Periodontal Disease—
This is the most frequent cause of loss of teeth in cats and dogs.
Certainly there are teeth lost to lesions in cats, fractures in both
species can result in loss of teeth, and cavities can destroy teeth, yet
most teeth are lost because of the destruction of the supporting
structures f the teeth, not because of pathology in the teeth
themselves.
The Role of Plaque—
Periodontal means- around the teeth and periodontal disease is disease
of the gingival (gums), periodontal ligament, and bone. The progression
of periodontal disease is the same for animals as for people.
Plaque consists of three main elements. The first is bacteria. Some of
the bacteria we take into our mouths is benigh, it will not hurt us
because it is basically noninvasive, the stomach will take care of most
bacteria with its acid bath, or we already have a degree of immunity to
it. The normal bacteria of the mouth is considered nonpathological, like
the normal bacteria on our skin.
People have essentially the same bacteria in their mouths as cats and
dogs do. Normal oral bacteria are beneficial because their presence
inhibits other microorganisms, like disease-causing bacteria or fungi,
from becoming established.
The Second is Saliva. Saliva provides the moist environment that allows
the bacteria to live.
The Third component is food, which nourishes bacteria as well as
ourselves. That is why we would have to be dead if we didn’t have
plaque—because, like bacteria, we could not live without eating.
Undisturbed plaque undergoes two changes
with time. One change is that minerals in the saliva, especially
calcium, impregnate the soft plaque matrix and cause it to gradually
harden into dental calculus, the common name of which is tartar. In
addition, the dominant type of bacteria tends to change as periodontal
disease progresses. The thicker plaque and calcifying plaque tend to
shield bacteria from air and oxygen, and a different population of
bacteria begins to poliferate—anaerobic rods and spirochetes, which are
generally gram-negative and disease causing. As soon as this population
takes over, periodontitis begins in earnest.
Gingivitis, The first sign of Periodontitis
The acids and other by-products of metabolism of the normal flora, when
produced in abundance, can cause a reaction in the gingival. This first
affected the area adjacent to the plaque, the edge of the free gingival
margin, Its reaction to redden and swell, which is caused by the tissue
mobilizing an increased blood supply with white cells to fight the
invading bacteria. As the area begins to swell, it loses its ability to
cling to the tooth surface like think rubber on a bathtub. As a result
of relentless attach on the gingival without periodic removal of plaque
and calculus, bacterial colonies, and then plaque and calclus, are
established underneath the marginal gingival. The anaerobic bacteria are
now free to attach the attachments of the tooth. Gingivitis like this is
stage 1 of periodontitis and is totally reversible.
Attachment Loss—
Once bacteria infect these tissues, the attachments are assaulted by the
bacteria’s destructive capabilities combined with the tissue-dissolving
enzymes of the neutrophils responding to their presence. The tissues die
and serve as nourishment for the bacteria that thrive in dead tissue.
True tooth attachment has now been lost this is full-blown periodontal
disease.
The next area to be affected is the periodontal ligament, as the
ligament is destroyed, adjacent bone is also affected to a lesser
extent. The infection proceeds toward the root tip and the periodontal
pockets are formed.
Periodontal pockets 4 mm in dogs 2 mm in cats or beyond now need cleaned
out and closed root planing done.
Further Progression-
If let go you will end up with recession (loss) or hyperplasia (abnormal
and excessive growth). Once it has progressed this far there is
extensive bone loss under the gingival and there is no longer bone to
support the teeth. Finally in advanced cases, the gingivia is completely
destroyed, and the lesion continues all the way to the mucosa. When it
progresses far enough the tooth becomes loose and typically, two-thirds
of the periodontal ligament must be destroyed before a tooth shows
movement, but this differs by the tooth. As a rule, any movement of a
tooth with more than one tooth spells extraction because it takes
extensive periodontal ligament and bone destruction to effect
displacement.
There is an exception to the general movement rule. The lower incisors
may show slight or even advanced movement without signs of periodontal
pockets or even inflammation of the gingival. Why? This phenomenon,
sometimes called periodontosis, is usually seen in small dogs, it occurs
because there is so little space between teeth. In x-rays the teeth
appear to be floating in space. The teeth are useless and will come out
easily because they are merely anchored in the gingival.
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