Becoming aware of what your dog needs in oral health and hygiene can contribute to your pet’s overall health and well-being, says Dr. Frank Verstraete of the Veterinary Medical School at UC-Davis. Because periodontal disease often has a serious impact on a dog’s quality of life, learning the normal anatomy and structure of your dog’s teeth before any disease develops can provide you with the knowledge you need to give your pet prompt attention and good veterinary care.
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Anatomical Components
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Enamel, a crystalline, largely inorganic material, covers the exterior crown surface (the part above the gum line) of your dog’s teeth. The hardest substance in the canine body, according to Dr. Norman Johnston in “Oral Anatomy and Charting,” enamel protects the structure of the tooth formed by dentine, an acellular material that runs from the external surface to the pulp of the tooth.
The pulp of the dog’s tooth, contained inside the root canals and pulp chambers, holds blood vessels, nerves, collagen, connective and lymph tissues--all living substances. Cementum, similar to bone, covers the tooth roots and attaches to the periodontal ligament that holds the tooth in place on the alveolar bone, a densely vascular part of the animal’s jaw.
Attached Tissues
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Surrounding gum tissues, called gingiva, form pockets of nourishment for embedded teeth, bringing blood cells, skin cells and collagen to your dog’s teeth to keep them healthy and alive. Attached gingiva adheres to the tooth walls to withstand tearing and ripping of food. A pocket called the gingival sulcus encloses the tooth protecting the roots, while a band of tissue called free gingiva envelops the tooth crown and is visible to the naked eye. The bottom of the sulcus contains cells that attach the tooth root to the surrounding gingival tissues. This socket also holds what veterinarians call “crevicular fluid,” a substance that includes cells to fight microbes and bacteria.
Types and Functions
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The four types of dog teeth include incisors, canines, premolars and molars. Incisors, used for cutting, picking up objects and grooming, are located in the central front of the mouth on both upper and lower jaws. The canines, the large, pointed teeth directly behind the incisors, grasp and tear meat and prey with “great pressure,” says Dr. Jan Bellows of All Pets Dental Clinic. Premolars, the wide, pointed teeth behind the canines, hold and carry objects and break food into smaller pieces when chewing. The large, flat molars erupt in the back of the mouth and are used for grinding. Adult dogs typically have four molars in the maxilla, or upper jaw, and six molars in the mandible, or lower jaw.
Dentition
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Toothless at birth, a dog starts teething between 3 and 8 weeks of age, with all 28 deciduous (baby) teeth visible by the ninth week. Twelve incisors erupt between 4 to 6 weeks of age, the four canine teeth come in between 5 and 6 weeks, and by the 8th week your puppy should be showing all 12 premolars.
Permanent teeth begin replacing the deciduous teeth between the third and fifth month after birth with the incisors typically coming in first. The canines emerge next at 4 to 6 months of age, with 16 permanent premolars erupting at 4 to 5 months of age. By the time your dog is 5 to 7 months old, all 10 molars should be visible for a total of 42 permanent teeth, according to PetEducation.com.
Morphology
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Dogs, like humans, have what veterinarians call “brachydont” or low-crowned teeth. This form and structure of tooth, common among other carnivores such as cats and pigs, consists of a crown that shows above the gumline, a smaller neck at the gum line, and a deep root tied to the jawbone. This differs from the “hypsodont” or high-crowned teeth of horses and other herbivores in that dog teeth only erupt at one time in the animal’s life and stop growing once the animal is mature, according to Melissa Rouge of Colorado State University.
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