To extract or not extract teeth prior to head and neck radiotherapy? A systematic review and meta-analysis

Biomaterials and therapeutic strategies designed for tooth extraction socket healing

Tooth extraction is the most commonly performed oral surgical procedure, with a wide range of clinical indications. The oral cavity is a complex microenvironment, influenced by oral movements, salivary flow, and bacterial biofilms. These factors can contribute to delayed socket healing and the onset of post-extraction complications, which can burden patients' esthetic and functional rehabilitation. Achieving effective extraction socket healing requires a multidisciplinary approach. Recent advancements in materials science and bioengineering have paved the way for developing novel strategies. This review outlines the fundamental healing processes and cellular-molecular interactions involved in the healing of extraction sockets. It then delves into the current landscape of biomaterials for socket healing, highlighting emerging strategies and potential targets that could transform the treatment paradigm. Building upon this foundation, this review also presents future directions and identifies challenges associated with the clinical application of biomaterials for extraction socket healing.

Occurrence of Jaw Osteonecrosis and Frequency of Prophylactic Tooth Extractions Prior to Head and Neck Radiotherapy: A Retrospective Study of 497 Irradiated Patients

Background/Objectives: This retrospective study examined the relationship between prophylactic tooth extraction (PTE) and the occurrence of jaw osteoradionecrosis (JORN) in patients undergoing head and neck radiotherapy (HNR). The primary objective was to determine whether PTE resulted in a JORN rate comparable to that of patients who did not require or undergo PTE. Methods: A total of 497 patients were included. The primary predictor variable was PTE, and the primary outcome was JORN occurrence. Statistical analyses included univariate, bivariate, and multivariate regression, as well as Cox regression. The significance threshold was set at p ≤ 0.005. Results: JORN was more frequent in the PTE group than in patients who did not require or undergo PTE (17.1% vs. 13.0%; hazard ratio [HR] 1.71, 95% CI: 1.08-2.71, p = 0.021). However, a significant association could not be confirmed using multiple logistic regression (odds ratio [OR] 1.36, 95% CI: 0.82-2.26, p = 0.236). Suggestive associations were observed for HNR dose (HR 1.03 per Gy, p = 0.007) and tumor location (pharyngeal HR 0.52, p = 0.03; laryngeal HR 0.51, p = 0.02). Conclusions: Patients with PTE showed a higher JORN rate but the findings were only marginally significant, and no causal relationship was established. The differing results between Cox and logistic regression suggest a time-dependent effect of PTE, with an increased early risk for JORN. Further studies are needed to determine whether greater emphasis should be placed on tooth-preserving measures, limiting extractions before HNR to strictly non-preservable teeth.

Prevention of osteoradionecrosis in patients with head and neck cancer treated with radiation therapy

BACKGROUND

Osteoradionecrosis is a long-term, serious side effect of head and neck radiation therapy and is associated with significant morbidity and quality of life issues.

METHODS

This paper sought to determine consensus on the prevention and management of osteoradionecrosis by an international panel of multidisciplinary professionals expert in the management of patients with head and neck cancer using a Delphi methodology. Unique to this work is our direct inclusion of the views of patients and carers in our findings.

RESULTS

This study reached consensus on the importance of pre and post oral health assessment and education for patients with head and neck cancer. This was also noted by the patients and carers who took part in the study.

CONCLUSIONS

This work highlights the need for a standardized oral health assessment tool and multidisciplinary care of patients to prevent and manage osteoradionecrosis.

Planned Dental Extractions After Radiation Therapy

Importance

Nonrestorable teeth are recommended to be extracted prior to radiation therapy (RT). Occasionally, preradiation extractions introduce unacceptable delays in treatment initiation. Planned dental extractions immediately postradiation presents an alternative strategy, though outcomes are uncertain.

Objective

To evaluate the feasibility and safety of dental extractions immediately postradiation.

Design, Setting, and Participants

A prospective cohort study including patients planned for curative-intent RT but unable or unwilling to proceed with 1 or more extractions recommended pretreatment was carried out. From January 2020 to September 2022, 58 patients were screened and 50 enrolled. The dental care was performed at a single academic department and the cancer care at regional centers. Analysis took place between September 22, 2023, and June 10, 2024.

Exposure

On completion of RT, patients were recommended to complete extractions as soon as feasible, and ideally within 4 months.

Main Outcomes and Measures

The primary end point was the actuarial cumulative incidence of exposed alveolar bone noted by any practitioner at any time after extraction, calculated using Gray method with death as a competing risk. As a pilot study, no formal power calculation was performed; resources allowed for 50 evaluable patients.

Results

Among the 50 participants enrolled, RT was nonoperative for 32 patients (64%) and postoperative for 18 patients (36%). Intensity-modulated RT (IMRT) was delivered in all patients. Of the 50 patients, 20 (40%) declined dental extractions immediately postradiation and the remaining 30 (60%) underwent a median (range) of 8.5 (1-28) extractions at a median (range) of 64.5 (13-152) days after RT. The median (IQR) follow-up for survivors without exposed bone was 26 (17-35) months from the end of RT. The 2-year cumulative incidence of any exposed bone was 27% (95% CI, 14%-40%). The 2-year incidence of exposed bone for those who underwent dental extractions immediately postradiation was 40% (95% CI, 22%-58%) and 7% (95% CI, 0%-22%) for those who did not. Of the 13 who developed exposed bone: 4 resolved, 1 was lost to follow-up, and 8 were confirmed as osteoradionecrosis.

Conclusions and Relevance

This cohort study found that postradiation dental extractions incur considerable risk, even if performed within a 4-month window.

The incidence of osteoradionecrosis of the jaws in oral cavity cancer patients treated with intensity-modulated radiotherapy: a systematic review and meta-analysis

OBJECTIVE

A systematic review with meta-analysis was conducted to define the incidence of osteoradionecrosis (ORN) in patients with oral cavity cancer (OCC) treated with intensity-modulated radiotherapy (IMRT), and to identify the risk factors influencing its development.

STUDY DESIGN

Six databases were searched systematically. A meta-analysis was performed to determine overall, spontaneous, and dental extraction-attributed incidences of ORN. The Grading of Recommendations Assessment, Development, and Evaluation tool evaluated evidence certainty.

RESULTS

Out of 11 eligible studies, 6 underwent meta-analysis for the overall aggregated ORN incidence in OCC patients receiving IMRT, resulting in an incidence rate of 8% (95% CI: 6%-11%). Regarding development reasons, 2 studies were assessed, revealing an incidence of 36% (95% CI: 1%-98%) for spontaneous ORN, and 17% (95% CI: 5%-44%) ensued from dental extraction exclusively pre-RT. All rates had very low certainty of evidence. Factors significantly correlated with ORN development included postoperative RT use (78%), employment of therapeutic doses above 50 Gy, and mandibular involvement (80.5%).

CONCLUSION

The findings suggest that IMRT alone is not sufficient to decrease ORN rates in OCC patients, underscoring the importance of precisely identifying the involved risk factors. However, further detailed primary studies will be necessary.

Osteoradionecrosis - an old problem with new consequences

PURPOSE OF REVIEW

Osteoradionecrosis (ORN) is a devasting complication of radiation therapy (RT), especially in head and neck cancers (HNC), and is still poorly understood. The aim of this review is to report its incidence and consider the risk factors associated with ORN to highlight prevention strategies to decrease its incidence.

RECENT FINDINGS

The average incidence of ORN is between 2% and 23%, with incidence decreasing in more recent years with the introduction of modern RT technology and better oral health care. Smoking, diabetes mellitus, oropharyngeal and oral cavity cancers, pre- and post-RT dental extractions and a total radiation dose of over 60 Gy were all identified as risk factors for ORN. In prevention, strategies were mainly structured around minimising risk factors or targeting possible mechanisms of ORN's pathophysiology.

SUMMARY

At present, the controversy surrounding the risk factors and pathogenesis of ORN makes it difficult to establish a set of prevention guidelines for its incidence. In order to achieve this, more research examining its aetiology must be conducted as well as a universal staging system within which ORN may be classified.

Oral Surgery and Osteoradionecrosis in Patients Undergoing Head and Neck Radiation Therapy: An Update of the Current Literature

Osteoradionecrosis (ORN) is a serious long-term complication of head and neck radiotherapy (RT), which is often triggered by dental extractions. It results from avascular aseptic necrosis due to irradiated bone damage. ORN is challenging to treat and can lead to severe complications. Furthermore, ORN causes pain and distress, significantly reducing the patient's quality of life. There is currently no established preventive strategy. This narrative review aims to provide an update for the clinicians on the risk of ORN associated with oral surgery in head and neck RT patients, with a focus on the timing suitable for the oral surgery and possible ORN preventive treatments. An electronic search of articles was performed by consulting the PubMed database. Intervention and observational studies were included. A multidisciplinary approach to the patient is highly recommended to mitigate the risk of RT complications. A dental visit before commencing RT is highly advised to minimize the need for future dental extractions after irradiation, and thus the risk of ORN. Post-RT preventive strategies, in case of dento-alveolar surgery, have been proposed and include antibiotics, hyperbaric oxygen (HBO), and the combined use of pentoxifylline and tocopherol ("PENTO protocol"), but currently there is a lack of established standards of care. Some limitations in the use of HBO involve the low availability of HBO facilities, its high costs, and specific clinical contraindications; the PENTO protocol, on the other hand, although promising, lacks clinical trials to support its efficacy. Due to the enduring risk of ORN, removable prostheses are preferable to dental implants in these patients, as there is no consensus on the appropriate timing for their safe placement. Overall, established standards of care and high-quality evidence are lacking concerning both preventive strategies for ORN as well as the timing of the dental surgery. There is an urgent need to improve research for more efficacious clinical decision making.

Can the prophylactic use of pentoxifylline and tocopherol before dental extractions prevent osteoradionecrosis? A systematic review

PURPOSE

This systematic review aimed to determine whether the pentoxifylline and tocopherol (PENTO) protocol effectively reduce the risk of osteoradionecrosis (ORN) in patients undergoing tooth extraction after head and neck radiotherapy.

METHODS

We searched PubMed, SCOPUS, LILACS, EMBASE, Web of Science, and Cochrane databases up to August 2022. We considered only studies that included patients diagnosed with head and neck cancer undergoing tooth extraction with PENTO prophylaxis after radiotherapy.

RESULTS

Of the 642 studies identified, 4 were included. Across the included studies, 387 patients had 1871 teeth extracted while on PENTO prophylaxis. The interval of the PENTO protocol differed among the studies included. Overall, a total of 12 (3.1%) patients had ORN, whereas at the individual tooth level analysis the ORN rate was 0.9%.

CONCLUSIONS

Insufficient evidence exists to promote using the PENTO protocol before dental extractions to prevent ORN.

A systematic review, meta-analysis, and network analysis of diagnostic microRNAs in glaucoma

Glaucoma is a chronic neurodegenerative process of the optic nerve that is the leading cause of blindness worldwide, and early diagnosis of the disease could greatly affect patients' prognoses. The pathophysiology of glaucoma is complicated by a combination of genetic and epigenetic factors. Deciphering the early diagnostic biomarkers in glaucoma could attenuate the disease's global burden and help us understand the exact mechanisms involved in glaucoma. The microRNAs are members of a larger family of non-coding RNAs that play an essential role in the epigenetic basis of glaucoma. A systematic study and meta-analysis of diagnostic microRNAs in glaucoma, jointly with network analysis of target genes, were carried out on published papers assessing differentially expressed microRNAs in human subjects. In total, 321 articles were found, and, after screening, six studies were eligible for further analysis. 52 differentially expressed microRNAs were found, of which 28 and 24 were up-regulated and down-regulated, respectively. Only 12 microRNAs were qualified for meta-analysis, with overall sensitivity and specificity of 80% and 74%, respectively. Then, using network analysis, it became apparent that the VEGF-A, AKT1, CXCL12, and HRAS genes were the most important targets for the microRNAs. Perturbations in WNT signaling, protein transport, and extracellular matrix organization pathways were discovered to be important in the etiology of glaucoma using the community detection approach. This study tries to uncover the promising microRNAs and their target genes that govern the epigenetics of glaucoma.