Teeth Shapes: The Four Types of Teeth and What Each Does

Your teeth come in four shapes with different functions: incisors cut, canines tear, premolars crush and molars grind.

Teeth shapes vary, but most variations are harmless. If your teeth shapes are changing, it may be a sign of tooth wear, acid damage, decay or chipped teeth. To learn how many teeth you should have at different ages, see our tooth count guide.

Different Types of Teeth and Their Shapes

Adults have four types of teeth, each with a shape suited to its function. A full set has up to 32 adult teeth (or 28 plus up to four wisdom teeth).¹ You have two incisors, one canine, two premolars and up to three molars on each side of your upper and lower jaws.

Incisors

You have eight incisors, four at the front of each jaw. They are thin with flat, sharp edges that help cut your food. Your upper two central incisors are the widest.

Incisors also help you speak. Your tongue and lips press against them when you make sounds such as “f”, “v” and “th”. If you have a problem with one of your front teeth, it can contribute to a lisp.

Canines

Canines, sometimes called cuspids or eyeteeth, are the four teeth at the corners of your mouth. They are pointed, and each has a single cusp (raised point) that helps you grip and tear food.

Premolars

Premolars sit between your canines and molars, two on either side of your upper and lower jaws. These teeth usually have two cusps, and are sometimes called bicuspids. They help you crush your food.

Molars

Your molars are your largest teeth. They are square and broad, and they help you grind your food before swallowing. Your third molars, or wisdom teeth, come in last.

Wisdom teeth can be a problem if you don’t have enough room for them to come in properly, or if they come in at an angle.

Natural Variations in Tooth Shape

While no two people have exactly the same tooth shapes, variations are generally harmless, but some need a dentist’s check even without symptoms.

Front Teeth Shapes

Your dentist may describe the outline of your upper front teeth as:

• Square: with straight sides and a flat edge
• Oval: with rounded corners and a curved edge
• Tapered: wider at the biting edge and narrower at the gum line, like a triangle

Many people have a mixture of outlines. No outline is healthier than another, but if you are considering veneers or bonding, your outline is one of the factors your dentist may take into account.

Peg Laterals

A peg lateral is an upper lateral incisor, the tooth beside a front tooth, that formed small and cone-shaped. It doesn’t always need treatment, but it sometimes leaves a gap between the front teeth or affects your bite. Bonding, a veneer or a crown builds it up.

Mamelons

Mamelons: When your permanent incisors first come in, they often have three small bumps along the biting edge. These usually wear down with normal chewing, but your dentist can smooth any that last and bother you.

Other Shape Differences

Your dentist may also refer to:

• Shovel-shaped incisors, with raised ridges along the back edges
• An extra cusp, like a small bump inside an upper molar
• Unusually small or unusually large teeth
• Two teeth that have grown together or one tooth that has partially split into two
• Thin or soft enamel (the hard outer layer of your teeth) that has pits, grooves or chalky white, yellow or brown patches

While some of these conditions need no treatment, others (such as deep grooves or weaker enamel) can trap plaque, break down or lead to more rapid tooth decay. Let your dentist know about any of these, since joined or split teeth can also affect your bite or, in children, the adult teeth still forming.

Can Teeth Change Shape on Their Own?

Yes, and the change is permanent, since your teeth cannot grow new enamel.

Worn or Flattened Edges

Grinding or clenching your teeth (bruxism) can happen while sleeping or while awake. It can wear your teeth down, leading to flat biting edges and chipped or cracked teeth. If your front teeth look shorter or flat, that’s a common sign of grinding.

Cupped Chewing Surfaces

Acid from food, drinks or stomach reflux dissolves enamel, a process called dental erosion. It leaves shallow cupped dips or smooth, flat spots on back teeth.

Chipped or Broken Teeth

Biting on hard objects or an accident can chip teeth or break off cusps (especially around large old fillings).

This causes a sudden change in shape with a sharp jagged edge, but don’t try and file it off yourself as enamel does not grow back.

Tooth Decay

When tooth decay breaks down the enamel and dentin (softer inner part of the tooth) it causes small holes (called cavities). If the decay grows larger it can weaken the cusps of your back teeth and cause them to crack or break off.

How to Change the Shape of Your Teeth

Dentists can alter the shape of your teeth by adding to the tooth, taking some enamel off or reshaping your gums. Most of these changes are irreversible so should be considered carefully.

Crowns or Veneers

Crowns cover the whole tooth and restore the shape, size and strength of broken, worn, badly decayed, root canal-treated or misshapen teeth.

Veneers are thin shells bonded to the front of your teeth. Veneers are used primarily for cosmetic purposes and are not reversible as a thin layer of enamel needs to be removed from your tooth for them to fit. Veneers can fix:

• Chipped or broken teeth
• Small, pointy or misshapen teeth (like peg laterals)
• Small gaps between your teeth
• Stains that tooth whitening cannot remove

Dental Bonding

Dental bonding is when the dentist sculpts tooth-colored resin onto your tooth and hardens it using a special light. Bonding fixes small chips and gaps and alters the shape of short or misshapen teeth. Dental bonding usually needs touching up or replacing every 3-10 years.⁹

Enameloplasty

Enameloplasty or tooth contouring is when a little enamel is removed to smooth down chipped teeth, even the edges of teeth or remove mamelons (bumps).

As enamel doesn’t grow back, only a small amount is removed, otherwise the tooth is weakened and this can lead to sensitivity and raise your risk of cavities.

Gum Reshaping

Gingivectomy (gum contouring) is when some of your gum is removed or reshaped. This is used to fix ‘gummy smiles’ where too much gum makes the teeth appear short. The results are usually permanent, but in some people the gum can grow back.

Orthodontic Treatment

Braces or clear aligners don’t change the shape of your teeth, but they can move them to improve the way they line up and the appearance of your smile. Straight teeth are also easier to keep clean.

When to See a Dentist

A tooth whose shape changes needs a dental visit, especially if it hurts or feels sensitive. A shape you’ve always had may need no treatment. Even if it doesn’t bother you, have your dentist check whether it affects your bite, tooth strength or decay risk.

Book a visit if you notice:

• Worn, flat or chipped edges on your front teeth
• A new sharp or jagged edge, or a broken-off piece of tooth
• A hole, dark spot or rough patch on a tooth
• Cupped or flattened spots on your back teeth
• Pain or sensitivity to hot, cold or sweets with a shape change (book soon, since this can mean a cavity, crack or exposed root)
• In a child, a tooth with an unusual shape, pits, grooves or discoloration. Call your child’s dentist to ask how soon it should be checked, rather than waiting for symptoms. Get prompt care for pain, sensitivity or visible breakdown.³
• A shape or gap you’d like to change with bonding, veneers, contouring or orthodontics

Call your dentist for a same-day visit if a tooth breaks in an accident, you have severe tooth pain, or your gums or face swell. Facial swelling with a fever needs the ER if you can’t see a dentist right away. Swelling with a fever but no clear dental cause needs medical care the same day.

Call 911 if swelling makes it hard to breathe or swallow. Go to the ER now for:

• Swelling that spreads fast or toward your eye or neck
• Trouble opening your mouth along with facial swelling
• A swollen or painful eye, vision changes or a lot of swelling inside your mouth