PHOTO GALLERY 1
Top Left: Step-Plane of Occlusion
Mouth breathers need to establish an open oral airway. One way they can
do this is by habitually keeping the lips and jaws apart, flattening the tongue laterally and positioning its lateral borders over the surfaces of the lower posterior teeth. In the dysfunctional swallow that develops, the lateral borders of the tongue are positioned between the posterior dental arches. This is identifiable by a scalloped lateral border of the tongue in rest position and a step-plane of occlusion on the lower arch with the front six teeth higher than the posterior teeth (bicuspids and molars).
Top Right: Complete Over Bite
When the back teeth cannot erupt completely due to the tongue lying over
the teeth during the dysfunctional swallow, an over bite is the result. The
lower jaw needs to shift back in order for the back teeth to touch.
Notice the scalloped borders of the tongue, indicative of the dysfunctional swallow that causes the step-plane of occlusion and overbite.
Top Left: Posterior Cross Bite
Mouth breathers need an open oral airway to breathe. first, they habitually parth the lips. The tongue adaptively positions itself in the floor of the mouth. With the tongue in this position, the mouth is open to facilitate passage of air. The cheeks exert inward pressure but with no tongue to oppose movement, the teeth are pushed inward narrowing the palate and floor of the nose as well, possibly causing crossbites. The patient swallows with the tongue in the floor of the mouth. The crossbite occlusion that results can be either unilateral or bilateral. The lower posterior teeth are lateral to the uppers when biting, a situation called crossbite.
Top Right: Anterior Crossbite
In this photo, the patient has both anterior and posterior crossbites.
Mouth breathers can adapt with a tongue posture in the floor of the mouth to facilitate oral breathing. In those kids with a strong upper lip, the maxillary anterior teeth shift inward. An anterior crossbite can develop. The lower jaw may not be overdeveloped but rather the upper arch could be underdeveloped in these patients.
Anterior crossbite in a 6 year old child.