You may think your dental evaluation doesn’t start until you get in the chair and open your mouth wide, but the truth is, how your positioned at rest can relay a great deal of information to your dentist. One particular sign of muscle, joint, breathing and dental issues is “lip incompetence”.
Lip incompetence is an inability to maintain a lips together, closed mouth posture at rest and showing strain in the muscles around the face when a lip seal is attempted.
Lip Incompetence can result in changes in facial development, tooth eruption and alignment, breathing, swallowing and jaw joint function.
Facial development: Lip incompetence limits forward growth and increases vertical growth of the face and dental arches leading to a long face, narrow arches, gummy smile, recessed chin, droopy eyes, short upper lip and dimpling of the chin.
Tooth eruption and alignment: Teeth continue to erupt until they are in “occlusion”, when teeth meet together. With lip incompetence, teeth and dental arches lack adequate guidance from the occlusion, tongue position and orofacial muscle function. This leads to narrow arches, crowded teeth, and an open bite. Other orofacial muscles compensate for lack of lip seal and further alter the dental and facial development.
Jaw joint function: Normal “freeway space” between upper and lower back teeth is about 2-3mm (for reference there are 25mm in one inch). When that space is increased beyond normal for extending periods of time, teeth continue erupting causing more dental alignment issues. The jaw becomes recessed and the joint may become compressed. In contrast, once back teeth over erupt, teeth constantly together (decreased freeway space) causes pain and trauma to the teeth and jaw joint.
Tongue posture and swallowing: Lip incompetence is often accompanied by an abnormal, forward, interdental rest posture of the tongue. The tongue tends to come to the open space where teeth are separated, encouraging a thrusting swallow, further altering dental alignment and creating a dental open bite. This can also cause more air to be swallowed and a less efficient swallow leading to reflux, gas, bloating and stomach discomfort.
Breathing and health issues: Lip incompetence can be a sign of chronic nasal breathing, nasal obstruction, enlarged tonsils and adenoids or sleep disordered breathing. When the upper dental arch is developed high and narrow, it takes up space typically reserved for the nasal sinuses, further inhibiting nasal breathing.
Not only are the dental professionals at Dentistry by Dr. David trained to identify lip incompetence, but we are here to help! We have trained myofunctional therapists on our office who can help reprogram your lip and mouth posture. Lips continue to grow until approximately age 13, so retraining the lips and guiding proper growth is best done early for the most stable results. With that being said, adults are still able to benefit from the retraining of orofacial muscles for the sake of breathing, speech, proper swallowing, dental alignment and jaw position. Recapturing a normal resting dental vertical dimension is a primary goal Orofacial Myofunctional Therapy to prevent negative influence on dental eruption and facial growth. Establishing lips together rest posture through muscle resistance exercises can result in a repositioning of the tongue at rest into a normal position and is sometimes accompanied by a spontaneous reduction or elimination of tongue thrusting. Ask us about lip incompetence and what we can do to help. (978)779-2888