Upper Jaw (Maxilla): Forms a narrow and high palate. This leaves less space for the nasal sinuses, often affecting the airway and breathing. The tongue no longer has the space to fit easily in the roof of the mouth, where it should naturally rest.
Lower Jaw (Mandible): Develops smaller and is less prominent, creating a “weak or recessed chin” appearance. The profile can be drastically changed by the pressure of the thumb resting on the lower jaw and lower teeth.
Overall Appearance: A longer and narrower face shape is assumed. All of the structures have grown in downward patterns, because the jaw and mouth are constantly open to accommodate the thumb or finger. The jaw and cheek bones form to be much less prominent. A general ‘dull’ or sleepy appearance is also common due to a pull and improper muscles tone near the eyes.
Teeth: An open bite, cross bite of the back teeth, and/or an over-jet can form over time. A “buck tooth” appearance can be created by the pressure of the thumb on the front teeth. In general, if the tongue is not able to rest properly in the roof of the mouth a general crowding of teeth can be expected, due to lack of necessary pressures from the tongue.
Tongue: The thumb and fingers will train the tongue to rest low and forward in the mouth. An abnormal “tongue thrust” swallow is learned affecting eating, drinking, breathing, speech, appearance, and rest posture of the face.
