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Objectives: The conventional radiotherapy protocol to treat head-and-neck cancer is usually followed by tooth-decay onset. Radiation impact on mineralized tooth structures is not well-understood. This systematic review aimed to collect the recorded effects of therapeutic radiation on tooth chemical, structural and mechanical properties, in relation with their means of investigation., Data: Systematic search (January 01 2012 - September 30 2021) terms were "Radiotherapy", "Radiation effects", "Dental enamel", "Dentin", "Human" and "Radiotherapy" NOT "Laser"., Sources: PubMed, DOSS and Embase databases were searched., Study Selection: Selected studies compared dental enamel, coronal and root dentin properties before and after in vitro or in vivo irradiation up to 80 Gy., Results: The systematic search identified 353 different articles, with 28 satisfying inclusion criteria. Their reference lists provided two more. Twenty-two studies evaluated dental enamel evolution, nine assessed coronal dentin and eight concerned root dentin. Coronal and root dentin results indicate a major impact of the radiation on their organic matrix. Dental enamel's chemical properties are less modified. Enamel and root dentin's hardness are decreased by therapeutic radiation, but no consensus arises for coronal dentin., Conclusions: Our findings revealed some interesting information about enzymatic degradation mechanisms of dentin organic matrix and highlighted that dental hard-tissue characterization requires highly specific expertise in materials science. That scientific knowledge is necessary to design suitable protocols, adequately analyze the obtained data, and, thus, provide relevant conclusions., Clinical Significance Statement: Better knowledge and understanding of the mechanisms involved in the degradation of enamel and dentin would enable development of new preventive and therapeutic methods for improved medical care of patients undergoing radiotherapy., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: On the elastic profiles of human teeth after radiotherapy for head and neck cancers, generation of dental complications, which may bring several side effects preventing the quality of life, has not well clarified. Thus, we aimed to show the applicability of using 320 MHz Scanning Acoustic Microscopy (SAM) in the evaluation of the tooth damage acoustically at the micrometer level following radiation therapy, and also in the determination of the safe dose limits to impede severe dental damage., Methods: This prospective study was performed by SAM employed at 320 MHz by an azimuthal resolution of 4.7 μm resolving enamel and dentin. A total of 45 sound human third molar teeth collected between September 2018 and May 2019 were used for the acoustic impedance measurements pre- and post irradiation. Nine samples for each group (control, 2 Gy, 8 Gy, 20 Gy, 30 Gy and 60 Gy) were evaluated to acquire the acoustic images and perform a qualitative analysis. Scanning Electron Microscopy (SEM) images were obtained to establish a relationship between micromechanical and morphological characteristics of the teeth. Statistical analysis was conducted using the Student t-test succeded by Mann-Whitney U investigation (p < .05), while SEM images were assessed qualitatively., Results: The analysis included 45 sound teeth collected from men and women 18 to 50 years old. Post irradiation micromechanical variations of human teeth were significant only in the radiation groups of 30 Gy and 60 Gy compared to pre-irradiation group for enamel (7.24 ± 0.18 MRayl and 6.49 ± 028 MRayl; p < 0.05, respectively). Besides, the teeth subjected to radiation doses of 20, 30 and 60 Gy represented significantly lower acoustic impedance values relative to non-irradiated group for dentin (6.52 ± 0.43 MRayl, 5.71 ± 0.66 MRayl and 4.82 ± 0.53 MRayl p < 0.05), respectively., Conclusions: These results are evidence for a safe acoustic examination device which may be a useful tool to visualize and follow the safe dose limits to impede severe dental damage through the radiation therapy treatment for head and neck cancers.

During radiotherapy for head and neck tumours, the oral cavity and cheek area would be inevitably exposed to high energy radiation; thus, the material surface of the teeth, dental restorations with high atomic number, or alloy prosthodontics would generate backscatter electrons that cause the buccal mucosa adjacent to these materials to receive localized high dose enhancement, which primarily leads to side effects or oral mucositis. Based on the size of the adult oral cavity, this study aimed to use acrylic resin to create an oral phantom with two grooves on the left and right sides for placement of three molars. Moreover, the distance between the inner cheek and the side surface of the teeth could be accurately adjusted every 1 mm from 0 to 5 mm. This enhanced the dose in the buccal mucosa during head and neck radiotherapy and made the distribution measurement of the radiation dose simple and feasible at different depths (0-5 mm). Meanwhile, the study employed the film type optically stimulated luminescent dosimeter with a thickness of 0.3 mm to measure the absorbed dose inside the buccal mucosa to reduce the dose interference from radiotherapy. The study fixed three real molars in a row located at the left side of the phantom and employed 6 MV photons and intensity-modulated radiotherapy (IMRT) to treat and simulate oral cancer and measure the attenuation of the molar's backscatter dose from 0 to 5 mm in an up beam direction. The result showed that, in every 3 mm, the phantom had attenuated the enhancement of backscatter dose <3%. The irradiation dose enhancement in a single direction was twice higher than that through IMRT 7 field treatment. These measurement results were consistent with the results of previous studies.

Objective: Recent studies suggested that head and neck radiotherapy increases active forms of matrix metalloproteinases (MMPs) in the dentin-enamel junction (DEJ), leading to enamel delamination and radiation-related caries. This study aimed to assess the expression and activity of the gelatinases MMP-2 and MMP-9 in the DEJ and dentin-pulp complex tissues of teeth irradiated in vivo., Study Design: Thirty-six teeth were studied, including 19 irradiated and 17 non-irradiated controls. In situ zymography was used to investigate the gelatinolytic activity in the micromorphologic components of enamel, DEJ, dentin-pulp complex, and caries. Immunohistochemical analysis was conducted on the demineralized samples to assess MMP-2 and MMP-9 expression levels in the DEJ, dentin-pulp complex components, and caries., Results: No statistically significant differences were detected between groups in gelatinolytic activity or in MMP-2 expression levels (P > .05). Odontoblast MMP-9 expression was reduced in the irradiated group (P = .02)., Conclusions: The study rejected the hypothesis that MMP-2 and MMP-9 would be overexpressed or more activated in the DEJ and dentin-pulp complex of irradiated teeth. Direct effects of radiation should not be regarded as an independent factor for explaining radiation-related caries onset and progression., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Aim: The purpose of this study is to evaluate the effect of various dental restoration materials on dose distribution in radiotherapy of head and neck cancer with 6 MV photon beam of a medical linac., Setting and Design: The dental restorations include tooth, tooth with amalgam, tooth with Ni-Cr alloy, and tooth with Ceramco. Dose perturbation due to the dental restorations on 6 MV beam of Siemens Primus linac was calculated by MCNPX Monte Carlo code. These dental materials were separately simulated in a cubic water phantom., Materials and Methods: Photon percentage dose change in the presence of tooth, tooth with amalgam, tooth with Ni-Cr alloy, and tooth with Ceramco was calculated at various depths on the central axis of the beam relative to the dose in water. In another evaluation, the absolute dose (cGy) for water, tooth, tooth with amalgam, tooth with Ni-Cr alloy, and tooth with Ceramco was obtained by calculating 100 cGy dose at 0.75 cm depth in the water phantom., Results: Based on the calculations performed, maximum percentage dose change due to backscattering was 11%, 8%, 6%, and 4% for amalgam, Ni-Cr alloy, Ceramco and tooth at depth of 0.75 cm, respectively. The maximum dose perturbation by amalgam is due to its higher mass density and atomic number., Conclusion: Ignoring the effect of dental restoration compositions on dose distribution causes discrepancy in clinical treatment planning system calculations.

Background: Radiotherapy (RT) is frequently used in the treatment of head and neck cancer, but different side-effects are frequently reported, including a higher frequency of radiation-related caries, what may be consequence of direct radiation to dental tissue. The intensity-modulated radiotherapy (IMRT) was developed to improve tumor control and decrease patient's morbidity by delivering radiation beams only to tumor shapes and sparing normal tissue. However, teeth are usually not included in IMRT plannings and the real efficacy of IMRT in the dental context has not been addressed. Therefore, the aim of this study is to assess whether IMRT delivers lower radiation doses to dental structures than conformal 3D radiotherapy (3DRT)., Material and Methods: Radiation dose delivery to dental structures of 80 patients treated for head and neck cancers (oral cavity, tongue, nasopharynx and oropharynx) with IMRT (40 patients) and 3DRT (40 patients) were assessed by individually contouring tooth crowns on patients' treatment plans. Clinicopathological data were retrieved from patients' medical files., Results: The average dose of radiation to teeth delivered by IMRT was significantly lower than with 3DRT (p = 0.007); however, only patients affected by nasopharynx and oral cavity cancers demonstrated significantly lower doses with IMRT (p = 0.012 and p = 0.011, respectively). Molars received more radiation with both 3DRT and IMRT, but the latter delivered significantly lower radiation in this group of teeth (p < 0.001), whereas no significant difference was found for the other dental groups. Maxillary teeth received lower doses than mandibular teeth, but only IMRT delivered significantly lower doses (p = 0.011 and p = 0.003). Ipsilateral teeth received higher doses than contralateral teeth with both techniques and IMRT delivered significantly lower radiation than 3DRT for contralateral dental structures (p < 0.001)., Conclusion: IMRT delivered lower radiation doses to teeth than 3DRT, but only for some groups of patients and teeth, suggesting that this decrease was more likely due to the protection of other high risk organs, and was not enough to remove teeth from the zone of high risk for radiogenic disturbance (>30Gy).

Objectives: To correlate radiation dose to specific tooth-bearing portions of bone with adverse dental outcomes., Study Design: Eighty-nine patients treated with intensity-modulated radiation therapy with or without chemotherapy had radiation dose to specific tooth-bearing portions of the mandible and the maxilla. Data were collected prospectively during treatment planning, which resulted in 2490 data points. These patients underwent a comprehensive dental intake evaluation that included measurement of pocket depths and were then followed up with serial dental evaluations for a median of 2.5 years (range 0.2-6.9 years)., Results: At the patient level, the 3-year risks of osteoradionecrosis (ORN) and periodontal disease were 2.5% and 36.6%, respectively. For any individual tooth, the risks of ORN and periodontal disease were 0.1% and 5.1%, respectively, at 3 years. Radiation dose to individual tooth-bearing portions of bone was correlated with ORN development (P = .0165). Periodontal disease also demonstrated a significant, but more gradual, dose response (P = .0395)., Conclusions: Adverse dental outcomes directly correlate with increased tooth-specific doses., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objectives: Dosimetric distribution of intensity-modulated radiotherapy (IMRT) to tooth-bearing areas for common head and neck (H&N) cancer sites were analyzed to facilitate minimization of osteoradionecrosis (ORN) risk through preradiation dental treatment planning., Study Design: Fifty-four patients received IMRT with prescribed doses ranging from 6000 centigrays (cGy) (adjuvant) to 6930 cGy (primary) to treat base of tongue (BOT), tonsil, larynx, nasopharynx, and hypopharynx cancers. The average maximal radiation dose delivered was recorded in tooth-bearing areas (anteriors, premolars, and first, second, and third molars) of the maxilla and mandible., Results: All tooth-bearing areas in laryngeal cancer cases received less than 2500 cGy. Maxillary and mandibular molar regions for BOT, tonsil, and hypopharynx cancers received 5000 cGy or higher. In nasopharynx cancers, maxillary teeth received higher doses than mandibular teeth., Conclusions: Among 5 H&N subsites, mandibular molar regions for BOT, tonsil, and hypopharynx cancers received higher IMRT doses on average, posing the greatest ORN risk., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Cancer care has become one of the main targets of the National Health Service in England and with cancer patients surviving longer, it is likely that head and neck cancer patients will make up a large proportion of patients seen within secondary care settings in the future. The management of these patients can be very difficult for a number of reasons. Part one of this paper attempts to highlight the major oral health problems encountered by these patients during and after their cancer treatment and supported by the current literature. Part two of this series will address the dental management of head and neck oncology patients undergoing radiotherapy with particular attention of possible improvement to current management strategies for these patients.

Objective: The aim of the present study was to evaluate whether radiation damage on dental hard tissue depends on the mean irradiation dose the spared parotid gland is subjected to or on stimulated whole salivary flow rate., Material and Methods: Between June 2002 and October 2008, 70 patients with neck and cancer curatively irradiated were included in this study. All patients underwent dental treatment referring to the guidelines and recommendations of the German Society of Dental, Oral and Craniomandibular Sciences prior, during, and after radiotherapy (RT). During the follow-up period of 24 months, damages on dental hard tissues were classified according to the RTOG/EORTC guidelines. The mean doses (D(mean)) during spared parotid gland RT were determined. Stimulated whole saliva secretion flow rates (SFR) were measured before RT and 1, 6, 12, 24 months after RT., Results: Thirty patients showed no carious lesions (group A), 18 patients developed sporadic carious lesions (group B), and 22 patients developed general carious lesions (group C). Group A patients received a D mean of 21.2 ± 11.04 Gy. Group B patients received a D(mean) of 26.5 ± 11.59 Gy and group C patients received a D(mean) of 33.9 ± 9.93 Gy, respectively. The D(mean) of group A was significantly lower than the D(mean) of group C (p < 0.001). Additionally, the mean SFR 6 months after RT of group A was significantly higher than the mean SFR of group C (p < 0.01)., Conclusions: Irradiation damage on dental hard tissue correlates with increased mean irradiation doses as well as decreased salivary flow rates., Clinical Relevance: Parotid gland sparing resulting in a dose below 20 Gy reduces radiation damage on dental hard tissues, and therefore, the dose may act as a predictor for the damage to be expected.

Radiation therapy plays an important role in the care of patients with head and neck cancer. When the oral cavity and the salivary glands are exposed to high doses of radiation, there can be dramatic effects on the patient's oral health. The clinical consequences of radiation can include mucositis, hyposalivation, taste loss, osteoradionecrosis, radiation caries and trismus. This paper looks at the available literature regarding the effects of radiotherapy on the oral environment and outlines practical clinical approaches to prevent or reduce the adverse side effects of treatment.

Several thousand patients are diagnosed annually with head and neck cancer (HANC) in the United Kingdom. This represents a significant proportion of all cancers that are diagnosed and a common treatment modality for this is radiotherapy to the head and neck region. Radiotherapy can be highly successful in managing HANC but also has several side-effects in the oral cavity and associated structures. These sequelae present considerable short and long-term problems for dental professionals involved in the care of HANC suffers.

Objectives: The objective of this study is to analyse the effect of the radiation dose of oral radiotherapy for cancer on the presence of apical periodontitis in patients without dental pre-screening or specific preventive measures., Materials and Methods: All selected patients had been diagnosed with cancer in the head and neck region and presented in the dental clinic post radiotherapy with side effects (mainly radiation caries). The panoramic radiographs of these patients were examined for several parameters, including tooth decay and apical periodontitis. The total radiation dose per tooth was determined., Results: A total of 36 patient files were included, which accounted for 628 teeth to be scored. Tooth decay was present in 88.2% of teeth. Radiographic signs of apical periodontitis were found in 9.1% of the teeth. Teeth with apical periodontitis had significantly more caries present. The radiation dose was significantly higher for teeth with apical periodontitis (37.2 vs. 24.9 Gy). Binary logistic regression found the radiation dose to be the only explanatory variable in the presence of apical periodontitis., Conclusions: This study found that in zones with higher radiation dose, inflammation of the jawbone due to bacterial infection of the root canal is more likely to develop. This is probably due to bone changes post radiotherapy., Clinical Relevance: An increase of this prevalance of apical periodontitis in irradiated bone found in this study needs to be taken into account in the dental evaluation before the start of radiotherapy.

Purpose: To propose an automatic atlas-based segmentation framework of the dental structures, called Dentalmaps, and to assess its accuracy and relevance to guide dental care in the context of intensity-modulated radiotherapy., Methods and Materials: A multi-atlas-based segmentation, less sensitive to artifacts than previously published head-and-neck segmentation methods, was used. The manual segmentations of a 21-patient database were first deformed onto the query using nonlinear registrations with the training images and then fused to estimate the consensus segmentation of the query., Results: The framework was evaluated with a leave-one-out protocol. The maximum doses estimated using manual contours were considered as ground truth and compared with the maximum doses estimated using automatic contours. The dose estimation error was within 2-Gy accuracy in 75% of cases (with a median of 0.9 Gy), whereas it was within 2-Gy accuracy in 30% of cases only with the visual estimation method without any contour, which is the routine practice procedure., Conclusions: Dose estimates using this framework were more accurate than visual estimates without dental contour. Dentalmaps represents a useful documentation and communication tool between radiation oncologists and dentists in routine practice. Prospective multicenter assessment is underway on patients extrinsic to the database., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Pre-irradiation dental care depends on teeth health, fields and dose of irradiation, compliance to fluorides, cessation of tobacco and psychosocial cofactors. Dental care aims at preventing complications and preserving the quality of life (eating, speech and aesthetics). Approximately 11% of patients do not require any pre-irradiation dental care. Dental complications vary from slight colorations of the teeth to major complication such as osteoradionecrosis. Osteoradionecrosis rates vary from 1 to 9%, and may be decreased by using a 21-day delay between extractions and irradiation, provided that it does not postpone cancer treatment, with a dose-dependent risk (<6% if <40 Gy; 14% between 40 et 60 Gy; > or =20% if >60 Gy). Osteoradionecrosis occurs spontaneously (35%), mostly involves the mandibula (85%)., (Copyright (c) 2009 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.)

It is known that ionizing radiation is used in medicine for Roentgen diagnostics and for radiation therapy. The radiation interacts with matter, in particular with biological one, essentially by scattering, photoelectric effect, Compton effect and pair production. To what extent the biological material is changed thereby, depends on the type and the amount of radiation energy, on the dose and on the tissue constitution. In modern radiation therapy two different kinds of radiation are used: high energy X-rays and electron radiation. In the case of head-neck tumors the general practice is an irradiation with high energy X-rays with absorbed dose to water up to 70 Gy. Teeth destruction has been identified as a side effect during irradiation. In addition, damage to the salivary glands is often observed which leads to a decrease or even the complete loss of the salivary secretion (xerostomia). This study shows how the different energy and radiation types damage the tooth tissue. The effects of both, high X-ray energy and high energy electrons, on the mechanical properties hardness and elasticity of the human dental tissue are measured by the nanoindentation technique. We compare these results with the effect of the irradiation of low X-ray energy on the dental tissue.

From 2001 to 2005, 66 patients referred for perioperative hyperbaric oxygen therapy (HBO2) for debridement of necrotic tissue or prevention of radionecrosis were assessed with quality of life measures, before and after completion of HBO2 and surgery. The Medical Outcomes Short Form 36 (SF-36) and Hospital Anxiety and Depression Scale (HADS) showed no significant changes. The European Organisation for Research and Treatment of Cancer Core (EORTC-C30) questionnaire showed significant improvement in pain, global health, and dyspnoea (p=0.011; p=0.027; p=0.008, respectively). The Head and Neck sub-module (H&N35) identified significant improvements in teeth, dry mouth and social contact (p=0.002; p=0.038; p=0.029, respectively). The University of Washington Scale (UW), showed significant changes in relation to chewing and shoulders (p=0.031; p=0.047). When sub-group analysis using 'osteoradionecrosis' and 'dental extraction or implants' was performed on the EORTC and UW data, variations in the patterns of significance were found. Adjunctive HBO2 should be considered for the treatment and prevention of some of the long-term complications of radiotherapy.

Unlabelled: Head and neck cancer represents a heterogeneous group of neoplasms affecting a number of sites in the aerodigestive tract, histologically primarily epithelial in type. Most are sensitive to a treatment regime of ablative surgery followed by radiotherapy. The incidence in Ireland of head and neck cancers is approximately 11.8 per 100,000 population and is the 8th commonest cancer in males and the 16th in females. Many of these cancers will manifest with oral signs and symptoms thus placing the GDP in the unique position of being able to detect and positively influence outcomes: the GDP also has a vital, proactive role to play in supportive care before, during and following surgery and radiotherapy., Clinical Relevance: The aim of this paper is to review the rationale for the different treatment modalities and the oral/dental side-effects of each.

Purpose: To describe potential effects of multimodality therapy on dental and facial development in long-term survivors of head and neck rhabdomyosarcoma., Patients and Methods: The medical records of all patients aged 20 years or less presenting between 1985 and 1996 with a diagnosis of rhabdomyosarcoma and treated by protocol were reviewed. Head and neck rhabdomyosarcoma patients who were followed in the Dental Service and were alive and free of disease with at least a 5-year follow-up were included in the review. Ten patients satisfied the inclusion criteria and form the basis of this report. The median age at diagnosis of the 10 patients was 4.3 years (range 10 months to 19.5 years). All patients were treated with chemotherapy, two patients underwent surgery, and all but one patient received external beam radiation therapy., Results: Clinical or radiographic dentofacial abnormalities were observed in 8 of the 10 (80%) patients. Abnormalities included enamel defects, bony hypoplasia/facial asymmetry, trismus, velopharyngeal incompetency, tooth/root agenesis, and disturbance in root development. Bony hypoplasia and disturbance in root formation were the most common findings., Conclusions: Multimodality therapy for head and neck rhabdomyosarcoma can result in dentofacial abnormalities that affect the patient's quality of life. The care of the long-term survivor requires a multidisciplinary approach, including early involvement of the dental team.

Objectives: 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., Material and Methods: 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., Results: 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., Conclusions: 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.

Background: This review of children and adolescents with nonorbital soft-tissue sarcoma of the head and neck was undertaken to describe late sequelae of treatment, as manifested primarily by problems with statural growth, facial and nuchal symmetry, dentition, vision and hearing, and school performance., Procedure: Four hundred sixty-nine patients entered the IRS-II and -III protocols with localized, nonorbital soft-tissue sarcomas of the head and neck from 1978 through 1987. Their overall survival rate was 53% (250/469) at 5 years. Two hundred thirteen patients were surviving relapse-free 5 or more years after diagnosis, for whom there were serial height measurements at 2 or more years after initiation of therapy. Their median age at diagnosis was 5 years; the median length of follow-up was 7 years. All received multiple-agent chemotherapy, and all but 3 received irradiation to the primary tumor volume. Sixty-eight percent of the tumors arose in cranial parameningeal sites, 22% in nonparameningeal sites, and 10% in the neck. We reviewed flow sheets submitted to the IRS Group Statistical Office to ascertain which late sequelae were recorded., Results: One hundred sixty-four patients (77%) had one or more problems recorded. One hundred ninety of the two hundred thirteen patients (89%) were under 15 years of age at study entry, and at follow-up 92 (48%) had failed to maintain their initial height velocity, which had decreased by more than 25 percentile points from the original value. Thirty-six of the one hundred ninety patients (19%) were receiving growth hormone injections. Hypoplasia or asymmetry of tissues in the primary tumor site was reported in 74 patients, and 13 underwent reconstructive surgery. Poor dentition or malformed teeth were noted in 61 patients. Impaired vision developed in 37 patients, owing primarily to cataracts, corneal changes, and optic atrophy. Thirty-six patients had decreased hearing acuity, and 9 were fitted with hearing aids; 5 of these 9 had received cisplatin. Thirty-five patients were noted to have problems learning in school. Four patients developed a second malignancy (two sarcomas, one carcinoma, one leukemia)., Conclusions: Late sequelae affected the majority of these patients treated for soft-tissue sarcoma of the head and neck on IRS-II and -III. The potential impact of certain sequelae could be reduced by specific measures, such as surgical reconstruction and hormonal therapy. Late sequelae must be taken into account in designing future curative treatments., (Copyright 1999 Wiley-Liss, Inc.)

The authors describe the side-effects and complications occurring in the oral cavity during the irradiation treatment of head and neck tumours. They stress the necessity of dental therapy before, during and after irradiation so that occasional subsequent grave complications (for instance osteoradionecrosis) could be prevented. They emphasize the importance of basic radiological knowledge of dental surgeons and dentists and their cooperation with the irradiation therapists.

This is the first article in a two-part series dealing with the effects and manifestations in the oral cavity of radiation therapy of head and neck tumors. In this section, oral mucous membranes, taste buds, edema and trismus, diet, salivary glands, bone, periodontium, teeth, and composition of oral flora are discussed. Dental management of the dentulous patient is then approached; criteria for preradiation extraction are delineated. In the next issue of Head & Neck Surgery, the final article in this series will discuss preradiation and postradiation extractions and will elaborate on the dental management (fluoride treatments, follow-up, and restorative care) of the dentulous patient. Dental management of the edentulous patient will also be presented.

54 teeth from 20 patients irradiated for treatment of malignant tumors of the head and neck region were examined clinically, histologically and microradiographically. 18 teeth from 8 patients were used as controls. A significantly higher degree of hyposialia, radiation mucositis and atypical caries was found in the original group as compared to the control material. Occurrence of narrow gaps between dentin and cementum was also higher in the former group as compared with the latter.

The improvement in survival and local control rates in children with neoplasms in the head and neck region can be expected to demonstrate increased iatrogenic adverse effects of treatment. The authors report on mandibular growth and developmental abnormalities in 3 children with Hodgkin disease treated by external beam megavoltage therapy. Radiations to the mandible during mantle field therapy were measured and found to be significant. Possible methods of dose reduction are discussed.

The authors review the studies describing dental changes after radiotherapy or curietherapy of the cervicofacial region published over the last 50 years. They discuss more particularly: --direct and indirect effects on the teeth,--lesions of the salivary glands,--dental lesions,--fluoride prophylaxis for dental lesions after irradiation.