Dental maturity assessment in children with acute lymphoblastic leukemia after cancer therapy

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 age estimation in children that have undergone antineoplastic treatment

OBJECTIVE

Even though many studies have been performed to estimate DA in general population, limited research has been performed concerning medical compromised populations such as childhood cancer survivors. The aims of this case-control study were (a) to estimate dental age in a population of children that have undergone antineoplastic treatment with three different methods and (b) to compare it with the estimates from healthy subjects (control group).

MATERIALS AND METHODS

Seventy-three oncology patients and equal number of healthy control subjects from the Pediatric dentistry Department had their dental age estimated through recent orthopantograms using Dermijian's, Willems' and London Atlas methods. All OPGs randomly assessed by two calibrated observers. Mean age difference was calculated. Intraclass Correlation Coefficient was used to assess intra-observer reliability and the Concordance Correlation Coefficient used to assess inter-observer reliability.

RESULTS

Concerning the CCS group 35 subjects (48%) were males and 38 (52%) were females, with an overall mean chronological age 10.95 years, ranging between 5.37 and 15.83 years. Intra- and inter-examiner reliability was exceptional for all methods. Mean DA differences in both groups and were not statistically sinificant regardless of the method used. The marginally lower values when males and females were investigated separately is basically due to the corresponding reduction of the sample size.

CONCLUSION

An overestimation of DA observed in both groups by all methods was not significant. All three methods produced highly accurate comparable results when it comes to estimate the actual chronological age in both groups (CCS and control subjects) regardless of gender.

Effect of irinotecan on the tongue mucosa of juvenile male albino rat at adulthood

Irinotecan is one of the most important anti-tumour drugs against a broad spectrum of malignancies, but is known to be associated with possible oral complications. The aim of the present study was to evaluate the effect of irinotecan on the tongue mucosa of juvenile male albino rat at adulthood using different histological and immunohistochemical methods. Twenty juvenile male albino rats were divided equally into two groups: control and irinotecan-treated group (single injection of 200 mg irinotecan/kg, then kept for four weeks without treatment). The tongue specimens were processed for light microscopy and scanning electron microscopy. The irinotecan-treated group showed statistically significant shortening and thinning of the lingual papillae. There was loss of the normal appearance of the filiform papillae with focal cell loss alternating with areas of hyperkeratosis. Focal separation of the keratin layer, some nuclear changes and vacuolation of some epithelial cells were detected. Dilated congested blood vessels and mild mononuclear cellular infiltration were encountered. Atrophic fungiform papillae with ill-defined taste bud cells were observed. A statistically significant decrease in the pattern of Ki67 immunohistochemical staining reaction was detected in comparision to the control group. Scanning electron microscopy revealed different signs of atrophy of the tongue papillae. Focal areas of desquamation of lingual papillae were observed revealing some filiform papillae with desquamated surface, bisected tips and evident thinning. Some extravasated red blood cells could be detected. Thus irinotecan caused significant morphological and morphometrical alterations of the tongue mucosa in particularly the filiform papillae.

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.

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.

DENTAL CONSIDERATIONS FOR LEUKEMIC PEDIATRIC PATIENTS: AN UPDATED REVIEW FOR GENERAL DENTAL PRACTITIONER

The early signs of leukemia can usually manifest in the oral cavity due to infiltration of leukemic cells or due to associated decline in normal marrow elements, especially in the acute phase of leukemia, as common lesions at this stage of the disease can be screened and diagnosed by the dentist. Therefore, the dental community should be aware of the oral manifestations of leukemia and oral complications of anticancer treatment. This can eliminate the oral symptoms of the disease and to improve quality of life for these patients. An extensive search in PubMed line using a combination of terms like “leukemia, children, dental, Acute lymphoblastic leukemia, pediatric” for last ten years was made. Reviews and case reports concerned about acute lymphoblastic leukemia in children were all collected and analyzed and data were extracted. Accordingly, the aim of this review is to highlight on the oral presentations of leukemia in children attending dental clinics and the management of its undesirable side effects.

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.

A rat model of radiation injury in the mandibular area

BACKGROUND

Radiation technology focuses on delivering the radiation as precisely as possible to the tumor, nonetheless both acute and long-term damage to surrounding normal tissue may develop. Injuries to the surrounding normal tissue after radiotherapy of head and neck cancer are difficult to manage. An animal model is needed to elucidate good treatment modalities. The aim of this study was to establish a rat model where a certain radiation dose gives reproducible tissue reactions in the mandibular area corresponding to injuries obtained in humans.

METHOD

The left mandible of male Sprague Dawley rats was irradiated by external radiotherapy (single fraction 15 Gy, total dose 75 Gy) every second week five times. Endpoint was six weeks after last radiation treatment, and the test group was compared to non-irradiated controls. Morphological alterations of the soft tissues, bone and tooth formation, as well as alterations of salivation, vascularity and collagen content were assessed. An unpaired, non-parametric Mann-Whitney test was used to compare the statistical differences between the groups.

RESULTS

Analysis of the soft tissues and mandible within the radiation field revealed severe unilateral alopecia and dermatitis of the skin, extensive inflammation of the submandibular gland with loss of serous secretory cells, hyperkeratinization and dense connective fiber bundles of the gingival tissue, and disturbed tooth development with necrosis of the pulp. Production of saliva and the vascularity of the soft tissues were significantly reduced. Furthermore, the collagen fibril diameter was larger and the collagen network denser compared to non-irradiated control rats.

CONCLUSION

We have established an animal model of radiation injury demonstrating physiological and histological changes corresponding to human radiation injuries, which can be used for future therapeutic evaluations.

Dental and chronological age in children under oncological treatment

The current oncology treatment has improved the survival of children with several types of cancer, and the effect of radiotherapy and/or chemotherapy treatment on dental maturation in comparison with chronological age is not widely known. The aim of this work was to evaluate and compare the impact of radiotherapy and/or chemotherapy treatment during dental maturation with chronological age in Chilean children diagnosed with cancer. Study Design was cross-sectional study on children diagnosed with different types of cancer and treated with radiotherapy and/or chemotherapy when they were ages of 0.1 to 13 years. Demirjian tables for both girls and boys are used to determine the dental age. The association between chronological and dental age was highly significant. Nevertheless, a linear relation between chronological and dental age was not observed when the data were stratified by BMI and type of treatment. This study confirmed that dental age is an indicator of chronological age but that other variables, such as body mass index, in children with cancer could be confounder variables. Thus, further studies are necessary to investigate the influence of BMI on tooth eruption/maturation in children under oncological treatment.

Oral complications and dental care in children with acute lymphoblastic leukaemia

Acute leukaemia is the most common type of childhood cancer, the acute lymphoblastic type accounting for the majority of cases. Children affected by leukaemia receive various forms of treatments including chemotherapeutic agents and stem cell transplants. Leukaemia and its treatment can directly or indirectly affect oral health and further dental treatments. The oral complications include mucositis, opportunistic infections, gingival inflammation and bleeding, xerostomia and carious lesions. An additional consideration in children is the impact of the treatments on the developing dentition and on orofacial growth. The aim of this review is to describe the oral complications in children with acute lymphoblastic leukaemia and the methods of prevention and management before, during and after the cancer treatment.

Effect of radiotherapy on the eruption rate and morphology of the odontogenic region of rat incisors

OBJECTIVE

The goal in this study was to evaluate the results of doses of 5 and 15 Gy of radiation in odontogenic region of the rats inferior mandibular-incisors by a histological analysis and the rate of eruptions.

DESIGN

Animals were divided into three groups: control, radiotherapy 5 Gy and radiotherapy 15 Gy. In which tooth-eruption-rate was measured every two days.

RESULTS

Animals in Group 5 Gy presented values similar to those of the control group. Animals in Group 15 Gy presented reduction in tooth-eruption-rate as of the sixth day of the experiment, vast disorganization of odontoblasts and ameloblasts, apparent reduction in cell population in the follicle region and alterations in cervical loop formation of the dental organ.

CONCLUSIONS

It was concluded that there was a difference between the researched doses, and histological alteration at 15 Gy lead to statistical reduction in tooth-eruption-rate.