Ethnic variation in medial orbital wall anatomy and its implications for decompression surgery

Efficacy of Nasal Septal Complex in the Endoscopic Reconstruction of Medial Orbital Wall

The aim of this study is to investigate the efficacy of nasal septal complex reconstructing the medial orbital wall under some specific circumstances. The authors performed a study that included 10 patients who underwent isolated medial orbital wall fracture (blow-out fracture). All the reconstruction surgery of the patient included in this study fixed defect of medial orbital wall using autologous nasal septal complex (composed of nasal septal cartilage and perpendicular plate of ethmoid). The authors observed postoperative improvements of diplopia or ocular motility disorders of the affected orbit. The surgeries had gained satisfactory results, and without severe postoperative complications. After long-term follow-up, postoperative CT indicated the implant-covered defect of medial orbital wall, and there's no incarceration of the medial rectus. Meanwhile, the authors found there is no crack in the implant, and the surgery using nasal septal complex achieved premorbid orbital form. Autologous nasal septal complex provides a better complement to endoscopic reconstruction of medial orbital wall; this strategy allows nasal septum to reconstruct isolated medial orbital wall defects of various degrees, such as nasal septum fracture and dysplasia of perpendicular plate of ethmoid.

Clinical Significance of the Inferomedial Orbital Strut in Orbital Blowout Fractures: Incidence of Symptomatic Diplopia in a Fractured vs. Intact Strut

Background/Objectives: This study aims to compare the clinical findings, particularly symptomatic diplopia, associated with an inferomedial orbital strut fracture versus intact strut and to determine the clinical significance of the inferomedial orbital strut in patients with orbital floor and medial orbital wall fractures. Methods: A 10-year retrospective observational study involving orbital blowout fracture cases was conducted in our institution. Patients with fractures of the orbital floor medial to the infraorbital groove and medial orbital wall, as seen on computed tomography (CT) scans, were included in this study. Patients with concomitant orbital rim fracture and those with old orbital fractures were excluded. Fracture of the inferomedial orbital strut was diagnosed via coronal CT images and patients were classified into those with an inferomedial orbital strut fracture and those without. Results: A total of 231 orbits from 230 patients was included in the study (fractured strut on 78 sides and intact strut on 153 sides). Approximately 2/3 of patients in both groups had the field of binocular single vision in primary position upon first examination (p = 0.717). Patients with strut fractures demonstrated only comminuted or open fractures, while those without strut fractures showed diverse fracture patterns (p < 0.001). Conclusions: Inferomedial orbital strut fracture does not automatically result in diplopia in patients with orbital blowout fractures. The integrity of the orbital periosteum plays a more essential role in hampering extraocular muscle displacement, thereby preventing symptomatic diplopia in these patients.

Gender differences in ethmoid sinus morphology_ 3D reconstruction of computed tomographic images

BACKGROUND

The ethmoid sinus (ES) is a three-dimensional (3D) complex structure, a clear understanding of the ES anatomy is helpful to plan intranasal surgery. However, most prior studies use 2D measurements, which may not accurately depict the 3D structure. The current study measured the gender differences in ES morphology based on 3D reconstruction of computed tomography (CT) images.

METHODS

The 3D models were reconstructed using CT images. Twenty-one males and 15 females were enrolled in the study. The ES dimensions, including width, height and aspect ratio (AR) of each cutting-plane section, were measured at 10% increments along with the anteroposterior axis of the ES. The gender differences in the above parameters were further evaluated by an independent t-test.

RESULTS

The width of the ES for males is 12.0 ± 2.1 mm, which was significantly greater than that in females (10.0 ± 2.1 mm). The average height for males is 18.4 ± 3.5 mm, and 18.2 ± 3.4 mm for females. The AR of female (male) is around 0.56 (0.63) for the anterior ES and 0.66 (0.75) for the posterior. There are significant differences between genders in the parameters of width and AR (p < 0.05).

CONCLUSION

This study found that the aspect ratio greatly varies along the length of ES, indicating that the cross-section of the ES in the anterior is closer to an elliptical shape and turns closer to a circular shape near its posterior. There is a significant difference between genders in width and aspect ratio. The results would be helpful to know the complex anatomic details of the ethmoid sinus.

Analysis of sphenoid sinus and ethmoid sinus volume and asymmetry by sex: A 3D-CT study

PURPOSE

To measure the volume of the sphenoid and ethmoid sinuses and to analyse the asymmetry index values by age/gender.

METHODS

Three-dimensional (3D) Computed Tomography (CT) images of 150 individuals (75 females, 75 males) of both sexes between the ages of 18-75 were included in our study. Sphenoid and ethmoid sinus volumes were measured using the 3D Slicer software package on these images, and the asymmetry index was calculated.

RESULTS

In our study, mean sphenoid sinus volume (female right: 4264.4 mm3, left: 3787.1 mm3; male right: 5201.1 mm3, left: 4818.2 mm3) and ethmoid sinus volume (female right: 3365.1 mm3, left: 3321.2 mm3; male right: 3440.9 mm3, left: 3459.5 mm3) were measured in males and females. Left sphenoid sinus values of males were statistically higher than females (p = 0.036). No statistically significant relationship existed between age, sinus volumes, and asymmetry index (p > 0.05). A statistically weak positive correlation existed between males' left sphenoid and ethmoid sinus volume (rho = 0.288; p = 0.012). There was no statistical relationship between asymmetry index in the whole group (p > 0.05). A statistically weak negative correlation was found between sphenoid and ethmoid sinus asymmetry index in males (rho=-0.352; p = 0.002). There was no statistical relationship between asymmetry index in females (p > 0.05).

CONCLUSION

Knowing paranasal sinus morphology, morphometry, and asymmetry index value will be significant for preoperative and postoperative periods.

Pressure Onto the Orbital Walls and Orbital Morphology in Orbital Floor or Medial Wall Fracture: A 3-Dimensional Printer Study

The purposes of this study were to compare the pressure onto the orbital floor and medial orbital wall between 3-dimensional printer skull models with unilateral orbital floor and medial orbital wall fractures and to compare the morphology of the orbital floor and medial orbital wall between patients with unilateral orbital floor and medial orbital wall fractures. The skull models were created based on computed tomographic (CT) data obtained from every 10 patients with unilateral orbital floor and medial orbital wall fractures. The orbital spaces of these models were filled with silicone, the silicone surface was pushed down, and pressures onto the orbital floor and the medial orbital wall were measured. On preoperative computed tomographic images taken in the same 20 patients, the superior and lateral bulges of the orbital floor and medial orbital wall were measured, respectively. The measurements were done on the unaffected sides. Consequently, the pressure onto the orbital floor was significantly higher in the orbital floor fracture models than in the medial orbital wall fracture models, although the pressure onto the medial orbital wall was not significantly different between the models. As for the morphologic study, the superior bulge of the orbital floor was higher in the orbital floor fracture group than in the medial orbital wall fracture group. The results of this study indicate that since the orbital floor with a high superior bulge receives high hydraulic pressure, patients with a high superior bulge have a greater risk of orbital floor fracture.