Changing Paradigms in Prosthetic Rehabilitation Following Maxillary and Midfacial Malignant Disease

Chris Butterworth, BDS (Hons), MPhil, FDSRCS, FDS (Rest), RCS (Eng), a leading maxillofacial prosthodontist at Merseyside Head & Neck Cancer Centre, Liverpool, United Kingdom, shared his experience and the results of his clinical research over the past 12 years in the rehabilitation of patients treated for maxillary and midfacial malignant disease. He outlined the challenges in managing this rare but deserving group of patients and the importance of utilizing specialized tools such as zygomatic, oncology zygomatic (featuring an unthreaded, machined-surface mid-section), and Co-Axis^® (Southern Implants) implants in their early prosthetic and prosthodontic management. Over the past 12 years, he has built up the largest case series of oncology patients treated with zygomatic implants and has thoroughly reviewed the current literature on this important topic. He presented the results of his recent 10-year prospective study.

Butterworth's study, "Primary vs Secondary Zygomatic Implant Placement in Head and Neck Cancer Patients - A 10-Year Study," currently in press, was previously awarded the best oral clinical presentation at the 2017 Academy of Osseointegration meeting. It examined the survival and performance of zygomatic and modified zygomatic implants placed in patients with head and neck cancer over a 10-year period. It also compared patients who received zygomatic implants at the time of cancer surgery compared with those who were treated at a later time point.

Despite the fact that 50% of all the patients treated were smoking at the time of surgery and 49% had received radiotherapy before or immediately after implant placement, Butterworth's results demonstrated a 12-month zygomatic implant survival rate of 94% and a 5-year implant survival rate of 92%. His research also showed that while there was a small trend for higher implant survival with implants placed primarily compared to a secondary time point, the difference was not statistically significant. There also was no statistically significant difference in survival between conventionally placed zygomatic implants and  oncology-modified implants placed in a maxillary defect situation.

Butterworth also described the changing and more aggressive approach to rehabilitation of the maxillectomy and midfacial malignancy patients within his unit, with the trend being toward always seeking to place implants at the time of resective cancer surgery and restore the implants as quickly as patient recovery allows. Since 2016, Butterworth and his surgical colleagues have been combining the use of zygomatic implant placement together with microvascular soft-tissue reconstruction for low-level maxillectomy defects to maximize the benefits for patients. He outlined and presented his new technique, the zygomatic-implant-perforated (ZIP) flap, with several clinical examples.

The ZIP flap technique, published in 2017 in the International Journal of Implant Dentistry,¹ combines the advantages of a soft-tissue surgical reconstruction with the use of zygomatic and oncology implants, placed at the time of resective surgery, to provide the patient with a fixed dental rehabilitation that is completed in a matter of weeks postoperatively.

Figure 1 through Figure 8 demonstrate the ZIP flap technique for a patient with a large, left-sided maxillary tumor with resection of the tumor and placement of oncology-modified implants into the left residual zygomatic bone, together with extraction of residual teeth and placement of conventional zygomatic implants on the contralateral side. Multi-unit abutments were placed and impression and registration techniques were used to help fabricate the initial prosthesis. The large surgical defect between the mouth and nose was closed with a radial forearm-free flap, which is inset, and then perforated to allow the abutments on the oncology implants to be accessed postoperatively.

The initial fixed dental prosthesis was then fitted some 3 to 4 weeks after surgery, which can be done even when the patient requires postoperative adjuvant radiotherapy. With the defect closed surgically and the dental rehabilitation fixed, the ongoing prosthodontic maintenance was minimal and the patient's quality of life was vastly improved.

Research is continuing into this new and exciting technique, but the initial results presented by Butterworth on the first 12 patients treated this way are extremely encouraging.

Chris Butterworth, BDS (Hons), MPhil, FDSRCS, FDS (Rest), RCS (Eng)

Figures and Images

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Fig 1. Left-sided maxillary tumor resection, zygomatic and oncology implant placement, impression, and registration procedures.

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Fig 2. Left-sided maxillary tumor resection, zygomatic and oncology implant placement, impression, and registration procedures.

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Fig 3. Left-sided maxillary tumor resection, zygomatic and oncology implant placement, impression, and registration procedures.

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Fig 4. Left-sided maxillary tumor resection, zygomatic and oncology implant placement, impression, and registration procedures.

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Fig 5. Perforated radial forearm flap in situ with provisional bridge in place 4 weeks postoperatively and oral appearance 4 months later.

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Fig 6. Perforated radial forearm flap in situ with provisional bridge in place 4 weeks postoperatively and oral appearance 4 months later.

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Fig 7. Perforated radial forearm flap in situ with provisional bridge in place 4 weeks postoperatively and oral appearance 4 months later.

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Fig 8. Perforated radial forearm flap in situ with provisional bridge in place 4 weeks postoperatively and oral appearance 4 months later.