Redesign and treatment planning orbital floor reconstruction using computer analysis anatomical landmarks

Abstract

Orbital floor fractures are one of the most commonly encountered maxillofacial fractures due to their weak anatomical structure. Restoration of the orbital floor following a traumatic injury or a tumor surgery is often difficult due to inadequate visibility and lack of knowledge on its anatomical details. The aim of this study is to investigate the locations of the inferior orbital fissure (IOF), infraorbital groove (G), and infraorbital foramen (Fo) and their relationship with the orbital floor using a software. Measurements from the inferior orbital rim (IOR) using the Fo, the IOF, G, and the optic canal (OC) were calculated in 268 orbits as reference points. The surgical landmarks from the G and the OC, the G and the IOF, the G and the intersection point were measured as 31.6 ± 6, 12.9 ± 4, and 12 ± 5 mm, respectively. The mean distances between the G and the IOR, the Fo and the IOF, and the Fo and the OC were found as 8.3 ± 2.1, 28.7 ± 3.5, and 53.6 ± 5.9 mm, respectively. The mean angles were calculated as OC-IOF-G 68.1° ± 16.4°; intersection-G-IOF as 61.4° ± 15.8°; IOF-OC-G as 19° ± 5.5°; OC-G-intersection as 31.5° ± 11.9°, G-intersection-OC as 129.5°, IOF-intersection-G as 50.5°. Furthermore, variable bony changes on the orbital floor which may lead to the differences at intersection point of the G and Fo were determined. In 28 specimens (20.9 %), unilateral accessory Fo (AcFo) was present. In 27 specimens, AcFo was situated supermaedially (96.4 %) on the main aperture. In one specimen, two intraorbital canals and Fo emerged from different points and coursed into different apertures. The measured mean distances of the AcFo-IOR and the AcFo-Fo were as 7 ± 2 and 7.3 ± 3.2 mm, respectively. The primary principle in the oculoplastic treatment of orbital floor reconstructions must be repositioning the herniated orbital aperture by maintaining the infraorbital artery and the nerve in the orbital floor. The IOF and the G were recommended as the more reliable oculoplastic surgical landmarks for identifying the orbital floor. To avoid pinching of the orbital floor structures, the triangle (IS-G-IOF) should be equilateral with an exigence of a 70° angle within it. Among each distance of the intersection-IOF, IOF-G, G-intersection should be equal. With the help of certain software, this study made possible to investigate the variability of the orbital floor structures, observe the variety in measurements and calculate the parameters which are crucial in implementing personalized reconstruction and implanting support.

Reconstruction of the Orbital Skeleton Using Computer- Aided Individualized Titanium Mesh Compared to Conventional Titanium Mesh

“…By two different procedures we evaluated the function of the infra orbital nerve which included pin prick test and electrical pulp testing we found that, there was significant difference between the two groups (P= 0.020 and 0.005 respectively). This in agreement with the study of Ozer et al 2016 (11) who reported that the recovery of the infra orbital nerve function need precise reduction he was evaluated with two different procedures which included electrical detection threshold and pin prick method. At 1 month time, post operatively 50% patients having electrical hyperesthesia when test with electrical detection threshold.…”

“…The differences between two sites were found to be significant statistically (p=0.05). Although there is no international consensus on the ideal material to be used for orbital reconstruction (11). However, in our study the success of orbital fracture repair depends not only on the use of material that restores the premorbid orbital volume and shape, but also the capacity to visualize the geometry of the bony defect spatially and to place the titanium mesh to fit the original contour with no evidence of inflammatory and fibrogenic response to the surrounding tissue.…”

Morphometric evaluation and surgical implications of the infraorbital groove, canal and foramen on cone-beam computed tomography and a review of literature

“…There are many bone [2,12,18,20,38,45,53,57,58,60,66,68] and cadaver [6,14,25,39,44,59,66,71] studies in which the relationship between morphometry of IOG, IOC, and IOF and their relations to the surrounding structures have been examined. Kazkayasi et al [38] evaluated 35 dry skulls both in bones and cephalometric radiography.…”

Improving the Treatment Outcome of Naso-Orbito-Ethmoido-Maxillary Fractures Using Virtual Three-Dimensional Anthropometric Data

“…The Rhi–FMO and N–FMO distances are of real help in the case of lateral orbital wall fractures when the restoration of the orbital contour as accurately as possible offers superior aesthetic results. Other points, segment or angle measurements would be required for orbital reconstruction, especially for the orbital floor [ 27 ]. For results with a satisfactory accuracy, the relationship of bone structures with the periorbital soft tissues should not be ignored [ 28 ].…”