We read the response to our retrospective study (Mizbah et al. ) thoroughly. The algorithm that was proposed is similar to the protocol that was applied in our ‘during ablative surgery’ (DAS-implants) group and indeed is an asset to the literature.
In our retrospective study, two treatment protocols were compared in 510 consecutive patients diagnosed with a primary squamous cell carcinoma in the oral cavity. At Radboud University Nijmegen Medical Centre (RUNMC), 249 patients were involved; at the University Medical Centre Utrecht (UMCU), 261 patients were included. At RUNMC implants were placed, if possible and feasible, in the original non-reconstructed mandible during ablative surgery (DAS-protocol). At UMCU implants were only installed on condition that during the first postoperative year no recurrence had occurred. Analysis of the two groups revealed no statistical differences for tumour classification, tumour characteristics, pathology features of the resection specimens, and oncologic therapy. In addition, the calculated hazard ratios were small, indicating a small relative difference between the variables. Based on this, it is valid to draw the conclusion that, as the complication rate for both groups was the same, implant placement during ablation is favourable because three times more patients benefit 20 months earlier from their implant-supported denture. Of course this conclusion is drawn within the context of this retrospective study.
The responding authors state that the outcome measure, that patients provided with DAS-implants will be subjected to earlier prosthetic rehabilitation without an increased complication rate, is a non-issue. We oppose this statement. Obviously, patients who are treated after 1 year postoperatively receive their overdenture later. The main issue, however, is not only the delay, but also the fact that in the end three times fewer patients received an implant-retained overdenture. This item has, until now, never been addressed in any large cohort prospective or retrospective study.
Secondly, the finding that the complication rate was similar in the two groups is extremely important. To date, some clinicians expect that implants placed during the ablative surgery, thus about 6 weeks before irradiation is started, will have a better prognosis, which is apparently not the case!
Obviously, a prospective study with a strict protocol at both centres would be preferable; only then would it be possible to rate the functional outcome and quality of life. However, retrospective studies also contribute to scientific insight and often inspire the instigation of a prospective study.
With regard to the need for hyperbaric oxygen (HBO), we agree with the reasoning of the authors; they refer to an article that was released in 2004. However, patients were included in the years 2000–2005. At that time HBO was still part of the standard patient treatment protocol in Utrecht.
Our study compared two existing treatment strategies that were viable during those years. It is our scientific duty to research our results, learn from them, and inform others.
Finally, it is positive to remark that other centres have also incorporated the prosthetic rehabilitation of oral oncology patients in their work-up.