What Are Tongue Tie, Lip Tie & Oral Restrictions in Infants?

Infant oral restriction describes any structure in the mouth that limits normal movement. The most common causes of oral restriction in babies are tongue ties and lip ties.

A tongue tie (ankyloglossia) occurs when the thin tissue under the tongue, the lingual frenulum, restricts the tongue’s movement. When the tongue cannot lift, extend, or cup normally, feeding is often affected.

A lip tie occurs when the tissue connecting the upper lip to the gum restricts the lip from fully lifting. Babies with a restrictive lip tie may struggle to create a deep, secure latch at the breast or bottle.

How Do Oral Restrictions Affect Feeding?

When a baby cannot move the tongue or lip normally, common feeding challenges include:

• Painful latch

• Misshapen or creased nipples after feeds

• Clicking, smacking, or leaking milk while feeding

• Poor milk transfer

• Frequent or prolonged feeds

• Fussiness during letdown

• Reflux-like symptoms or excessive air intake

• Slow or plateaued weight gain

It's important to remember: all babies have frenula, but only some have ties. A frenulum is normal anatomy. It is only considered a tie when it:

1. Appears short, tight, or restrictive

2. Limits function

3. Causes symptoms

A clinical diagnosis should always include appearance + function + symptoms, not appearance alone.

Why Does Tongue Tie Happen?

The exact cause is still being studied. Research suggests tongue tie may be an embryological remnant, tissue that did not fully recede in utero. Some studies point to autosomal-dominant inheritance and potential involvement of mutated genes, though ongoing research continues to refine our understanding.

When Should Parents Seek an Evaluation?

If feeding is consistently painful, inefficient, or your baby is not gaining weight as expected, a feeding-focused evaluation is recommended. A comprehensive assessment includes oral anatomy, tongue and lip function, suck mechanics, and feeding behaviors at the breast or bottle.

Early support can make a tremendous difference for both parent and baby.

Sources

Acevedo AC et al. Autosomal dominant ankyloglossia and tooth number anomalies. J Dent Res. 2010.

Baeza C et al. Incidence and Prevalence of Tongue Tie. Clinical Lactation. 2017.

Han SH et al. Genetic inheritance of ankyloglossia. Arch Plast Surg. 2012.

Hazelbaker A. Tongue Tie. Aidan and Eva Press. 2010.

Healthy Children, American Academy of Pediatrics. Tongue Tie in Infants and Young Children. 2017.

Messner A et al. Clinical Consensus Statement on Ankyloglossia in Children. 2020.