Clinical application of 3D pre-bent titanium implants for orbital floor fractures

Application of CAD/CAM-assisted technique with surgical treatment in reconstruction of the mandible

OBJECTIVE

The purpose of this clinical study was to explore the optimal method of reconstruct mandible defects individually and immediately.

STUDY DESIGN

Three-dimensional model simulation technique and vascularized fibular osteomyocutaneous flap were used to repair 15 cases of mandible defects, which were caused by ameloblastoma. A three-dimensional computed tomography (CT) images were converted to a virtual model using CAD software and the 3-dimensional (3D) simulated resin models of skeleton and fibula were used to design the osteotomies, bone segment replacement and titanium mesh shaping preoperatively.

RESULTS

Fibula flaps were alive and no complication occurred. The patients were satisfied with the results both esthetically and functionally.

CONCLUSIONS

This preliminarily clinical study and case demonstrated that CAD/CAM-assisted technique with surgical treatment offers an individual anatomical reconstruction of the mandible in ameloblastoma patients. The procedures guarantee intraoperatively an exact placement of the preformed mesh even for precise reconstruction of extensive mandible defects.

Orbital trauma: keep an eye for the details!

Orbital injuries are often missed out when they occur concomitantly with other facial bone fractures. Clinical examination and plain radiographic findings alone may prove inadequate in the detection of orbital floor fractures. Refined imaging techniques like CT scans and MRI are immensely helpful in the diagnosis of orbital blowout fractures. A case of 'impure' orbital blowout fracture which went undetected at the time of initial examination and its secondary surgical reconstruction is reported here. This case report emphasizes the importance of careful clinical and radiologic evaluation in orbital injuries.

Recent advances in reconstructive oral and maxillofacial surgery

Reconstruction within the head and neck is challenging. Defects can be anatomically complex and may already be compromised by scarring, inflammation, and infection. Tissue grafts and vascularised flaps (either pedicled or free) bring healthy tissue to a compromised wound for optimal healing and are the current gold standard for the repair of such defects, but disadvantages are their limited availability, the difficulty of shaping the flap to fit the defect and, most importantly, donor site morbidity. The importance of function and aesthetics has driven advances in the accuracy of surgical techniques. We discuss current advances in reconstruction within oral and maxillofacial surgery. Developments in navigation, three-dimensional imaging, stereolithographic models, and the use of custom-made implants can aid and improve the accuracy of existing reconstructive methods. Robotic surgery, which does not modify existing techniques of reconstruction, allows access, resection of tumours, and reconstruction with conventional free flap techniques in the oropharynx without the need for mandibulotomy. Tissue engineering and distraction osteogenesis avoid the need for autologous tissue transfer and can therefore be seen as more conservative methods of reconstruction. Recently, facial allotransplantation has allowed whole anatomical facial units to be replaced with the possibility of sensory recovery and reanimation being completed in a single procedure. However, patients who have facial allotransplants are subject to life-long immunosuppression so this method of reconstruction should be limited to selected cases.

The use of modern imaging techniques in the diagnosis and treatment planning of patients with orbital floor fractures

BACKGROUND

Ocular motility impairment associated with orbital trauma may have several causes and manifest with various clinical symptoms. In some cases orbital reconstructive surgery can be very challenging and the results are often unsatisfactory. The use of modern imaging techniques aids proper diagnosis and surgical planning.

CASE REPORT

The authors present the case of a 29-year-old male who sustained trauma to the left orbit. Orthoptic examination revealed limited supra- and infraduction of the left eye. The patient reported diplopia in upgaze and downgaze with primary position spared. Dynamic magnetic resonance imaging (dMRI) was performed, which revealed restriction of the left inferior rectus muscle in its central section. A patient-specific anatomical model was prepared on the basis of 3-dimensional computed tomography (CT) study of the intact orbit, which was used to prepare a custom pre-bent titanium mesh implant. The patient underwent reconstructive surgery of the orbital floor.

CONCLUSIONS

Modern imaging techniques such as dMRI and 3-dimensional CT reconstruction allow us to better understand the pathophysiology of orbital floor fractures and to precisely plan surgical treatment.

Biomaterials and implants for orbital floor repair

Treatment of orbital floor fractures and defects is often a complex issue. Repair of these injuries essentially aims to restore the continuity of the orbital floor and to provide an adequate support to the orbital content. Several materials and implants have been proposed over the years for orbital floor reconstruction, in the hope of achieving the best clinical outcome for the patient. Autografts have been traditionally considered as the "gold standard" choice due to the absence of an adverse immunological response, but they are available in limited amounts and carry the need for extra surgery. In order to overcome the drawbacks related to autografts, researchers' and surgeons' attention has been progressively attracted by alloplastic materials, which can be commercially produced and easily tailored to fit a wide range of specific clinical needs. In this review the advantages and limitations of the various biomaterials proposed and tested for orbital floor repair are critically examined and discussed. Criteria and guidelines for optimal material/implant choice, as well as future research directions, are also presented, in an attempt to understand whether an ideal biomaterial already exists or a truly functional implant will eventually materialise in the next few years.

Orbital change following Le Fort III advancement in syndromic craniosynostosis: quantitative evaluation of orbital volume, infra-orbital rim and globe position

Patients with syndromic craniosynostosis suffering from shallow orbits due to midface hypoplasia can be treated with a Le Fort III advancement osteotomy. This study evaluates the influence of Le Fort III advancement on orbital volume, position of the infra-orbital rim and globe. In pre- and post-operative CT-scans of 18 syndromic craniosynostosis patients, segmentation of the left and right orbit was performed and the infra-orbital rim and globe were marked. By superimposing the pre- and post-operative scans and by creating a reference coordinate system, movements of the infra-orbital rim and globe were assessed. Orbital volume increased significantly, by 27.2% for the left and 28.4% for the right orbit. Significant anterior movements of the left infra-orbital rim of 12.0mm (SD 4.2) and right infra-orbital rim of 12.8mm (SD 4.9) were demonstrated. Significant medial movements of 1.7mm (SD 2.2) of the left globe and 1.5mm (SD 1.9) of the right globe were demonstrated. There was a significant correlation between anterior infra-orbital rim movement and the increase in orbital volume. Significant orbital volume increase has been demonstrated following Le Fort III advancement. The position of the infra-orbital rim was moved forward significantly, whereas the globe position remained relatively unaffected.

Features of cranio-maxillofacial trauma in the massive Sichuan earthquake: analysis of 221 cases with multi-detector row CT

OBJECTIVE

In a massive earthquake, cranio-maxillofacial trauma was common. The present study was to determine the features of cranio-maxillofacial trauma sustained in the massive Sichuan earthquake by multi-detector row computed tomography (MDCT).

METHODS

The study included 221 consecutive patients (123 males and 98 females; age range, 1-83 years; median age, 35 years) with cranio-maxillofacial trauma in the Sichuan earthquake, who underwent cranio-maxillofacial MDCT scans. The image data were retrospectively reviewed focusing on the injuries of the cranio-maxillofacial soft tissue, facial bones and cranium.

RESULTS

All patients had soft tissue injuries frequently with foreign bodies. Ninety-seven (43.9%) patients had fractures (1.5 involved sites per patient, range from 1 to 8) including single cranial fractures in 36 (37.1%) cases, single maxillofacial fractures were seen in 48 (49.5%) and cranio-maxillofacial fractures in 13 (13.4%). Single bone fracture was more common than multiple bone fractures (p<0.05). Nasal, ethmoid bones and the orbits were the most commonly involved sites of the craniofacial region. Thirty-eight (17.2%) patients had intracranial injuries, the commonest being subarachnoid haemorrhage and the commonest sites were the temporal and frontal regions. Coexisting intracranial injuries were more common in patients with cranial fractures than in patients with maxillofacial fractures (p<0.05).

CONCLUSION

Our results indicate that the cranio-maxillofacial trauma arising from the massive Sichuan earthquake had some characteristic features, and a significant number of individuals had the potential for combined cranial and maxillofacial injuries, successful management of which required a multidisciplinary approach.

Treatment with individual orbital wall implants in humans - 1-Year ophthalmologic evaluation

BACKGROUND

In 2009 a method of creating individual, patient specific orbital wall implants using rapid prototyping (RP) was shown in a preliminary human study. That study showed that it is financially viable to produce anatomical models and that this technology could be used in the repair of orbital floor fractures.

MATERIALS AND METHODS

In this study, 24 consecutive subjects who had sustained orbital fractures (14 males, 6 females) without any coexisting central nervous system or globe injury were assessed post-operatively. The first series of 12 patients, recruited during the period 2005-2006, were treated with classical method (CM) of forming titanium mesh by manual manipulation, based on individual subjective assessment of the extent and shape of damaged orbital walls. The following 12 cases, recruited between 2007 and 2008, were treated with patient specific titanium mesh implants designed with an RP method. Early (2 weeks) and late (12 months) follow-up was performed. Patients were evaluated by binocular single vision (BSV) test and an assessment of eye globe motility.

RESULTS

The superiority of the RP treatment method over CM was shown on the basis of early results when BSV loss area and reduction of vertical visual disparity (VVD) in upgaze were considered. Better outcomes for the RP group were confirmed in the late follow-up results which showed a reduction of BSV loss area, correction of primary globe position and a very significant improvement in upgaze.

CONCLUSIONS

One-year post-operatively, functional assessment of pre-bent individual implants of the orbital wall has shown the technique to be a predictable reconstruction method. Nevertheless longer follow-up and an increase in the number of cases treated are required for the full evaluation of the technique.