How do molars and premolars differ?

The human dentition - what are molars and premolars?

Theirs is characteristic of the molars large occlusal surfacewhich has a relief of cusps (tubercles) and pits (fissures) for optimal chopping of the food. The molars have the largest chewing surfaces (medically occlusal surfaces) of all teeth in human dentition. In young people, but also in adults with pronounced fissures and an increased risk of tooth decay, the dentist can seal the fissures in order to fluoridate and protect the chewing surfaces.

The smaller premolars (Latin "Dentes premolares") usually have two, less often three, cusps. Another name for the premolar tooth is therefore bicuspid - composed of the two Latin words "bi" (= two, twice) and "cuspis" (= point).

The molars are Teeth with multiple roots. In humans, the molars in the upper jaw have three roots, sometimes more. The usually particularly strong root on the palate is called the palatal root; the two smaller roots on the cheek side are called the vestibular roots. In order to be able to distinguish and name these two exactly, the anterior root on the cheek is medically correctly called the mesio-vestibular root and the posterior disto-vestibular root. Most dentists abbreviate this: palatal, mesial and distal roots. It's easier to pronounce, and every dentist knows immediately what is meant by it.

The lower jaw molars each have two roots, one anterior (mesial) and one posterior (distal). All molars have at least one root canal per tooth root. The fact that there are often more root canals than tooth roots can make root and root canal treatments more difficult. To find the root canals and reach them precisely, the dentist can use a special microscope. This is often more helpful in this demanding work than the X-ray images, on which the fine canals, their length and their exact course can often hardly be seen.

The wisdom teeth can also be counted among the molars. The number of their roots, however, is very variable. Some wisdom teeth only have one root, others two, three, four or even five. Because of their position at the very back of the row of teeth - and because the "eights" in the jaws of "modern" people often have too little space - the roots of wisdom teeth are often severely deformed, for example crooked, stunted or barbed. This can lead to complications when removing the wisdom teeth. But the dentist is already prepared for this, because X-rays are usually made before pulling or operating on a wisdom tooth.