Dental anatomy is the study of the structure and function of the teeth and their supporting tissues. Dental anatomy is important for understanding how to maintain good oral health, prevent dental problems, and perform dental procedures. In this article, we will cover the basics of dental anatomy, including the types, names, and parts of teeth, as well as their blood supply and innervation.
Types and Names of Teeth
Humans have two sets of teeth during their lifetime: deciduous (baby) teeth and permanent (adult) teeth. Deciduous teeth start to erupt around 6 months of age and are replaced by permanent teeth between 6 and 12 years of age. Deciduous teeth are 20 in number, while permanent teeth are 32 in number.
The teeth are divided into four quadrants: upper right, upper left, lower right, and lower left. Each quadrant contains four types of teeth: incisors, canines, premolars, and molars. Incisors are the front teeth that are used for cutting and biting food. Canines are the pointed teeth that are used for gripping and tearing food. Premolars are the teeth behind the canines that have two cusps (points) and are used for grinding and crushing food. Molars are the largest and strongest teeth that have four or more cusps and are used for chewing and mashing food.
The teeth are named and numbered according to different systems. The most widely used system is the FDI notation system, which assigns each tooth a two-digit code. The first digit indicates the quadrant (1 for upper right, 2 for upper left, 3 for lower left, 4 for lower right) and the second digit indicates the position from the midline (1 for central incisor, 2 for lateral incisor, 3 for canine, 4 for first premolar, 5 for second premolar, 6 for first molar, 7 for second molar, 8 for third molar). For example, the upper right central incisor is 11 and the lower left second molar is 37.
Parts of a Tooth
A tooth consists of two main parts: the crown and the root. The crown is the visible part of the tooth above the gum line, while the root is the hidden part of the tooth below the gum line that anchors it to the jawbone. The crown and the root are connected by a narrow region called the neck.
The tooth has three layers of tissue: enamel, dentin, and pulp. Enamel is the outermost layer that covers the crown. It is the hardest and most mineralized tissue in the body that protects the tooth from wear and tear. Dentin is the middle layer that forms the bulk of the tooth. It is a yellowish-white substance that supports the enamel and transmits sensations to the pulp. Pulp is the innermost layer that fills the pulp chamber in the crown and the root canal in the root. It is a soft tissue that contains blood vessels, nerves, and connective tissue that provide nourishment and sensation to the tooth.
Blood Supply and Innervation of Teeth
The blood supply of teeth comes from branches of the maxillary artery (for upper teeth) and mandibular artery (for lower teeth). These arteries give rise to smaller arteries that enter each tooth through a small opening at the tip of the root called the apical foramen. The blood vessels then branch into capillaries that supply oxygen and nutrients to the pulp tissue.
The innervation of teeth comes from branches of the trigeminal nerve (cranial nerve V), which is responsible for sensation in most of the face. The upper teeth are innervated by branches of the maxillary nerve (V2), while
the lower teeth are innervated by branches of
the mandibular nerve (V3). These nerves give rise to smaller nerves that enter each tooth through
the apical foramen along with
the blood vessels. The nerves then branch into nerve fibers that transmit pain,
and touch sensations from
the pulp tissue.
Dental anatomy is a fascinating subject that helps us appreciate