Osteoradionecrosis incidence and the timing of dental extractions

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Osteoradionecrosis is devitalised and exposed bone in a previously irradiated site that is not associated with persisting or recurrent tumour.  The risk of developing osteoradionecrosis following radiotherapy is estimated to be around 3% although under-reporting may be an issue. Although an uncommon complication it has a significant impact on morbidity and quality of life.

The aim of this review was to examine whether the incidence of osteoradionecrosis differed between patients who have dental extractions before or after radiotherapy (RT).

Methods

Searches were conducted in the PubMed, Embase, Evidence Based Medicine (EBM) Reviews (Ovid), and Web of Science (ISI) databases with no date restrictions. Studies published in English in peer-reviewed journals involving patients over the age of 18 exposed to RT (any modality) of the head and neck for malignancies were considered. Two reviewers independently screened and selected studies and extracted data with risk of bias being assessed using the ROBINS-I tool. Meta-analyses were conducted using random-effects models.

Results

  • 24 studies (19 retrospective 5 prospective) were included
  • Studies were conducted in Australia (1), Belgium (1), Brazil (2), Canada (n = 1), Finland (1), Hong Kong (1), Japan (1), Korea (1), Saudi Arabia (1), Singapore (2), Sweden (1), Taiwan (3) and the United States (8).
  • A range of malignancies were included involving the oral cavity, oropharynx, nasopharynx, larynx, hypopharynx, and salivary glands.
  • The definition of osteoradionecrosis varied across the studies as did the modality of RT.
  • 21 studies examined pre-RT extractions and 21 post-RT extractions.
  • There was no statistically significant difference in the incidence of osteoradionecrosis for pre- and post-RT groups.

Pre-RT extraction

  • Incidence of osteoradionecrosis ranged from 0.55% to 20.8%.
  • Meta-analysis (21 studies) showed a pooled incidence = 5.5% (95%CI; 2.1% to 10.1%).

Post-RT extraction

  • Only 7 studies presented timings of extractions
  • Meta-analysis (21 studies) showed a pooled incidence = 5.3% (95%CI; 2.9% to 8.2%).

Conclusions

The authors concluded: –

This systematic review supports the need for further research to establish a safe time frame for dental extractions in patients undergoing RT to the head and neck. Future, well designed, prospective, multicentre studies examining these key factors in appropriately defined cohorts of patients are recommended. In addition, to advance knowledge in this field, adequate years of follow up are required to prospectively review patients.

Comments

While the reviewers have searched a good range of databases restricting included studies to this published in English may have excluded some relevant publications.  Only 5 of the included studies were prospective with retrospective studies more likely to have missing data items and be more likely to suffer from bias. As the authors note the definition of osteoradionecrosis varied across the studies as did RT methods and site of head and neck malignancies as did the level of detail reported about the timing of extraction relative to RT, so levels of heterogeneity in the metanalyses were high. Consequently, the findings of the review should be treated cautiously.

A 2019 Cochrane review (Dental Elf – 29th Nov 2019) looked at interventions for preventing osteoradionecrosis following extractions after RT identified 4 RCTs or quasi-RCTs but because of suboptimal reporting and small sample sizes evaluating the interventions was uncertain. Well conducted and reported prospective studies of adequate size are needed to provided better evidence on timing of extractions and procedures to prevent osteoradionecrosis.

Links

Primary Paper

Beaumont S, Bhatia N, McDowell L, Fua T, McCullough M, Celentano A, Yap T. Timing of dental extractions in patients undergoing radiotherapy and the incidence of osteoradionecrosis: a systematic review and meta-analysis. Br J Oral Maxillofac Surg. 2020 Oct 20: S0266-4356(20)30577-5. doi: 10.1016/j.bjoms.2020.10.006. Epub ahead of print. PMID: 33685773.

Other references

Dental Elf – 29th Nov 2019

Osteoradionecrosis of the jaws: Prevention in adult patients with head and neck cancer

 

 

 

 

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