it is estimated that there are 1.4 million blind children in the world , two - thirds of whom live in the developing countries . maintaining oral hygiene is one of the difficult tasks along with other tasks for visually impaired children . when compared with children with normal sight , the children with visual impairment will have poorer oral hygiene and high caries index . studies performed by anaise in israel , shaw et al . in uk , and purohit et al . in south india found poor oral health attributes among special care children . unfortunately , conventional methods of teaching maintenance of oral hygiene like using visual aids , disclosing agents does not help the visually impaired children who depend of touch and feel to learn . maintenance of oral health , removal of plaque , and proper brushing of teeth are the difficult tasks for these children . the difficulty in making the child understand to maintain oral hygiene and children following the instructions properly are the major hurdles . chemical plaque control , individual care and training for visually impaired children will help in maintaining oral health . even though these children are visually impaired , their true ability of understanding things is often unnoticed . oral hygiene instructions given to their understanding by any other means will improve their practice . braille is a tactile writing system used by the blind and the visually impaired people . there are a very few studies in which visually impaired children are given braille instructions for oral hygiene maintenance and their performances are evaluated . in this study , we compared the oral hygiene of visually impaired children who were given oral hygiene instructions in braille and audio recordings using the patient hygiene performance ( php ) index of podshadley and haley ( 1968 ) . prior to the study , ethical clearance was obtained from the institutional ethical committee of navodaya dental college and hospital , raichur , karnataka . the study design was explained to the district educational officer of raichur district and permission to conduct the study was obtained . permission was taken from a private residential institution for visually challenged children in raichur city after explaining the benefits of the study . a total of 50 children from the age group of 620 years were included in the study . the children with a recent history of dental treatment , systemic antibiotics or topical fluoride treatments 3 months prior to baseline , habitual use of dairy probiotics , xylitol chewing gums , severe medical conditions were excluded from the study . fifty visually impaired children with no systemic diseases and those who are not using probiotic products and any other oral hygiene supplements , such as mouthwashes , were included in this study . the children were randomly divided using chit selection into two equal groups ( n = 25)groups a and b. children in group a were given written instructions in braille and those in group b were given audio recordings . these children were instructed to use circular motion of brushing twice daily , to gargle with water after every meal , and to do regular flossing . they were also given soft manual toothbrushes and toothpaste ( colgate with 1000 ppm fluoride ) . the instructions on to how to brush and floss are given both in braille and audio instructions to the children as mentioned earlier . the children were given balanced diet meal throughout the study period and snacks in between meals are restricted . the resident school in - charge was keeping the track to make sure that all the children follow the instructions properly . after 7 days , the php index was taken to check the efficacy of children maintaining their oral hygiene and data were recorded . the children were instructed to continue the practice for 3 more months and then again the php index was checked . the data thus obtained were subjected to statistical analysis by using student 's paired t - test and turkey 's honest significant difference ( hsd ) test was applied for multiple comparisons . the results were tabulated and statistical analysis was performed using statistical package for the social sciences ( spss ) version 17.0 ( spss inc . 233 south wacker drive , 11 floor , chicago , ii , 60606 - 6412 ) . table 1 depicts the comparison of the php index between the two groups at baseline , 7 days , and 3 months . the mean php score of group a at baseline was 3.88 compared to 3.90 of group b. at 7 days , the php scores of group a and group b were 3.42 and 3.45 , respectively . at 3 months , the php scores of group a and group b were 2.47 and 2.86 , respectively . even though over a period of time the mean score of php index reduced the score comparison between the two groups were not statistically significant . average oral hygiene at baseline , 7 days , and after 3 months table 2 depicts the comparison of php index within the group at baseline , 7 days , and 3 months . in group a , the mean difference of php score between the baseline and 7 days was 0.46 , between the baseline and 3 months it was 1.40 . b , the mean difference of php score between baseline and 7 days was 0.44 , between baseline and 3 months it was 1.03 . the best and the most beautiful things in the world can not be seen or even touched . oral health is a vital component of overall health , which contributes to each individual 's well - being and quality of life by positively affecting physical and mental healthiness , appearance , and interpersonal relations . the oral health of children who are visually impaired tends to be compromised as they are at a disadvantage and are often unable to adequately apply the techniques necessary to control plaque . providing comprehensive dental care for the visually impaired children is like a community service and also rewarding to the health - care providers . often dental plaque is the main reason for the development of periodontal diseases and dental caries . early signs of oral diseases may be unnoticed and not possible for people with low vision , and because of this they may not be able to take the necessary action to prevent or treat a particular oral condition . , we compared the oral hygiene status using php index of podshadley and haley among institutionalized visually impaired children aged between 6 years and 20 years given with braille and audio instructions . persons with disabilities ( equal opportunities , protection of rights and full participation ) act , 1995 ,  which defines  blindness  as a condition where a person suffers from total absence of sight or visual acuity not exceeding 6/60 or 20/200 in the better eye even with correction lenses or limitation of the field of vision subtending an angle of 20 or worse . even though both the groups showed decrease in plaque score , inter - group comparison of php index score was not statistically significant . in a study conducted by mendona , it was stated that the absence of visual stimuli prevents rapid learning , representing a challenge for surgeons and dentists in motivating these individuals to have appropriate oral hygiene . however , it is arguable that , when well - trained , blind children are able to learn the brushing techniques , thus maintaining good oral condition . the present study showed a decrease in the mean plaque scores ( that is increase in mean difference of php score ) at all time intervals in individual group as compared to the baseline that was statistically significant . this shows that a proper method of educating the visually impaired children will decrease the plaque score that in turn will improve the oral hygiene [ figure 1 ] . confirm that there was marked reduction in rates of biofilm and good oral hygiene can be achieved by the usage of appropriate brushing techniques . proper education and motivation were the key behind this success in these visually impaired children . vargas and goulart in their study showed that , even though they can not see it , visually impaired patients do express concerns about the functional aspects of oral cavity . these individuals understand the functional importance of the teeth and mouth , citing the pain as the main factor in seeking care . the aesthetic aspect of oral hygiene is rarely mentioned and seems to have less relevance to these individuals . visually impaired people have equal right to have a good oral health and social care information needs which are worthy of exploration . visual impairment may have an impact on the access to dental care and oral health information . the present study shows improvement of oral health status in both the study population by the decreasing the mean plaque score . hence , continuous motivation and reinforcement in the form of braille and audio instruction are essential to achieve good oral hygiene levels in visually impaired children . further , long - term study on larger population has to be conducted to obtain a result that will differentiate statistically between the motivational tools for visually impaired children .
aim : the aim of this study is to compare the oral hygiene status among institutionalized visually impaired children of age between 6 and 20 years given with braille and audio instructions in raichur city of karnataka.materials and methods : a total of 50 children aged between 6 to 20 years were included in this study from a residential school for visually impaired children . 
 these children were randomly divided into two equal groups . 
 one group was given oral hygiene instructions by audio recordings and another written in braille and were instructed to practice the same . after three months time the oral hygiene status and dental caries experience was recorded and compared using patient performance index . 
 statistical analysis was done by student paired t test and multiple comparison by tukey 's hsd ( honest significant difference ) test.results:the mean php ( patient hygiene performance ) score of group a at baseline was 3.88 compared to 3.90 of group b. at 7 days php score of group a and group b was 3.42 and 3.45 respectively . at 3 month php score of group a and group b was 2.47 and 2.86 respectively . 
 even though over a period of time the mean score of php index reduced the score comparison between the 2 groups were statistically non significant . in group 
 a the mean difference of php score between baseline and 7 days was 0.46 , between baseline and 3 months it was 1.40 . 
 the php score between 7 days and 3 months was 0.94 . 
 all the above values were statistically significant.conclusion:effective dental health education method has to be instituted for visually impaired children . 
 the present study shows improvement of oral health status in both the study population by decrease in the mean plaque score . hence continuous motivation and reinforcement in the form of braille and audio instruction is beneficial to achieve good oral hygiene levels in visually impaired children 
 .