Sustained pacifier use is associated with smaller vocabulary sizes at 1 and 2 years of age: A cross-sectional study

Pacifier use during childhood has been hypothesized to interfere with language processing, but, to date, there is limited evidence revealing detrimental effects of prolonged pacifier use on infant vocabulary learning. In the present study, parents of 12- and 24-month-old infants were recruited in Oslo (Norway). The sample included 1187 monolingual full-term born (without visual, auditory, or cognitive impairments) infants: 452 (230 girls; 222 boys) 12-month-olds and 735 (345 girls; 390 boys) 24-month-olds. Parents filled out an online Norwegian Communicative Development Inventory (CDI), which assesses the vocabulary in comprehension and production for 12-month-old infants and in production only for 24-month-old infants. CDI scores were transformed into age- and sex-adjusted percentiles using Norwegian norms. Additionally, parents retrospectively reported their child's daytime pacifier use, in hours, at 2-month intervals, from birth to the assessment date. Maternal education was used to control, in the analyses, for the socio-economic status. We found that greater pacifier use in an infant's lifespan was associated with lower vocabulary size. Pacifier use later in life was more negatively associated with vocabulary size than precocious use, and increased the odds of being a low language scorer. In sum, our study moves beyond the findings of momentary effects of experimentally induced "impairment" in articulators' movement on speech perception and suggests that, from 12 months of age, constraints on the infant's speech articulators (pacifier use) may be negatively associated with word comprehension and production. RESEARCH HIGHLIGHT: 1.We examined the relationship between pacifier use and vocabulary sizes in production at 24 months of age and comprehension and production at 12 months of age. 2.Lifespan Pacifier Use (LPU) was negatively correlated with vocabulary sizes in comprehension and production among 12-month-old infants and negatively correlated with production for 24-month-olds. 3.Later pacifier use was found to be more negatively correlated with vocabulary size in infants, as compared to more precocious use. 4.The amount of pacifier use in the 2 months prior to a child's second birthday was predictive of a higher prevalence of low vocabulary scores in 24-month-olds.

Age of Bottle Cessation and BMI-for-Age Percentile among Children Aged Thirty-Six Months Participating in WIC

Background: Children's age at bottle weaning typically ranges from 12 to 24 months. The recommended age of bottle weaning varies. The American Academy of Pediatrics recommends weaning by 12 months; The American Academy of Pediatric Dentistry recommends 12-15 months; The US Department of Agriculture recommends 18 months. Prolonged bottle use is associated with dental caries, iron-deficiency anemia, and child overweight or obesity. We examined factors associated with age of bottle cessation, and the association between age of bottle cessation and BMI-for-age percentile at age 36 months among Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) participants. Methods: Data were from the WIC Infant and Toddler Feeding Practices Study-2 (ITFPS-2). The ITFPS-2, a longitudinal study of WIC participants (mothers and their children) began in 2013. We used Cox proportional hazards models to identify factors associated with bottle cessation and multivariate linear regression to examine the association between age of bottle cessation and BMI. Results: About 34% of children used a bottle longer than 12 months, and 13% longer than 18 months. Bottle cessation at older ages was associated with Hispanic ethnicity, multiparity, low income, low education, higher caregiver weight, and not initiating breastfeeding. The adjusted children's BMI-for-age percentile at age 36 months increased by 0.47 for each additional month of bottle use. Conclusion: Prolonged bottle use was associated with increased children's BMI-for-age percentile. Future research is warranted to determine the optimal age to recommend bottle cessation for WIC participants.

Does the duration and frequency of dummy (pacifier) use affect the development of speech?

BACKGROUND

The current literature suggests a link between dummy (or pacifier) use and a number of both positive and detrimental consequences. Positive consequences include soothing effect and protection from sudden infant death syndrome (SIDS), while negative ones include increased risk of otitis media and dental malformation. However, there is little research surrounding the impact of dummy use on the development of speech sounds.

AIMS

To investigate whether duration (in number of months) and frequency per day of dummy use have an individual or combined effect on the development of a child's speech, and if so, in what way.

METHODS & PROCEDURES

A total of 100 British-English children aged 24-61 months and growing up in the UK were recruited through nurseries, playgroups and by word of mouth. Their parents were asked to complete a questionnaire about the duration and frequency of dummy use and factors known to influence the development of speech. Following this, the children's speech was assessed using the phonology section of the Diagnostic Evaluation of Articulation and Phonology (DEAP). Analysis of the DEAP was conducted to determine the percentage of consonants correct, number of age-appropriate, delayed and atypical errors. Dummy use and speech outcome measures were then analysed qualitatively and quantitatively using mean and median group comparisons alongside multivariate generalized least squares and generalized negative binomial modelling approaches to test for significant associations.

OUTCOMES & RESULTS

The results showed that the majority of speech outcomes are not significantly associated with dummy use, however measured, in bivariate or multivariate analyses. However, there is a significant association between increased atypical errors and greater frequency of daytime dummy use. This association is strengthened by restricted sampling within the younger members of the sample, with this association not observable within children older than 38 months, the median sample age.

CONCLUSIONS & IMPLICATIONS

The evidence base for any effects of dummy use on speech is very small. Dummy use may increase the number of atypical speech errors a young child makes. However, only the frequency of daytime use seems relevant, not the duration or night-time use, and these errors may resolve over time. What this paper adds What is already known on this subject The use of a dummy with infants in Western countries is comparatively high (between 36-85%). A number of positive and detrimental consequences of dummy use have been documented in the literature; however, research on the effect of dummy use on speech development is significantly lacking. Past studies have included small sample sizes or used single measures of speech outcomes, which may not be specific enough to reveal how speech may be affected. Many speech and language therapists speculate that the use of a dummy could be contributing to many of the conditions they treat, yet this claim remains largely unsubstantiated. Clinical implications of this study The study suggests that only prolonged use of a dummy over several hours and during the day may start to show any impact on speech; even then, professionals need to be aware that the evidence base for any speech effects is very small. Clinicians and other professionals who parents consult on dummy use should make sure to provide both the pros and cons of dummy use, in order to enable parents to make an informed decision.

Toward a speech-motor account of the effect of Age of Pacifier Withdrawal

Recently published works suggest that prolonged pacifier use affects abstract word processing later in life. Using the pacifier beyond age 3 years affects the conceptual relations used to define the meaning of words at age 6 years. Similarly, when semantically categorizing a set of abstract, concrete and emotional words, children aged 8 years who used the pacifier for a longer period of time were slower to process abstract stimuli, but not concrete and emotional ones. The children of these studies had typical development and no diagnosis of cognitive or linguistic disorders. These results, although correlational, suggest a possible relationship between extended use of a pacifier and the development of language skills, particularly for abstract words. The first goal of this theoretical work is to outline current evidence suggesting an association between prolonged pacifier use and the processing of abstract words. The second goal is to propose an account of the effect of Age of Pacifier Withdrawal (APW) within the DIVA neurocomputational model of speech development and production (Guenther & Vladusich, 2013). Using the pacifier during social interaction for a longer period might impede the processing of proprioceptive information and speech-motor programs (i.e., by limiting the co-articulation of speech, it could inhibit the building and consolidation of speech-motor articulatory gestures) as well as auditory input (because the child receives inaccurate input about his/her own speech). Thus, it seems useful to explore the auditory speech representation of children who use a pacifier beyond 3 years of age. We suggest that after the first year of life pacifier use should be impeded during social interaction and limited to use at bed time.

Multidisciplinary Evaluation of Pacifier Removal on Oro-Dentofacial Structures: A Controlled Clinical Trial

It is well recognized that pacifier habit leads to occlusal and orofacial functional changes in children. However, the effects of the interruption of prolonged pacifier habit on the development of the dento-facial complex has not yet been fully characterized. Thus, the aim of this study was to investigate the influence of pacifier removal on aspects of oro-dentofacial morphology and function in preschool children. For that, a pacifier group (n = 28) and a control group (n = 32) of 4-year-old children with and without pacifier habit, respectively, were followed up by a group of dentists and speech therapists at baseline, 6 and 12 months after habit removal. Bite force and lip pressure were assessed using digital systems, and the evaluation of breathing and speech functions was performed using validated protocols, together with the measurements of dental casts and facial anthropometry. The Two-way mixed model ANOVA was used in data analysis. After 12 months, a decrease in malocclusion frequency was observed in pacifier group. Additionally, a change over time was observed in facial, intermolar and palate depth measurements, as well in bite and lip forces and speech function scores, increasing in both groups (p < 0.01). The upper and lower intercanine widths and breathing scores differed between groups at baseline and changed over time reducing the differences. The presence of speech distortions was more frequent in the pacifier group at baseline and decreased over time (p < 0.05). The interruption of pacifier habit improved the maxillary and mandibular intercanine widths, as well as the breathing and speech functions, overcoming the oro-dentofacial changes found. Trial Registration: This clinical trial was registered in the Brazilian Clinical Trials Registry (ReBEC; http://www.ensaiosclinicos.gov.br/), protocol no. RBR-728MJ2.