Background: Facial bones frequently need to be reconstructed from tumor resection. The vast majority of facial tumors are malignant and require complex reconstructions due to the need for adequate margins and to withstand post-resection radiation treatments. Benign bony tumors of the facial bones is more uncommon and can be reconstructed more simply, using employing free or non-vascularized bone grafts. But not all facial bone tumor removals require a bony reconstruction if the only functional purpose of the bone is aesthetic structural support.
Case Study: This 55 year-old female presented with a painful bump on the side of her cheek. She discovered the lump about a year previously and it had been slowly growing in size. What bothered her most, however, was the pain that it caused by pressing on the skin. She had some discomfort on widely opening her mouth and had a slight jaw deviation to that affected side. She had complete function of all facial nerve branches.
A 3-D CT scan showed a round bony growth off of the inferior portion of her left zygomatic arch. The surrounding arch bone appeared normal. Its appearance was consistent with an osteoma or other benign bony tumor types. The origin of this zygomatic arch bony tumor was unknown and its appearance is very rare. It is not a bony neoplasm location that I had ever seen before. A search using Google and in the Index Medicus using the term ‘zygomatic arch bony tumor’ failed to reveal any other similar cases.
Reconstruction was planned using a titanium reconstruction plate after the resection of the tumor. This was considered based on my experience with partial or complete resorption of bone grafts in the mid-portion of the zygomatic arch. The resection with 5mm margins was first done on the skull model and the titanium reconstruction plate similarly designed spanning the virtual defect. Three screw holes were designed on each side of the intervening full-thickness plate reconstruction implant.
Under general anesthesia, the zygomatic tumor was approached through an upper facelift or temporal incision. The incision extended down to the tragus in front of her ear. The dissection plane down to the zygomatic arch was done under the deep temporal fascia on top of the temporalis muscle. The zygomatic arch and the tumor bulge was easily seen dissecting anteriorly along the arch. A reciprocating saw was used to make a full thickness cut behind and in front of the arch tumor. It was removed and send to pathology which eventual was diagnosed as an osteoma.
The titanium plate was applied, positioned and three screws placed into the posterior portion closest to the incision. A percutaneous technique was used to apply three screws into the front holes of the plate over the zygomatic body. The incision was closed in two layers like that of a facelift closure. A circumferential pressure dressing was applied to be used over nite.
Her surgery was done as an outpatient procedure and completed in one hour of surgical time. The computer-generated implant obviated the need for harvesting a bone graft, avoiding the need for a donor site, and lengthening the time of the operation. Access for the surgery through a temporal incision posed no problem for visibility with the exception of screw placement in the front portion of the implant way anterior in the zygomatic body which was done through a percutaneous technique. The reconstruction implant, as predicted and designed on the skull model, was a perfect fit as was expected. Simulating the surgery on the skull model saved considerable operative time and assured a perfect aesthetic outcome.
Case Highlights:
1) Facial bone resection and reconstruction is significantly aided through the use of computer-generated technology and facial implant fabrication.
2) Zygomatic arch surgery can be done through a limited temporal incision with good visibility without the need for a larger coronal scalp incision.
3) The zygomatic arch is best reconstructed by an implant because bone grafts suspended in ‘air’ are prone to resorption.
Dr. Barry Eppley
Indianapolis, Indiana