Remarkable anatomic variations in paranasal sinus region and their clinical importance.
ABSTRACT With the advent of functional endoscopic sinus surgery (FESS) and coronal computed tomography (CT) imaging, considerable attention has been directed toward paranasal region anatomy. Detailed knowledge of anatomic variations in paranasal sinus region is critical for surgeons performing endoscopic sinus surgery as well as for the radiologist involved in the preoperative work-up. To be in the known anatomical variants with some accompanying pathologies, directly influence the success of diagnostic and therapeutic management of paranasal sinus diseases. A review of 512 (1024 sides) paranasal sinus tomographic scans was carried out to expose remarkable anatomic variations of this region. We used only coronal sections, but for some cases to clear exact diagnosis, additional axial CT scan, magnetic resonance imaging (MRI) and nasal endoscopy were also performed. In this pictorial essay, rates of remarkable anatomic variations in paranasal region were displayed. The images of some interesting cases were illustrated, such as the Onodi cell in which isolated mucocele caused loss of visual acuity, agger nasi cell, Haller's cell, uncinate bulla, giant superior concha bullosa, inferior concha bullosa, bilateral carotid artery protrusion into sphenoid sinus, maxillary sinus agenesis, bilateral secondary middle turbinate (SMT) and sphenomaxillary plate. The clinical importance of all these variations were discussed under the light of the literature. It was suggested that remarkable anatomic variations of paranasal region and their possible pathologic consequences should be well defined in order to improve success of management strategies, and to avoid potential complications of endoscopic sinus surgery. The radiologist must pay close attention to anatomical variations in the preoperative evaluation.
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ABSTRACT: Objective Infraorbital ethmoid (Haller) cells are extensions of the anterior ethmoid sinus into the floor of the orbit and superior aspect of the maxillary sinus. The aim of this retrospective study was to evaluate the frequency, volume, and surface area of infraorbital ethmoid cells on cone-beam computed tomography (CBCT). Methods In this retrospective study, 150 CBCT evaluations were determined for infraorbital ethmoid cells. One CBCT examination was carried out for each of the patients and interpreted for the presence of infraorbital ethmoid cells. Volumetric measurements were performed using CBCT scans. All of the CBCT scans were assessed and analyzed using MIMICS 14.0 software. Results In the 150 CBCT evaluations, 65 (43.3 %) were noted as having infraorbital ethmoid cells. In these patients, 47 (31.3 %) were unilateral and 18 (12 %) bilateral. The majority of the cells were round in shape. The frequency of unilocular infraorbital ethmoid cells occurring unilaterally was highly significant. There were no significant differences in the volume and surface area of right and left infraorbital ethmoid cells between males and females. Conclusions Infraorbital ethmoid cells were well demonstrated and the volume and surface area of infraorbital ethmoid cell could be measured on CBCT scans. These cells may provide useful differential diagnoses for patients suffering from orofacial pain of sinus origin.Oral Radiology 09/2014; 30(3):219-225. DOI:10.1007/s11282-014-0167-3 · 0.15 Impact Factor
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ABSTRACT: To determine the Keros classification and asymmetrical distribution rates of the ethmoid roof and the frequency of anatomic variations of the paranasal sinuses. Paranasal sinus scans of 500 patients obtained using computed tomography were evaluated retrospectively. Measurements were performed using a coronal plan with right-left comparison and with distance measurement techniques. The depth of the lateral lamella was calculated by subtracting the depth of the cribriform plate from the depth of the medial ethmoid roof. The results were classified according to their Keros classification. Any asymmetries in the ethmoid roof depth and fovea ethmoidalis configuration were examined. The anatomic variations frequently encountered in paranasal sinuses (pneumatized middle concha, paradoxical middle concha, agger nasi cells, Haller cells, Onodi cells, etc.) were defined. The mean height of the lateral lamella cribriform plate (LLCP) was 4.92±1.70 mm. The cases were classified as 13.4% Keros Type I, 76.1% Keros Type II, and 10.5% Keros Type III. There was asymmetry in the LLCP depths of 80% of the cases, and a configuration asymmetry in the fovea in 35% of the cases. In 32% of the cases with fovea configuration asymmetry, there was also asymmetry in the height of the right and left LLCP. The most frequent variations were nasal septum deviation (81.8%), agger nasi cells (63.8%), intralamellar air cells (45%), and concha bullosa (30%). Using the Keros classification for LLCP height, higher rates of Keros Type I were found in other studies than in our study. The most frequent classification was Keros Type II. The paranasal sinus variations in each patient should be carefully evaluated. The data obtained from these evaluations can prevent probable complications by informing rhinologists performing endoscopic sinus surgery about preoperative and intraoperative processes.
Article: Dev konka bülloza piyoseli06/2014; 36(2):256-260. DOI:10.7197/1305-0028.2331