Orthodontic terminology

Terms and definitions

Crowding

WHAT: Teeth too big or jaws too small

CAUSE: Blame your parents

PROBLEMS: Thin bone over teeth roots can cause gum problems. Impacted teeth may not grow through the jaw properly. Undesirable appearance. Abnormalrelationships of teeth can cause early tooth wear problems.

Overjet or protruding teeth

WHAT: Upper front teeth “jet”

out over the lower teeth by an abnormal amount. Orthodontists refer to this as a Class II division 1 malocclusion.

MANAGEMENT: In some cases we will commence treatment with a headgear appliance or functional appliances. Once all the adult teeth have erupted, braces are placed. More severe protrusions may need removal of some adult teeth to allow correction. We do a detailed analysis before such an option, and not all patients are suitable candidates for treatment with removal of teeth. More severe cases, some adults, and certain facial profile types would be best treated with a combination of braces and jaw surgery (see section on jaw surgery).

CAUSE: Blame your parents or thumb/finger sucking.

PROBLEMS: Upper front teeth may be more prone to injury (e.g. knocked at sport).

Deep overbite

WHAT: Overbite refers to the vertical overlap of the teeth. The lower front teeth bite too far up behind the upper front teeth. One type of deep bite is the Class II division 2 malocclusion.

MANAGEMENT: Braces on the teeth. In severe cases, jaw surgery is also an option if ideal correction desired (see section on jaw surgery)

CAUSE: Blame your parents

PROBLEMS: May get gum damage from lower teeth biting into the roof of?the mouth. A deep bite can also contribute to excessive wear of the incisor teeth.

Open bite

WHAT: The upper and lower teeth don’t touch when biting down.

CAUSE: Blame your parents, dummy or finger or thumb sucking or abnormal tongue habits

PROBLEMS: There is a lack of function with an openbite. People with anterior openbites are unable to incise food such as lettuce, and rely on their back teeth only for chewing. They still can eat a healthy diet as people with openbites learn to adapt to their condition. Although often only the very back teeth are in contact, in fact, it is very rare that there is increased wear of these teeth. The type of jaw pattern that commonly causes an openbite is the type also related to a lower bite strength due to the direction of muscle pull.

MANAGEMENT: In thumbsucking, we like to break the habit by 8 years of age. In persistent cases we use a tongue guard. The photos show correction obtained with only a tongue guard. In what we term skeletal openbites, where the openbite is due to the inherited jaw shape, we treat following the adolescent growth spurt. This is because such skeletal openbites can become worse with growth. Braces together with jaw surgery can be required in severe cases (see Jaw Surgery).