A new study published in Clinical and Translational Radiation Oncology suggests that predicting radiation dose exposure across different jaw and dental regions may help clinicians make more individualized dental rehabilitation decisions before head and neck RT.
The study, titled “Prediction of high-dose regions in the jaw as a basis for decision-making in dental rehabilitation prior to radiotherapy in the head and neck area,” aimed to reduce unnecessary radical tooth extractions while still protecting patients from osteoradionecrosis.
Why This Study Matters
Radiotherapy for head and neck cancer can cause important oral complications, including xerostomia, radiation caries, mucositis, and osteoradionecrosis.
Osteoradionecrosis is rare but serious. It can severely affect quality of life, jaw integrity, nutrition, pain, and long-term oral function.
Because tooth extraction after radiotherapy can increase the risk of osteoradionecrosis, dental rehabilitation is usually recommended before treatment starts. However, without knowing which jaw regions will receive high radiation doses, clinicians may choose very radical extraction strategies.
This can lead to loss of teeth that might not actually have been at high risk.
Study Design
This retrospective study included 112 patients treated with intensity-modulated radiotherapy for head and neck squamous cell carcinoma.
Patients were grouped according to:
Tumor location: oral cavity, oropharynx, hypopharynx, or larynx
Treatment concept: definitive or adjuvant radiotherapy
Dental region: anterior, intermediary, or posterior regions of the upper and lower jaw
The authors calculated mean radiation dose exposure across 48 dental subregions.
They used commonly applied risk thresholds:
- Below 40 Gy: low risk
- 40 to 50 Gy: moderate risk
- Above 50 Gy: high risk
Based on these findings, they created a clinical decision tree for dental rehabilitation planning before radiotherapy.
Key Findings
Radiation dose to the jaw varied substantially depending on tumor location, treatment concept, jaw, and dental region.
The highest doses were generally seen in patients with tumors of the oral cavity and oropharynx.
The lower jaw received significantly higher mean doses than the upper jaw.
The posterior dental regions, especially molar regions, were more likely to receive higher doses than anterior regions.
Definitive radiotherapy was often associated with higher exposure, although differences depended on tumor location.
Across the 48 evaluated dental regions, 8 were classified as high risk, 10 as moderate risk, and 30 as low risk.
What This Means Clinically
The findings suggest that radical tooth extraction before radiotherapy may not be necessary in many dental regions, especially when predicted radiation exposure is below 40 Gy or within the moderate-risk range.
For low-risk regions, dental treatment may be planned similarly to patients not receiving radiotherapy.
For moderate-risk regions, individualized decision-making is needed, especially considering periodontal and apical inflammation.
For high-risk regions, more radical dental treatment, including extraction of teeth with inflammatory processes, may still be appropriate according to local guidelines.
Decision Tree Concept
The authors developed a practical decision tree to support dental rehabilitation planning before radiotherapy.
In general, tumors at a lower anatomic level, such as laryngeal and hypopharyngeal cancers, were less likely to expose dental regions to high-dose radiation.
Tumors at an upper anatomic level, especially oral cavity and oropharyngeal cancers, were more often associated with higher jaw doses and therefore greater need for careful dental planning.
This approach could help clinicians avoid a “one-size-fits-all” extraction strategy.
Important Message
The study does not suggest that dental rehabilitation before radiotherapy is unnecessary.
Rather, it argues that dental decisions should be dose-adapted whenever possible.
Unnecessary tooth extraction can impair chewing, aesthetics, nutrition, and quality of life. It may also require prosthetic rehabilitation, which can create its own risks in irradiated patients.
Therefore, preserving teeth when safe may be an important part of supportive cancer care.
Limitations
The study was retrospective and conducted at a single institution.
Several subgroups were small, especially for adjuvant radiotherapy in laryngeal and hypopharyngeal tumors.
Edentulous patients were excluded, which was necessary for regional dental dose analysis but may limit generalizability.
The authors also note that future prospective studies should correlate dosimetric predictions with actual osteoradionecrosis outcomes.
Clinical Takeaway
This study shows that tumor location can help predict which jaw regions are likely to receive high radiation doses during head and neck radiotherapy.
By using dose-based risk categories, clinicians may be able to personalize dental rehabilitation, reduce unnecessary tooth extractions, and better protect long-term oral function.
The key message is simple: before head and neck radiotherapy, dental treatment should be risk-adapted, not automatically radical.
Read full article here.