Osteoradionecrosis (ORN) is a severe late complication after radiotherapy but current knowledge on ORN risks in the setting of postoperative radiotherapy (PORT) is limited. We studied the incidence and risk factors of ORN in patients with oral cavity cancers (OCC, treated with PORT. A retrospective cohort study was conducted including OCC patients (mainly squamous cell) treated with postoperative intensity modulated radiotherapy between 2010 and 2018 with > 1 year disease-free survival. Cumulative incidences of ORN were computed using the Kaplan Meier method. Clinical and dosimetric risk factors for mandibular ORN were evaluated using Cox regression models. Within our cohort (N = 227, median follow-up 49 months) we observed 46 cases of ORN, mainly in the mandible (n = 41). The cumulative incidence of mandibular ORN was 15.9 % (SE 2.5 %) at three years and 19.8 % (SE 3.0 %) at five years. At univariable analysis, smoking, mandibular mandibulotomy or segment resection, mean dose to the mandible, and mandible volume (%) ≥ 60 Gy (V60) were significantly associated with increased ORN risks. At multivariable analysis, smoking (HR 2.13, 95 %CI 1.12-4.06) and V60 (HR 1.02 per 1 % increase, 95 %CI 1.01-1.04) remained predictive factors. For active smokers with a high V60 ≥ 40 % we observed rapid ORN development with a 1-year incidence of 29 % vs 6 % for others (p < 0.01). OCC Patients treated with PORT are at high risk for mandibular ORN. We identified the mandibular volume receiving ≥ 60 Gy as the dominant risk factor, especially in active smokers. Limiting high-dose volumes at treatment planning may decrease ORN risks.

Objectives: To compare two ridge preservation techniques and spontaneous healing in terms of hard and soft tissue changes 2 months after tooth extraction.Material and methods: The study was designed as a randomized controlled trial and included 75 patients. After single tooth extraction in the maxillary incisor/premolar area, patients were randomly allocated to one of the following groups: (a) ridge preservation with a xenogeneic bone substitute covered with a collagen matrix (CM‐group), (b) ridge preservation with a xenogeneic bone substitute covered with a free palatal graft (PG‐group) or (c) spontaneous healing (control). Eight weeks after tooth extraction, implants were placed and clinical, profilometric and radiographic evaluations were performed. In addition, the need for further guided bone regeneration (GBR) at implant placement was assessed. The differences between the treatment groups were compared with the One‐way ANOVA or Kruskal–Wallis test with the corresponding post hoc analysis. The proportions of the categorical parameters were compared with the Fisher´s exact test.Results: Seventy‐five patients underwent early implant placement 8 weeks after tooth extraction and were evaluated. CM‐group (−0.9 SD 0.6 mm) and PG‐group (−1.0 SD 0.8 mm) showed less horizontal bone resorption compared to the control group (−3.2 SD 2.1 mm) (p < .001). Moreover, the necessity of GBR at implant placement was significantly less in CM‐group (32%) and PG‐group (24%) when compared to control group (72%) (p = .001). Patients in CM‐group experienced less pain than PG‐group, one week after tooth extraction (p = .042). No significant differences were found regarding graft evaluation, post‐operative complications, and soft tissue contour.Conclusions: Ridge preservation using a xenogeneic bone substitute covered with a collagen matrix or a palatal graft, results in less bone resorption and fewer GBR procedures at early implant placement compared to spontaneous healing.

Objectives: To test whether early implant placement with alveolar ridge preservation (ARP) results in different esthetic, clinical and patient‐reported outcome measures (PROMs) compared with early implant placement without ARP.Material and methods: Seventy‐five patients requiring single tooth extraction in the anterior maxilla were recruited. Following tooth extraction, the patients were randomly allocated to three groups: (a) ARP using demineralized bovine bone mineral containing 10% collagen (DBBM‐C) covered by a collagen matrix (CM) (n = 25), (b) ARP using DBBM‐C covered with a palatal graft (PG) (n = 25) and (c) spontaneous healing (control) (n = 25). Eight weeks after tooth extraction, a CBCT was taken and early implant placement was performed in all patients. Esthetic, clinical and PROMs were evaluated one year post‐loading.Results: A total of 70 patients were available for re‐examination at one year post‐loading. The median mid‐facial mucosal margin change amounted to −0.02 mm (IQR −0.27–0.46) in the CM group, −0.13 mm (IQR −0.44–0.25) in the PG group and −0.14 mm (IQR −0.29–0.07) in the control group, with no significant differences between the groups. Mean PES scores amounted to 7.0 ± 1.4 in the CM group, 7.1 ± 1.5 in the PG group and 7.3 ± 1.7 in the control group without significant differences between the groups. Plaque, bleeding on probing and probing depth did not differ between treatment groups. PROMs in general revealed no significant differences between the groups.Conclusion: Early implant placement with ARP using either a collagen matrix or a palatal graft rendered similar esthetic, clinical and PROMs to early implant placement without ARP. When a failing tooth can be replaced with an implant within 2 months after tooth extraction, the added value of ARP might be clinically negligible.

Evaluation of long-term health-related quality of life (HRQOL) is essential for optimizing functional and psychological outcomes after major head and neck surgery. Because research on this topic is scarce, this study aimed to assess long-term HRQOL in patients following segmental mandibulectomy and osseous reconstruction. A retrospective, cross-sectional study was performed, including all consecutive patients who underwent segmental mandibulectomy and subsequent osseous reconstruction between 1993 and 2024. The primary outcome was HRQOL, assessed using the FACE-Q Head and Neck Cancer Module. Descriptive statistics summarized FACE-Q domain scores. Multivariable analyses identified associations between clinical variables and HRQOL. Of all 333 reconstructed patients, 117 were still alive and eligible for inclusion of whom 74 responded (response, 63 %) with a mean follow-up of 7.6 years (SD, 6.3) after surgery. In the long term, functional domains of the FACE-Q were most affected while psychological functioning scores remained relatively more favorable. Radiotherapy was significantly associated with lower scores in the domains of salivation (β = -28.6; p = 0.008), smile (β = -20.4; p = 0.046), and swallowing (β = -27.8; p = 0.004). Anterior mandibular defects (Brown class III-IV) were associated with poorer speech outcomes (β = -18.2; p = 0.012). Higher age at surgery was associated with poorer eating and drinking scores (β = -0.5; p = 0.008), while dental rehabilitation was associated with better scores (β = 11.7; p = 0.016). At long-term follow-up after segmental mandibulectomy and osseous reconstruction, various functional domains of HRQOL were affected, while psychological functioning scores seemed to remain relatively more favorable. Targeting modifiable factors may enhance long-term HRQOL in this population.

Background: Head and neck squamous cell carcinoma (HNSCC) displays a large heterogeneity in treatment response, and consequently in patient prognosis. Despite extensive efforts, no clinically validated model is available to predict tumor response. Here we describe a functional test for predicting tumor response to radiation and chemotherapy on the level of the individual patient. Methods: Resection material of 17 primary HNSCC patients was cultured ex vivo, irradiated or cisplatin-treated, after which the effect on tumor cell vitality was analyzed several days after treatment. Results: Ionizing radiation (IR) affected tumor cell growth and viability with a clear dose-response relationship, and marked heterogeneity between tumors was observed. After a single dose of 5Gy, proliferation in IR-sensitive tumors dropped below 30% of the untreated level, while IR-resistant tumors maintained at least 60% of proliferation. IR-sensitive tumors showed on average a twofold increase in apoptosis, as well as an increased number and size of DNA damage foci after treatment. No differences in the homologous recombination (HR) proficiency between IR-sensitive and –resistant tumors were detected. Cisplatin caused a decrease in proliferation, as well as induction of apoptosis, again with marked variation between the samples. Conclusions: Our functional ex vivo assay discriminated between IR-sensitive and IR-resistant HNSCC tumors, and may also be suitable for predicting response to cisplatin. Its predictive value is currently under investigation in a prospective clinical study.