Mewing is a technique promoted online to achieve correct resting tongue posture, aiming to alter facial structure over time. Rooted in the principles of orthotropics, this practice emphasizes the consistent placement of the tongue against the roof of the mouth. Credible scientific research has not proven the efficacy of mewing in significantly reshaping facial bones, especially in adults. Despite the lack of robust clinical evidence, the discussion focuses heavily on achieving optimal oral posture, which leads to a fundamental question: should the upper and lower teeth touch during this process?
Defining the Ideal Jaw Resting Posture
The short answer is that your teeth should not be forcefully touching or clenching during the correct jaw resting posture associated with mewing. The jaw should remain relaxed, a state that naturally creates a slight separation between the upper and lower teeth. Professionals refer to this natural space as the “freeway space” or “interocclusal clearance.”
This gap is a biological necessity that allows the jaw muscles to rest and recover from the constant micro-movements of speaking and chewing. The typical measurement for this slight separation is approximately two to four millimeters at the molars. When the jaw is in this relaxed position, the lips should be closed gently and without strain, maintaining a soft seal. While your teeth should not be in sustained contact, light, momentary contact might occur naturally during the act of swallowing saliva.
The Role of Proper Tongue Placement
The relaxed jaw posture is a direct result of achieving the correct tongue position against the palate, which is the core action of mewing. The technique requires positioning the entire dorsal surface, or body, of the tongue against the hard palate, which is the roof of the mouth. This includes ensuring that the back third of the tongue is engaged and lifted, not just the tip.
Practitioners often recommend using a swallowing motion to help learn this posture, as the tongue naturally presses against the palate during a proper swallow. Another method is to make the “N” sound, which naturally guides the tongue’s tip to the correct spot just behind the front teeth without touching them. Once the tongue is fully suctioned against the palate, it exerts a gentle, consistent pressure upward.
This pressure helps elevate the lower jaw into the correct resting position while the jaw muscles remain relaxed. The goal is for this position to become the unconscious, habitual rest state, supporting nasal breathing and optimal muscle function.
Potential Implications of Incorrect Jaw Position
Failing to maintain the correct, relaxed jaw position can lead to several negative physical consequences. If the teeth are forcefully touching or the jaw is held too tensely, this constitutes clenching, a form of bruxism. Sustained clenching places undue stress on the temporomandibular joints (TMJ), which can result in jaw pain, chronic headaches, and increased muscle fatigue.
Hyper-contact between the teeth also leads to excessive enamel wear and tear, which is a concern because enamel does not regenerate. Conversely, if the jaw is allowed to hang too low, creating a large gap between the teeth, it indicates that the tongue is not properly engaged with the palate. This low tongue posture encourages habitual mouth breathing, which is associated with various health and orthodontic issues.
Trying to hold the tongue or jaw with too much tension or uneven force can lead to muscle soreness and potentially increase facial asymmetry. Incorrect pressure, particularly pushing the tongue tip forward against the front teeth, can result in unintended tooth movement and the creation of gaps. The practice must focus on gentle, consistent posture rather than intense, forceful muscle contraction.