1 Introduction to Veterinary Dentistry

Why Veterinary Dentistry?

Just like humans need dental care, animals require veterinary dental care to maintain overall health. In addition to the discomfort caused by dental disease, the associated disease processes may cause systemic problems.

Dental Anatomy and Dental Terminology

Communication in veterinary dentistry is as important as communication in veterinary medicine. Medical records and charts must be annotated. Dental terminology differs from that of veterinary medicine because the focus is on the teeth and their relationship to each other and the mouth.

General Anatomy

To be able to recognize oral disease, technicians must first understand oral health. After establishing this baseline, technicians can recognize the changes that occur as oral disease progresses. Another reason that understanding normal anatomy is so important is that it helps veterinarians and technicians select the appropriate technique to use to prevent and treat disease. For example, without knowing the number of roots that a tooth has, the practitioner could not extract the tooth.

Types of Heads

Three types of skulls are common: mesaticephalic, brachycephalic, and dolichocephalic. These words have a common root, cephalic, which means head.

The upper jaw, called the maxilla, is made up of many bones (Figure 1-4). The incisal and maxillary bones hold the teeth. The roof of the mouth comprises the hard and soft palates. The hard palate is the portion of the roof of the mouth that consists of hard bone. The hard palate is covered with a mucous membrane that has irregular ridges, called the rugae palatinae. The incisive papilla lies behind the central incisors. The nasopalatine ducts exit on each side of the incisive papilla. The soft palate is the posterior portion of the roof of the mouth, which does not have underlying bone. This portion separates the oral cavity from the pharynx, which leads to the nasal cavity. Close observation reveals that the teeth are surrounded by the gingiva. The area in which the two jaws join in the back of the oral cavity is known as the lateral palatine fold.

FIGURE 1-4 The maxilla or upper jaw.

Mandible

The lower jaw is known as the mandible (Figure 1-5). It is connected to the maxilla by a hinge joint called the temporomandibular joint (TMJ). The two mandibles are fused together at the mandibular symphysis. The tongue lies between the two mandibles, and the structures and surfaces beneath the tongue are referred to as sublingual. The mandible is covered ventrally by muscle and skin. The oral cavity is covered with a mucous membrane, which becomes the gingiva at the mucogingival line.

FIGURE 1-5 The mandible or lower jaw.

Cheeks and Lips

The mucous membrane, or oral mucosa, is the tissue that forms the lining of most of the oral cavity outside the mucogingival line. The oral mucosa ends at the lips. The vestibule of the oral cavity is the part between the cheeks or lips and the alveolar ridge (Figure 1-6).

FIGURE 1-6 The vestibule is the area between the teeth/gingiva and cheek.

Tooth Anatomy

The puppy has 28 teeth, whereas the adult dog has 42 teeth. The kitten has 26 teeth, whereas the adult cat has 30 teeth.

External Tooth

The tooth may be divided into the crown, neck, and root (Figure 1-7). The tip of the crown is known as the cusp. The crown is covered with enamel, the hardest substance in the body. It will survive normal use and even some abuse without problems. However, it may fracture in patients who chew bones and other hard substances. Normally, enamel is present only above the gumline. Enamel is produced by cells called ameloblasts as the tooth is developing. Where the enamel thins close to the gumline, many teeth have a slight indentation. This indentation is known as the neck. Underneath the gumline is the root. The deepest part of the root is known as the apex. At the apex, blood vessels and nerves enter the tooth through a series of small channels known as the apical delta or through larger canals known as the apical foramen. The cusp is the tip or pointed prominence on the occlusal surface of the crown.