Molars, which include your set of wisdom teeth, are rounded, flat teeth in the back of the mouth.
Also called molar teeth, molars can vary in size and shape but are the largest teeth in the mouth. While your smaller, sharper front teeth are used for biting and tearing food, the molars' role is to grind food into pieces that are easy to swallow.
This article looks at the types of molars, the purpose of wisdom teeth specifically, and problems that can develop with these large, powerful teeth.
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Types of Molars
The average adult has 12 molars, three on each side of both your upper and lower jaws. Each of the three molars is a different type:
- First molars, also called six-year molars because they come in around age 6
- Second molars, also called 12-year molars because they erupt around age 12
- Third molars, also called wisdom teeth, which appear between the ages of 17 and 21
Molars are designed to sustain great amounts of force from chewing, grinding, and clenching. That's thanks to their large surface area and two to four roots that are firmly implanted in the jaw bone.
Why Do We Have Wisdom Teeth?
The third molars, or wisdom teeth, are vestiges from our evolutionary past when the human mouth was larger and could accommodate more teeth. They were useful in chewing especially coarse foods, such as roots, nuts, leaves, and tough meats.
This type of diet was tough on the teeth—especially without the helpful maintenance tools we enjoy today, such as toothbrushes, toothpaste, and dental floss. Thus, our ancestor's teeth were subject to significant wear and loss due to tooth decay.
Modern humans don't eat foods that require these extra teeth. However, evolution hasn't yet caught up to this change, so people still get those extra teeth around the time they reach adulthood.
Not Everyone Has Them
Reported rates of missing molars vary by geographic location. Estimates of people who never developed wisdom teeth or are missing at least one of the four range from 5% to 37% worldwide.
The Problem of Wisdom Teeth
Wisdom teeth have become a problem because evolution has shrunk the human jawbone. This presents a range of problems when those vestigial wisdom teeth try to squeeze in.
- As wisdom teeth form, they can become blocked by other teeth so they can't come in properly. This is referred to as being "impacted."
- If a wisdom tooth does come in, it can crowd the mouth and create hard-to-clean places where bacteria can thrive, leading to serious infections of the gums and surrounding tissue.
- When wisdom teeth don't come in, you can be at risk for cysts or tumors that may damage the jawbone (mandible) and teeth if they're not taken out.
It is very common for third molars to become impacted. According to some research, as many as 67% of the population might be affected by impacted wisdom teeth. However, those studies have been challenged. A rate of around 23% may be more accurate once you factor in racial differences and balance the age at which assessments are done.
Even in cases where third molars come in without any problems, your dentist may recommend removing the wisdom teeth to avoid problems that might develop later in life. Having preventive surgery at a young age will allow you to heal faster and avoid complications that older adults are at risk for.
How to Take Care of Your Molars
As molars come in, known as eruption, you may experience painful inflammation and swelling along the gum. This is known as pericoronitis. Normally, it should last about four days.
To help ease the pain and ensure your teeth come in without problems, it's good to pay extra attention to oral hygiene:
- Carefully brush the area with toothpaste.
- Use floss or soft picks for interdental cleaning.
- Rinse with a chlorhexidine mouthwash, which contains an antibacterial to fight gum disease.
If you experience pain, take pain relieving medication in tablet or pill form. Never leave medication in the mouth next to the pericoronitis. If the pain lasts more than four days or gets worse, see a dentist since you may need to have the tooth pulled.
Regular Care of Molars
Like all teeth, once molars have come in, they are susceptible to a variety of disorders or problems. If you feel pain in fully mature molars, you should see your dentist to check for the following:
- Cavities
- Broken or cracked tooth
- Abscessed tooth
- Damaged filling
- Teeth grinding
Make an appointment right away if you also have swelling, fever, pain that radiates to your jaw or ear, a bad taste in your mouth, or sensitivity to hot or cold, since these could be signs of a serious abscess.
Tooth Pain: Causes, Treatment, and When to See a Dentist
Summary
Molars are the big flat teeth in the back of your mouth. They're designed to crush and grind food and can withstand considerable force.
The three types are 6-year molars, 12-year molars, and wisdom teeth. The modern human diet no longer requires wisdom teeth, so they're called vestigial, meaning they're left over from an earlier time.
The human jaw has shrunk through evolution, and therefore there's often not enough room for wisdom teeth to come in. That can lead to various problems and most people have their wisdom teeth removed at some point. The surgery is safer and easier to recover from when you're young.
Frequently Asked Questions
When do baby molars come in?
Your baby's first molars will probably begin to come in between 13 and 19 months old. The last set of baby molars may finish coming in around 25 to 33 months old. These later fall out to make way for adult molars.
When do kids lose their molars?
It varies. On average, kids tend to lose their baby molars when they're between 9 and 12 years old.
Learn More:When Do Baby Teeth Fall Out?
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Ghoncheh Z, Zade BM, Kharazifard MJ. Root morphology of the maxillary first and second molars in an Iranian population using cone beam computed tomography.J Dent (Tehran). 2017;14(3):115-122.
Jung YH, Cho BH. Prevalence of missing and impacted third molars in adults aged 25 years and above. Imaging Sci Dent. 2013;43(4):219–225. doi:10.5624/isd.2013.43.4.219
Rakhshan V. Congenitally missing teeth (Hypodontia):A review of the literature concerning the etiology, prevalence, risk factors, patterns and treatment.Dent Res J (Isfahan). 2015;12(1):1-13. doi:10.4103/1735-3327.150286
Kahn S, Ehrlich P, Feldman M, Sapolsky R, Wong S. The jaw epidemic: recognition, origins, cures, and prevention.BioScience. 2020;70(9):759-771. doi:10.1093/biosci/biaa073
Yıldırım H, Büyükgöze-Dindar M. Investigation of the prevalence of impacted third molars and the effects of eruption level and angulation on caries development by panoramic radiographs.Med Oral Patol Oral Cir Bucal. 2022;27(2):e106-e112. Published 2022 Mar 1. doi:10.4317/medoral.25013
California Academy of General Dentistry. Surgical and Non-Surgical Management of Third Molars.
Renton T, Wilson NH. Problems with erupting wisdom teeth: signs, symptoms, and management.Br J Gen Pract. 2016;66(649):e606-e608. doi:10.3399/bjgp16X686509
Siqueira JF, Rôças IN.Microbiology and treatment of acute apical abscesses.Clin Microbiol Rev. 2020;26(2):255-73. doi:10.1128/CMR.00082-12
American Dental Association. Eruption charts.
By Shawn Watson
Shawn Watson is an orthodontic dental assistant and writer with over 10 years of experience working in the field of dentistry.
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