On the Cusp of a Dental Discovery: How Teeth Sometimes Have Extra Cusps

When you look closely at your teeth, you can easily imagine the role played by each one during the mastication of food. The only teeth that do not possess cusps are incisors, the four upper and four lower teeth in the front of the mouth. The further back you go into the mouth, the more cusps each tooth has.

Cusps Tear and Break up Food

Canine teeth, or eyeteeth, have one cusp. This protrusion helps canine teeth to rip chunks of food into smaller pieces. Once cut by the incisors and ripped by the canine teeth, pieces of food naturally drift back to the pre-molar and molar teeth. Pre-molars have two cusps, and molars generally have 4-5 cusps, all used to grind and tear food into small particles.

However, some people have more cusps than usual. These extra cusps are known as accessory cusps and can be present on molars, incisors and canines.

Cusp of Carabelli (Molar Cusp)

Accessory molar cusps are generally present on the first molar of the upper jaw and, in rare cases, can even be bilaterally present. Instead of having 4 cusps, the first molar has 5 cusps, with the fifth cusp located on the lingual, or tongue-side, of the tooth. Dental professionals refer to this extra cusp as a cusp of carabelli or carrabelli's tubercle.

In 1842, Dr. Georg Carabelli, a Hungarian dentist and Professor of Dental Surgery at the Academy of Petrograd (St. Petersburg from 1991) in Russia, discovered what then came to be known as the cusp of carabelli. Research shows that the presence of this cusp is an indication of European heritage.

Talon Cusp (Incisor and Canine Cusp)

Talon cusps, so called because of their similarity in appearance to an eagle's claw, are generally present on permanent, upper central and lateral incisors. In rare cases, they may also appear on upper canines or lower central incisors. Since these accessory cusps are usually located on the backs of teeth, an affected tooth may resemble the letter "T" when viewed from below.

A person that has one or more talon cusps is likely to have Asian, Inuit or Native American ancestry.

Accessory Cusps Require Good Dental Hygiene

A patient that has one or more of the aforementioned accessory cusps should take care to include the extra cusp when cleaning their teeth. An extra cusp, in both cases, means at least one extra groove or pit to clean.

If you have a carabelli or talon cusp, be sure to include the area around it in your daily oral hygiene routines. For more information, contact a local dentist.