For the longest of time, dentists' approach to crooked teeth is to straighten them. A commonly heard statement is that 4 teeth will be removed before putting on braces to straighten them. And that was exactly my experience when I was a teenager.
After becoming a dentist, I thought about how I can PREVENT my patients and my children from going through similar fate. How can they have a set of straight teeth with a nice smile without removing any healthy tooth?
My son is now 2 years old and bottle feeding has made him susceptible to crooked teeth. In fact he is showing signs of teeth crowding. What are the causes of him having crooked teeth? Is it because he has larger teeth or is his jaw not developing well enough?
“Functional dental growth” explains the situation he is in. Bottle feeding is preventing his jaw from developing to its full potential and his teeth are pushed into an awkward position. The position of the tongue and facial muscles are of paramount to the development of the jaw and positions of the teeth. The tongue and facial muscles sandwich the teeth in the middle. If there are unfavourable forces from these soft tissue structure (sucking of bottle), the upper teeth will be pushed inwards and jaw development will be impeded, resulting in crowding.
In an ideal situation, everyone should breathe through the nose and nasal breathing will result in an expansive force on the upper jaw.[1] Secondly, the tongue should naturally rest on the palate (roof of the mouth) and not floor of the mouth. Correct positioning of the tongue will help to react against the inwards pressure from the cheek muscle (buccinator). Lastly, the lips should be closed together (competent) to have a favourable inwards pressure on the front teeth to prevent them from protruding forward. With favourable forces, the jaw will develop normally and crooked teeth can be prevented. The ideal position of the tongue and lips are prevented with habits like tongue sucking, mouth breathing, bottle feeding or use of most pacifier.
How does the tongue move differently during breastfeeding & bottle feeding? Breastfeeding requires the child to position his/her tongue towards the palate by pushing the nipple onto the palate to obtain the milk. Bottle feeding often result in the child positioning his/her tongue onto the floor of the mouth to create space for the bottle teat. With bottle feeding, the child will use an inwards pressure from cheek muscle to obtain the milk instead of the tongue. While it is easy to expect every mum to breastfeed her children, in reality it may not be a straightforward choice for mothers. In some cases, the child’s tongue is tied to the floor of the mouth, preventing it from touching the palate.
Instead of using a milk bottle to sooth, a good alternative is Dentistar range of products. Dentistar pacifier is designed by a German dentist and it allows the tongue to touch the palate when the pacifier is in the mouth. My twin babies are using Dentistar Singapore to sooth, to allow their teeth to grow into their natural positions.
In addition, some children are not able to breathe through their nose due to airway inflammation, allergic rhinitis, asthma, swollen adenoids and tonsils. [2] This will result in the child adapting to breathe through his/her mouth, causing the cheek muscle to exert an inwards pressure and tongue to position at floor of the mouth.
Looking beyond crooked teeth, the improper development of the jaws may lead to sleep apnea [3]. Sleep apnea in children is linked to ADHD [4] and in adults it is linked to high blood pressure and heart failure [5].
In the past, crooked teeth are often managed when all the permanent teeth are out. The understanding of functional dental growth allows us to take precaution at a younger age while the jaw is still developing, in the hope to prevent the need for extraction for braces at an older age.
“Functional dental growth” does not explain how we can prevent all forms of teeth and jaw alignment issue. Some cases of alignment are skeletal (jaw bone problem) or genetic in nature which we may not be able to prevent fully at this stage. However, with our knowledge and resources now, we can prevent some causes of crooked teeth, namely from our modern lifestyle and hopefully prevent future generation from having their teeth taken out to create a nicer smile.
Resources
1- Gungor, Ahmet Yalcin, and Hakan Turkkahraman. “Effects of airway problems in maxillary growth: a review”Eur K Dent 3.3 (2009): 250-4
2 - Small, Peter, and Harold Kim. “Allergic rhinitis.” Allergy, Asthma & Clinical Immunology 7.1 (2011): S3
3 - http://www.aafp.org/afp/1999/1115/p2279.html
4 - Youssef NA, Ege M, Angly SS, Strauss JL, Marx CE. “Is obstructive sleep apnea associated with ADHD?” Ann Clin Psychiatry. 2011 Aug; 23(3):213-24.
5 - Jean Louis, Girardin, et al, “Obstructive sleep apnea and cardiovascular disease: role of the metabolic syndrome and its components.” J Clin Sleep Med 4.3 (2008): 261-72