Chronic radiation effects on dental hard tissue (radiation caries). Classification and therapeutic strategies

Universitätsklinik und -poliklinik für Mund-, Kiefer- und Gesichtschirurgie, Mainz.
Strahlentherapie und Onkologie (Impact Factor: 2.91). 03/2001; 177(2):96-104.
Source: PubMed


Since the first description of rapid destruction of dental hard tissues following head and neck radiotherapy 80 years ago, "radiation caries" is an established clinical finding. The internationally accepted clinical evaluation score RTOG/EORTC however is lacking a classification of this frequent radiogenic alteration.
Medical records, data and images of radiation effects on the teeth of more than 1,500 patients, who underwent periradiotherapeutic care, were analyzed. Macroscopic alterations regarding the grade of late lesions of tooth crowns were used for a classification into 4 grades according to the RTOG/EORTC guidelines.
No early radiation effects were found by macroscopic inspection. In the first 90 days following radiotherapy 1/3 of the patients complained of reversible hypersensitivity, which may be related to a temporary hyperemia of the pulp. It was possible to classify radiation caries as a late radiation effect on a graded scale as known from RTOG/EORTC for other organ systems. This is a prerequisite for the integration of radiation caries into the international nomenclature of the RTOG/EORTC classification.
The documentation of early radiation effects on dental hard tissues seems to be neglectable. On the other hand the documentation of Late radiation effects has a high clinical impact. The identification of an initial lesion at the high-risk areas of the neck and incisal part of the tooth can lead to a successful therapy as a major prerequisite for orofacial rehabilitation. An internationally standardized documentation is a basis for the evaluation of the side effects of radiooncotic therapy as well as the effectiveness of protective and supportive procedures.

Download full-text


Available from: Bilal Al-Nawas
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Disertationsschrift
    Preview · Article ·
  • [Show abstract] [Hide abstract]
    ABSTRACT: Patients with squamous cell carcinomas of the oral cavity are being increasingly treated by multimodal interdisciplinary regimes using a combination of surgery, chemo- and radiotherapy. Inflammatory alterations of the vascular endothelium following preoperative radiotherapy frequently cause healing delays of free flaps in the irradiated graft bed. The aim of the study was to investigate quantitative and qualitative changes of irradiated neck recipient vessels and transplant vessels used for microsurgical anastomoses in free flaps in patients undergoing preoperative radiotherapy or radiochemotherapy. Patients and Methods: In 348 patients (October 1995–March 2002) receiving primarly or secondarly 356 microvascular hard- and soft tissue reconstruction, a total of 209 vessels were obtained from neck recipient vessels and transplant vessels during anastomosis. Three groups were analysed: group 1 (27 patients) treated with no radiotherapy or chemotherapy; group 2 (29 patients) treated with preoperative irradiation (60–70 Gy) and chemotherapy (800 mg/m2/day 5-FU and 20 mg/m2/day cisplatin) 1.5 months prior to surgery; group 3 (20 patients) treated with radiotherapy (60–70 Gy) (median interval 78.7 months; IQR: 31.3 months) prior to surgery. From each of the 209 vessel specimens, 3 sections were investigated histomorphometrically, qualitatively and quantitatively (ratio media area/total vessel area) by NIH-Image-digitized measurements. To evaluate these changes as a function of age, radiation dose and chemotherapy, a statistical analysis was performed using an analysis of covariance and 2tests (p > 0.05, SPSS V10). Results: In group 3, qualitative changes (intima dehiscence, hyalinosis) were found in recipient arteries significantly more frequently than in groups 1 and 2. For group 3 recipient arteries, histomorphometry revealed a significant decrease in the ratio media area/total vessel area (median 0.51, IQR 0.10) in comparison with groups 1 (p = 0.02) (median 0.61, IQR 0.29) and 2 (p = 0.046) (mdeian 0.58, IQR 0.19). No significant difference was found between the vessels of groups 1 and 2 (p = 0.48). There were no significant differences in transplant arteries and recipient or tansplant veins between the groups. Age and chemotherapy did not appear to have a significant influence on vessel changes in this study (p > 0.05). Conclusions: Following irradiation with 60–70 Gy, significant qualitative and quantitative histological changes to the recipient arteries, but not to the recipient veins, could be observed. In contrast, irradiation at a dose of 40–50 Gy and chemotherapy given at a median interval of 1.5 months prior to operation did not lead to significant histological changes to the recipient vessels.
    No preview · Article · Apr 2002 · Strahlentherapie und Onkologie
  • [Show abstract] [Hide abstract]
    ABSTRACT: Has a conscious exclusion of the contralateral major salivary glands (parotid, submandibular, and sublingual glands) a significant impact on the milieu of the oral cavity (saliva flow, pH, buffer capacity, and colonisation with Streptococcus mutans) in patients with ENT tumors receiving radical radiotherapy? 20 consecutive consenting patients with ENT tumors were evaluated once before, weekly during, and 6 weeks after the end of treatment in regard to saliva flow, ph, buffer capacity, and colonisation with Streptococcus mutans. In 13 patients the major salivary glands on both sides were included in the treated volume, in seven patients the treatment portals excluded consciously the contralateral major salivary glands. The stimulated saliva flow decreases already during the 1st week of radiotherapy, the decrease follows the dose exponentially; the saliva flow is further reduced in the weeks after the end of treatment. The effect is less pronounced in patients with sparing of contralateral major salivary glands. The majority of patients with unilateral sparing of the major salivary glands retain the baseline value of buffer capacity, whereas buffer capacity of all patients with inclusion of all major salivary glands is markedly reduced with 20 Gy already, without signs of recovery when treatment has stopped. With unilateral salivary gland sparing the pH always remains basic, in bilaterally irradiated patients the pH changes from a mean of 7.3 to 5.8 during treatment. The colonisation with Streptococcus mutans varies little in both groups during the radiotherapy; after the end of therapy, it is higher in bilaterally irradiated patients. The conscious arrangement of irradiation portals in order to spare contralateral major salivary glands in patients with radical radiotherapy of ENT tumors has a significant influence on the oral environment: the stimulated saliva flow is higher, the buffer capacity retains the baseline value, the saliva pH remains basic, and the colonisation with Streptococcus mutans is reduced.
    No preview · Article · Jan 2003 · Strahlentherapie und Onkologie
Show more