Development of an Ex Vivo Functional Assay for Prediction of Irradiation Related Toxicity in Healthy Oral Mucosa Tissue.

Radiotherapy in the head-and-neck area is one of the main curative treatment options. However, this comes at the cost of varying levels of normal tissue toxicity, affecting up to 80% of patients. Mucositis can cause pain, weight loss and treatment delays, leading to worse outcomes and a decreased quality of life. Therefore, there is an urgent need for an approach to predicting normal mucosal responses in patients prior to treatment. We here describe an assay to detect irradiation responses in healthy oral mucosa tissue. Mucosa specimens from the oral cavity were obtained after surgical resection, cut into thin slices, irradiated and cultured for three days. Seven samples were irradiated with X-ray, and three additional samples were irradiated with both X-ray and protons. Healthy oral mucosa tissue slices maintained normal morphology and viability for three days. We measured a dose-dependent response to X-ray irradiation and compared X-ray and proton irradiation in the same mucosa sample using standardized automated image analysis. Furthermore, increased levels of inflammation-inducing factors-major drivers of mucositis development-could be detected after irradiation. This model can be utilized for investigating mechanistic aspects of mucositis development and can be developed into an assay to predict radiation-induced toxicity in normal mucosa.

Quality of life in 583 head and neck cancer survivors assessed with the FACE-Q head and neck cancer module.

OBJECTIVES: Long-term health-related quality of life (HRQOL) is frequently affected in head and neck cancer (HNC) survivors. Due to the shortage of studies investigating long-term patient-reported outcomes, we investigated long-term HRQOL using the novel FACE-Q HNC Module. METHODS: A retrospective cross-sectional single-center study was performed, including all patients who underwent curative treatment for HNC between 2006 and 2013. All eligible patients (n = 863) were invited to participate of whom 540 completed the questionnaires. Additionally, a prospective longitudinal cohort of 43 HNC patients treated between 2020 and 2022 was included who preoperatively filled in the FACE-Q, and at three, six, and 12 months postoperatively. HRQOL domain scores were analyzed to visualize group characteristics by tumor site and type of surgical resection. RESULTS: Both surgical and non-surgical HNC treatments predominantly affected long-term functional HRQOL domains (eating, salivation, speech, and swallowing), eating distress, and speaking distress, with distinct profiles depending on tumor site and type of treatment. In contrast, few long-term intergroup differences between HNC patients were observed for appearance, smiling, drooling distress, and smiling distress. Longitudinal data showed significant deterioration across all functional HRQOL domains in the short-term following treatment. Patients predominantly reported long-lasting negative treatment effects at 12 months follow-up for functional domains, whereas psychological domains showed near-complete recovery at group level. CONCLUSIONS: At long-term, various function-related and psychosocial HRQOL domains still are affected in head and neck cancer survivors. The results may serve to better inform patients with regard to specific treatments and highlight HRQOL domains which may potentially be optimized.

Personalizing dental screening and prevention protocols in dentulous patients with oropharyngeal cancer undergoing radiotherapy: A retrospective cohort study.

Objectives: Patients with head and neck cancer are routinely screened for dental foci prior to radiotherapy (RT) to prevent post- RT tooth extractions associated with an increased risk of osteoradionecrosis. We evaluated the risk factors for post-RT tooth extraction to personalise dental screening and prevention protocols prior to RT. Materials and methods: This retrospective cohort study included dentulous patients diagnosed with oropharyngeal cancer who had undergone radiation therapy at doses 60-70 Gy and achieved a disease-free survival of ≥ 1 year (N = 174). Risk factors were assessed using Cox regression models. Results: The cumulative incidence of post-RT tooth extraction was 30.7 % at 5 years. Main indications for extraction (n = 62) were radiation caries (n = 20) and periodontal disease (n = 27). Risk factors associated (p < 0.05) with radiation caries-related extractions included active smoking, alcohol abuse, poor oral hygiene, parotid gland irradiation, and mandibular irradiation. A high-dose volume in the mandible was associated with periodontal disease events. Conclusion: Post-RT extractions due to radiation caries were influenced by lifestyle factors and RT dose in the mandible and parotid glands. Periodontal disease-related extractions were primarily associated with the mandibular dose. During dental screening these post-RT risk factors should be taken into account to prevent osteoradionecrosis.

Alveolar ridge changes 1-year after early implant placement, with or without alveolar ridge preservation at single-implant sites in the aesthetic region: A secondary analysis of radiographic and profilometric outcomes from a randomized controlled trial.

OBJECTIVES: To assess both the radiographic and profilometric outcomes of early implant placement with or without alveolar ridge preservation (ARP) (using two different ARP techniques) after 1 year of loading. MATERIALS AND METHODS: Seventy-five patients with a failing single tooth in the anterior maxilla were randomly allocated to three groups (1:1:1): (a) ARP using demineralized bovine bone mineral containing 10% collagen (DBBM-C) covered by a collagen matrix (CM), (b) ARP using DBBM-C covered with a palatal graft (PG), and (c) unassisted socket healing (control). Eight weeks after tooth extraction, early implant placement was performed in all patients. Cone-beam computed tomography (CBCT) and impressions were taken 8 weeks after tooth extraction (ARP/unassisted healing) prior to implant placement and 1-year post-loading. Radiographic and profilometric outcomes were evaluated. RESULTS: Out of the 70 patients available for re-examination at 1-year post-loading, 55 datasets could be assessed (ARP-CM 19; ARP-PG 17; Control 19). The need for additional guided bone regeneration (GBR) at implant placement amounted to 31.6% (ARP-CM), 29.4% (ARP-PG), and 68.4% (unassisted healing). Adjusted models revealed that residual buccal bone height and additional GBR at implant placement significantly influenced the magnitude of the alveolar changes at 1 year (p < 0.05). In patients with ARP (group ARP-CM or ARP-PG) without additional GBR, the presence of bone convexity amounted to 36.0% (9/25) at 1-year post-loading. For patients that received ARP and additional GBR at implant placement, the frequency of bone convexity increased to 72.7% (8/11) (p = 0.042). Regarding profilometric measurements, a tendency toward agreement with radiographic outcomes was observed. CONCLUSIONS: Early implant placement with ARP can attenuate alveolar ridge changes at 1-year post loading by minimizing both radiographic and profilometric alterations. However, early implant placement with simultaneous GBR consistently yields superior radiographic and profilometric outcomes, regardless of whether ARP is performed.

Intraoperative assessment of resection margins by Raman spectroscopy to guide oral cancer surgery.

Patients with oral cavity cancer are almost always treated with surgery. The goal is to remove the tumor with a margin of more than 5 mm of surrounding healthy tissue. Unfortunately, this is only achieved in about 15% to 26% of cases. Intraoperative assessment of tumor resection margins (IOARM) can dramatically improve surgical results. However, current methods are laborious, subjective, and logistically demanding. This hinders broad adoption of IOARM, to the detriment of patients. Here we present the development and validation of a high-wavenumber Raman spectroscopic technology, for quick and objective intraoperative measurement of resection margins on fresh specimens. It employs a thin fiber-optic needle probe, which is inserted into the tissue, to measure the distance between a resection surface and the tumor. A tissue classification model was developed to discriminate oral cavity squamous cell carcinoma (OCSCC) from healthy oral tissue, with a sensitivity of 0.85 and a specificity of 0.92. The tissue classification model was then used to develop a margin length prediction model, showing a mean difference between margin length predicted by Raman spectroscopy and histopathology of -0.17 mm.

Ex Vivo Functional Assay for Evaluating Treatment Response in Tumor Tissue of Head and Neck Squamous Cell Carcinoma.

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.

Osteoradionecrosis after postoperative radiotherapy for oral cavity cancer: A retrospective cohort study.

OBJECTIVE: 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. PATIENTS AND METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Early implant placement with or without alveolar ridge preservation in single tooth gaps renders similar esthetic, clinical and patient-reported outcome measures: One-year results of a randomized clinical trial.

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.

Intraoperative Assessment of Resection Margins in Oral Cavity Cancer: This is the Way.

The goal of head and neck oncological surgery is complete tumor resection with adequate resection margins while preserving acceptable function and appearance. For oral cavity squamous cell carcinoma (OCSCC), different studies showed that only 15%-26% of all resections are adequate. A major reason for the low number of adequate resections is the lack of information during surgery; the margin status is only available after the final histopathologic assessment, days after surgery. The surgeons and pathologists at the Erasmus MC University Medical Center in Rotterdam started the implementation of specimen-driven intraoperative assessment of resection margins (IOARM) in 2013, which became the standard of care in 2015. This method enables the surgeon to turn an inadequate resection into an adequate resection by performing an additional resection during the initial surgery. Intraoperative assessment is supported by a relocation method procedure that allows accurate identification of inadequate margins (found on the specimen) in the wound bed. The implementation of this protocol resulted in an improvement of adequate resections from 15%-40%. However, the specimen-driven IOARM is not widely adopted because grossing fresh tissue is counter-intuitive for pathologists. The fear exists that grossing fresh tissue will deteriorate the anatomical orientation, shape, and size of the specimen and therefore will affect the final histopathologic assessment. These possible negative effects are countered by the described protocol. Here, the protocol for specimen-driven IOARM is presented in detail, as performed at the institute.

Soft tissue contour and radiographic evaluation of ridge preservation in early implant placement: A randomized controlled clinical trial.

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.

Esthetics and Patient-Reported Outcomes of Implants Placed with Guided Bone Regeneration and Complete Native Bone: A Prospective Controlled Clinical Trial.

PURPOSE: When encountering a buccal bone defect during implant placement, guided bone regeneration (GBR) is a well-accepted method for bone reconstruction. However, it is still unclear if the esthetic and patient-reported outcomes are comparable to implants placed in native bone. The purpose of this prospective trial was to compare implants placed with a GBR procedure for a small (≤ 4 mm) buccal defect with implants placed completely in native bone (control). MATERIALS AND METHODS: Patients were allocated to the GBR group or control group during implant placement in the esthetic zone. Implants were placed after at least 12 weeks of healing of the extraction sockets. A buccal bone defect of ≤ 4 mm resulted in allocation to the GBR group. Follow-up was performed until 12 months after loading. Outcome measurements were as follows: esthetic scores, patient-reported outcome measurements, implant survival and complications, clinical indices, and radiographic measurements. RESULTS: In total, 45 patients were included, of which 23 underwent a GBR procedure after implant placement, and in 22 patients no GBR was necessary. No significant differences in esthetic outcomes were seen between the two groups. At the final follow-up, a mean pink esthetic score (PES) of 7.8 (SD: 1.5) was seen for the GBR group and 8.4 (SD: 1.4) for the control group. Regarding the white esthetic score (WES), a mean of 9.1 (SD: 1.0) was found for both groups. Patients of both groups were equally satisfied with their mucosa and crown. A mean visual analog score (VAS) for the soft tissues of 8.6 (SD: 1.0) in the GBR group and 8.8 (SD: 0.9) for the control group was noted. A mean VAS of 9.2 (SD: 0.8) was noted for the crown in the GBR group and 8.6 (SD: 2.0) in the control group. Implant survival was 100%, and there were no significant differences in complications, plaque/bleeding/gingiva indices, width of attached mucosa, and marginal bone loss. CONCLUSION: Implants placed in the esthetic zone with GBR or complete native bone coverage showed successful esthetic outcomes and satisfied patients with predictable clinical and radiographic parameters after more than 1 year of loading. Within the limits of this study, GBR for a small buccal bone defect seems to be a reliable technique with good esthetics and patient-reported outcomes.

The effect of resorbable membranes on one-stage ridge augmentation in anterior single-tooth replacement: A randomized, controlled clinical trial.

AIM: To evaluate the effect of resorbable membranes on one-stage ridge augmentation procedures in small (2-4 mm) buccal bony dehiscences in anterior maxillary single-tooth replacement. MATERIALS AND METHODS: Patients with a buccal bony dehiscence after implant placement in the esthetic zone were randomly allocated to one-stage ridge augmentation with (M+) or without a membrane (M-). Second-phase surgery was performed after 8 weeks, and follow-up was performed 1, 6, and ≥12 months after loading. Outcomes included implant survival and success, complications, clinical and radiographic parameters, esthetic results and patient satisfaction. RESULTS: Fifty-two patients were randomized to one-stage ridge augmentation with (n = 25) or without use of a membrane (n = 27). No significant differences in implant survival and success have been observed. The risk of having a small mucosal dehiscence was more than six times higher in the M+ group than in the M- group (RR 6.24, 95% CI 0.81 to 48.21). At the last follow-up, the bleeding index (BI) was marginally higher in the M+ group (14/9/2/0) compared to the M- group (24/2/0/0) (U = 205, Z = -2.97, p = .003, r = .42). The median change in marginal bone level was statistically lower in the M+ group (0.06 mm) than the M- group (0.60 mm) at last follow-up (U = 120, Z = -2.73 a p = .006 r = .42). Total pink esthetic index (PES) and white esthetic score (WES) and combined PES/WES were not significantly different between treatment groups at more than 12 months after loading. Only the subcategory root convexity/soft tissue color scored significantly lower in the M+ group (1.5) compared to the M- group (2.0) at the last follow-up (U = 172, Z = -2.34, p = .019 r = .34). No differences were found in patient satisfaction. CONCLUSION: The use of a resorbable membrane in small buccal bony dehiscences in anterior maxillary single-tooth replacement resulted in less marginal bone loss, but showed more mucosal dehiscences, higher bleeding scores and lower scores on root convexity and soft tissue color after at least one year of loading. No effect was seen on implant survival and success, overall esthetic results, and patient satisfaction. The research protocol was registered at the Dutch Trial Register (NTR) with ID NTR6137.

The clinical value of membranes in bone augmentation procedures in oral implantology: A systematic review of randomised controlled trials.

PURPOSE: To determine the clinical value of membranes in bone augmentation procedures such as ridge augmentation with simultaneous (one-stage) and delayed (two-stage) implant placement, sinus augmentation surgery, ridge preservation and immediate implant placement. MATERIALS AND METHODS: In April 2016, Embase, Medline (Ovid-SP), Cochrane Central, Web of Science and PubMed (as supplied by the publisher) were searched. There were no restrictions regarding language or publication date. Randomised controlled trials that reported membranes in bone augmentation procedures with a minimum follow-up period of 6 months after implant loading or that described geometrical changes of the bone graft at re-entry were included. Membrane placement had to be the only variable in the procedure. Outcomes were implant failure, complications, horizontal bone gain and resorption, graft resorption, defect height reduction, marginal bone loss around implants, aesthetic results and patient satisfaction. The results were pooled using fixed-effect models with mean differences (MDs) for continuous outcomes and odds ratios (ORs) for dichotomous outcomes. RESULTS: After screening the titles and abstracts of 1843 papers, 32 potentially eligible articles were selected. Seventeen articles involving 10 trials were included in this review. These studies presented outcome data for 355 patients. Seven trials were considered to be at a high risk of bias, two at a low risk of bias and one at an unclear risk of bias. Insufficient evidence was found to determine whether there were differences in implant failure rates, marginal bone level changes, aesthetic results or patient satisfaction. For one-stage ridge augmentation (two trials; n = 52), there was evidence of more horizontal bone gain (MD: 0.84 mm, 95% CI: 0.46 to 1.21, P < 0.00001; two trials), defect height reduction (MD: 18.36%, 95% CI: 10.23 to 26.50, P < 0.00001; two trials), and prevention of graft resorption (P = 0.004; one trial) in favour of the membrane-covered group, although substantial heterogeneity was found for horizontal bone gain (Chi2; P = 0.05, I2=74%). There was insufficient evidence to determine whether any differences exist in two-stage ridge augmentation (three trials; n = 81), sinus augmentation (one trial; n = 104) and ridge preservation (one trial; n = 20). For immediate implant placement (three trials; n = 98), there was evidence of an increased defect height reduction in favour of the membrane-covered groups (MD: 6.25%, 95% CI: 1.67 to 10.82, P = 0.007; two trials), although with substantial heterogeneity (Chi2; P = 0.03, I2 = 79%). More complications were observed when a membrane was used (OR: 2.52, 95% CI: 1.07 to 5.93, P = 0.03; three trials). CONCLUSIONS: There is insufficient evidence regarding the effects of membranes on bone augmentation procedures to support any definitive conclusions. Only 10 studies were included; they had limited sample sizes and short follow-up periods, and the majority were at a high risk of bias. However, no difference in implant failure was found, and the possible clinical value is still unknown, as long-term clinical parameters such as marginal bone loss, aesthetic results and patient satisfaction have been insufficiently studied. Conflict-of-interest and source-of-funding statement: The authors declare that they have no possible conflicts of interest. No funding for this review was received.