Dentofacial development in long-term survivors of acute lymphoblastic leukemia. A comparison of three treatment modalities

Oral manifestations in pediatric patients with leukemia: A systematic review and meta-analysis

BACKGROUND

Leukemia is the most common malignancy in pediatric patients, and it has extramedullary involvement. Oral manifestations have been reported in the literature, but to the authors' knowledge, no systematic review has presented the general prevalence of these manifestations. This review aimed to determine the prevalence of oral manifestations in pediatric patients with leukemia.

TYPES OF STUDIES REVIEWED

The authors conducted a search of PubMed-MEDLINE, Embase, Latin American and Caribbean Health Sciences Literature, Web of Science, and Scopus. Additional searches were carried out in the gray literature and via hand searching of reference lists of included studies. The inclusion criteria were observational studies that investigated the prevalence and occurrence of oral lesions in pediatric patients with leukemia. Two independent reviewers collected data from the selected articles in a prepiloted Excel (Microsoft) spreadsheet.

RESULTS

From 67 included studies, 79 oral manifestations were reported. The most frequent alteration in children with acute lymphoblastic leukemia during the treatment were caries (81%), with moderate certainty of evidence. The prevalence of gingivitis was 73%, oral mucositis was 50%, and lymphadenopathy was 45%, with very low certainty of evidence. After the therapy, the prevalence of dental anomalies was 61%, and the most common were enamel hypoplasia (40%), dental agenesis (22%), and microdontia (22%), presenting very low certainty of evidence. The high heterogeneity among studies contributed significantly to reduce the certainty of the evidence.

PRACTICAL IMPLICATIONS

The findings of this study show that pediatric patients with leukemia have oral manifestations predominantly during and after treatment. Health care professionals must be aware of oral manifestations and refer the patients to dentists during the oncological treatment. Thus, the dentist must support pediatric patients with leukemia to help ensure a better quality of life.

Oral Chronic Graft-versus-Host Disease and Oral Health after Allogeneic Hematopoietic Cell Transplantation - What the Care Team Needs to Know

Oral chronic graft-versus-host disease (cGVHD) can present with a multitude of clinical signs and is associated with morbidity and lower quality of life. Oral cGVHC may affect the oral mucosa (reticular white striae, erythema, and/or ulcerations), the salivary glands (hyposalivation and/or xerostomia) and the peri-oral soft tissues (fibrosis and trismus). This review provides a practical and concise approach to the diagnosis and management of oral health needs in pediatric and adult alloHCT recipients within the first 2 years post-transplantation.

Salivary and Dental Complications in Childhood Cancer Survivors Treated With Radiation Therapy to the Head and Neck: A PENTEC Comprehensive Review

PURPOSE

Radiation therapy (RT) to the head and neck (H&N) region is critical in the management of various pediatric malignancies; however, it may result in late toxicity. This comprehensive review from the Pediatric Normal Tissue Effects in the Clinic (PENTEC) initiative focused on salivary dysfunction and dental abnormalities in survivors who received RT to the H&N region as children.

MATERIALS & METHODS

This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method.

RESULTS

Of the 2,164 articles identified through a literature search, 40 were included in a qualitative synthesis and 3 were included in a quantitative synthesis. The dose-toxicity data regarding salivary function demonstrate that a mean parotid dose of 35 to 40 Gy is associated with a risk of acute and chronic grade ≥2 xerostomia of approximately 32% and 13% to 32%, respectively, in patients treated with chemo-radiation therapy. This risk increases with parotid dose; however, rates of xerostomia after lower dose exposure have not been reported. Dental developmental abnormalities are common after RT to the oral cavity. Risk factors include higher radiation dose to the developing teeth and younger age at RT.

CONCLUSIONS

This PENTEC task force considers adoption of salivary gland dose constraints from the adult experience to be a reasonable strategy until more data specific to children become available; thus, we recommend limiting the parotid mean dose to ≤26 Gy. The minimum toxic dose for dental developmental abnormalities is unknown, suggesting that the dose to the teeth should be kept as low as possible particularly in younger patients, with special effort to keep doses <20 Gy in patients <4 years old.

Late Complications in Long-Term Childhood Cancer Survivors: What the Oral Health Professional Needs to Know

With diagnostic and therapeutic advances, over 80% of children diagnosed with cancer become long-term survivors. As the number of childhood cancer survivors (CCS) continues to increase, dental practitioners become more likely to have CCS among their patients. CCS may develop late complications from damage caused by their cancer treatment to endocrine, cardiovascular, musculoskeletal, and other organ systems. These complications may surface decades after the completion of treatment. Adverse outcomes of childhood cancer treatment frequently involve oral and craniofacial structures including the dentition. Tooth development, salivary gland function, craniofacial growth, and temporomandibular joint function may be disturbed, increasing oral health risks in these individuals. Moreover, CCS are at risk of developing subsequent malignancies, which may manifest in or near the oral cavity. It is important that dental practitioners are aware of the childhood cancer history of their patients and have knowledge of potential late complications. Therefore, this narrative review aims to inform dental practitioners of late oral complications of cancer treatment modalities commonly used in pediatric oncology. Furthermore, selected common non-oral late sequelae of cancer therapy that could have an impact on oral health and on delivering dental care will be discussed.

Tooth agenesis: An overview of diagnosis, aetiology and management

Patients with one or more developmentally absent teeth are routinely encountered in dental practice. Tooth agenesis can be associated with significant functional, aesthetic and psycho-social problems. The present article provides an overview of the prevalence and aetiology of tooth agenesis, as well as the condition's clinical characteristics and management options with reference to the evidence base. A timely diagnosis can facilitate the appropriate planning and management which might not be straightforward, and patient care will likely require multi- and inter-disciplinary input. It is critical that dental care practitioners are aware of the clinical characteristics and management options for tooth agenesis.

Antineoplastic therapy in childhood cancer patients presents a negative impact in the periodontal tissues: a cohort study

OBJECTIVES

To investigate the effect of antineoplastic therapy (AT) in the periodontal tissues of childhood cancer (CC) patients.

MATERIALS AND METHODS

Seventy-two individuals were divided into CC (n=36) and healthy individuals (control group-CG, n=36). Demographics, hygiene habits, CC type, and AT were collected. Salivary flow and the presence and concentration of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Fusobacterium nucleatum were analyzed. Clinical evaluation included plaque (PI) and gingival indexes (GI), periodontal probing depth (PPD), and clinical attachment level (CAL). Patients were classified into periodontal health, gingivitis, or periodontitis. Descriptive statistics, T test, Mann-Whitney test, chi-square, Fisher's exact test, and two-way analysis of variance were used (p<0.05).

RESULTS

The mean age of the patients was similar (CC 12.0±3.9 years and CG 12.0±4.0 years). In the CC group, all patients underwent chemotherapy and nine radiotherapy. Color/race, income, and family education showed significant differences between groups. There was no difference between groups in salivary flow. Higher levels of Fusobacterium nucleatum were seen in CC (p=0.02). Significant difference between groups was found for PI (CC: 30.5%, CG: 22.6%), GI (CC: 28.8%, CG: 17.3%), PPD (CC: 1.77 mm, CG: 1.61 mm), and CAL (CC: 1.77 mm, CG: 1.57 mm), periodontal health (CC: 3, CG: 7), gingivitis (CC: 16, CG: 24), or periodontitis (CC: 17, CG: 5).

CONCLUSION

AT in CC patients presents a negative impact in the periodontal and microbiological parameters.

CLINICAL RELEVANCE

Childhood cancer individuals showed worse periodontal parameters and higher levels of Fusobacterium nucleatum in the saliva when compared to healthy individuals.

Complications after proton radiotherapy in children, focusing on severe late complications. A complete Swedish cohort 2008-2019

BACKGROUND

Proton radiotherapy (RT) is an attractive tool to deliver local therapy with minimal dose to uninvolved tissue, however, not suitable for all patients. The aim was to explore complications, especially severe late complications (grades 3-4), following proton RT delivered to a complete Swedish cohort of paediatric patients aged <18 years treated 2008-2019.

MATERIAL AND METHODS

Data was downloaded from a national registry. Complications with a possible causation with RT are reported. Proton treatments until July 2015 was performed with a fixed horizontal 172 MeV beam (The Svedberg Laboratory (TSL), Uppsala) in a sitting position and thereafter with gantry-based pencil-beam scanning technique (Skandion Clinic, Uppsala) in a supine position.

RESULTS

219 courses of proton RT (77 at TSL and 142 at Skandion) were delivered to 212 patients (mean age 9.2 years) with various tumour types (CNS tumours 58%, sarcomas 26%, germ cell tumours 7%). Twenty-five patients had severe acute complications (skin, mucous membrane, pharynx/oesophagus, larynx, upper gastrointestinal canal, lower gastrointestinal canal, eyes, ears). Fifteen patients had severe late complications; with increased proportion over time: 4% at 1-year follow-up (FU), 5% at 3-year, 11% at 5-year. Organs affected were skin (1 patient), subcutaneous tissue (4), salivary glands (1), upper GI (1), bone (7), joints (2), CNS (2), PNS (1), eyes (1) and ears (5). Twenty-one of the 28 patients with 10-year FU had at least one late complication grades 1-4 and fourteen of them had more than one (2-5 each).

CONCLUSION

The most important result of our study is the relatively low proportion of severe late complications, comparable with other proton studies on various tumours. Furthermore, the numbers of late complications are lower than our own data set on a mixed population of photon and proton treated paediatric patients, assuring the safety of using proton therapy also in the clinical practice.

Complications of Cancer Therapy in Children: A Comprehensive Review of Neuroimaging Findings

ABSTRACT

Complications of cancer therapy in children can result in a spectrum of neurologic toxicities that may occur at the initiation of therapy or months to years after treatment. Although childhood cancer remains rare, increasing survival rates mean that more children will be living longer after cancer treatment. Therefore, complications of cancer therapy will most likely occur with increasing frequency.At times, it is very difficult to differentiate between therapeutic complications and other entities such as tumor recurrence, development of secondary malignancy, and infection (among other conditions). Radiologists often play a key role in the diagnosis and evaluation of pediatric patients with malignancies, and thus, awareness of imaging findings of cancer complications and alternative diagnoses is essential in guiding management and avoiding misdiagnosis. The aim of this review article is to illustrate the typical neuroimaging findings of cancer therapy-related toxicities, including both early and late treatment effects, highlighting pearls that may aid in making the appropriate diagnosis.

Early in vivo Radiation Damage Quantification for Pediatric Craniospinal Irradiation Using Longitudinal MRI for Intensity Modulated Proton Therapy

Purpose

Proton vertebral body sparing craniospinal irradiation (CSI) treats the thecal sac while avoiding the anterior vertebral bodies in an effort to reduce myelosuppression and growth inhibition. However, robust treatment planning needs to compensate for proton range uncertainty, which contributes unwanted doses within the vertebral bodies. This work aimed to develop an early in vivo radiation damage quantification method using longitudinal magnetic resonance (MR) scans to quantify the dose effect during fractionated CSI.

Methods and Materials

Ten pediatric patients were enrolled in a prospective clinical trial of proton vertebral body sparing CSI, in which they received 23.4 to 36 Gy. Monte Carlo robust planning was used, with spinal clinical target volumes defined as the thecal sac and neural foramina. T1/T2-weighted MR scans were acquired before, during, and after treatments to detect a transition from hematopoietic to less metabolically active fatty marrow. MR signal intensity histograms at each time point were analyzed and fitted by multi-Gaussian models to quantify radiation damage.

Results

Fatty marrow filtration was observed in MR images as early as the fifth fraction of treatment. Maximum radiation-induced marrow damage occurred 40 to 50 days from the treatment start, followed by marrow regeneration. The mean damage ratios were 0.23, 0.41, 0.59, and 0.54, corresponding to 10, 20, 40, and 60 days from the treatment start.

Conclusions

We demonstrated a noninvasive method for identifying early vertebral marrow damage based on radiation-induced fatty marrow replacement. The proposed method can be potentially used to quantify the quality of CSI vertebral sparing and preserve metabolically active hematopoietic bone marrow.

Dental caries and dental developmental defects as adverse effects of antineoplastic treatment in childhood cancer survivors

PURPOSE

To evaluate the prevalence of dental caries and dental developmental defects (DDD) in childhood cancer survivors (CCS) and identify disease and treatment-related risk factors.

METHODS

CCS aged up to 21 years, diagnosed with a malignancy before the age of 10 years and in remission for at least one year were included. Data were collected from patients' medical records and through a clinical examination where presence of dental caries and prevalence of DDD were recorded. Fisher's exact test was used to assess possible correlations and multivariate regression analysis to determine risk factors for defect development.

RESULTS

Seventy CCS with a mean chronological age of 11.2 years at the time of examination, mean age at cancer diagnosis of 4.17 years, and a mean post-treatment follow-up time of 5.48 years were included. Mean DMFT/dmft was 1.31, with 29% of survivors presenting with at least one carious lesion. Younger patients on the day of examination and patients treated with higher radiation dose, showed significantly higher prevalence of dental caries. The prevalence of DDD was 59%, with demarcated opacities being the defect most commonly observed (40%). Age at dental examination, diagnosis, age at diagnosis, and time that have elapsed since the end of treatment were the factors significantly affecting its prevalence. Regression analysis revealed that age at examination was the only factor significantly associated with the presence of coronal defects.

CONCLUSION

A great number of CCS presented with at least one carious lesion or a DDD, with the prevalence being significantly associated with various disease-specific characteristics, but age at dental examination the only significant predictor.

Endodontic management strategies for permanent teeth with immature apices

This article will provide a summary of causes of incomplete root end closure and the implications of this on endodontic treatment. The limitations and benefits of traditional and more contemporary materials including the use of bioceramic cements are considered. The apical barrier technique is described in detail for teeth with immature apices utilising a variety of bioceramic cements and regenerative endodontic procedures with an overview of appropriate instruments to successfully complete the procedure.

Factors for poor oral health in long-term childhood cancer survivors

BACKGROUND

Survivors of childhood cancer are at risk for therapy-related dental diseases. The purpose of the study was to investigate the associations between clinical, socioeconomic, and demographic factors and oral diseases in the St. Jude Lifetime Cohort (SJLIFE) participants.

METHODS

We performed a retrospective medical chart review and evaluated longitudinal self-reported dental outcomes in 4856 childhood cancer survivors and 591 community controls participating in the St. Jude Lifetime Cohort (SJLIFE) study. Univariate and multivariable logistic regression models were used to assess the impact of socioeconomic factors, treatment exposures and patient demographics on dental outcomes.

RESULTS

Cancer survivors were more likely to report microdontia (odds ratio (OR) = 7.89, 95% confidence interval (CI) [4.64, 14.90]), abnormal root development (OR = 6.19, CI [3.38, 13.00]), hypodontia (OR = 2.75, CI [1.83, 4.33]), enamel hypoplasia (OR = 4.24, CI [2.9, 6.49]), xerostomia (OR = 7.72, CI [3.27, 25.10]), severe gingivitis (OR = 2.04, CI [1.43, 3.03]), and ≥ 6 missing teeth (OR = 3.73, CI [2.46, 6.00]) compared to controls without cancer history. Survivors who received classic alkylating agents (OR = 1.6, CI [1.36, 1.88]), anthracycline antibiotics (OR = 1.22, CI [1.04, 1.42] or radiation therapy potentially exposing the oral cavity (OR = 1.48, CI [1.26, 1.72]) were more likely to report at least one dental health problem after controlling for socioeconomic factors, age at last follow-up and diagnosis, other treatment exposures, and access to dental services. Survivors who had radiation therapy potentially exposing the oral cavity (OR = 1.52, CI [1.25, 1.84]) were also more likely to report at least one soft tissue abnormality after controlling for socioeconomic factors, age at last follow-up and diagnosis, other treatment exposures, and access and utilization of dental services.

CONCLUSIONS

Childhood cancer survivors have a higher prevalence of oral-dental abnormalities than the controls without a cancer history. Cancer treatment, socioeconomic factors, and access to oral health care contribute to the prevalence of dental abnormalities.

Presentation of a Case of Short Root Anomaly in an 11-Year-Old Child

Short root anomaly (SRA) is a developmental anomaly in which the affected teeth present morphologically normal crowns and short, round roots. The exact cause of SRA is unknown. A case of an 11-year-old female patient with SRA is described. The patient presented short, round roots of all permanent teeth but first molars. Maxillary lateral incisors presented severe root resorption and mobility. Treatment plan included preservation of the maxillary lateral incisors by splinting them to their adjacent teeth using a stainless steel coaxial wire. A custom mouthguard for dental trauma protection was also constructed using a computer-aided design - computer-aided manufacturing (CAD-CAM) system in order to fabricate 3D-printed dental casts. At 2-year follow-up, the mobility of maxillary lateral incisors decreased, and the patient's dentition remained stable. Considerations regarding differential diagnosis, orthodontic management, and treatment options after an eventual loss of teeth are thoroughly discussed.

Oligomicrodontia in a Pediatric Cancer Survivor after Chemotherapy: A Case Report

Chemotherapy used on pediatric patients especially those below 3 years of age causes disturbances in dental development. The aim of this case report was to present the late dental effects of chemotherapy in a patient treated for anaplastic ependymoma (WHO III) at an early age. Radiographic findings at the age of 9 years showed oligomicrodontia of six teeth, maxillary lateral incisors, and maxillary and mandibular first premolars. Pediatric cancer survivors after chemotherapy have an increased risk of one or more dental development disorders. To ensure proper dental care and to assess the long-term effects on oral health, tooth development, and occlusion, the involvement of a dentist is crucial. Adequate diagnosis and well-planned treatment of the dental defect can significantly improve patient oral health-related quality of life.

Tooth Formation as Experimental Model to Study Chemotherapy on Tissue Development: Effect of a Specific Dose of Temozolomide/Veliparib

Background: Chemotherapy treatment of cancer in children can influence formation of normal tissues, leading to irreversible changes in their structure and function. Tooth formation is susceptible to several types of chemotherapy that induce irreversible changes in the structure of enamel, dentin and dental root morphology. These changes can make the teeth more prone to fracture or to caries when they have erupted. Recent studies report successful treatment of brain tumors with the alkylating drug temozolomide (TMZ) in combination with veliparib (VLP) in a glioblastoma in vivo mouse model. Whether these drugs also affect tooth formation is unknown. Aim: In this study the effect of TMZ/VLP on incisor formation was investigated in tissue sections of jaws from mice and compared with mice not treated with these drugs. Materials and method: The following aspects were studied using immunohistochemistry of specific protein markers including: (1) proliferation (by protein expression of proliferation marker Ki67) (2) a protein involved in paracellular ion transport (expression of tight junction (TJ) protein claudin-1) and (3) in transcellular passage of ions across the dental epithelium (expression of Na+, K+ 2Cl- cotransporter/NKCC1). Results: Chemotherapy with TMZ/VLP strongly reduced immunostaining for claudin-1 in distal parts of maturation ameloblasts. No gross changes were found in the treated mice, either in cell proliferation in the dental epithelium at the cervical loop or in the immunostaining pattern for NKCC1 in (non-ameloblastic) dental epithelium. The salivary glands in the treated mice contained strongly reduced immunostaining for NKCC1 in the basolateral membranes of acinar cells. Discussion/Conclusions: Based on the reduction of claudin-1 immunostaining in ameloblasts, TMZ/VLP may potentially influence forming enamel by changes in the structure of TJs structures in maturation ameloblasts, structures that are crucial for the selective passage of ions through the intercellular space between neighboring ameloblasts. The strongly reduced basolateral NKCC1 staining seen in fully-grown salivary glands of TMZ/VLP-treated mice suggests that TMZ/VLF could also influence ion transport in adult saliva by the salivary gland epithelium. This may cause treated children to be more susceptible to caries.

Dental Caries and Dental Anomalies in Children Undergoing Chemotherapy for Malignant Diseases

Purpose

The study aims to evaluate the prevalence of dental caries and anomalies in pediatric patients undergoing chemotherapy or those who have completed chemotherapy.

Methods

A total of 250 pediatric patients within the age group of 6 months to 17 years, either admitted to hospitals for chemotherapy or on follow-up, were included as a part of the study. Complete oral examination inclusive of the diet history, oral hygiene methods, past dental history, the decayed, missing, and filled teeth (DMFT), def score, and any dental anomaly was diagnosed clinically and radiographically using an orthopantomogram. The samples were further categorized under type of malignancies and duration of chemotherapeutic drug usage groups (from 6 months to 10 years and more than 10 years) to establish a correlation of these variables with the prevalence of dental caries and dental anomalies.

Results

Among all patients, 108 (43.2%) had completed the treatment (chemotherapy), while 142 (56.8%) were undergoing the treatment. Forty-three (17.2%) patients showed positive findings for dental anomalies.

Conclusion

The present study confirms the strong positive correlation between long-term exposure to chemotherapeutic agents and the prevalence of dental anomalies and dental caries in children.

How to cite this article

Talekar AL, Musale PK, Kothare SS. Dental Caries and Dental Anomalies in Children Undergoing Chemotherapy for Malignant Diseases. Int J Clin Pediatr Dent 2022;15(4):428-432.

Long-Term Effect of Anticancer Therapy on Dentition in Childhood Cancer Survivors: An Observational, Cross-Sectional Study

OBJECTIVES

To evaluate the presence of developmental dental anomalies, like microdontia, hypodontia, abnormally shaped teeth (AST), and developmental defects of enamel (DDE) in childhood cancer survivors and compare it with the healthy controls.

METHODS

This cross-sectional analytical study was conducted in 2 groups: childhood cancer survivors (CCS) group including children (> 12 y, m/f) who had undergone anticancer therapy (ACT) before 8 y of age and healthy control group (> 12 y, m/f) without any systemic disease. Pearson chi-square test was used to analyze the difference between the CCS group and the control group for microdontia, hypodontia, AST, DDE and for intragroup analysis in CCS group. Odds ratio was also calculated.

RESULTS

A total of 120 and 121 children were included in CCS and control group, respectively. The prevalence of microdontia, hypodontia, abnormally shaped teeth, and DDE was 17.5% (21), 5% (6), 8.33% (10), and 37.5% (45), respectively in CCS group. It was 8.2% (10), 2.5% (3), 1.65% (2), and 22.3% (27), respectively in the control group. A statistically significant difference was seen in microdontia (p = 0.032), abnormally shaped teeth (p = 0.017) and DDE (p = 0.01). Higher prevalence was seen when ACT began at an early age.

CONCLUSION

An association between developmental dental anomalies and anticancer therapy (ACT) exists with significantly higher difference in microdontia, abnormally shaped teeth and DDE among survivors of childhood cancer as compared to healthy population. These known adverse effects of ACT on developing teeth should be considered during treatment planning of the children having cancers.

The prevalence of dental developmental anomalies among childhood cancer survivors according to types of anticancer treatment

Survival following childhood cancer has increased considerably. In an observational cross-sectional study, we assessed the prevalence of dental developmental anomalies (DDA) among childhood cancer survivors according to types of anticancer treatment. Permanent teeth were examined clinically and radiographically in 121 adolescents with a history of childhood malignancies, to identify DDA, namely hypomineralization or hypoplasia, microdontia, root changes and hypodontia. DDA were observed in 56/121 individuals (46%), in 309/3388 teeth (9%). Hypomineralization or hypoplasia of enamel appeared in 21 (17%) patients. Altered root development appeared in 26 patients and hypodontia affected 13 (10%). Dental anomalies were observed in 36 (43%) individuals who received chemotherapy and not radiation, in 20 (52%) who received radiotherapy, and in 15 (60%) of those who received head and neck radiotherapy. Among patients who received only chemotherapy, young age (6 years or younger) was associated with a higher number of malformed teeth. In conclusion, antineoplastic treatment that combines chemotherapy and radiotherapy appears to increase the risk of DDA. Radiation to the head and neck area was shown to particularly increase the risk of DDA. No specific chemotherapy agent was found to be associated more than the others with DDA.

Factors and Mechanisms Involved in Acquired Developmental Defects of Enamel: A Scoping Review

BACKGROUND

Developmental Defects of Enamel (DDE) is a pathology of the teeth that can greatly alter the quality of life of patients (hypersensitivity, esthetic issues, loss of function, etc.). The acquired DDE may occur as a result of a wide range of acquired etiological factors and his prevalence of this pathology may reach up to 89.9%. The main objective of this research was to identify and analyze, in current literature, the factors related to acquired DDE, in order to propose a general theory about the mechanisms involved.

METHODS

The search of the primary literature was conducted until [December 31, 2021]. Our search strategy uses the Pubmed/MEDLINE database and was structured around 3 terms ["Development," "Defect," and "Enamel"]. To be included, references had to be primary studies, written in English. Exclusion criteria were reviews, in vitro, animal, genetic or archeology studies, and studies focused on clinical management of DDE. One hundred and twenty three articles were included in this scoping review: 4 Randomized clinical trials, 1 letter, 5 cases reports, 2 fundamentals studies, and 111 observational studies (33 Cross-sectional studies, 68 Cohort study and 10 Case-control study). The quality of evidence was assessed using the PEDro scale for clinical trials, the Newcastle-Ottawa scale for observational studies, and a published tool to assess the quality of case reports and case series.

RESULTS

A scoping review of the literature identified 114 factors potentially involved in acquired DDE. The most frequently encountered pathologies are those causing a disorder of calcium homeostasis or a perturbation of the ARNT pathway in mother or child. The link between the ARNT pathway and metabolism deficiency in uncertain and needs to be defined. Also, the implication of this mechanism in tissue impairment is still unclear and needs to be explored.

CONCLUSIONS

By identifying and grouping the risk factors cited in the literature, this taxonomy and the hypotheses related to the mechanism allow health practitioners to adopt behaviors that limit the risk of developing aDDE and to set up a prevention of dental pathology. In addition, by reviewing the current literature, this work provides guidance for basic research, clinical studies, and literature searches.

Oral and dental late effects in long-term survivors of childhood embryonal brain tumors

PURPOSE

To investigate oral and dental late effects in survivors of childhood brain tumors medulloblastoma (MB) and central nervous system supratentorial primitive neuroectodermal tumor (CNS-PNET).

METHODS

This cross-sectional study assessed oral and dental late effects in MB/CNS-PNET survivors treated before 20 years of age, and with a minimum of 2 years since treatment. Participants went through an oral and radiographic examination. We assessed oral status using the decayed-missing-filled index (DMFT), oral dryness, maximum mouth opening (MMO), fungal infection, and registration of dental developmental disturbances (DDD) in the form of hypodontia, microdontia, and enamel hypoplasia.

RESULTS

The 46 participants' mean age at enrolment was 27 ± 12.8 years and at treatment 8.5 ± 5.2 years, and the mean time since treatment was 18.9 ± 12 years. Over a third (35%) of survivors had reduced mouth opening (mean 29.3 ± 5.6 mm (range 16-35)). A significantly lower MMO was found in individuals treated ≤ 5 years compared to survivors treated > 5 years (p = 0.021). One or more DDD were registered in 30.4% of the survivors, with a significantly higher prevalence in individuals treated ≤ 5 years (p < 0.001). Hypodontia was the most prevalent type of DDD. There was no difference in DMFT score in relation to age at treatment. Oral dryness was not frequently reported or observed in these survivors.

CONCLUSION

Survivors of childhood MB/CNS-PNET are at risk of oral and dental late effects including reduced mouth opening and DDD. The risk is highest in survivors treated before the age of 5.

A Long-Term Follow-Up of Dental and Craniofacial Disturbances after Cancer Therapy in a Pediatric Rhabdomyosarcoma Patient: Case Report

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents. A boy aged seven years and five months was diagnosed with stage three group III embryonal parameningeal RMS with intracranial extension. He received chemotherapy for 23 weeks in combination with localized radiotherapy during the inductive phase of nine weeks (a total tumor dose of 5040 cGy). Three months later, he was referred to the department of pediatric dentistry for radiation-induced caries, the treatment of which was later terminated because of severe trismus and radiation-induced oropharyngeal mucositis. Three years later, the patient returned for the fitting of a prosthesis because of mastication problems. The dental treatments performed included: extraction, banding, composite resin restorations, root canal fillings, and stainless steel crown fabrication. An interim denture was fitted due to the poor retention of the fixed prosthesis. As the patient grew older, they developed facial asymmetry as a result of the prominent atrophy of their right cheek. By the age of 32, they had lost multiple teeth and exhibited severe facial deformity. Therefore, it is essential not only to involve a multidisciplinary medical team before, during, and after cancer therapy, but also to initiate long-term follow-ups given the potential effects of late sequelae after chemoradiation in multiple developmental areas.

Dental late effects of antineoplastic treatment on childhood cancer survivors: Radiographic findings

BACKGROUND

Dental anomalies are common late side effects of childhood cancer therapy and may lead to anatomical, functional, and aesthetic sequelae.

AIM

The study aimed to record dental late effects of antineoplastic treatment and associate them with disease and treatment characteristics in order to identify possible risk factors.

DESIGN

Orthopantomograms of 70 survivors aged 4-21 years, who were treated at ages 0-10 years for any type of malignancy and completed antineoplastic treatment at least one year before, were examined. Incidence of developmental disturbances was recorded. Their severity was calculated, and odds ratios for the development of severe defects were estimated.

RESULTS

Root defects presented in 62% of the participants, with impaired root growth being the most common (58%). Increased incidence was associated with combination treatment protocols, irradiation to the head and neck region, and administration of antimetabolites, steroids, and vincristine. Mean DeI value was 17.46 with risk factors for the development of severe root defects being diagnosis of acute lymphoblastic leukemia, combination treatment protocols, administration of cyclophosphamide and steroids, and hemopoietic stem cell transplantation.

CONCLUSIONS

Root defects are common among childhood cancer survivors, with their incidence and severity being affected by multiple disease and treatment characteristics.

Long-Term Effects of Childhood Cancer Treatment on Dentition and Oral Health: A Dentist Survey Study from the DCCSS LATER 2 Study

Simple Summary

We aimed to identify the prevalence of and independent risk factors for dental and oral problems in childhood cancer survivors (CCSs). This cross-sectional study is part of the Dutch Childhood Cancer Survivor Study (DCCSS) LATER 2. Our study included survey data on 154 CCSs, on whom information from dentists on oral health data was received (71.3%). In total, 36.3% of survivors were reported to have at least one dental developmental disorder (DDD). The most prevalent DDDs were short-root anomaly (14.6%), agenesis (14.3%), and microdontia (13.6%). Risk factors for at least one DDD were younger age at diagnosis (<3 years vs. 5+ years) and dose-dependent alkylating agent therapy. This study provides more insight into risk factors for oral health problems in Dutch CCSs. This information is essential in order to improve early detection, prevention, and dental care of oral health problems in CCSs.

Abstract

Objectives: The aim of this study was to identify the prevalence of and independent risk factors for long-term effects of childhood cancer treatment on the dentition and oral health in childhood cancer survivors (CCSs). Methods: This cross-sectional study is part of the Dutch Childhood Cancer Survivor Study (DCCSS) LATER 2. CCSs were diagnosed with cancer between 1963 and 2001. This study focuses on survey data of 154 CCSs on whom information about their oral health was received from their dentists (71.3%). Descriptive statistics and univariable and multivariable Poisson regression analyses were performed to determine the association between treatment characteristics and oral health data. Results: Of the study group, 36.3% had at least one DDD. The most prevalent DDDs were short-root anomaly (14.6%), agenesis (14.3%), and microdontia (13.6%). Risk factors for at least one DDD were younger age at diagnosis (<3 years) and dose-dependent alkylating agent therapy. Conclusions: This study provides more insight into risk factors for oral health problems in Dutch CCSs. This information is essential in order to improve early detection, prevention, dental care, and quality of life. Further studies are needed in order to better define dose-related radiotherapy exposure of the developing teeth in correlation with oral health problems.

Head and neck radiotherapy-induced changes in dentomaxillofacial structures detected on panoramic radiographs: A systematic review

Purpose

This study aimed to summarize the impact of neck and head radiation treatment on maxillofacial structures detected on panoramic radiographs.

Materials and Methods

In this systematic review, the authors searched PubMed Central, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar for original research studies up to February 2020 that included the following Medical Subject Headings keywords: words related to “radiotherapy” and synonyms combined with keywords related to “panoramic radiography” and “oral diagnosis” and synonyms. Only original studies in English that investigated the maxillofacial effects of radiotherapy via panoramic radiographs were included. The quality of the selected manuscripts was evaluated by assessing the risk of bias using Cochrane's ROBINS-I tool for non-randomized studies.

Results

Thirty-three studies were eligible and included in this review. The main objectives pertained to the assessment of the effects of radiation on maxillofacial structures, including bone architecture alterations, periodontal space widening, teeth development abnormalities, osteoradionecrosis, and implant bone loss. The number of participants evaluated ranged from 8 to 176.

Conclusion

The interaction between ionizing radiation and maxillofacial structures results in hazard to the tissues involved, particularly the bone tissue, periosteum, connective tissue of the mucosa, and endothelium. Hard tissue changes due to radiation therapy can be detected on panoramic radiographs.

Late adverse effects of childhood acute lymphoblastic leukemia treatment on developing dentition

BACKGROUND

Childhood cancer survivors show a variety of late adverse effects on dental health. The purpose of this study was to examine the prevalence and severity of dental abnormalities in permanent dentition in childhood leukemia survivors.

MATERIALS AND METHODS

Retrospective analysis of panoramic radiographs was performed for 178 childhood leukemia survivors aged below 17 years at the time of diagnosis. Sex, age at diagnosis, interval between ALL diagnosis and the follow-up radiograph, treatment protocol, and risk grouping were recorded. Abnormalities of tooth development and defect index were used to assess the frequency and severity of dental abnormalities.

RESULTS

One hundred eight (61%) patients had no dental abnormalities at follow-up examination at a median of 6.1 years after diagnosis. Microdontia was more frequent in children under 6 years of age at the time of diagnosis (5.7% vs. 0.6%, p < .001). Significant differences were noted between distinct ALL treatment protocols with more common microdontia in patients treated according to the NOPHO ALL2008 protocol. Tooth agenesis was more frequent in patients that underwent therapy according to high-risk arms compared to intermediate- or standard-risk arms (3.8% vs. 1.4%, p = .01). Patients under 6 years of age at diagnosis had a significantly higher average defect index score than older patients (7.0 vs. 2.8, p = .01).

CONCLUSIONS

Children and adolescents who received ALL treatment were at risk for dental damage. Young age and high-intensity therapy were associated with the severity of dental abnormalities.

Comparison of Oral Health Impact Profile (OHIP-14) Values in Cancer Survivor Patients Treated Orthodontically with Either Rapid or Standard Duration Protocols of Treatment-A Prospective Case-Control Study

BACKGROUND

The aim of the study was to compare the oral-health-related quality of life (OHRQoL) between cancer survivors: with rapid orthodontic treatment (TX) (up to 12 months) and standard TX (orthodontic treatment time longer than 16 months).

METHODS

There were 76 cancer survivors (48 women and 28 men) allocated into groups with rapid (36 people) or standard (40 people) duration of TX. OHRQoL was assessed on the basis of Oral Health Impact Profile (OHIP-14) values, measured before TX, 2 weeks and 3 months after the onset of TX, and after the end of TX. A repeated ANOVA test was used to check the statistical significance between the scores.

RESULTS

There were no significant differences regarding the OHIP-14 values between the examined groups at all stages of the examination. Both groups presented significant (p < 0.001) improvement of the values of OHRQoL at the end of TX comparing to the values achieved before the onset of TX.

CONCLUSIONS

Duration of orthodontic treatment by itself had no impact on oral-health-related quality of life.

Oral and Dental Abnormalities Caused by a Pediatric Rhabdomyosarcoma Tumor Treatment: A Clinical Case Report

Rhabdomyosarcoma is one of the most common soft-tissue sarcomas in children. The therapy for this condition has evolved significantly over recent decades, as has survival rates. Nevertheless, multiagent chemotherapy, radiation therapy, surgical resection or a combination of these modalities still have to be performed. This case report presents a 16-year-old boy with oral and dental effects after rhabdomyosarcoma treatment, diagnosed at the age of 4 years old. This report highlights the key role of dentists in the clinical management of rhabdomyosarcoma cases before, during and after treatment, and its potential side effects.

Late effects of chemo and radiation treatment on dental structures of childhood cancer survivors. A systematic review and meta-analysis

BACKGROUND

This systematic review summarizes the prevalence of dental defects after chemo and radiation therapy and correlates the findings with specific characteristics of each treatment modality.

METHODS

Database search was performed for studies reporting dental late effects of chemo and radiation therapy. After data extraction and risk of bias assessment, prevalence of crown and root defects was assessed. Correlations between each defect and the characteristics of the antineoplastic treatment were performed.

RESULTS

Sixteen nonrandomized studies were included, yielding a total of 1300 patients with a mean age at diagnosis of 4.5 years. Results reported that root defects were more common than crown defects. The most common root defect was impaired root growth and microdontia the most common crown defect. Age, radiation dose and field were statistically associated with higher prevalence of dental defects.

CONCLUSION

Defects were associated with combination of chemotherapy and radiotherapy, as used in current therapeutic antineoplastic modalities.

Dental and craniofacial alterations in long-term survivors of childhood head and neck rhabdomyosarcoma

OBJECTIVE

Rhabdomyosarcoma (RMS) represents the most common soft tissue sarcoma that affects children. Treatment involves chemoradiotherapy. This study aimed at evaluating the long-term alterations to teeth and cranial bones in children, teenagers, and young adults after oncologic treatment.

STUDY DESIGN

We conducted a cross-sectional study of patients undergoing treatment for head and neck RMS between 1988 and 2011. We evaluated demographic, clinical, and treatment data and performed panoramic radiography, cephalometry, and photography.

RESULTS

We evaluated 27 long-term survivors, most of whom had been treated between ages 0 to 5 years (51.9%). The total radiation dose applied was 50.4 Gy, and the chemotherapy combination included vincristine, actinomycin D, and cyclophosphamide in 51.9% of the cases. We observed 603 dental alterations, among which 377 (62.7%) occurred in patients ages 0 to 5 years, and root shortening was the most frequent alteration observed (24.2%). With regard to facial bones, 74% of the patients had some level of facial asymmetry, 70.4% had reduced facial depth, 48.4% had mandibles of short size, and 77.8% had reduced facial height.

CONCLUSIONS

Children submitted to RMS treatment involving chemotherapy and radiotherapy displayed significant dental and craniofacial alterations, especially when treatment occurred between ages 0 and 5 years.

Supernumerary Incisors in CB6F1 Mice Conditioned with Chemotherapy and Total Body Irradiation before Bone Marrow Transplantation

Multiple adult female CB6F1 mice presented with supernumerary incisors after preconditioning with chemotherapy and total body irradiation for bone marrow transplantation (BMT). Mice received nonmyeloablative total body irradiation (3 Gy) and either cyclophosphamide or bendamustine, followed by BMT and posttransplantation cyclophosphamide or bendamustine. Here we describe the clinical presentation, μCT findings, and histopathologic evaluation of the affected mice. These analyses confirmed the gross diagnosis and revealed details of the abnormal tooth morphology. We surmise that the combination of total body irradiation and chemotherapy resulted in the abnormal formation of supernumerary incisors. Supernumerary teeth should be considered as a potential confounding factor in tracking weight loss after BMT. These conditions can be managed to allow animals to reach their intended scientific endpoint.

Mandibular growth in survivors of pediatric parotid gland carcinoma treated with interstitial brachytherapy

BACKGROUND

The aim of the study was to present long-term results of mandibular growth in pediatric parotid gland carcinoma survivors treated with interstitial brachytherapy.

PROCEDURE

Twenty-five survivors of pediatric parotid gland carcinoma treated with iodine-125 seed interstitial brachytherapy were included for quantitative analysis, including three dimensional (3D) cephalometry and measurement of mandibular volume.

RESULTS

3D cephalometry showed that the median fore-and-aft increments of the lengths of the condyle, the ramus, and the body of the mandible were 1.23, 0.19, and 1.66 mm for the affected side, respectively, and were 1.37, 1.95, and 3.42 mm for the unaffected side, respectively. The difference in increments of the ramus was statistically significant between the affected side and the unaffected side (P = 0.003; P < 0.05). Moreover, mandibular volume measurements showed that the median fore-and-aft increments of the volumes of the condyle, the ramus, and the body of the mandible were 290.62, 220.14, and 1706.40 mm³ for the affected side, respectively, and were 269.15, 370.40, and 1469.86 mm³ for the unaffected side, respectively. The difference in increments was statistically significant between the affected side and the unaffected side for the ramus (P = 0.005; P < 0.05) and the body (P = 0.043; P < .05).

CONCLUSION

Mandibular growth was affected by interstitial brachytherapy, especially for the ramus, in pediatric parotid gland carcinoma survivors treated with interstitial brachytherapy. Nevertheless, the impact was mild in these survivors.

Clinical Risk Factors Influencing Dental Developmental Disturbances in Childhood Cancer Survivors

PURPOSE

Although studies regarding dental developmental disturbances after childhood cancer treatment have increased, they have many limitations. Studies analyzing the significance of independent clinical risk factors with regard to the dental health status are also rare. We aimed to investigate the risk factors for dental developmental disturbances, particularly severe disturbances, in childhood cancer survivors (CCS).

MATERIALS AND METHODS

Oral examinations and retrospective reviews of medical and panoramic radiographs were performed for 196 CCS (mean age, 15.6 years). Cancer type, age at diagnosis, treatment modality, type and accumulated dose of administered drugs, and dose and site of radiation were recorded. Dental developmental disturbances were diagnosed using panoramic radiographs and graded for severity according to the Modified Dental Defect Index (MDDI). Descriptive statistics and multivariate analyseswere performed to determine the association between dental abnormalities and clinical factors.

RESULTS

In total, 109 CCS (55.6%) exhibited at least one dental anomaly, and the median value of MDDI was 2.5. Microdontia (30.6%) was the most prevalent anomaly, followed by tooth agenesis (20.4%), V-shaped roots (14.8%), and taurodontism (10.2%). Multivariate analysis revealed that a young age at diagnosis (≤ 3 years), a history of hematopoietic stem cell transplantation, the use of multiple classes of chemotherapeutic agents (≥ 4 classes), and the use of heavy metal agents were significant risk factors for severe dental disturbances.

CONCLUSION

CCS with any of the above risk factors for severe developmental disturbances should be comprehensively followed up to minimize adverse consequences to their dental development and preserve their future dental health.

Long-Term Effects of Acute Myeloid Leukemia Treatment on the Oral System in a Pediatric Patient

Introduction:

Acute Myeloid Leukemia (AML) in pediatric patients is a serious disease, although, for the subgroup of patients who receive proper treatment, a long-term survival rate above 50% is typical. The cycles of chemo- and radiotherapy used to treat AML can impair dental development.

Case Report:

Herein, we describe the oral condition of a 25-year-old male patient treated for AML with chemo- and radiotherapy from 5 to 7 years of age; his AML has remained in remission for the past 18 years. He had lost only one permanent tooth, but the remaining teeth demonstrated serious deformations and radicular hypoplasia. Two teeth required immediate extraction and subsequent replacement by implant-supported crowns. We found that the decayed, missing, filled teeth (DMFT) index was not representative of the real oral condition. Here, we report the full case and provide a brief review of the literature.

Conclusion:

Antitumor treatment of pediatric leukemia can induce total impairment of dental development and function. These adverse effects may become clinically evident many years after the resolution of cancer, and can be significantly detrimental to the patient’s quality of life.

The effect of a single injection of irinotecan on the development of enamel in the Wistar rats

Cancer is the second most frequent cause of death in children. Because the prognosis for childhood malignancies has improved, attention has now focused on long-term consequences of cancer treatment. The immediate effects of chemotherapy on soft tissues have been well described; however, there is less information about long-term effects of chemotherapy on the development of dental tissues. To test the association between the effect of chemotherapy on enamel development, we examined two groups of rats: one that had received an intraperitoneal dose of 200 mg/kg of irinotecan, whereas the other (control) group had received vehicle only. Rats were killed at 6, 48 and 96 hr post-injection; the mandibles dissected out, fixed for histological evaluation and scanned for mineralization defects by Micro-CT. Our results showed structural changes in the ameloblast layer along with a significant reduction in mineralization and thickness of enamel at 96 hr after chemotherapy. These data demonstrate that irinotecan induces structural changes in forming enamel that become apparent after anticancer chemotherapy treatment.

Evaluating Intensity Modulated Proton Therapy Relative to Passive Scattering Proton Therapy for Increased Vertebral Column Sparing in Craniospinal Irradiation in Growing Pediatric Patients

PURPOSE

At present, proton craniospinal irradiation (CSI) for growing children is delivered to the whole vertebral body (WVB) to avoid asymmetric growth. We aimed to demonstrate the feasibility and potential clinical benefit of delivering vertebral body sparing (VBS) versus WVB CSI with passively scattered (PS) and intensity modulated proton therapy (IMPT) in growing children treated for medulloblastoma.

METHODS AND MATERIALS

Five plans were generated for medulloblastoma patients, who had been previously treated with CSI PS proton radiation therapy: (1) single posteroanterior (PA) PS field covering the WVB (PS-PA-WVB); (2) single PA PS field that included only the thecal sac in the target volume (PS-PA-VBS); (3) single PA IMPT field covering the WVB (IMPT-PA-WVB); (4) single PA IMPT field, target volume including thecal sac only (IMPT-PA-VBS); and (5) 2 posterior-oblique (-35°, +35°) IMPT fields, with the target volume including the thecal sac only (IMPT2F-VBS). For all cases, 23.4 Gy (relative biologic effectiveness [RBE]) was prescribed to 95% of the spinal canal. The dose, linear energy transfer, and variable-RBE-weighted dose distributions were calculated for all plans using the tool for particle simulation, version 2, Monte Carlo system.

RESULTS

IMPT VBS techniques efficiently spared the anterior vertebral bodies (AVBs), even when accounting for potential higher variable RBE predicted by linear energy transfer distributions. Assuming an RBE of 1.1, the V10 Gy(RBE) decreased from 100% for the WVB techniques to 59.5% to 76.8% for the cervical, 29.9% to 34.6% for the thoracic, and 20.6% to 25.1% for the lumbar AVBs, and the V20 Gy(RBE) decreased from 99.0% to 17.8% to 20.0% for the cervical, 7.2% to 7.6% for the thoracic, and 4.0% to 4.6% for the lumbar AVBs when IMPT VBS techniques were applied. The corresponding percentages for the PS VBS technique were higher.

CONCLUSIONS

Advanced proton techniques can sufficiently reduce the dose to the vertebral body and allow for vertebral column growth for children with central nervous system tumors requiring CSI. This was true even when considering variable RBE values. A clinical trial is planned for VBS to the thoracic and lumbosacral spine in growing children.

Orthodontic Therapy for Paediatric Cancer Survivors: A Review

The paper aims at reviewing the possibilities of orthodontic therapy for paediatric cancer survivors. It is important to understand the fundamental disease, it's treatment protocols, effects on growing skeleton, dental development, oral cavity and oral mucosa, dental caries, bone, orthodontic tooth movement.

Antineoplastic chemotherapy and congenital tooth abnormalities in children and adolescents

AIM OF THE STUDY

Chemotherapeutic treatment in children and adolescents carries a risk of congenital tooth disorders and dentinoma. Study objective is to assess the correlation between tooth abnormalities, early complications of multidrug chemotherapy, and chemotherapeutics used in different antineoplastic therapies in children and adolescents.

MATERIAL AND METHODS

Enamel defects (developmental defects of enamel index - DDE index) and defects in tooth number, size, and structure were assessed clinically and radiologically in 60 patients who underwent chemotherapy on average 4.9 ±3.4 years earlier (PCH), and 60 generally healthy subjects (control group - CG), aged 6-18 years. Höltta's defect index (DeI) was calculated. Medical files provided information on neoplasm type, age at treatment start and chemotherapy duration, chemotherapeutic type and dose, vomiting, and mucositis (CTCAE v4.0). Statistical significance of differences between groups was assessed with the Mann-Whitney U test and the correlation between dental defects and chemotherapy with Spearman's rank correlation coefficient (significance p ≤ 0.05).

RESULTS

Enamel defects, tooth agenesis, microdontia, root resorption, taurodontism, and dentinoma occurred statistically significantly more often in the PCH group. A correlation was established between vincristine use and dose and all types of dental defects; cyclophosphamide, doxorubicin, and isophosphamide and hypodontia; microdontia, root resorption, and enamel defects; etoposide and cisplatin and microdontia, root resorption, and enamel defects; methotrexate root resorption and enamel defects; carboplatin and dentinoma and enamel defects. Mucositis and vomiting promoted root resorption, microdontia, and enamel defects.

CONCLUSIONS

Dental defects are related to both the use of respective chemotherapeutics, especially vincristine, cyclophosphamide, doxorubicin, and isophosphamide, and to early complications in multidrug chemotherapy - mucositis and vomiting. Vincristine and carboplatin use may promote dentinoma.

Strategies to Overcome Late Complications from Radiotherapy for Childhood Head and Neck Cancers

Most pediatric head and neck cancers are treated with radiotherapy, but the morbidity associated with radiotherapy has become a prominent issue. This article discusses the common long-term complications associated with head and neck radiotherapy for childhood cancers. It reviews approaches to minimize toxicity and details the toxicities that head and neck radiation inflicts on relevant functional measures. In addition, it discusses the risk of radiation-induced secondary cancers in childhood cancer survivors, as well as strategies to reduce them. Thus, this article addresses approaches to minimize long-term radiation toxicities in order to improve the quality of life for childhood cancer survivors.

Long-term effect of chemotherapy-intensity-modulated radiation therapy (chemo-IMRT) on dentofacial development in head and neck rhabdomyosarcoma patients

Dentofacial developmental abnormalities have been reported in head and neck rhabdomyosarcoma (HNRMS) patients treated with conventional radiotherapy technique and chemotherapy. This current study investigates dentofacial long-term effects among HNRMS survivors managed with intensity-modulated radiotherapy (IMRT) and chemotherapy. In general, IMRT is a more effective 3D-conformal radiotherapy technique, which delivers high doses of radiation to the tumor target while minimizing doses received by the surrounding normal tissues. The medical records and radiographs of thirteen patients were reviewed to identify the following: 1. Facial asymmetry and jaw hypoplasia. 2. Effects on the dental tissue causing tooth agenesis/hypodontia, root agenesis/stunting/malformation, and/or enamel hypoplasia. 3. Trismus, hyposalivation/xerostomia. Seven patients presented with facial asymmetry and jaw hypoplasia, 9 patients presented with effects on the dental tissue [root agenesis/stunting/malformation (9), tooth agenesis/hypodontia (7) and enamel hypoplasia (3)] and 7 patients developed trismus and /or xerostomia. All patients with facial asymmetry and jaw hypoplasia also developed dental abnormalities. Patients with dentofacial developmental abnormalities were ≤7 years of age at treatment. Our study shows that dentofacial developmental abnormalities are still a burden in the era of IMRT and as prognosis of childhood malignancy improves and more patients survive, these late dentofacial sequelae among childhood cancer survivors will become more common. Dental oncologists should be integral members in the management of children with head and neck cancers.

Malformations of the tooth root in humans

The most common root malformations in humans arise from either developmental disorders of the root alone or disorders of radicular development as part of a general tooth dysplasia. The aim of this review is to relate the characteristics of these root malformations to potentially disrupted processes involved in radicular morphogenesis. Radicular morphogenesis proceeds under the control of Hertwig's epithelial root sheath (HERS) which determines the number, length, and shape of the root, induces the formation of radicular dentin, and participates in the development of root cementum. Formation of HERS at the transition from crown to root development appears to be very insensitive to adverse effects, with the result that rootless teeth are extremely rare. In contrast, shortened roots as a consequence of impaired or prematurely halted apical growth of HERS constitute the most prevalent radicular dysplasia which occurs due to trauma and unknown reasons as well as in association with dentin disorders. While odontoblast differentiation inevitably stops when growth of HERS is arrested, it seems to be unaffected even in cases of severe dentin dysplasias such as regional odontodysplasia and dentin dysplasia type I. As a result radicular dentin formation is at least initiated and progresses for a limited time. The only condition affecting cementogenesis is hypophosphatasia which disrupts the formation of acellular cementum through an inhibition of mineralization. A process particularly susceptible to adverse effects appears to be the formation of the furcation in multirooted teeth. Impairment or disruption of this process entails taurodontism, single-rooted posterior teeth, and misshapen furcations. Thus, even though many characteristics of human root malformations can be related to disorders of specific processes involved in radicular morphogenesis, precise inferences as to the pathogenesis of these dysplasias are hampered by the still limited knowledge on root formation.

Long-Term Effects of Exposure to Ionizing Irradiation on Periodontal Health Status - The Tinea capitis Cohort Study

Studies among long-term survivors of childhood cancer who had received high-dose irradiation therapy of 4–60 Gy, demonstrated acute and chronic dental effects, including periodontal diseases. However, the possible effects of low to moderate doses of radiation on dental health are sparse. The aim of this study is to investigate the association between childhood exposure to low–moderate doses of ionizing radiation and periodontal health following 50 years since exposure. The study population included 253 irradiated subjects (treated for Tinea capitis in the 1950s) and, 162 non-irradiated subjects. The estimated dose to the teeth was 0.2–0.4 Gy. Dental examination was performed according to the community periodontal index (CPI). Socioeconomic and health behavior variables were obtained through a personal questionnaire. Periodontal disease was operationally defined as “deep periodontal pockets.” A multivariate logistic regression model was used for the association of irradiation status and other independent variables with periodontal status. The results showed that among the irradiated subjects, 23%, (95% CI 18–28%) demonstrated complete edentulousness or insufficient teeth for CPI scoring as compared to 13% (95% CI 8–19%) among the non-irradiated subjects (p = 0.01). Periodontal disease was detected among 54% of the irradiated subjects as compared to 40% of the non-irradiated (p = 0.008). Controlling for education and smoking, the ORs for the association between radiation and periodontal disease were 1.61 (95% CI 1.01–2.57) and 1.95 (95% CI 1.1–3.5) for ever never and per 1 Gy absorbed in the salivary gland, respectively. In line with other studies, a protective effect for periodontal diseases among those with high education and an increased risk for ever smokers were observed. In conclusion, childhood exposure to low-moderate doses of ionizing radiation might be associated with later outcomes of dental health. The results add valuable data on the long-term health effects of exposure to ionizing radiation and support the implementation of the ALARA principle in childhood exposure to diagnostic procedure involving radiation.

Radioprotective effect of sodium selenite on developing teeth

Radioprotective agents like selenium are used to reduce the damage caused by radiation in healthy tissues. The aim of this study was to evaluate the effect of sodium selenite on the development of the molars of offspring of rats irradiated during odontogenesis. Twenty pregnant rats were randomly divided into 4 groups: control, irradiated, selenium and selenium/irradiated. The selenium and selenium/irradiated groups received 0.3 mg/kg of sodium selenite at 18 days of pregnancy. The rats of the irradiated and selenium/irradiated groups received a single dose of 4 Gy of X rays on the abdominal region at the 19th day of pregnancy. The offspring was sacrificed at 3 and 4 days after birth for evaluation of the birefringence of the enamel organic matrix, and at 30 days for evaluation of the intercuspal dimensions of the molars. The selenium/irradiated group was similar to the irradiated group with respect to the thickness and irregularity of the enamel organic matrix region in the evaluated birefringence, as the intercuspal dimensions of the molars. In conclusion, sodium selenite had no radioprotective action on the development of the molars of offspring of rats irradiated during odontogenesis and had a toxic effect in the initial time.

Cyclophosphamide-Induced Morphological Changes in Dental Root Development of ICR Mice

Background

Survivors of childhood cancer are at risk of late dental development. Cyclophosphamide is one of the most commonly used chemotherapeutic agents against cancer in children. The aim of this study was to investigate the effects of cyclophosphamide on root formation in the molars of growing mice and to assess the morphological changes in these roots using three-dimensional structural images.

Methods

We treated 16 12-day-old ICR mice with cyclophosphamide (100 mg/kg, i.p.) and 16 control mice with saline. At 16, 20, 24, and 27 days of age, the mandibular left first molars were scanned using soft micro-computed tomography. After scanning, the structural indices were calculated using a three-dimensional image analysis system, and the images were subjected to three-dimensional reconstruction. The length and apical foramen area of all distal roots were assessed. Histological changes in the apical region were then assessed via hematoxylin and eosin staining.

Results

The mandibular molars of all experimental mice showed evidence of cytotoxic injury, which appeared in the form of anomalous root shapes. Although all roots developed further after cyclophosphamide injection, the three-dimensional structural images showed that the roots in the experimental group tended to develop more slowly and were shorter than those in the control group. At 27 days of age, the mean root length was shorter in the experimental group than in the control group. Conversely, the apical foramen of the roots in the experimental group tended to close faster than that of roots in the control group. In addition, hematoxylin and eosin staining of the distal roots in the experimental group showed increased dentin thickness in the apical region.

Conclusion

Our results suggest that cyclophosphamide can result in short root lengths and early apical foramen closure, eventually leading to V-shaped or thin roots.