Infant Oral Anatomy: Structure, Function and Feeding

Your baby’s mouth is made up of several structures that work together for feeding, swallowing, breathing and early oral development. The lips, cheeks, gums, palate, tongue and the structures around them all have different roles, but they do not work independently.

There is also considerable normal variation in infant oral anatomy. The appearance of one structure does not necessarily tell you how well it is functioning.

Anatomy provides information. Function provides context.

Understanding the different parts of your baby’s mouth can help you recognise what is normal, what may vary between babies, and when a feeding or oral assessment may be helpful.

The lips

Your baby’s lips are muscular structures that help create a seal around the breast or bottle during feeding. They also contribute to sucking, controlling milk flow and coordinating movements of the mouth.

The appearance and tone of the lips can vary between babies. You may notice differences in lip colour, posture or how tightly or loosely the lips rest together. These observations need to be considered alongside feeding and oral function rather than interpreted in isolation.

Some babies develop a small sucking blister or callus on the upper lip. This can occur as a result of repeated friction or pressure during feeding and is often a normal finding.

There is also a fold of tissue called the upper labial frenulum, which connects the inside of the upper lip with the gum. Its appearance varies considerably between babies. A prominent upper labial frenulum is not, by itself, evidence that it is causing a feeding problem.

The term “lip-tie” is sometimes used when the upper labial frenulum appears to restrict movement of the lip. However, the appearance of the frenulum alone does not establish that feeding is being affected, and the evidence regarding lip-tie as a cause of breastfeeding or bottle-feeding difficulties remains limited.

For more information, see Lip-tie: what does it actually mean?

The cheeks

Your baby’s cheeks provide support and stability during feeding. The cheeks contain specialised fat pads, sometimes referred to as buccal fat pads, which are particularly prominent in young infants.

These structures help maintain the shape and stability of the cheeks while your baby sucks. The cheeks also work with the lips, jaw and tongue to help create and maintain an effective oral seal.

You may come across the term “buccal tie”, referring to a fold of tissue within the cheek. This is an emerging term and there is currently no published evidence establishing that a so-called buccal-tie causes breastfeeding or bottle-feeding problems.

The Association of Tongue-tie Practitioners currently states that there is no published evidence supporting a link between lip-tie or buccal-tie and breastfeeding or bottle-feeding difficulties (ATP, 2026).

The gums and developing teeth

A newborn baby’s gums are covered by soft gum ridges. Beneath these are the developing primary teeth, which are also called deciduous or milk teeth.

Although most babies begin to show their first teeth at around six months, there is considerable normal variation.

Occasionally, a baby is born with a tooth already present. This is called a natal tooth. A tooth that erupts during the first 30 days after birth is generally described as a neonatal tooth.

These teeth are usually part of the normal primary dentition. Most do not require treatment, but a dental or medical assessment may be appropriate if a tooth is very mobile, creates a risk of aspiration, or causes injury to the baby’s tongue or difficulty with feeding.

The palate: the roof of the mouth and floor of the nose

The palate forms the roof of your baby’s mouth. The front portion is the hard palate, which is formed from bone. The posterior portion is the soft palate, which contains muscle and can move during swallowing.

The palate also forms much of the floor of the nasal cavity, so the mouth and nose are anatomically very closely related.

Palate shape varies between babies. Some babies have a relatively broad and shallow palate, while others have a higher or narrower palate.

A high or narrow palate does not automatically mean that a baby will have feeding or breathing difficulties. However, palate shape can influence the space available for tongue movement and the relationship between the tongue, palate, jaw and other oral structures.

The tongue also changes position as babies develop, and its resting position and movement need to be considered alongside the shape of the palate and the overall pattern of oral function.

For more information, see Understanding your baby’s resting tongue posture.

The tongue

The tongue is a highly specialised muscular structure made up of intrinsic and extrinsic muscles.

These muscles allow the tongue to change shape, move forwards and backwards, elevate, depress and move from side to side. The tongue is involved in sucking, swallowing, early oral development and the management of milk within the mouth.

The tongue does not function in isolation. Its movement and resting position are influenced by the palate, jaw, lips, cheeks and surrounding soft tissues.

During early infancy, breathing is predominantly nasal. The tongue, jaw and surrounding oral structures have a close relationship with the upper airway, but a particular tongue resting position should not be interpreted as a simple test of whether a baby can breathe effectively through their nose.

As babies grow and develop, their oral structures and motor skills also change. What is seen in a newborn should therefore be considered within the context of their age and developmental stage.

The floor of the mouth and lingual frenulum

The floor of the mouth contains several important structures, including muscles, glands, nerves and connective tissues.

A fold of tissue called the lingual frenulum can be seen beneath the tongue. Frenula are normal anatomical structures and their appearance varies considerably between individuals.

Seeing a frenulum does not mean that a baby has a tongue-tie.

The term ankyloglossia, commonly called tongue-tie, is generally used when a restrictive lingual frenulum limits tongue movement and affects function.

This means that the presence and appearance of a frenulum should not be assessed separately from what the tongue can actually do.

For more information, see What is a tongue-tie?.

Other oral frenula

Frenula are folds of tissue found at several locations in the body. Within the mouth, you may see or feel frenula connecting the lips or cheeks with the surrounding oral tissues.

The upper and lower labial frenula are visible between the lips and gums. Small buccal frenula may also be visible within the cheeks.

The appearance of these structures varies naturally between babies.

Terms such as “lip-tie” and “buccal-tie” are increasingly used to describe particular appearances or perceived restrictions. However, terminology does not establish function, and current evidence does not demonstrate that these findings cause breastfeeding or bottle-feeding difficulties.

The ATP’s 2026 position statement specifically notes that there is currently no published evidence supporting a link between lip-tie or buccal-tie and breastfeeding or bottle-feeding issues (ATP, 2026).

Other things you may see inside your baby’s mouth

There are several normal or relatively common findings that may be seen when looking inside a newborn or young baby’s mouth.

Epstein pearls

Epstein pearls are small white or yellowish cysts that can appear along the gums or roof of the mouth. They are common in newborn babies and are harmless. They usually disappear without treatment.

Bohn’s nodules and dental lamina cysts

Other small cysts can occur around the gums or palate. Bohn’s nodules and dental lamina cysts are benign developmental findings and generally resolve naturally.

The terminology used to describe these cysts can sometimes overlap, which is why they may be given different names depending on their location and appearance.

Tonsillar tissue

Tonsillar tissue is part of the immune system and forms part of the tissues surrounding the entrance to the throat. It is normal for these structures to be present, although their appearance changes as children grow.

Cleft lip and palate

A cleft lip or cleft palate occurs when structures of the lip and/or palate do not join together completely during development before birth.

The presentation varies considerably. Some clefts are immediately visible, while others may involve only part of the palate.

Babies with a cleft affecting the palate may require additional feeding support because the separation between the mouth and nasal cavity can affect their ability to create the pressure needed for feeding.

Other unusual findings

Occasionally, a baby may have a lesion, swelling or other finding that is not part of normal oral variation. Anything that is persistent, enlarging, bleeding, painful, associated with feeding difficulties, or affecting breathing or swallowing should be assessed by an appropriate healthcare professional.

Facial shape, birth and developing muscle tone

The appearance of a baby’s face and mouth is influenced by many factors.

Before birth, a baby’s position within the uterus can influence temporary shaping of the head and face. Birth itself can also be associated with temporary moulding, swelling or asymmetry.

These changes usually settle as the baby adapts after birth.

Genetics, growth and development also influence facial shape. Muscle tone and soft-tissue tension can affect how the jaw, lips, cheeks and tongue are positioned and how they move.

This does not mean that a particular mode of birth causes oral dysfunction. Birth history is simply one part of the wider picture that may be considered when looking at a baby’s early oral function.

How does a baby swallow?

Feeding requires the baby to coordinate several systems at the same time.

During breastfeeding or bottle feeding, a baby needs to coordinate sucking, swallowing and breathing. Milk must be collected and managed within the mouth before the swallow is initiated, while the airway is protected as the swallow occurs.

This coordination develops rapidly during infancy and is influenced by neurological maturity, oral motor skills, milk flow and the physical characteristics of the feeding method.

Some signs that may indicate that a feeding and swallowing assessment would be helpful include:

• repeated coughing or spluttering during feeds

• repeated choking episodes

• changes in breathing during feeding

• colour changes during feeds

• persistent wet or noisy breathing after feeding

• significant difficulty coordinating sucking, swallowing and breathing

• becoming excessively tired during feeds

• consistently prolonged feeds

These signs are not specific to one particular condition. They should be considered alongside the baby’s age, development, feeding history, growth and overall presentation.

Oral anatomy, feeding and breathing

Breastfeeding and bottle feeding both require coordinated use of the lips, cheeks, jaw and tongue.

The palate provides a stable surface against which the tongue can move, while the lips and cheeks contribute to the oral seal. The tongue helps manage milk within the mouth and participates in the movements required for swallowing.

Breathing also has to be coordinated with feeding.

This is why looking at one anatomical structure in isolation can sometimes give an incomplete picture. A visible difference does not necessarily indicate a functional problem, and an apparently typical structure does not guarantee that feeding will be comfortable or efficient.

For more information about oral function and feeding, see A guide to understanding your baby’s oral function.

When might your baby benefit from an oral or feeding assessment?

If you have concerns about your baby’s feeding, swallowing, oral movements, breathing or the appearance of their mouth, an assessment can help put the findings into context.

Assessment may include looking at:

• how your baby feeds at the breast or from a bottle

• positioning and attachment

• milk transfer

• the movement and function of the lips, cheeks, jaw and tongue

• oral tone and coordination

• swallowing and suck–swallow–breathe coordination

• resting oral posture

• palate shape

• your baby’s growth and development

• your experience of feeding and any difficulties you are noticing

An IBCLC can assess breastfeeding and feeding mechanics and can identify when further assessment or referral may be appropriate. Other healthcare professionals may also be involved depending on the concern.

It is not recommended to try to diagnose an oral restriction or other oral condition from photographs or by comparing your baby’s mouth with pictures online.

For more information, see Who can assess a baby’s feeding and oral function?.

Looking at the whole picture

Your baby’s mouth is a connected system rather than a collection of separate structures.

The lips, cheeks, jaw, palate, tongue, gums and developing teeth all have their own anatomy and roles, but they also interact during feeding, swallowing, breathing and development.

When considering whether something is significant, it is therefore helpful to look beyond what a structure looks like and consider how your baby is functioning.

This includes feeding, breathing, oral movement, resting posture, muscle tone, symmetry, growth, development and, importantly, the experience of the feeding dyad.

A finding can be anatomically interesting without being a problem.

Equally, a baby can have an apparently uncomplicated oral examination while still experiencing feeding difficulties that deserve further assessment.

The aim is not simply to identify differences. It is to understand what those differences mean in the context of the individual baby.

References

Association of Tongue-tie Practitioners (ATP) (2026) Lip-tie and Buccal-tie Position Statement. Available at: https://www.tongue-tie.org.uk/position-statements (Accessed: 19 September 2026).

Bode-Johnson, F. et al. (2020) ‘Neonatal oral findings and their significance’, Journal of Paediatrics and Child Health.

MedlinePlus (2026) ‘Epstein pearls’. U.S. National Library of Medicine.

Messner, A.H. et al. (2020) ‘Ankyloglossia in children: a multidisciplinary approach to diagnosis and management’, Otolaryngology–Head and Neck Surgery, 162(5), pp. 597–611.

Mills, N. et al. (2019a) ‘What is a tongue tie? Defining the anatomy of the in-situ lingual frenulum’, Clinical Anatomy, 32(6), pp. 749–761.

Mills, N. et al. (2019b) ‘Defining the anatomy of the neonatal lingual frenulum’, Clinical Anatomy, 32(6), pp. 824–835.

Neville, B.W. et al. (2016) Oral and Maxillofacial Pathology. 4th edn. St Louis: Elsevier.

Stanford Medicine Newborn Nursery (n.d.) ‘Mouth’. Stanford University School of Medicine.