Effects of vincristine on the developing hamster tooth germ in vitro

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.

Dental Anomalies as Late Adverse Effect among Young Children Treated for Cancer

Purpose

The aim of this study was to compare the incidence of dental complications in childhood cancer survivors with that of healthy control subjects, and to determine the possible influence of various factors associated with patient and treatment.

Materials and Methods

Sixty-one panoramic radiographs of the dentition of cancer survivors were compared with 521 radiographs of healthy patients at a similar age, between 5 and 18 years. The mean period from termination of therapy was 4.9 years (58.9±34.3 months), and 51 children (83.60%) were under age 5 when therapy began.

Results

Dental anomalies were found in 38 cancer survivors (62.29%) and 69 control subjects (13.24%) (p < 0.001). Agenesis of teeth was found in 19 cancer patients (31.14%) and in 48 control subjects (9.21%). Microdontic teeth were found in 22 cancer survivors (36.06%) and 15 control subjects (2.87%) (p < 0.001), whereas teeth with short roots were found in seven cancer patients (11.47%) and 15 control subjects (2.87%) (p < 0.01). Dental anomalies in cancer patients were more common in some tooth groups and were not observed in others. The frequency of dental anomalies did not show correlation with age at the beginning or termination or time of therapy.

Conclusion

Children under the age of 5 are in a high risk group for dental complications after anticancer treatment. Rudimentary chemotherapy has a considerable impact on the occurrence of dental anomalies.

Long-term effects of chemotherapy on dental status in children treated for nephroblastoma

Dental abnormalities among children treated at a young age for Wilms tumor are reported. The authors retrospectively reviewed the dental records and panoramic radiographs of 27 children treated for nephroblastoma between 1994 and 1998. They evaluated the frequency of apparent microdontia, excessive caries, root stunting, hypodontia, and enamel hypoplasia and compared this group to a control group of 78 children. Seventy percent of the children developed dental abnormalities, comprising root stunting (44%), enamel hypoplasia (22%), microdontia (18%), and hypodontia (7%). Results of control subjects were significantly different regarding dental abnormalities, especially microdontia and taurodontia. These results indicate that chemotherapy in children may lead to troubles affecting teeth growing at the time of treatment. Information and prospective dental care are needed, and further investigations are required.

Disturbed root development of permanent teeth after pediatric stem cell transplantation. Dental root development after SCT

BACKGROUND

Deficient dental root development has been reported after conventional pediatric anticancer therapy, but less information is available on stem cell transplantation (SCT) recipients.

METHODS

Root-crown (R/C) ratios of fully developed permanent teeth were assessed from panoramic radiographs of 52 SCT recipients, who were treated when they were age < 10 years. Using standard deviation scores (SDSs), the authors compared the R/C ratios to the corresponding tooth and gender-specific values in a healthy population. The percentage of affected R/C ratios per individual was examined in a subgroup of 39 (SG39) patients with advanced tooth development. The effects of total body irradiation (TBI) and SCT age on the R/C ratios were studied in TBI and high-dose chemotherapy (HDC = non-TBI) groups and in 3 age groups (< or = 3.0 years, 3.1-5.0 years, > or = 5.1 years).

RESULTS

Per individual, 77% of the fully developed permanent teeth were affected in SG39. At the tooth level, in 77% of the 945 teeth studied (52 patients), the R/C ratios were outside +/-2 SDSs. More teeth were affected in the TBI (85%) than in the non-TBI (55%) group (P < 0.001). The teeth of the patients who were ages 3.1-5.0 years old at SCT presented with the most severe aberrations of the R/C ratio (mean SDS = -4.4) whereas the teeth of the youngest (age < or = 3.0 years) and the oldest (age > or = 5.1 years) patients were equally affected (mean SDSs = -3.1 and -3.0, respectively).

CONCLUSIONS

Disturbances of dental root growth always followed pediatric SCT. HDC alone intensely harmed root growth but TBI further increased the adverse effects that were most extensive in the patients 3.1-5.0 years at SCT. These sequelae should be taken into account during the lifelong dental follow-up to minimize the clinical consequences of dental injuries.

Agenesis and microdontia of permanent teeth as late adverse effects after stem cell transplantation in young children

BACKGROUND

The objective of the current study was to examine the occurrence of tooth agenesis and microdontia in pediatric stem cell transplantation (SCT) recipients.

METHODS

The impact of total body irradiation (TBI) and age at SCT on agenesis and microdontia of permanent teeth was examined in 55 patients from panoramic radiographs. Assessment A1 (for tooth agenesis and microdontia) excluded the third molars, and assessment A2 (for tooth agenesis) included the third molars. Patients were grouped according to TBI status (the TBI group vs. the non-TBI group) and age at SCT (patients age < or = 3.0 years [Group Y], patients ages 3.1-5.0 years [Group M], and patients age > or = 5.1 years [Group O]).

RESULTS

From 1 to 12 teeth were missing in 77%, 40%, and 0% of patients (assessment A1) in Groups Y, M, and O, respectively (Group Y vs. Group M, P=0.055; Group Y vs. Group O, P < 0.001; and Group M vs. Group O, P=0.002), increasing to 83%, 78%, and 43%, respectively, when the third molars were included (assessment A2; P values were not significant). Correspondingly, 75%, 60%, and 13%, respectively, of patients had 1-12 microdontic teeth (assessment A1: Group Y vs. Group M, P=0.306; Group Y vs. Group O, P <0.001; and Group M vs. Group O, P=0.003). Recipient age at the time of SCT was found to have a negative correlation with the number of missing teeth (P=0.001) and microdontic teeth (P=0.005). TBI appeared to have little effect on the prevalence of tooth agenesis (assessment A1: TBI group, 32%; non-TBI group, 29%; assessment A2: TBI group, 72%; non-TBI group, 46%; P values were not significant) or on the prevalence of microdontia (assessment A1: TBI, 41%; non-TBI, 50%; P value was not significant). A tendency toward an increased number of affected teeth was noticed in the group of patients who received TBI.

CONCLUSIONS

Depending on their age at SCT, 50-100% of pediatric SCT recipients will later present with agenesis and/or microdontia of permanent teeth that may jeopardize occlusal development. Young age (< or = 5.0 years) at SCT was found to be a stronger risk factor than TBI, although TBI caused additive impairment.

Long-term adverse effects on dentition in children with poor-risk neuroblastoma treated with high-dose chemotherapy and autologous stem cell transplantation with or without total body irradiation

Chemo- and radiotherapy may have injurious effects on developing teeth. In this long-term follow-up study among poor-risk neuroblastoma (NBL) survivors our aims were: (1) to assess both the type and extent of the side-effects of the anticancer treatment on tooth development; and (2) to develop an index for expressing total damage to the permanent dentition. We studied the dental development from panoramic radiographs (PRG) of 18 long-term survivors treated under the age of 6 years with high-dose (HD) chemotherapy and autologous stem cell transplantation (ASCT) for poor-risk NBL. The myeloablative therapy was either HD chemotherapy and fractionated total body irradiation (TBI) of 10-12 Gy (TBI group, n = 10) or HD chemotherapy only (non-TBI group, n = 8). A defect index (DeI) was developed to describe the damage to the permanent dentition. The DeI was also tested in 18 healthy adolescents. All NBL patients had disturbances in dental development including short roots, arrested root development, microdontia and tooth aplasia. After TBI, 9/10 patients had very severe root defects, in contrast to none in the non-TBI group. All children in the TBI group had 2-12 (mean 6.6) missing permanent teeth, while 2/5 in the non-TBI group (3/8 excluded due to young age) had two and four missing permanent teeth, respectively. Microdontia was found at equal frequency in both groups. The mean value of the DeI was 70.0 (range 28-117) in the TBI group, 15.2 (range 4-34) in the non-TBI group (P<0.001, Mann-Whitney U test) and 1.8 (range 0-15) in healthy adolescents. Disturbances in dental development may compromise occlusal function in poor-risk NBL patients after ASCT, especially when TBI is included in the conditioning regimen. Long-term dental follow-up and rehabilitation is required.

Daunorubicin-induced pathology in the developing hamster molar tooth germ in vitro

The aim of this study was to evaluate, under organ culture conditions, the cytotoxic effects of daunorubicin on tooth development. Three-day-old maxillary hamster second molars were exposed for 24 h in vitro to 108-10-4 M daunorubicin and then evaluated biochemically and histologically. At 10-6 M daunorubicin dose-dependently decreased tooth germ dry weight, cell proliferation ([3H]thymidine uptake), and insoluble [32P] phosphate uptake (phosphorylation of macromolecules). [45Ca]calcium uptake, a marker for mineralization, was significantly affected only at the highest concentration (10-4 M) tested. Histologically, 10-6 M daunorubicin induced necrosis of the proliferating but not the differentiated protein-secreting cells. At 10-4 M, however, all cells were dead. These results indicate that daunorubicin is particularly toxic to the proliferating cells of the tooth germ. Thus, it can be postulated that children treated with daunorubicin may develop defects in the erupted teeth mainly associated with those regions that were in the proliferating stage at the onset of anticancer chemotherapy.

Effects of actinomycin D on developing hamster molar tooth germs in vitro

The aim of this study was to evaluate the toxic effects of actinomycin D on the developing hamster tooth germ in organ culture. Hamster tooth germs during early secretory amelogenesis were exposed in vitro for 24 h to 10(-9) M-5 x 10(-5) M actinomycin D. Actinomycin D dose-dependently (> or = 10(-7) M) decreased the tooth germ dry weight but mineralization was affected only by doses > or = 10(-5) M. However, the uptakes of TCA-insoluble 32P and [3H]thymidine were significantly reduced dose-dependently from > or = 10(-8) M actinomycin D, indicating that the drug inhibits the synthesis of phosphate-containing macromolecules as well as DNA synthesis. Histologically, 10(-8) M actinomycin D was the lowest dose which was not toxic to any cell type in the developing tooth germ. At 10(-7) M actinomycin D, the most sensitive cells were the proliferating pre-odontoblasts followed by pre-ameloblasts; the mature secretory ameloblasts and odontoblasts appeared unaffected. Higher doses resulted in increased cytotoxicity to the secretory cells and, eventually, total degeneration of most cells. The data suggest that children treated for cancer during tooth development using anti-chemotherapy cocktails containing actinomycin D (serum levels > 10(-7) M) may develop defects later on in the mature dentition as a direct consequence of the toxicity of the drug to the tooth organ.