Crowding and Invisalign — Can Invisalign fix my crooked teeth?

Dental Designs Clinic Singapore
22 May, 2023

There are many misconceptions about Invisalign, with one being it can only fix slightly crooked teeth and will not work on overcrowded teeth. This is simply not true — Invisalign is far more than just a retainer and can be used in almost all dental situations to straighten teeth. Granted, severely crooked teeth might need traditional metal braces, but this is usually due to severe misalignment of the jaw that Invisalign cannot fix. Otherwise, in general, Invisalign can straighten crooked teeth caused by crowding and give you the perfect smile you’ve always dreamed of.

How do I know if I have crowded teeth?

Crowded teeth may either be mild or severe, but they are usually characterised by poor alignment of the upper and lower teeth. They cause symptoms which include:

  • Altered facial appearance
  • Discomfort when biting or chewing
  • Biting of the tongue or inner cheeks, can occur when chewing or talking
  • Noticeable speech problems that sounds like a lisp
  • Breathing difficulties (in severe cases)


What causes crowded teeth?

In most cases, crowded teeth are inherited. If you have crowded teeth, your might notice that your parents and siblings likely have this dental issue too. Genetics aside, certain habits and conditions especially if developed since young can alter the shape and structure of your jaw, leading to crowded and crooked teeth. They include:

  • Consistent use of oral objects in early childhood, including thumb sucking and/or continuous use of a pacifier past age three or four
  • Extensive use of bottles in early childhood
  • Early loss of baby teeth
  • Injuries or trauma that misaligned the jaw
  • Cleft lip or palate
  • Gum disease
  • Excessive pressure on teeth and gums
  • Ineffective dental care i.e. poorly fitted dental crowns, braces or fillings 

Why is it important to fix crooked teeth caused by crowding?

Apart from aesthetic reasons which some may or may not mind, it is important for misaligned teeth to be fixed as they can cause:

  • Difficulty chewing
  • Straining of the jaws and teeth
  • Teeth to be broken easily
  • Difficulty cleaning teeth, increasing the risk of gum disease, cavities and tooth decay

How can Invisalign fix crowded teeth?

To first ensure your suitability for Invisalign, your dentist will take X-rays and 3D images of your face and teeth and make teeth impressions. The X-rays will allow the dentist to locate the exact position of your teeth and their roots, as well as see if there are any teeth hidden in the gums. Your dentist will likely also use the 3D images to study the relationship between your teeth, jaw and head. At Dental Designs, we use an Invisalign iTero scanner that can successfully capture teeth from all angles to help us create aligners.

Most patients with misaligned teeth should be able to qualify for Invisalign, as these are strong, hard plastic that is capable of shifting very crooked teeth. During the entire treatment process, patients wear their custom-made aligners over their teeth for at least 22 hours everyday, and take them out during meals or when brushing and flossing.

About every two weeks or so, patients switch to a new set of aligners to keep moving their teeth in the right direction. Each set of aligners might look slightly different, as they place gentle pressure on teeth to force them into moving into their correct positions. Treatment times vary depending on each patient’s condition, but the average time is about 12 to 18 months. 

How can I benefit from using Invisalign to treat my crowded teeth?

Some of the main benefits existing patients enjoy and future patients can look forward to are:

Improved appearance

Patients can expect straighter teeth without any obvious metals or wires showing when they smile. Unlike traditional braces, Invisalign aligners can hardly be seen. This allows patients to still look good even during the treatment.

Better dental hygiene

The clear aligners must be taken out during meals and when you brush and floss your teeth. This ensures no food particles will get stuck in the aligners and your teeth remain clean.

Personalised treatment

Each aligner is uniquely designed based on your condition. They fit securely thanks to the accurate 3D impressions taken, and are the most comfortable form of straightening treatment for overcrowded teeth.

Convenient and fits into your lifestyle

As mentioned, the Invisalign aligners must be removed during meals and cleaning, but you can take them off anytime you need to, such as during an outdoor game. As long as the aligners are on for at least 22 hours daily, they can be removed anytime to accommodate your lifestyle.


  1. Fernandez, C., Pereira, C., Luiz, R. R., Vieira, A. R., & De Castro Costa, M. (2018). Dental anomalies in different growth and skeletal malocclusion patterns. The Angle orthodontist, 88(2), 195–201.
  2. Weir T. (2017). Clear aligners in orthodontic treatment. Australian dental journal, 62 Suppl 1, 58–62.