Abstract  PURPOSE: Prolonged duration of non-nutritive sucking behaviors may have consequences in regard to the developing orofacial structures and occlusion. Little is known as to why some children have prolonged sucking habits beyond the first 2 to 3 years of life. This paper reports on non-nutritive sucking patterns among a large cohort of healthy children from birth to 36 months of age and older, and identifies factors predictive of prolonged non-nutritive sucking habits.

METHODS: Over 600 children were followed from birth to at least 36 months of age using mailed questionnaires sent when children reached the ages of 6 weeks, and 3, 6, 9, 12, 16, and 24 months, and then yearly thereafter. Parents answered questions concerning non-nutritive sucking behaviors including use of pacifier and digit sucking. The study categorized children who maintained habits to 36 months of age or older as having prolonged habits, and using multivariate analyses, compared them to children without prolonged habits on various sociodemographic variables.

RESULTS: The study found that for over 20% of the children, a non-nutritive sucking habit was prolonged to 36 months of age or older. Factors associated with prolonged sucking habits included older maternal age, higher maternal education level, and having no older siblings.

CONCLUSIONS: Identifying factors related to prolonged non-nutritive sucking habits may be important in developing and targeting recommendations regarding such behaviors in an effort to prevent malocclusions that result from prolonged sucking habits.

Abstract  The effect of stimulation (oral-gustatory with sucrose, tactile-bucal, and tactile-manual) on the frequency of hand contact with the oral (hand-mouth and hand sucking) and perioral (hands near the mouth) regions was compared in 24 full-term newborns. The 16-minute evaluation was divided into four equal periods, without intervals: (A) Baseline, no stimulation applied; (B) tactile-bucal, the newborn was allowed to suck the distal phalange of the researcher's little finger; (C) tactile-manual, the newborn was allowed to grasp the researcher's index finger; (D) 0.3 ml sucrose solution was administered orally to the newborns. After every three newborns were tested, the sequence of stimulation application was changed. The frequencies of the hand behaviors were calculated. It was observed that the sucrose significantly increased the frequency of hand sucking (p<0.05). Sucrose was, therefore, the most effective stimulus for eliciting the behavior of hand sucking.

Abstract  Detailed information on children's mouthing activities helps researchers assess children's exposure to toxicants via the non-dietary ingestion route (i.e., exposure resulting from contacts between the mouth and non-dietary objects such as fingers, toys, and dirt). For the analyses presented in this article, 38 children (20 female and 18 male) aged 1 to 6 years were videotaped for 2 hours each during natural play primarily in the outdoor residential environment. The data were analyzed separately by location (i.e., indoor or outdoor). For each location, mouthing frequency, contact duration, and hourly duration data were analyzed along gender and ≤ 24 months > 24 months age groupings. Several significant differences were found for mouthing activities occurring outdoors. Children ≤ 24 months of age were found to have significantly longer contact durations with the hands than children > 24 months of age (p = 0.04). Furthermore, for all ages, frequencies of mouthing contacts with the hands and non-dietary objects were significantly higher for girls than boys (p = 0.01 and p = 0.008, respectively). Girls also had significantly shorter hand-to-mouth contact durations than boys (p = 0.04). Although not statistically significant, mouthing frequencies with hands and non-dietary objects were higher indoors than outdoors while contact durations were similar between the two locations.

Abstract  Children's mouthing and food-handling activities were measured during a study of nondietary ingestion of pesticides in a south Texas community. Mouthing data on 52 children, ranging in age from 7 to 53 months, were collected using questionnaires and videotaping. Data on children's play and hand-washing habits were also collected. Children were grouped into four age categories: infants (7-12 months), 1-year-olds (13-24 months), 2-year-olds (25-36 months) and preschoolers (37-53 months). The frequency and type of events prompting hand washing did not vary by age category except for hand washing after using the bathroom; this increased with increasing age category. Reported contact with grass and dirt also increased with increasing age category. The median hourly hand-to-mouth frequency for the four age groups ranged from 9.9 to 19.4, with 2-year-olds having the lowest frequency and preschoolers having the highest. The median hourly object to mouth frequency ranged from 5.5 to 18.1 across the four age categories; the frequency decreased as age increased (adjusted R-2 = 0.179; P = 0.003). The median hourly hand-to-food frequency for the four age groups ranged from 10.0 to 16.1, with the highest frequency being observed in the 1-year-olds. Hand-to-mouth frequency was associated with food contact frequency, particularly for children over 12 months of age (adjusted R-2 = 0.291; P = 0.002). The frequency and duration of hand-to-mouth, object-to-mouth and food-handling behaviors were all greater indoors than outdoors. Infants were more likely to remain indoors than children in other age groups. The time children spent playing on the floor decreased with increasing age (adjusted R-2 = 0.096; P = 0.031). Parental assessment was correlated with hand-to-mouth activity but not with object-to-mouth activity. The highest combined (hand and object) mouthing rates were observed among infants, suggesting that this age group has the greatest potential for exposure to environmental toxins.

Abstract  This report provides a set of early-life stage age groups for U.S. Environmental Protection Agency (EPA, or the Agency) scientists to consider when assessing children's exposure to environmental contaminants and the resultant potential dose. These recommended age groups are based on current understanding of differences in behavior and physiology that may impact exposures in children. A consistent set of early-life age groups, supported by an underlying scientific rationale, is expected to improve Agency exposure and risk assessments for children by increasing the consistency and comparability of risk assessments across the Agency, improving accuracy and transparency in assessments for those cases where current practice might too broadly combine behaviorally and physiologically disparate age groups, and fostering a consistent approach to future exposure surveys and monitoring efforts to generate improved exposure factors for children.

Abstract  To determine whether a single intra-oral administration of sucrose would calm infants and elicit mouthing and hand-mouth contact, crying newborn and six-week-old infants were given sucrose solution before one feed and sterile water before another in a cross-over trial. Six-week-old infants were also given sucrose and water after feeding. For the newborn infants, the calming effect was rapid, substantial and lasted for at least four minutes. Mouthing and hand-mouth contact increased, but for shorter durations. For the six-week-old infants, sucrose calmed for one minute only before feeding, but had no effects on mouthing or hand-mouth contact. The results imply that intra-oral sucrose has acute age-related effects on crying and suckling-feeding behaviour mediated by a pre-absorptive mechanism. Sucrose may tap a functional system for reducing distress related to feeding and/or regulation of infant state.

Abstract  This research identifies a coordinative structure of action that integrates hand and mouth activities within hours after birth. Infants in the supine position received 7 presentations of 12% sucrose solution. Differences in hand–mouth coordination relative to preceding and succeeding epochs of nonsucrose presentation were striking: 32% of the sucrose period was spent by infants with hands inside the mouth or in contact with it, and 18%, for the same measures during periods of nonsucrose delivery. In addition the hand was brought to the mouth 50% more often during the sucrose period. These data provide evidence for oropharyngeal control over intergration of gross motor patterns of hand movement as they relate to the mouth. A possible functional significance of these findings is discussed.