2019. © 2018 Wiley Periodicals, Inc.

Risk of frontal sinus anterior table fractures after craniofacial trauma and the role of anatomic variations in frontal sinus size: A retrospective case-control study

INTRODUCTION

Purpose of this study was to evaluate a probable risk of frontal sinus size for traumatic depressed anterior table fractures in patients with similar forehead trauma.

METHODS

We conducted a retrospective case-control study with a case group of consecutive treated patients with displaced frontal sinus anterior table fractures. The control group was randomly sampled from patients who presented with a blunt forehead trauma in our institution's emergency unit. In computed tomography data sets, all patients' frontal sinus size was categorized by Guerram's classification that is defined as aplasia, hypoplasia, medium-size and hyperplasia. Odds for prevalence of the sinus types as well as sinus total width and height were compared between both groups.

RESULTS

In total, 47 cases and 93 controls were identified. Hyperplasia in the case group had an odds ratio of 46:1 (p < 0.001) compared to the controls. Mean sinus width (73 mm vs. 46 mm; p < 0.001) and sinus height (30 mm vs. 15 mm; p < 0.001) were larger in the case group.

CONCLUSION

Depressed traumatic fractures of the anterior table are an injury with a high risk specific for enlarged frontal sinus sizes. Anatomy is the predictive factor for this mode of craniofacial trauma.

Wormian Bone of the Orbit: A Case Report

Wormian bones are formed due to abnormal ossification centers in various locations in the skull. Genetic and/or environmental factors have been proposed to explain their formation. These bones can be normal anatomical variants or associated with a number of pathological conditions. The literature reports the most common locations of these bones as the cranial sutures, and reports of the presence of these bones in the orbit are rare. Clinically, these bones in the orbit can simulate fractures on imaging or can dislodge during surgery causing injury to the surrounding structures. Herein, we report a case of wormian bones of the orbit and discuss other reports from the literature.