Karl Semmelmayer

Objectives: To evaluate oral sequelae after head and neck radiotherapy (RT) when using two different types of intraoral appliances. Thermoplastic dental splints (active control) protect against backscattered radiation from dental structures. Semi-individualized, 3D-printed tissue retraction devices (TRDs, study group) additionally spare healthy tissue from irradiation. Materials and Methods: A total of 29 patients with head and neck cancer were enrolled in a randomized controlled pilot trial and allocated to receive TRDs (n = 15) or conventional splints (n = 14). Saliva quality and quantity (Saliva-Check, GC), taste perception (Taste strips, Burghart-Messtechnik), and oral disability (JFLS-8, OHIP-14, maximum mouth opening) were recorded before and 3 months after RT start. Radiotherapy target volume, modality, total dose, fractionation, and imaging guidance were case-dependent. To evaluate intra-group developments between baseline and follow-up, nonparametric Wilcoxon tests were performed. Mann-Whitney-U tests were applied for inter-group comparisons. Results: At follow-up, taste perception was unimpaired (median difference in the total score; TRDs: 0, control: 0). No significant changes were found regarding oral disability. Saliva quantity (stimulated flow) was significantly reduced with conventional splints (median −4 mL, p = 0.016), while it decreased insignificantly with TRDs (median −2 mL, p = 0.07). Follow-up was attended by 9/15 study group participants (control 13/14). Inter-group comparisons showed no significant differences but a tendency towards a better outcome for disability and saliva quality in the intervention group. Conclusion: Due to the small cohort size and the heterogeneity of the sample, the results must be interpreted with reservation. Further research must confirm the positive trends of TRD application. Negative side-effects of TRD application seem improbable.

Surgical therapy of osteoradionecrosis of the jaw (ORN) is challenging and requires treatment of the affected hard and soft tissue. To understand how tissue injury after irradiation influences surgical outcomes, the objective of this study was to find out whether (a) bone-related, (b) soft tissue-related, and (c) treatment-related parameters influence the surgical success of patients with ORN. A total of 175 patients (324 lesions) were included in this retrospective, single-center study. All patients were diagnosed with ORN and underwent surgical therapy. The primary outcome was complete soft tissue recovery (mucosa/skin) and the absence of symptoms 3 months after surgery. At the time of follow-up, 58% of patients (189 of 324 lesions) had intact intraoral or extraoral soft tissue. The extent of bone destruction had no effect on treatment success, whereas soft tissue injury due to fibrosis (OR: 0.344; CI 0.142–0.834; p = 0.01818) and xerostomia (OR: 0.163; CI 0.064–0.419; p = 0.00016) increased the probability of treatment failure. Soft tissue reconstruction with a microvascular graft improved therapeutic success compared to local wound closure (OR: 2.998; CI 1.371–6.555; p = 0.006). Thus, for the treatment of ORN, it is extremely important to pay attention not only to the extent of bone destruction but especially to soft tissue defects. Because the extent of soft tissue injury is a predictor for therapeutic success, it should influence the choice of surgical treatment.