What Are Tooth Malocclusion and Jaw Misalignment?


At a Glance:

  • Crooked, crowded or twisted teeth are typically referred to as malocclusion
  • Malocclusion refers to when the top and bottom teeth don’t align properly due to a misaligned jaw 
  • Aside from aesthetic issues, having a misaligned jaw may lead to a number of problems common to misaligned teeth, such as problems with biting and chewing, proper cleaning, excess wear, gum disease and speech issues
  • A number of treatment options are available for both conditions, including braces, aligners and dental surgery

What is Misalignment or Malocclusion?

In an ideal world, all your teeth should fit comfortably within your mouth, with no spacing issues and no rotation or twisting of teeth. Unfortunately, for many people, this is not the case. Aside from the aesthetic value of straight teeth there is another reason to have misalignment corrected - protecting your teeth from damage. Having crowded or twisted teeth may become a major risk factor for dental problems. 

Complications of misaligned teeth vary  depending on the way the teeth are maloccluded. Teeth that are too far apart may lead to the gums becoming irritated and inflamed when eating. Crowded teeth may make it harder for people to clean their teeth leading to a buildup of plaque, tartar and eventually the development of cavities. Twisted teeth can also be hard to clean, affect the ability to bite and lead to excessive wear on teeth.

Other complications of misaligned teeth include:

  1. Periodontitis - the buildup of plaque and tartar on misaligned teeth may lead to periodontal disease, potentially causing more damage to your teeth and jaw
  2. Digestive problems - misaligned teeth can cause a problem with biting and chewing, potentially leading to digestive problems stemming from poorly masticated food
  3. Speech Difficulties - having misaligned teeth may impact a person’s ability to correctly form sounds leading to speech issues such as a lisp

Malocclusion refers to when the top and bottom teeth don’t align properly due to a misaligned jaw. Your upper teeth should overlap your lower teeth to a small degree, so that the ridges in the top and bottom molars essentially fit into each other. If the teeth are not aligned properly, this may cause problems such:

  • Overbite - the top teeth cover too much of the lower teeth
  • Overjet - the top teeth are too far in front of the lower teeth
  • Underbite - the bottom teeth are aligned forward of the top teeth
  • Crossbite - the upper and lower teeth are misaligned to the left or right
  • Open Bite - the molars meet in such a way that the front teeth cannot fully close, leading to a gap between the top and bottom front teeth

Aside from aesthetic issues, having a misaligned jaw may lead to a number of problems common to misaligned teeth, such as problems with biting and chewing, proper cleaning, excess wear, gum disease and speech issues. In addition, proper alignment of the jaw protects the cheeks and tongue from being bitten. Everyone bites their cheek or tongue every now and then, and it’s rarely a pleasant experience. People with overbites and underbites are much more prone to cheek and tongue biting respectively.  

Malocclusion is classified into three categories depending on the severity of the jaw and tooth misalignment.

Class 1 Malocclusion
The most common form of malocclusion, class 1 malocclusion is the diagnosis of the top and bottom teeth overlapping slightly but not to the extent that the bite isn’t compromised.

Class 2 Malocclusion
A class 2 malocclusion is diagnosed when a severe overbite and/or overjet is present and the top jaw and teeth significantly overlap the bottom teeth The condition is also referred to as retrognathism or retrognathia.

Class 3 Malocclusion
A class 3 malocclusion is diagnosed when the bottom jaw and teeth protrude forward causing a severe underbite. Class 3 malocclusion is also referred to as prognathism. 


If you have crooked or crowded teeth, or issues with the position of your jaw and they are causing you problems, schedule an appointment to see a dentist to discuss possible treatment options. The fastest and easiest way to search for and book healthcare appointments online is through MyHealth1st.


What Causes Malocclusion and Misalignment?

There are many reasons that people may have maloccluded teeth or a misaligned jaw, ranging from genetic predisposition and heredity to injury, dental hygiene and even repetitive behaviours. 

Causes for misaligned (crooked or crowded) teeth include:

  1. Childhood Nutrition - poor nutrition as a child may lead to damage to baby teeth as well as issues with the development of adult teeth. This may lead to weakened or crooked adult teeth 
  2. Diet - it is believed that as humans have developed and innovated one of the effects has been the softening of food, first through cooking and later through processing in different ways. As a result, modern humans don’t need to chew as much or as powerfully as our early Homo genus (homo erectus, homo neanderthalensis, etc) ancestors. 

As our jaws became suited to eating softer foods, it became smaller, but the number of teeth remained the same, leading to frequent crowding of teeth.

  1. Facial Injury - trauma to the face, mouth or jaw can knock teeth out of alignment or cause damage to the jaw leading to crooked teeth
  2. Genetic Predisposition - if either or both of your parents have crooked or crowded teeth you may be more likely to have misaligned teeth
  3. Malocclusion - having a maloccluded jaw (overbite, underbite, cross bite or open bite) may also lead to crooked teeth, as the teeth are shifted due to uneven pressure
  4. Myofunctional Behaviours -  repetitive behaviours may have a lasting effect on the muscles, structure or function of the jaw and teeth. Prolonged thumb sucking, pacifier sucking or bottle feeding may all lead to misaligned teeth or may even lead to an overbite
  5. Poor Dental Care - poorly constructed bridges, veneers and other dental prosthetics may cause pressure on surrounding teeth causing them to become misaligned 
  6. Poor Dental Hygiene - poor dental hygiene may lead to gum disease and other dental problems, many of which may cause damage to the gums or jaw, potentially causing the misalignment of teeth  

Misalignment is typically an inherited condition, but in some cases behaviour, injury and other causes may change the structure or shape of the jaw.

Potential causes of misalignment include:

  • Cleft Lip/Palate - a baby’s lip forms between the fourth and seventh week of pregnancy. The palate (roof of the mouth) forms between the sixth and ninth week of pregnancy. A cleft lip or palate occurs when the tissue doesn’t fully join, leaving a gap. A cleft lip and palate may also feature jaw abnormalities
  • Impacted or Abnormal Teeth - severely impacted or abnormally shaped teeth may alter the shape of the jaw
  • Improper Dental Care - poorly fitted dental bridges, plates, braces and crowns may alter the shape or orientation of the jaw
  • Injury - unjust to the mouth or face may change the alignment or shape of the jaw 
  • Myofunctional Behaviours - much like in the case of misaligned teeth, prolonged thumb sucking, bottle feeding and pacifier use may lead to developmental changes in the shape of the mouth or jaw  
  • Tumours - tumours (both malignant and benign) in the mouth or jaw may lead to a change in the structure or shape of the jaw

How is Malocclusion and Misalignment Treated?

Depending on the nature, cause and severity of the misalignment or malocclusion, potential treatments vary. In some cases, straightening teeth may be nothing more than a cosmetic adjustment, so no treatment is really necessary, but in others, especially those in which the misalignment or malocclusion is severe and impacts health or lifestyle in some way, treatment is definitely recommended.

A number of treatment options are available for misaligned teeth, including braces, tooth aligners, and even dental straightening surgery. Some instances of malocclusion may similarly be treated with braces to correct the position of teeth so as to allow the jaw to sit more comfortably. Other potential treatments for malocclusion include the removal of teeth to open up space in the jaw, jaw surgery for reshaping or the reshaping of teeth.

Before any form of treatment is entered into, your dentist will discuss treatment options with you if any are necessary, potential price points and any additional factors that may impact your decision. 

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