Baby won’t close mouth [Reasons & Solutions]

Verified by Edna Skopljak MD
Verified by Edna Skopljak MD

Edna Skopljak is a medical doctor and an editor at BJBMS medical journal. She graduated from the University of Sarajevo School of Science and Technology.

As a new parent or caregiver, it’s natural to be attentive to your baby’s every move and development. One aspect that can be puzzling is when your little one appears to constantly have their mouth open. Rest assured, you’re not alone in your concerns.

Many parents wonder why their baby won’t close their mouth and what it could mean. In this article, we’ll discuss possible reasons for this behavior, when to seek professional help, and strategies to encourage mouth closure.

Our goal is to provide a friendly, empathetic guide to help you understand and support your baby’s oral development.

Possible reasons for a baby not closing their mouth

Oral motor development and muscle tone

As your baby grows, they are constantly learning and developing new skills, including control over their facial muscles.

It’s important to remember that each child’s development is unique, and your baby may simply be taking their time to build muscle tone and control in their mouth.

It’s not uncommon for babies to have their mouths open as they practice and refine their oral motor skills.

Breathing issues

Sometimes, a baby may keep their mouth open due to difficulty breathing through their nose. This could be caused by temporary issues such as nasal congestion or more chronic problems like allergies.

If you suspect your baby is having trouble breathing, it’s essential to consult your pediatrician for guidance and possible treatments.


Teething can cause your baby to have their mouth open more frequently as they experience new sensations in their gums.

The pressure of emerging teeth can lead to increased drooling, and keeping their mouth open may provide some relief. While teething can be uncomfortable for your little one, it is a normal part of their development.

Sensory processing and exploration

Babies are constantly discovering and exploring the world around them, and their mouths play a significant role in this process.

An open-mouth posture could be your baby’s way of exploring new textures, tastes, and sensations. This curiosity is a healthy part of their growth and development, so try not to worry too much.

In conclusion, there are various reasons why your baby might not be closing their mouth, ranging from developmental milestones to temporary discomfort. Understanding these potential causes can help you better support your baby as they grow and develop.

When to seek professional help

While many of the reasons for a baby not closing their mouth can be attributed to normal development, there are instances when it might be necessary to consult a professional. Here are a few scenarios to watch for:

Persistent open-mouth posture

If your baby consistently keeps their mouth open and shows no sign of improvement over time, it may be worth discussing the issue with your pediatrician.

They can assess whether there’s an underlying issue that needs to be addressed or if it’s simply a matter of your baby’s unique developmental timeline.

Signs of breathing difficulties or feeding problems

Monitor your baby for any signs of breathing difficulties or feeding problems, such as frequent coughing, choking, or difficulty latching while breastfeeding or taking a bottle.

If you notice any of these issues, it’s crucial to consult your pediatrician, as they may indicate an underlying health concern that needs prompt attention.

Developmental delays

If your baby is showing signs of developmental delays in other areas, such as motor skills, speech, or social interactions, it’s essential to discuss these concerns with your pediatrician.

They can help determine if the open-mouth posture is related to a broader developmental issue and guide you on the appropriate steps to support your child’s growth.

Remember that every baby is unique, and reaching out for professional help is a responsible and caring action to take. Your pediatrician is there to support you and your baby on this journey, so don’t hesitate to voice your concerns and seek guidance when needed.

Strategies to encourage mouth closure

If you’re looking for ways to gently encourage your baby to close their mouth, there are several strategies you can try.

Remember to be patient and supportive as your little one learns and grows.

Oral motor exercises and activities

Engaging your baby in activities that promote oral motor development can help strengthen their facial muscles and encourage mouth closure.

For instance, you can offer teething toys, encourage your baby to make different facial expressions, or help them practice blowing on a toy windmill.

Always ensure that any objects used for these activities are age-appropriate and safe for your baby.

Tummy time and positional changes

Incorporating tummy time and varying your baby’s position throughout the day can help promote better overall muscle tone, including the muscles in their face and mouth.

Tummy time encourages your baby to lift their head and engage their neck and facial muscles, which can contribute to improved oral motor control.

Parental modeling and positive reinforcement

As your baby’s primary role model, you can play a significant role in encouraging mouth closure by demonstrating appropriate behaviors.

Exaggerate closing your mouth when you’re eating, speaking, or at rest, and offer praise and encouragement when your baby mimics your behavior.

Positive reinforcement can go a long way in helping your little one develop healthy oral habits.

By being proactive and supportive, you can help your baby develop the necessary skills to close their mouth effectively.

Keep in mind that it’s essential to be patient and understanding as your baby learns and grows at their own pace.


As parents and caregivers, it’s natural to worry about every aspect of our baby’s growth and development.

When it comes to your baby not closing their mouth, it’s essential to remember that there could be various reasons for this behavior, many of which are a normal part of their development.

By understanding the possible causes and knowing when to seek professional help, you can provide the best support for your little one.

Always approach your baby’s development with patience, empathy, and love, and try implementing some of the strategies mentioned above to gently encourage mouth closure.

Remember that every baby is unique, and your understanding and support will go a long way in helping your child grow and thrive.