Intermaxillary fixation screws for conservative condylar fracture treatment: a torsion strength comparison and screw pattern recommendation

256 Retrospective review of orbital fractures in the Auckland region from 2010 to 2015 L. Anand Department of Oral and Maxillofacial Surgery, Middlemore Hospital, Auckland, New Zealand

more conservative, tissue sparing and with the least complications in terms of facial nerve injury. Conclusions: The effectiveness of these plates proves that fixation along an ideal osteosynthesis line enables effective resistance to the bone tension forces acting on condylar process during mandibular movements. http://dx.doi.org/10.1016/j.ijom.2017.02.863

Objective: The objective of this study was to review the orbital fractures managed by our department, especially epidemiological aspects, treatment options and postoperative sequelae. Method: A retrospective review of the orbital fractures treated by the Department of Oral and Maxillofacial Surgery at Middlemore Hospital (Auckland, New Zealand) from 2010 to 2015 was undertaken. Patients were evaluated by age, gender, aetiology, time to surgery, type of reconstructive material used and complications. Results: The most common cause of orbital fracture was interpersonal violence (46%), followed by sporting injuries (25%). Males accounted for 80% of the fractures, with 50% of these being aged between 18 and 30 years old. The most significant complications were ongoing pain and restriction in movement requiring further intervention (6%), infection (3%) and retrobulbar haemorrhage (<1%). Conclusions: In the catchment area for our Hospital, which has a population of approximately 1.5 million, interpersonal violence is the leading cause of orbital fractures. Postoperative complications cannot be evaluated definitively until a few months after surgery. http://dx.doi.org/10.1016/j.ijom.2017.02.862 Two-dimensional lambda versus three-dimensional delta plates in subcondylar fracture using modified mini retromandibular subparotid approach S. Anchlia ∗ , R. Parmar, V. Nagwadia, J. Dhuvad, J. Shah, H. Domadia Government Dental College and Hospital, Ahmedabad, India Background: Condyle fractures are one of the most controversial maxillofacial injuries. In open reduction and internal rigid fixation of such fractures, to keep in mind are the functional loads which result in compressive stress patterns along the posterior border and tensile stress patterns along the anterior border of ramus and in the zone situated below the sigmoid notch. This study compares the efficacy of two-dimensional (2D) lambda plate and three-dimensional (3D) delta plates fixed in condylar fracture management. Methods: 30 adult patients with subcondylar fractures, 15 in each group using modified mini retromandibular subparotid approach. The indications were: - Adult patients - Occlusal disturbance - Ramal height decrease of over 4 mm - Fracture dislocation of TMJ Both plates were compared in terms of time taken to plate segments, functional restoration with amount of mouth opening, status of occlusion, condylar range of motion, deviation on mouth opening and postoperative complications. Results: There were no significant differences in terms of evaluation parameters between the two groups. But modified mini retromandibular subparotid approach can definitely be considered

Emergency management for orbital compartment syndrome — how important is decompression? A case report I. Basu ∗ , A. Ujam, M. Perry Northwick Park Hospital, London, United Kingdom The management of acute orbital compartment syndrome includes immediate lateral canthotomy and cantholysis, followed by open surgical decompression. Medical treatment is controversial, but is advocated in an attempt to reduce intraorbital pressures prior to surgical intervention. This consists of high dose steroids, mannitol and acetozolamide. Studies suggest that optic ischaemia for more than 90 min can result in permanent damage and therefore initial treatment needs to be commenced promptly. Treatment for late presenting cases is debatable, however, if not treated clinicians may be scrutinised and be accused of medical negligence. We present a case of delayed presentation of retrobulbar haemorrhage and loss of vision that improved with no intervention. A 76-year-old man blind in one eye, presented having sustained trauma to the other eye in which he had vision. He was referred to the maxillofacial team 5 h after the injury and a computed tomography confirmed a retrobulbar bleed with oedema. On examination he was noted to have proptosis, a fixed dilated pupil, loss of vision and ophthalmoplegia. The patient had a complex medical history that included chronic renal failure and peptic ulceration which were contraindications to diuretics and high dose steroids. Lateral canthotomy/cantholysis and decompression was refused by the patient in view of his comorbidities. This patient surprisingly made a full recovery after 48 h with no intervention. In contrast to the current literature, this case would appear to cast some doubt over the understanding of the role of orbital compartment syndrome/retrobulbar haemorrhage in the aetiology of blindness. http://dx.doi.org/10.1016/j.ijom.2017.02.864 Intermaxillary fixation screws for conservative condylar fracture treatment: a torsion strength comparison and screw pattern recommendation A. Bins ∗ , J. Koolstra, J. Baart, T. Forouzanfar, J. van Loon Department of Oral and Maxillofacial Surgery/3D Innovationlab VU University Medical Center, Amsterdam, The Netherlands Background: Material breakage, especially screws, can occur during intermaxillary fixation (IMF) for the treatment of condylar fractures. Further there is no consensus about the amount of screws required during these treatment procedures. Objectives: The present study was conducted to investigate the breakage moments of different screwing systems. The material properties of the best screwing system were used to develop a

257 computer simulation system to investigate the force distribution on the screw and to determine the minimal amount of screws required for IMF in the treatment of condylar fractures. Methods: Instructed for hand-tight insertion, three maxillofacial surgeons applied eight screws each of every screwing system (KLS Martin, Synthes, Jeilmed) into porcine mandibles. These handtight torque values were compared with breaking torque values, for which eight screws per screwing system were inserted till breakage. To determine the minimal amount of screws needed for IMF, a digital biomechanical model of the human masticatory system was constructed, with all masticatory muscle attachments. Findings: All screws had significant safety margins between hand-tight and breaking torque values. No difference in safety margins existed between screwing systems. After simulating a condylar fracture on the model, a digital analysis calculated the forces needed per screw to remain in IMF following different activations of the masticatory muscles. Conclusion: Screw selection should not be based on torsion strength but on other clinical factors, such as ease of usage and patient comfort. The digital model for calculating the minimal amount of screws seems valid, but still has to be evaluated clinically.

with this pathology, clinical features; mechanisms of the lesions and evolution are discussed. A 17-year-old male patient referred for left ocular motor palsy and exophthalmos after craniofacial trauma. Computed tomography (CT) scan showed orbitonasal dislocation and a bone fragment in contact with the optic nerve. Postoperative restricted vision to a distance of four meters and persistence of ocular motor palsy were the outcome of long-term follow up. The second observation is of a 40-year-old male patient referred to us after a traffic accident, complaining about loss of his right vision and light perception. On examination we noted a limitation in the upper gaze. Ophthalmoscopy revealed a papillary oedema and paleness of the retina of ischaemic nature. CT imaging showed a displaced fracture of the lateral wall of the right orbit and elongation of the right optic nerve. Despite early corticotherapy the blindness was the definitive result. Posttraumatic neuropathy is a rare cause of blindness due to direct and indirect injury of the optic nerve. The diagnosis becomes difficult when the patient has lost conscious. Ophthalmoscopy shows only nonspecific signs and imaging views confirm direct lesion of the optic nerve nailed by a bony fragment but they are less contributive in analysing intrinsic injury. The visual evolution in most cases is of poor prognosis.

http://dx.doi.org/10.1016/j.ijom.2017.02.865 http://dx.doi.org/10.1016/j.ijom.2017.02.867 Rare fractures of the maxilla: the isolated fracture of the anterior nasal spine and of the posterior wall of the maxillary sinus

Optimising the field surgical equipment used by maxillofacial surgeons deploying on future military operations

M. Bouzaiene ∗ , J. Hamila, H. Msek, H. Touil

J. Breeze ∗ , J. Combes, N. MacKenzie, A. Gibbons

University Hospital Center, Mahdia, Tunisia

Royal Centre for Defence Medicine, United Kingdom

There are exceptional fractures of the maxilla that have not been described in the literature. They are characterised by their proper mechanism and particular circumstances related to the anatomic conditions. These fractures ought to be described to define novel clinical features. Fracture of the nasal spine needs to happen a direct choc on the nasal base with an anatomically long spine. Clinical presentation showed important oedema of the upper lip, ecchymosis and a swelling of the superior vestibular sulcus. The diagnosis is confirmed by means of an X-ray revealing the fracture on the profile incidence. Isolated fracture of the posterior wall of the maxillary sinus is another rare entity created by a direct choc on the maxillary tuberosity. We advocate as a possible hypothesis that direct trauma of this region causes intrasinus high pressure leading to the fracture of the posterior wall. The authors tend to describe these rare fractures and to establish their anatomic and clinical aspects.

Background: The 2015 Ministry of Defence Strategic Defence Strategy Review identified the need for highly mobile medical facilities for future conflicts. Field hospitals will include military maxillofacial surgeons capable of providing damage control surgery for injuries to the head and neck. The requirement for speed and mobility necessitates optimisation of the maxillofacial specific equipment. Objectives: The aim of this study was to identify field surgical equipment that can be utilised by maxillofacial surgeons to manage acute head and neck trauma in the current deployed military environment. Methods: A systematic review of the medical and commercial literature was undertaken with Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology to identify surgical procedures necessary to identify portable surgical equipment capable of treating head and neck trauma in the deployed military environment. Findings: A maxillofacial specific field module will be required to supplement the existing orthopaedic module to manage hard tissue craniofacial trauma. This should enable facial fracture intermaxillary and external fixation as well as craniotomy within 72 h. Equipment for internal fixation will be required for 5–7 days post injury. Conclusions: A lightweight, modular and compact trauma module for future conflicts based upon these recommendations is currently being built. All drills and craniotomes are should be battery operated, but the use of compression units are recommended to improve torque. Rapid resupply modules should be available for commonly used components. A cadaver based training

http://dx.doi.org/10.1016/j.ijom.2017.02.866 Direct impairment of the optic nerve in case of orbitocranial trauma M. Bouzaiene ∗ , H. Touil University Hospital Center, Mahdia, Tunisia Posttraumatic optic neuropathy is a dread and rare complication of facial trauma. The authors describe two clinical cases dealing