Thumbs, Pacifiers, and the Shape of a Child's Bite

The craniomandibular system — the jaws and the joints that move them — is shaped by a mix of genetics and the things a child's mouth does every day. This systematic review focused on a particular set of those habits: non-nutritive sucking, meaning thumb sucking and pacifier use that isn't about feeding. The authors set out to map how these habits relate to malocclusion.

Alongside breastfeeding and bottle feeding, prolonged thumb sucking or pacifier use applies repeated, directional force to the growing jaws and teeth. The review gathered the evidence on what that force does over time — open bites, narrowed arches, and other malocclusion traits that can follow a habit carried on too long.

This matters because it identifies a modifiable, everyday cause of facial development gone sideways. Unlike genetics, a sucking habit can be changed. Recognising it early — and understanding that the tongue and lips are powerful sculptors of the growing mouth — gives parents and clinicians a concrete lever to pull before a temporary habit hardens into a permanent bite problem.