br In the SG when the type of
In the SG, when the type of AT was associated with the presence of DA, impacted teeth were the only DA that presented with this association (p < 0.05). From the 8 (100%) individuals with impacted teeth, 6 (75%) individuals of them were undergoing CHT concomitant with RT and 2 (25%) individuals only CHT.
Analysing the association among age of cancer diagnosis and duration of of AT with the most prevalent DA in PR of CCS (microdontia, hypodontia and DRA), the microdontia was the only DA associated with the age of cancer diagnosis (p < 0.05) and the duration of AT did not present statistical difference (p > 0.05) (Table VI).
In DM evaluation, when we compared the dental age and chronological age between the SG and the CG, there was no significant statistical difference (p > 0.05) (Table VII).
AT in children occurs when they are physically and emotionally in development and maturation.5 The permanent dentition begins its development with the calcification of the first molar between one to four years old,15 it CH 223191 ends with the complete mineralisation of the third molar at 18 years old.16 In the present study, all the CCS were in the development stage of the permanent dentition when they were submitted to CHT and/or RT. The majority of the CCS (88, 90.72 %) were less than 163 months old, and the remaining CCS (9, 9.28%) were between 168 and 190 months old.
Some studies that reported DA such us microdontia, hypodontia and DRA used Dahllof mehtod 17 and Holtta’s defect index 18, both of them, were developed to analyse these specific DA. In addition to these DA, other studies have reported that CCS may also present taurodontism, supernumerary teeth and root dilacerations.7,9,19 Our study evaluated DA through a methodology that allowed for the evaluation of 16 different types of DA, which included not only DA already reported in the literature but also other DA that had not been reported before. It was useful in order to show that DA in CCS can be present not only because of the influence of the AT but also because other factors such as hereditary or genetic factors that increase the final quantity of DA for each individual. Our study revealed that CCS had a high quantity of DA (10 or >10) in contrast to the majority of the health individuals who have low quantity of DA (1 or <1).
In this study, when the DA were compared between the CCS and the healthy individuals, the most prevalent DA in the CCS were microdontia, hypodontia (hypoplastic DA) and DRA. These results are consistent with some studies that reported these three DA as the most common in CCS when they were compared to healthy individuals.8,20,21 This can be explained because of the association between the action of the CH and the RT in the cell proliferation of odontogenesis and/or rhizogenesis. Differently to other studies that mentioned taurodontism, supernumerary teeth and root dilacerations as late effects of AT 7,9,22 , our study revealed similar prevalence and distribution of these DA in both the SG and the CG.
CHT (systemic action) and RT (local action) can cause the disruption or a decrease in cell proliferation during odontogenesis and/or rhizogenesis 23, and
when those stages in the dental formation suffer alterations in some of their stages, they may develop some DA of size, shape, number or structure.24
Disturbances in the morphodifferentiation stage of odontogenesis can provoke microdontia, where a smaller amount of cells are arranged to sketch the size of the tooth with an altered morphological pattern.25 In our study, in the CCS, the second molars and second premolars were the most affected teeth by microdontia, coinciding with other studies.9,26 In healthy individuals, microdontia is more prevalent in the upper lateral incisor and third molar.27