Should babies be given pacifiers or be allowed to suck their thumbs?

This question has perplexed generations of mums and dads.

Concerns centre on whether sucking habits will impact tooth alignment and speech development.

A study published last week suggested that long-term pacifier use, thumb-sucking and even early bottle use increases the risk of speech disorders in children, reported the Los Angeles Times.

The researchers looked at the association between sucking behaviours and speech disorders in 128 children, aged three to five years old, in Chile.

They found that delaying bottle use until a child was at least nine months old reduced the risk of developing a speech disorder.

However, children who sucked their thumbs, fingers or used a pacifier for more than three years were three times as likely to develop speech impediments.

Breastfeeding did not have a detrimental effect on speech development.

The authors of the study, which was published in the journal BMC Pediatrics, noted that other research suggested that the use of a pacifier or thumb-sucking for less than three years also increases the risk of a speech problem.

The sucking motion may change the normal shape of the dental arch and bite.

However, breastfeeding seems to promote positive oral development.

'It is believed that breastfeeding promotes the mobility, strength and posture of the speech organs," the scientists wrote.

This article was first published in Mind Your Body, The Straits Times.