Detailed Anatomical Analysis of the Sphenoid Sinus and Sphenoid Sinus Ostium by Cone-Beam Computed Tomography

Application of expanding bilateral sphenoid sinus plasty in the treatment of sphenoid sinus diseases

Expanding bilateral sphenoid sinus plasty is an essential technique for the treatment of sphenoid sinus diseases, such as refractory sphenoid sinusitis, sphenoid sinus cyst, fungal sphenoid sinusitis, sphenoid sinus carcinoma and sphenoid sinus chordoma. The present study evaluated the potential application of expanding bilateral sphenoid sinus plasty in the treatment of sphenoid sinus diseases. A retrospective medical record review of 42 patients treated with the expanding bilateral sphenoid sinus plasty from December 2012 to December 2018 was performed in a tertiary-care university hospital. A follow-up of the surgical effects and complications was performed. Of the 42 patients, the symptoms were relieved after operation in all except preoperative hyposmia in 2 and impaired vision in one with no obvious improvement. No complications such as nasal bleeding, olfactory hypofunction and perforation of nasal septum occurred. Follow-up data revealed good mucosal epithelization in all patients within a mean time of 8.6 weeks. Endoscopic sinus reexamination demonstrated that the sphenoid sinus orifice was well opened, and no cases of sphenoid sinus orifice closure were observed. Expanding bilateral sphenoid sinus plasty, with advantages of clearly exposed surgical field, full opening of the sinus cavity, high surgical safety, short epithelialization time and intuitionistic postoperative follow-up, demonstrated great promise for greater use in the treatment of sphenoid sinus diseases in the future.

Association of accessory sphenoidal septum with protrusions of sphenoid sinus

PURPOSE

Accessory sphenoidal septum (ASS) is a septal variation that exists in addition to the primary septum of the sphenoid sinus and can be found in or near anatomically essential structures. This study aimed to investigate the relationships between protrusions of vital structures around the sphenoid sinus and the ASSs.

METHODS

This cross-sectional retrospective study is based on the analysis of CBCT scans of 314 patients in axial, coronal, and sagittal planes with 0.2-0.3 slice thicknesses. Optic nerve (ON), internal carotid artery (ICA), both ON and ICA, maxillary nerve (MN), vidian canal (VN) and ASSs were detected, and the relationship between protrusions of these vital anatomical structures and ASS was evaluated.

RESULTS

Statistically significant relationship was observed between the right Type 1 ON protrusion (p < 0.05) and left Type 1 ON protrusion (p = 0.001); left Type 3 ON protrusion (p < 0.05); right Type 4 ON protrusion (p < 0.05) and ASS. Statistically significant relationship was also observed between the right ICA protrusion and ASS (p < 0.05). The right Type 1 VN protrusion (p = 0.001); left Type 2 VN protrusion (p < 0.001); right and left Type 3 VN protrusions (p < 0.001) were found to be significantly associated with the ASS.

CONCLUSIONS

ASSs have significant associations with some protrusions, and they tend to cause potentially severe complications in endoscopic sinus surgery. This variability requires a comprehensive understanding of regional sphenoid sinus anatomy with detailed three-dimensional tomographic imaging.

Location of the Sphenoid Sinus Ostium in Relation to Adjacent Anatomical Landmarks

PURPOSE

The variability of sphenoid pneumatization and its relationship with the surrounding structures has been suggested. The aim of this study was to examine the effect of the surrounding bony structures on the position of the sphenoid ostium (SO).

METHODS

A prospective radiological review of computed tomography images of paranasal sinuses of 150 patients (300 sides) was conducted. Parameters investigated included the presence of Onodi cells, sphenoid rostrum pneumatization, and the type of sphenoid pneumatization on the coronal and sagittal planes. Their effect was studied on the vertical and horizontal plane using lines of measurement 1 through 5.

RESULTS

The most common location of the SO on the horizontal plane was found to be in the middle third and was significantly affected by the rostrum pneumatization (P value <.001) and sphenoid pneumatization on the coronal plane (P value = .018). The location of the SO on the vertical plane was most commonly in the middle third. It was significantly affected by Onodi cell pneumatization (P value = .021) as well as the sphenoid height (P value <.001).

CONCLUSIONS

Pneumatization of the sphenoid sinus and adjacent bony structures can affect the location of the SO. Presence of rostrum pneumatization and lateral sphenoid pneumatization shift the SO laterally. Presence of Onodi cell and low sphenoid roof shift the SO inferiorly. These variations need to be studied carefully before surgery in order to avoid operative complications.

Morphometric Analysis of Sphenoid Sinus in Patients With Nasal Septum Deviation

This retrospective study aimed to assess the association of the volume and types of the sphenoid sinus with deviated nasal septum by analyzing multislice computed tomography images. A total of 93 patients with a deviated nasal septum and 70 healthy controls were included in the study. Patients with sinonasal morbidities other than deviation were excluded. Three-dimensionally reconstructed computed tomography images of the study participants were acquired. A total of 326 sphenoid sinus volumes from the patient and control groups were obtained and compared between the groups. Sphenoid sinus volumes and the angle of the deviation were measured for standardization and assessment of the severity. Deviated nasal septum was found on the right in 49.5% (n = 46) and on the left in 50.5% (n = 47) of the study participants. Deviation angles were in the range from 7.2° to 22.4° and the mean value was 13.2° ± 5.0°. The measured volumes were in the range from 1.8 cm to 9.6 cm with a mean of 4.8 ± 1.5 cm. In the control group, the median values for the sphenoid sinus volumes were 4.40 cm (0.80-8.90 cm) on the right and 4.20 cm (0.90-8.70 cm) on the left. In the study group, sphenoid sinus volumes were found to be statistically significantly different between those on the ipsilateral and contralateral side of the septal deviation. Sphenoid sinus volumes were significantly smaller on the same side with septal deviation compared with those on the contralateral side. There was no statistical relationship between the presence of septal deviation, age and gender, and the type of sphenoid sinus.

Evaluation of sphenoid sinus variations by using cone beam computed tomography in patients with cleft lip/palate

OBJECTIVE

The purpose of this study is to evaluate the sphenoid sinus variations in patients with cleft lip/palate.

METHODS

Sixty three (63) patient's cone beam computed tomography (CBCT) images, taken from the head and neck region, were evaluated. Images were divided into two groups; [Group 1; patients with cleft lip/palate (CLP Group) (n = 23) Group 2; patients without cleft lip/palate (control group) (n = 40)]. The main pneumatization types (conchal, sellar, and presellar) of sphenoid sinuses were assessed on sagittal sections of the CBCT images. The sphenoid body, lateral and lesserwing types were evaluated on coronal sections and anterior type pneumatization was evaluated on axial sections.

RESULTS

The mean age ranged from 12 to 26 (16.57 ± 4.46) in Group 1 and 12 to 25 (16.58 ± 3.71) in Group 2. In both groups, the male and female distribution was found similar (P = 0.342). The sellar type was the most common pneumatization type of sphenoid sinus both for the Group 1 (91.3%) and Group 2 (80%). Any statistically significant difference was not found between the two groups in terms of the incidence of pneumatization types. Combined type pneumatization was detected in 65.6% of the Control group and 76.2% of the CLP group.

CONCLUSIONS

In this study, the prevalence of sphenoid sinus pneumatization types in CLP patients was compared with the normal population. Any significant difference was not determined in the two groups.

Sphenoid Sinus in Relation to Age, Gender, and Cephalometric Indices

The sphenoid sinus is located in the center of the cranial base and is surrounded by numerous neurovascular structures. The aim of this study was to determine sphenoid sinus types and subtypes, dimensions of the sinus and cranium, and the relations of these to age and gender.Computed tomography data was obtained from 144 patients to determine right sphenoidal volume (sphVOLR), left sphenoidal volume (sphVOLL), total sphenoidal volume (sphVOLT), anteroposterior length of the sphenoid sinus (sphAP), laterolateral length of the sphenoid sinus (sphLL), head circumference (crHC), fronto-occipital length (crFO), and biparietal length (crBP), with OSIRIX software. The patients' ages ranged between 9 and 83 years (mean age 38 ± 15.5 years). The study included 89 males (mean age 39 ± 15.5 years) and 55 females (mean age 38 ± 15.6 years).Conchal (1.4%), presellar (8.3%), sellar (23.6%), and postsellar (66.7%) type sphenoid sinuses were determined based on the extension of pneumatization around the sella turcica. Each type of sphenoid sinus was classified into the following 5 types based on the direction of pneumatization: body, full lateral, pterygoid, lesser wing, and greater wing subtypes. Mean sphAP was determined as 29.72 mm and mean sphLL as 37.73 mm. In 5 patients only (3.4%), the sphenoid sinus was not divided into right and left by the intersphenoidal septum.The variations in the extensions of pneumatization of the sphenoid sinus and its dimensions might be used to estimate the selection of a surgical approach to lesions bordering the sinus.

Determining the Margin of Safety for Damaging the Sphenoid Sinus with Nasal Septum Osteotome during Le Fort I Surgery in Young Adults

Nasal septum (Obwegeser) osteotome is a basic instrument used for separating the nasal septum and maxilla during Le Fort I osteotomy. If this instrument is placed too high or tilted into the nasal cavity, sphenoid sinus and various adjacent vital structures may be damaged and serious bleeding, neurological complications, or blindness or even death may occur. The aim of this study is to determine the margin of safety for damaging the sphenoid sinus and the adjacent structures with nasal septum osteotome in the young adults: 49 male and 51 female patients between 15 and 25 ages who required a Cone Beam Computed Tomography (CBCT) examination as part of their routine examination. In the study sample consisting of CBCT images, the aimed surgical line, the line between spina nasalis anterior and vomer and the base of sphenoid sinus (undesired line), and tilt angle between surgical and undesirable lines were measured. As the primary outcome of this study, margin of safety for damaging the sphenoid sinus and adjacent vital structures with nasal septum osteotome during Le Fort surgeries in young adults recommended as 5 mm and 12⁰. For this reason the importance of planning with preoperative CBCT before Le Fort I osteotomies has been revealed.

Comparison of hand and semiautomatic tracing methods for creating maxillofacial artificial organs using sequences of computed tomography (CT) and cone beam computed tomography (CBCT) images

INTRODUCTION

The aim of this study was to compare the paranasal sinus volumes obtained by manual and semiautomatic imaging software programs using both CT and CBCT imaging.

METHODS

121 computed tomography (CT) and 119 cone beam computed tomography (CBCT) examinations were selected from the databases of the authors' institutes. The Digital Imaging and Communications in Medicine (DICOM) images were imported into 3-dimensonal imaging software, in which hand mode and semiautomatic tracing methods were used to measure the volumes of both maxillary sinuses and the sphenoid sinus. The determined volumetric means were compared to previously published averages.

RESULTS

Isometric CBCT-based volume determination results were closer to the real volume conditions, whereas the non-isometric CT-based volume measurements defined coherently lower volumes. By comparing the 2 volume measurement modes, the values gained from hand mode were closer to the literature data. Furthermore, CBCT-based image measurement results corresponded to the known averages.

CONCLUSIONS

Our results suggest that CBCT images provide reliable volumetric information that can be depended on for artificial organ construction, and which may aid the guidance of the operator prior to or during the intervention.