Clinical and surgical implications regarding morphometric variations of the medial wall of the orbit in relation to age and gender

Cellina

Journal of Craniofacial Surgery

et al. 2021

Nine years later, the patient presented to the outpatient clinic in July 2019 for refractory left acute sinusitis. He had no right-sided symptoms. Endoscopic findings showed a grade 2 polyp and mucopus on the left side. The findings were unremarkable on the right side. A non-enhanced computed tomography scan of the paranasal sinuses (shown in Fig. 1B and C) showed opacification of the left frontal sinus. It was incidentally noted that the previously dehiscent right frontal sinus posterior wall had reformed entirely, with a well-ventilated right frontal sinus. DISCUSSIONThe natural course of a paranasal sinus mucocele is that it will gradually expand, consequently leading to increased pressure of the affected sinus. Significant pressures and potent inflammatory cytokines such as interleukin-1 (IL-1) and vascular adhesion molecules such as ICAM-1 and E-selectin found uniquely in mucoceles 3 results in bony re-modeling and bony erosion. Early decompression is recommended to avoid intracranial complications.The list of causes for defects in the posterior wall of the frontal sinus is not exhaustive and includes trauma, mucocele formation, infection, and tumors. Typically, severe comminuted posterior wall fractures are managed by either cranialisation 4 or obliteration 5,6 of the frontal sinus. It is well established that complications occurring within six months of the posterior wall breach include CSF leak, meningitis, and frontal sinusitis, and late complications include persistent CSF leak, mucocele, mucopyocele, cerebral abscess, and osteomyelitis. However, in recent years, the trend has been to manage small posterior wall defects conservatively where suitable. 2,4 Freeman et al's experience with 42 cases of posterior wall defects from various causes suggests that mild (<1 mm) and moderately severe (>1 mm and <5 mm) breaches of the posterior wall of the frontal sinus can be safely managed with preservation of the frontal sinus and with comparable or lower risk of complications. 7 The right frontal sinus posterior wall defect in this patient was not repaired after the initial sinus surgery.The dura is well known for its osteogenic properties. 8-10 Yu et al 8 showed that dura could induce osteogenesis in cutaneous tissue in the absence of other central nervous system structures. O ¨zc ¸elik et al 9 demonstrated that osteogenesis and chondrogenesis were possible in zygomatic fractures by transplanting neonatal dura grafts to the bony defects in rats. The same study also highlighted that periosteum is crucial in osteogenesis, without which results in bony resorption of the fracture sites. Similarly, O ¨zerdem et al 10 studied the osteogenic potential of the dura, periosteal, and adjacent skeletal tissue in osteonecrotic cranial bone in rats. The results show that osteogenesis is significantly higher when periosteum and dura mater surround and provide support to the bony defects.Extrapolating from O ¨zerdem's animal studies, we postulate that the presence of dura beneath the bony deformity of the posterior frontal s...

Section: Discussionsupporting

confidence: 92%

Anatomical Variations of Anterior Ethmoidal Foramen and Cribriform Plate: Relations With Sex

Cellina

Journal of Craniofacial Surgery

et al. 2021

Journal of Craniofacial Surgery

“…Morales-Avalos et al21 reported an age-related variation in the anteroposterior diameter of the medial wall of the orbit, with the distances from the AEF to the posterior ethmoidal foramen being significantly greater among individuals older than 40 years. In our study, we found that the AEF-ANS distances and angles were negative correlated with age.…”

Section: Discussionmentioning

confidence: 99%

A Simple Clinical Application for Locating the Anterior Ethmoidal Artery Using the Anterior Ethmoidal Foramen and the Anterior Nasal Spine

Yang

et al. 2022

Purpose: The anatomy and variations of the anterior ethmoidal artery (AEA) are clinically relevant. The anterior ethmoidal foramen (AEF) can be used to locate the initial site of the AEA, and the anterior nasal spine (ANS) is a constant bony marker in the anterior nasal atrium. However, there is no relevant research on AEF and ANS targeting the AEA. Hence, this study aimed to accurately locate the AEA through AEF and ANS using computed tomography. Methods: A total of 120 (240 sides) sinus computed tomography scans were retrospectively selected and studied. The AEA was classified into grades I, Ⅱ, and Ⅲ group based on the relationship between the AEA and the skull base. The distance between AEF and ANS and the angle between AEF-ANS and the axial plane were measured. Results:The average distance from AEF to ANS was 58.26 ± 3.64 mm, and the corresponding angle was 60.05 ± 5.93 degrees. The AEF-ANS distances and angles were negatively correlated with age. Moreover, the distances from AEF to ANS were significantly increased in the grade Ⅲ group compared with the grade Ⅱ group. Conclusion:The measurements obtained in this study add anatomic knowledge that can serve as a better intraoperative localization method of the AEA, which can help surgeons avoid relative complications during endoscopic sinus surgery.

“…Unlike the extensive literature on surgical techniques, there remains little data on the anatomical variations of the medial orbital wall despite their recognition clinically [11]. The few cadaveric [12,13], dry skull [14,15] and radiological-based studies [16,17] on medial orbital wall anatomy, have not covered any inter-ethnic variation. Understanding of ethnic variation in medial orbital wall anatomy would improve the safety and efficacy of apical decompression for oculoplastic surgeons and help to identify boundaries for medial wall decompression.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

Background To describe the inter-ethnic variation in medial orbital wall anatomy between Chinese, Malay, Indian and Caucasian subjects. Methods Single-centre, retrospective, Computed Tomography (CT)-based observational study. 20 subjects of each ethnicity, were matched for gender and laterality. We excluded subjects younger than 16 years and those with orbital pathology. OsiriX version 8.5.1 (Pixmeo., Switzerland) and DICOM image viewing software CARESTREAM Vue PACS (Carestream Health Inc., USA) were used to measure the ethmoidal sinus length, width and volume, medial orbital wall and floor angle and the relative position of the posterior ethmoid sinus to the posterior maxillary wall. Statistical analyses were performed using Statistical Package for Social Sciences version 25.0 (IBM, USA). Results There were 12 males (60 %) in each group, with no significant difference in age (p = 0.334–0.994). The mean ethmoid sinus length in Chinese, Malay, Indian and Caucasian subjects, using the Chinese as reference, were 37.2, 36.9, 38.0 and 37.4mm, the mean width was 11.6, 10.5, 11.4 and 10.0mm (p = 0.020) and the mean ethmoid sinus volume were 3362, 3652, 3349 and 3898mm3 respectively. The mean medial orbital wall and floor angle was 135.0, 131.4, 131.0 and 136.8 degrees and the mean relative position of posterior ethmoid sinus to posterior maxillary wall were − 2.0, -0.2, -1.5 and 1.6mm (p = 0.003) respectively. Conclusions No inter-ethnic variation was found in decompressible ethmoid sinus volume. Caucasians had their posterior maxillary sinus wall anterior to their posterior ethmoidal walls unlike the Chinese, Malay and Indians. Awareness of ethnic variation is essential for safe orbital decompression.