![]() ![]() Finally, the bone conduction theory, first proposed in 1972, 7 suggested that the trauma to the infraorbital rim may transmit force directly to the thinner orbital floor, causing disruption of the bone without fracture of the rim. In 1957, it was proposed the hydraulic theory, 6 according to which blowout fractures are caused by the increase of intraorbital pressure. A study published in 1943 5 supported the globe-to-wall contact theory, reporting 24 cases of internal fracture of the orbit, and explained that the posteriorly displaced eyeball transmitted the force of a blow directly to the orbital wall. However, no consensus has been achieved until now. The mechanisms, which lead to blowout fractures, have been the aim of many researches. The patient remained under surveillance for six months, with no complaint of paresthesia, no signs of visual disturbances or diplopia. A computed tomography scan was carried out after the surgery, showing a satisfactory repositioning of the soft tissue previously herniated and a good adaptation of the titanium mesh ( Figs. There were no complications and the patient was discharged 1 day after surgery. A 6-0 non-resorbable suture (nylon, ETHICON ®, Johnson & Johnson, USA) was used along the skin margin. A forced duction test was conducted with a negative result and the globe mobility was intact. The herniated soft tissue was repositioned and the orbital floor defect covered with a trapezoidal titanium mesh with approximately 25 mm on the orbit margin and 20 mm on the posterior width (Neo-ortho, Curitiba, PR, Brazil), which was fixed on the orbital rim with 3 monocortical, 1.5 mm profile (Neo-ortho, Curitiba, PR, Brazil), 2 screws of 5 mm and 1 screw of 4 mm ( Fig. A tarsorrhaphy suture was used, to protect the cornea during the operative procedure, followed by a subtarsal approach to access the orbital floor ( Fig. A week after the trauma, the patient was submitted to a reconstruction of the orbital floor, under general anesthesia. A computed tomography scan was done and it revealed a blowout fracture of the floor of the right orbit and a herniation of the orbital soft tissue into the maxillary sinus ( Figs. Nevertheless, no ocular movement restriction was found. He was submitted to a clinical evaluation and showed orbital ecchymosis, paresthesia of the infraorbital nerve and diplopia during vertical and horizontal ocular movements. Case reportĪ 27 year old man was examined at the Oral and Maxillofacial Surgery Department of the University Hospital of Uberlândia after physical aggression. We describe a clinical case of orbital floor reconstruction, with a titanium mesh as a treatment option for pure blowout fracture. The choice is based on the surgeon's experience and the availability of the material. 4 Therefore, natural and synthetic materials, like autogenous bone and titanium mesh, are available to reconstruct the orbital walls when it is necessary. ![]() Joining and stabilizing small, thin and delicate bone fragments is usually impossible. In the treatment of blowout fractures, it is important to reconstruct and maintain the accurate anatomical structural support of the orbit, against herniation forces during the initial phase of healing to obtain a functional and an esthetic result. Repairing the orbital wall fractures is still a surgical problem, due to the drawbacks of the reconstruction materials and technical errors, 3 such as misdiagnosis, timing of treatment as well as the accuracy during the repositioning of the soft tissue and the adaptation of the reconstruction material. The computed tomography is a radiological tool for evaluation of orbital fractures, which helps the surgeon to see if there is any incarceration or entrapment of soft tissue related to the orbit within the adjacent sinus. Common symptoms of this fracture are diplopia, enophthalmos, dystopia, paresthesia of the infraorbital nerve, and soft tissue incarceration or entrapment, leading to restriction of ocular movements. Three different theories have been proposed to explain the mechanism of blowout fractures: globe-to-wall contact theory, hydraulic theory and bone conduction theory. The term blowout fracture was first described in 1957 1 and it refers to a condition in which the displacement of an orbital wall occurs, but the orbital rim suffers no damage. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |