Posterior Crowding: Everything You Need To Know About It

Posterior Crowding: Everything You Need To Know About It

Overcrowding is one of the most common orthodontic conditions that warrants the need for orthodontic treatment. While some patients suffer from overcrowding due to larger-than-normal teeth, others suffer due to small jaws or extra teeth. All in all, overcrowding impedes good oral habits, contributing to the development of periodontal disease.

Overcrowding at the entrance of the mouth can be seen easily, with the teeth being crooked and overlapping one another. The issue of overcrowding can become serious if it occurs at the back of the mouth, especially at the lower jaw. Due to its location, overcrowding there is less obvious, which means that it often goes unrecognized. This orthodontic condition is known as posterior crowding.

Issues with lower 12-year-molars

When the lower jaw is smaller than the upper one, it often results in the development of crowded lower teeth and excessive overbite at the front of the mouth. It can also cause crowding at the back of the mouth that may not be as obvious visually. The most common symptom of posterior crowding in a pre-teen child is a partial eruption or impaction of the second molars.

Impacted second molars can be easily diagnosed through an X-ray examination. However, the crowding associated with the impacted second molars is often overlooked.

Removing bicuspids due to crowding is common

When overcrowding develops in both the lower and upper dental arches, removing bicuspids is a common procedure to reduce the number of teeth to fit in the available jaw space. Bicuspids, also known as premolar teeth, are permanent teeth located between the molar and the canine teeth. They help us to chew our food properly with their somewhat pointed cusps.

The removal of these teeth, especially when tooth irregularity occurs at the entrance of the mouth, is an effective approach to address crowding. Typically, when crowding occurs in both arches, removing four bicuspids will help to address the immediate crowding issue and create more space in the second molar area.

Removing bicuspids is not always the solution

However, there are situations where removing bicuspids is contraindicated. For example, when a patient has little to no crowding at the front of the mouth, has excessive overbite, poor lip support, or has upright front teeth that will look collapsed if they are moved back.

In these cases, removing bicuspids, especially in the lower arch, would only worsen the situation. So, how, then, do we deal with posterior crowding?

Moving lower molars forward is complicated

Some orthodontists might still consider removing the lower second bicuspids so that they can move the lower 6-year-molars forward to make more room for the crowded-out 12-year-molars. However, this process is often slow, difficult, and prolonged. The first two molars are almost twice as wide as bicuspids, have more roots, and take a longer time to move. The risk that the front teeth become compromised by collapsing in may sometimes be too much to bear.

Treatment options for crowded lower second molars

The second molars may still partially erupt or become impacted if no teeth are extracted during orthodontic treatment. So, what can be done? If the affected molars do not have sufficient space to erupt and are impacted, they can be extracted, similar to wisdom teeth or bicuspids.

If they do erupt but are covered with soft tissue, the gingiva will usually recede on its own over time, exposing the occlusal surfaces of the molar teeth. However, if the gum tissue becomes too thick and the situation does not improve on its own, an orthodontist or general dentist is able to remove the extra tissue with a simple surgery under local anaesthesia.


Overcrowding is an issue, whether posterior or anterior. Treating dental crowding is vital as crowded teeth result in overlapping of your teeth, making it harder to clean them completely. This can result in the build-up of plaque and bacteria in harder-to-reach places, which leads to the development of periodontal disease and tooth decay.

BigSmile Dental Clinic is here to help in such cases. With orthodontic solutions, such as invisible braces, overcrowding can be fixed. The right orthodontic treatment also depends on the condition of your teeth. Our team will ensure you get the best treatment plan. Contact us to get your orthodontic condition fixed.