Reconstruction of the Orbit
14 November 2014 (online)
Orbital reconstruction today is a classic example of the evolution of advanced surgical procedures in a challenging anatomical environment based on experience and science.
Not much paralleled in other regions of oral and maxillofacial surgery procedures, orbital reconstruction has both benefitted and suffered from tradition. Strict surgical guidelines overestimated rigid fixation for a long time and focused on the reestablishment of the orbital frame of the midface and orbit. With that perspective other issues, for example, the importance of realignment of the zygomatic arch for the sagittal midface projection and reconstruction of deep orbital areas has not been always realized.
Today's orbital surgery aim at more artistry in reconstruction and less fixation, by interdisciplinary cooperation.
Latest and almost revolutionary improvements arose from refinements of imaging possibilities pioneering image-guiding procedures with the transfer of imaging to precise and controllable surgical steps by complex, computer-aided planning, mirroring, and data fusion techniques.
Early reconstructions addressed the outer orbital frame as well as the use of bone grafts. Nevertheless, many clinics limited their reconstructions for a long time to exposition of the anterior orbital floor close to the infraorbital rim with placement of foils. Fear of a too far posterior dissection with possible iatrogenic injury of the optic nerve often prevented extended exposures.
Reports of postoperative blindness added to a hesitation of a consequent wide exposure and complete anatomical repositioning. Contouring, fixation, and unpredictable resorption of bone grafts remained unsolved problems.
Another consequence of longstanding traditions was perseveration of incisions in the cheek, the lower lid, the eyebrow, and across the nasoethmoidal region, providing only limited exposure and causing additional injuries as visible scars, ectropion, epiphora, and soft tissue sagging. These approaches often reflected the incomplete or inadequate understanding of the pathophysiology of orbital trauma with underestimation of key areas.
In the meantime conjunctival approaches and their extensions allowed a disease- or injury-specific exposure in most of the situations and a combination with intraoral and blepharoplasty incisions when needed. More and more the coronal approach was reserved for comminuted or complexed injuries.
Yesterday's plain X-ray techniques in two dimensions allowed a rough detection of midface and orbital frame fractures and permitted guessing on the existence of orbital wall fractures.
Today, modern imaging techniques and high-resolution computed tomography allow for a complete three-dimensional (3D) imaging of the underlying bony fractures of the orbit. These imaging techniques not only give complete diagnostic information, but also guide the surgeon in treatment planning and determining the strategy for reconstruction.
Evaluation of numerous data has led to the development of preoperatively prebent 3D orbital implants.
Today anatomically preshaped orbital implants are on the market that fit the majority of patients with or without very little bending and cutting. These implants have added a high safety as they very often can be applied exclusively via a relatively small conjunctival incision again needing additional little or no further tailoring.
Also, virtual placement of these implants during the planning procedure allows a prediction of the procedure.
The outcome can be controlled during surgery, as the virtual position of the implant can be data fused with the intraoperative 3D cone-beam image, thus allowing an immediate intraoperative quality control and avoiding possible revision surgery.
Interdisciplinary cooperations including correctional muscle surgery by the ophthalmologist, other oculoplastic soft tissue procedures added to the current high standard in complex soft and bone-tissue orbital reconstructions.
Together current orbital surgery has reached an extremely high level of perfection and predictable long-time rehabilitations of patients with orbital pathologies.
The future of orbital surgery may aim at the introduction of new alloplastic or possibly biological materials that may be created using chairside engineering procedures. The further minimalization of approaches and new techniques in data fusion will allow for even more precise reconstruction.
It might be possible that robot-assisted procedures will make a further contribution to that challenging and fascinating area of craniomaxillofacial surgery.