It has been suggested that children in the Chilean Patagonia use milk bottles and pacifiers far beyond recommendations of health personnel. Of primary importance is answering the question, what type of feeding, breast or bottle, is better for oral cavity architecture and the influence on the acquisition of early speech. The development of oral motor structures is reflected on craniofacial development and dentition [1
]. To identify potential risk factors for speech disorders in children, there is a need to better understand the association between early life feeding and sucking behaviors and subsequent speech development.
The relationships between children's sucking habits and the impact on the development of their oral anatomy and functioning have been described in the literature. Agurto et al
studied 1,110 Chilean children between the ages of 3 to 6 years of age. They reported bad oral habits were associated with development of dentomaxilar anomalies [2
]. Linder and Modeer studied 76 four year old children to investigate the relationship between sucking habits (dummy or fingers) and dental characteristics in children with unilateral cross bite. The results indicated that duration and intensity of sucking habits may adversely influence dental characteristics by reducing the transverse width of the maxillary arch [3
Duncan et al
studied a cohort of 867 children using a family questionnaire on sucking habits at 15, 24, and 36 months of age and a dental examination at 31, 43, and 61 months of age. The results indicated that at 15 months, 63% of children had a sucking habit, 38% used just a dummy and 23% used a digit. By 36 months, sucking had reduced to 40% with similar prevalence of dummy and digit sucking. Both habits had effects on developing dentition, most notably on upper labial segment alignment and the development of anterior open bites and posterior cross bites [4
]. In one study [5
] involving 108 children, a significant association between children who were bottle fed and presence of anteroposterior malocclusion was reported. Breastfeeding was also found to decrease the risk of getting this type of malocclusion. The investigators noted that when bottle feeding occurs, only the buccinator muscles and the orbicular muscle(s) of the mouth are exerted without stimulating other muscles. They concluded sucking only during breastfeeding promotes correct muscle activity, and thus proper development of the oral motor structures [5
Broad performed a study in 1972 in Putaruru, New Zealand that examined the effects of infant feeding on speech quality [6
]. Broad investigated clarity of articulation, tonal quality, confidence, and reading ability in 5 and 6 year old children. There was a significant association between clarity of speech and breastfed males but not females, and breastfeeding was associated with improved tonal quality and reading ability of both males and females [6
]. Breastfeeding has been found to be beneficial in other studies of linguistic and cognitive development [7
]. The development of coordinated breathing, chewing, swallowing and speech articulation has also been shown to be associated with breastfeeding. It is believed that breastfeeding promotes mobility, strength, and posture of the speech organs. Such speech organs include: lips, tongue, maxilla, mandible, cheeks, soft palate, hard palate, dental arch, floor of mouth, and more. In order for speech development to occur, the child must suck with consistent rhythm and strength. Movements while sucking can cause absorption of the sucking pads and growth of the mandible. As a result, the intra-oral space increases [1
]. Moreover, studies have shown that breastfeeding protects normal dentition [8
Fox et al
in their study of German children with speech-disorders reported a significantly higher incidence of bottle and pacifier use compared to normal children [11
]. Children of industrialized western countries are more likely to use pacifiers and to feed using a bottle than children in developing countries. Over the last few decades, use of bottles and pacifiers has increased approximately 75% to 79% in the West [12
]. In non-industrialized countries such as Tanzania and Zimbabwe, pacifier use and finger sucking are less common or non-existent [14
]. This has also been found in families with lower social economic status. A study conducted in Santiago, Chile by Olguin and Quintana reported 28% of breastfed and 52% of non-breastfed children used pacifiers [15
]. They also found that mothers (88% of the time) were more likely to use of pacifiers without a specific reason for their use [15
]. It is reasonable to conclude that whether a child is breast or bottle fed depends on both cultural and economic factors.
From the above it is apparent that feeding-sucking behaviors and speech-oral anatomy development have positive and negative impacts on speech. In the current study we intended to move beyond assessment of oral musculature to the speech disorder that may impair communication and literacy [16
]. We describe an observational study designed to evaluate risk factors among pre-school Chilean Patagonia children focusing on past and present sucking behaviors as reported by their parents. We also sought to see the extent to which early feeding and sucking patterns might influence speech disorders.