Worldwide there are around 900,000 new cases of head and neck cancer per year with smoking and alcohol consumption being important risk factors. Treatment typically includes surgery or radiotherapy alone or in combination with or without adjuvant chemotherapy. Dental implants are frequently used to support oral rehabilitation although radiotherapy may have implications for timing of placement of implants as well as survival
The aim of this review was to assess the effect of radiotherapy on the survival of dental implants in patients with head and neck cancer.
Searches were conducted in the Medline; Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases. Randomised controlled trials (RCT), cohort studies, case-control studies, and case reports of dental implants in head and neck cancer patients’ receiving radiotherapy with a follow-up period were considered. The main outcome was implant survival rate. Study quality was assessed using the risk of bias in non-randomised studies of interventions (ROBINS-I) tool. A meta-analysis was conducted.
- 7 studies (4 prospective, 3 retrospective) involving a total of 441 patients (1502 implants) were included.
- Meta-analysis (4 studies) showed significantly increased survival for implants placed in non-irradiated bone, Odds Ratio (OR) = 4.77 (95%CI; 2.57 to 8.89) for a mean follow up of 1- 3.8 years.
- Meta-analysis (3 studies) showed significantly higher implant survival in mandible than maxilla, OR = 5.03 (95%CI; 1.07 to 23.58).
The authors concluded:
- Implant-based rehabilitation is a viable treatment with favourable survival rates in irradiated head and neck cancer patients.
- Implant survival is significantly lower in irradiated compared with non-irradiated patients (p < 0.001).
- Radiation doses over 50 Gy are associated with lower survival rates.
- Implant placement should be delayed by at least six months following irradiation, although in selected cases primary placement may be favourable with good planning.
- Implant survival is significantly higher in the mandible than in the maxilla (p = 0.04). There are common side-effects of radio- therapy that are not amenable to improvement with implant- based rehabilitation, including xerostomia and limited mouth opening.
- Further research in the form of RCTs and high-quality comparative studies is recommended to confirm the validity of these claims.
While 3 major databases have been searched there is a lack of information about the study selection process as to whether this of the study quality assessment was conducted independently or in duplicate. No protocol for the review was registered. We have looked at an earlier review of this topic (Dental Elf – 5th Aug 2016) which included 40 studies and of the 7 studies included in this review all but two that have been published since were included. In addition, there are 3 further reviews (Zen Filho et al. 2016, Gupta et al. 2021, Toneatti et al. 2021) that have addressed very similar questions. Generally, these reviews agree that while implants show favourable survival rates in irradiated head and neck cancer patients the survival rates are lower. The authors of this review highlight implant placement guidelines according to radiation dose based on a narrative paper by Anderson et al, 2013. Although indicating that their results support Anderson limited information is provided to support this. From this and other reviews it is clear that additional high quality research is needed to clarify a number of questions related to the placement of dental implants in head and neck cancer patients receiving dental implants.
Shokouhi B, Cerajewska T. Radiotherapy and the survival of dental implants: a systematic review. Br J Oral Maxillofac Surg. 2022 May;60(4):422-429. doi: 10.1016/j.bjoms.2021.09.006. Epub 2021 Sep 16. PMID: 34903387.
Dental Elf – 5th Aug 2016
Zen Filho EV, Tolentino Ede S, Santos PS. Viability of dental implants in head and neck irradiated patients: A systematic review. Head Neck. 2016 Apr;38 Suppl 1:E2229-40. doi: 10.1002/hed.24098. Epub 2015 Jul 15. PMID: 25926008.
Gupta S, Mortellaro C, Panda S, Rovati M, Giacomello MS, Colletti L, Greco Lucchina A, Del Fabbro M. Dental implant survival rate in irradiated and non-radiated patients: a systematic review and meta-analysis. J Biol Regul Homeost Agents. 2021 Mar-Apr;35(2 Suppl. 1):53-65. doi: 10.23812/21-2supp1-5. PMID: 34281302.
Toneatti DJ, Graf RR, Burkhard JP, Schaller B. Survival of dental implants and occurrence of osteoradionecrosis in irradiated head and neck cancer patients: a systematic review and meta-analysis. Clin Oral Investig. 2021 Oct;25(10):5579-5593. doi: 10.1007/s00784-021-04065-6. Epub 2021 Aug 16. PMID: 34401944; PMCID: PMC8443505.
Anderson L, Meraw S, Al-Hezaimi K, Wang HL. The influence of radiation therapy on dental implantology. Implant Dent. 2013 Feb;22(1):31-8. doi: 10.1097/ID.0b013e31827e84ee. PMID: 23287974.