pain is a highly complex , dynamic , subjective experience that is useful in growing children , serving to warn them of danger and limiting exposure to additional injury . however , untreated , acute , or recurrent or chronic pain may have significant and lifelong consequences ( both physiologically and psychologically ) . since pain is an inherently subjective phenomenon , it is often said that the gold standard for pain assessment in both children and adults is verbal reporting [ 13 ] . it is the only way to determine the intensity and quality of the pain present . however , reliable description in children especially in intellectually disabled ( i d ) children is very difficult . children with intellectual disability have an added challenge of not being able to express the pain or verbalize it . hence , to gather pain relevant information , caregivers were interviewed regarding their children for expression of pain , experience , treatment , and coping behavior . research shows that children with developmental disabilities generally experience more pain than the normal children due to chronic systemic conditions associated with their disability [ 46 ] . many children have idiosyncratic behaviors such as moaning / grunting which may lead to over / underestimation of pain . the aim of the study was to evaluate the dental pain in children with intellectual disabilities from a caregiver 's perspective . the study was initiated after obtaining clearance from the institutional ethics committee , chettinad health city . they were residing at vasantham institution for intellectually disabled children , mogappair , chennai , tamil nadu , india . all the children in the control group were of normal intellectual growth as determined by their academic evaluations . age group ranged from 5 to 18 years.the study group has a history of intellectual disability as verified by the child 's medical file or caregivers reporting.caregivers were able to understand spoken english / tamil.the control group included children who had normal intellectual development . the study group has a history of intellectual disability as verified by the child 's medical file or caregivers reporting . the nature of the study was explained and the investigators assisted them in filling the questionnaire . to assess the change in behavior in intellectually disabled children during tooth ache , a dental discomfort questionnaire ( ddq+ ) was developed . the questionnaire was drafted after extensive interviews with parents or caregivers of children with pain by versloot et al . a lot of questions relating to the behavior of intellectually disabled children were added to the ddq+ . the questionnaire was filled during the interviews by the caregivers with the help of the investigators . the questions were tabulated and the caregivers had to select the most appropriate option that explained the occurrence of pain / discomfort in children . ( scored as one ) , and  always  ( scored as two ) . a total numeric mean for each child and a mean of the ddq+ for the group caregivers and investigators were also asked to rate the child 's dental pain on a ten point scale where  zero  represented the absence of pain and  ten  the maximum pain imaginable . the scale was converted to an ordinal scale with never , mild , moderate , and severe categories . mild pain was when the rating was between 1 and 3 , moderate was between 4 and 7 , and severe pain was between 8 and 10 . the caries examination was based on the  who  criteria according to which the dmft / dft ( decayed , missing , and filled teeth ) indices were scored . a frank cavitation which is a break of 0.5  mm or more into enamel any teeth filled with any restoration except sealants were considered as  filled  teeth . student 's t - test , degree of freedom , mean and standard deviation , and chi - square test were analyzed . the sample investigated in this study was a total of 236 children , out of which 111 were intellectually disabled children and 125 were healthy children . the dmft and dft scores of the sample investigated were tabulated ( table 1 ) . the difference in the number of filled teeth between the study and control group was negligible . the investigators put forward questions describing the specific behavioral pattern of the children experiencing dental pain . these questions were presented to the caregivers in order to find out the perception of dental pain between the control and study group and whether it was comparable . the behavioral pattern which was specifically exhibited by the children during dental pain was documented as per the caregiver 's perception . outcome of the tabulation in this study showed that i d children had problems in brushing teeth especially the upper teeth and it was statistically significant ( p = 0.00 ) . the other significant change during pain included biting with the molar instead of the other teeth ( p = 0.001 ) . most of the i d children reached for the cheek region while eating , a behavioral change depicting vague dental pain which they were unable to express otherwise . typically developing children reported ear pain at night ( p = 0.014 ) , during daytime ( p = 0.02 ) , and a few while eating ( p = 0.01 ) . in the entire study , excessive salivation in i d children during dental pain ( p = 0.00 ) was one of the most important behavioral changes observed by the caregivers . adding to this , the other significant behavioral change was the habit of placing their hand or objects inside the mouth ( p = 0.00 ) ( table 2 ) . according to the international association for study of pain ( iasp ) , pain is defined as  an unpleasant sensory and emotional experience associated with actual or partial tissue damage . a reliable description of such pain is generally difficult in children and even more challenging in i d children . intellectual disability is defined as mental retardation or impairment in the areas of development or cognitive activities . intellectual disability is  a disability characterized by significant limitations both in intellectual functioning and in adaptive behavior , which covers many everyday social and practical skills . dental problems are more common in people with special needs , sometimes not only because of the disability itself but also because of inadequate oral health care . these special children required special health care approaches as they had very poor oral hygiene . according to research and the literature , these children had physical , mental , sensory , behavioral , cognitive , emotional , and chronic medical conditions which required health care beyond the usual measures and which involved specialized knowledge , increased awareness , attention , and accommodation . information about pain in children with cognitive impairment was always insufficient and less reliable for a dentist [ 1113 ] . to gather any data related to pain the investigators or health care provider had to rely on the caregiver 's perception depending on the level of cognitive impairment , and pain coping and expression varied in these special children . the identification and interpretation of dental pain in severe cognitive communication and motor impairments were challenging . we concluded that there is a high incidence of dental pain and treatment needs that are not catered to . in spite of parents and caregiver 's educational qualifications , dental pain is rarely understood and treated ; this was due to the other major chronic systemic illnesses the children undergo . hence , dental pain in children goes unnoticed often and they are not brought to the dentist for routine checkup . mostly caregivers identify dental pain based on the i d children change in behavior and bring it to the notice of the healthcare provider . hence , mostly i d children reach the dentist in an acute state of pain leaving very few options to save the teeth . the data outcome of this study indicates that i d children have problem in brushing upper and lower teeth . this was because of fear and anxiety amongst intellectually disabled children in placing a foreign object into their mouth . children should be trained patiently to overcome these problems which require a dentist 's and a caregiver 's cooperation . reaching for cheek while eating and earache at night or during meals were also common behavioral changes during dental pain . the caregivers should understand these signs and bring the children to the dentist immediately because the pain expressed in such manner is mostly of acute nature . most of the i d children had excessive salivation and the habit of placing their hand or objects inside the mouth during dental pain . according to researches , an increase in dental caries causes more dental pain which leads to these pain related behavior . so caregivers and dentists have to work mutually to recognize specific changes in behavioral pattern . though this study was done based on research articles specializing on pediatric dentistry and cognitive impairment in children , it still had a number of limitations which include lack of professional assessment of i d children . future studies including the comparison between different degrees of intellectual disability could further provide more specific conclusions . intellectually disabled children had more problems in brushing upper teeth and exhibited the habit of reaching for the cheek while eating . the prevalence of reporting dental pain was more in typically developing children than in intellectually disabled children .