Commonly known as a “bad bite,” malocclusion is the medical term for teeth that don’t fit together properly.

When teeth and jaws don’t align as they should, the consequences can be serious: damaged teeth, gum disease, problems with the temporomandibular joint, headaches and facial pain, difficulty chewing, eating, and speaking, and struggles with confidence and self-esteem.

Classes of Malocclusions

Dentists identify three classes of malocclusions based on the alignment of the upper and lower molars:

  • Class I malocclusion: The most common form of malocclusion, in which the molars are aligned properly, but the front teeth may have issues such as overcrowding.
  • Class II malocclusion: The upper teeth and/or jaw are positioned too far forward of the lower teeth, which can cause overbites and overjets.
  • Class III malocclusion: The rarest form of malocclusion, which occurs when the lower teeth and/or jaw are positioned ahead of the upper teeth and jaw. An underbite is a Class III malocclusion.

Specific Types of Malocclusions

Within the classes of malocclusions are specific types of alignment issues, including:

  • Crossbite: One or a group of upper teeth fit inside lower teeth.
  • Crowding: The teeth can become twisted, crooked, or overlap each other when teeth are large and/or the jaw is small.
  • Open Bite: In an anterior open bite, the front teeth don’t make contact when biting down. With a posterior open bite, the back teeth don’t make contact when the front teeth close.
  • Overbite: The upper teeth significantly overlap the lower teeth.
  • Overjet: The upper front teeth protrude too far horizontally over the bottom teeth (sometimes called buck teeth).
  • Spacing: A large jaw, small teeth, or missing teeth can lead to gaps between teeth.
  • Underbite: The lower teeth and jaw extend further forward than the upper teeth and jaw.

The cause of malocclusion is often genetic, due to hereditary factors such as size and rate of growth in the upper and lower jaws, or tooth size and alignment. Malocclusions can also be caused by certain medical conditions, injuries, or habits like prolonged thumb sucking or tongue thrusting.

Treatments for Malocclusions

  • Braces: Traditional braces use brackets and wires to gently move the teeth into proper alignment. More discreet options include ceramic brackets and lingual (behind the teeth) braces.
  • Clear Aligners: These custom-designed trays use an individually tailored series of aligners to move the teeth into better alignment with each new phase of treatment.
  • Fixed or Removable Appliances: Appliances such as palatal expanders, Forsus™ devices, and Herbst® appliances are used to correct bite alignment and encourage symmetrical jaw growth as the bones develop.
  • Headgear: Headgear is designed to correct more serious tooth and jaw misalignment while the jaw is still growing.
  • Surgery: Surgery can be the best option when a malocclusion is skeletal in nature, because an oral and maxillofacial surgeon is able to reshape and reposition the bones in the jaw. Orthodontic treatment is usually needed as well.

While it’s common to treat malocclusions during the teen years, when most of the adult teeth have arrived and the jaw is still growing, you don’t have to be a teenager to benefit from orthodontic treatment.

Early intervention for younger children can help correct teeth and jaw problems before they become more serious. It can lead to easier orthodontic care in the teen years, and help prevent the need for surgery or extractions. This is the reason dentists and orthodontists recommend an orthodontic assessment for children around the age of seven.

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