Chapter 11B: Open Bite and Ankylosed Teeth

Open Bite

An open bite occurs when the upper and lower front teeth don't touch at all when biting down, leaving a visible gap even with the back teeth fully closed together. As noted in Chapter 6, this is frequently linked to prolonged thumb-sucking, pacifier use, or tongue-thrusting, though it can also arise from a skeletal growth pattern independent of any habit.

Ankylosed (Fused) Teeth

Occasionally, a baby tooth becomes fused directly to the underlying bone, a condition called ankylosis, causing it to appear to "sink" relative to neighboring teeth as they continue to erupt normally. An ankylosed tooth doesn't move with orthodontic forces the way a normal tooth does, so identifying it early matters for planning — whether it needs early removal to allow the permanent tooth beneath it to erupt properly, or whether it can simply be monitored until it's naturally lost.