Description and Function
The teeth are calcified structures contained within the mouth that are rooted into the upper and lower jaw. There are thirty-two human teeth with several functions such as breaking down food for digestion, speech, breathing, and providing structure to our face.
Structure of Teeth
The tooth can be divided into the crown and the root. The crown of the tooth is the area which is visible and the root is any part of the tooth embedded within the jaw.
The crown is covered by a strong substance called enamel which protects the inside of the tooth. Underneath the enamel lies the dentin, which has a critical role in protecting the inner pulp cavity, this part of the tooth is very sensitive as it contains vessels and nerves.
The root of the tooth is the part that sits within the jawbones. Part of the pulp cavity continues into the root. Cementum is a substance which covers the surface of the root and helps to attach teeth to the bone through the periodontal ligament.
Types of Teeth
In humans there are two types of teeth, primary teeth (milk teeth) and permanent teeth (adult teeth). Primary teeth are made up of eight incisors, four canines and eight molars. Permanent teeth consist of eight incisors, four canines, eight premolars and twelve molars.
The incisors help with biting pieces of food. The canines are used for tearing pieces of food. The premolars and molars crush and grind food into smaller pieces for the first stage of digestion.
Blood Supply to Teeth
Blood supply to the teeth is important and prevents structures in the mouth from decaying. The maxillary artery is the main supply to the mandible and the upper teeth. This artery gives rise to the inferior alveolar artery which supplies the mandible (lower jaw).
Nerve Supply to Teeth
Nerves of the teeth are located within the pulp and provide sensory information such as temperature. The maxillary branch of the trigeminal nerve provides sensory innervation to the teeth in the upper mouth. The mandibular branch of the trigeminal nerve provides sensory innervation to teeth in the lower mouth.