The Study of Parental Toothbrushing Efficacy Assessment With Triple-Headed and Single-Headed Toothbrushes in Preschool Children With Developmental Disability

Inclusion Criteria: * Developmental disability children aged 3 to 6 years old who have full primary dentition. * The caregivers who responsible for brushing their child's teeth that must be the same person throughout the study and able to attend both study sessions Exclusion Criteria: * Developmental disability children who have periodontal disease, soft tissue ulcers or gingival abscess. * Developmental disability children who have missing tooth more than one tooth per sextant. * Developmental disability children who have definitely negative behavior (Frankl behavior rating scale one) (89) during oral examination * Parents of Developmental disability children who have a physical or mental disability which may influence to their brushing ability.