When we observe cats, we often focus on their external appearance, such as the luster of their fur or the deep pupils of their eyes. The teeth and mouth are often overlooked by owners. Often, it's only when the cat opens its mouth and emits an unpleasant odor that they begin to pay attention to its teeth and mouth. Dental care is extremely important for cats and is the best defense against dental diseases. 
1. How many teeth does a cat have?
Cats are carnivores, and their teeth are naturally arranged and have special functions to adapt to hunting behavior and defense.
Normally, cats have an average of 28 permanent teeth, and regardless of breed, they generally have about 26 to 34 teeth. Among them, the canines are the longest and are usually used as sharp tools for grasping or biting things; the premolars are smaller and their main function is to grind food; the molars can cut food into small pieces for easy swallowing, a process called chewing; while the row of small incisors at the very front of the mouth actually has no function.
Kittens begin losing their baby teeth around four months of age, and they almost always replace them with permanent teeth around six months of age. At this time, it is common for permanent teeth to have grown in while baby teeth have not yet fallen out. If two teeth occupy the same spot, a veterinarian should be consulted to remove one of them.
In addition, malocclusion or asymmetrical teeth are common in some breeds of cats (e.g., Persian cats). This condition does not necessarily require correction unless it causes illness.
II. Tooth Growth
Generally, kittens begin to grow their milk canines (two sharp teeth on each side of the upper and lower jaws) and small incisors on the second or third week after birth, and by the fifth week, all their milk teeth have grown in.
Baby teeth are fully erupted in 2-3 months, and the process of losing baby teeth begins.
Starting around five months after birth, kittens begin losing their canine teeth. At this time, if you open a kitten's mouth, you can often see slightly red gums around the canines; this is a sign that new teeth are coming in. A week or two later, you'll see four canine teeth on the kitten's upper or lower jaw—two teeth in the same position, one slightly larger—these are the newly erupted teeth. As the new teeth grow, the baby canines gradually loosen, fall out, and are spat out by the kitten. If you observe carefully, you might find some of your kitten's shed teeth; keeping your kitten's baby teeth can be considered a keepsake!
When kittens are four or five months old, they are in the teething stage and may have a poor appetite. At this time, you should pay attention to the growth of the teeth in the kitten's mouth and provide it with easy-to-chew food to protect the new teeth.
Kittens begin to wear down their lower incisors a year after birth, and their canines begin to wear down after seven years. By the seventh year, the lower incisors are worn down to a rounded shape; by the age of ten, kittens have lost all of their upper incisors. Attentive cat owners should observe these changes in their cat's teeth and prepare different foods accordingly to promote their cat's health. By six months, all permanent incisors have grown in. After one year, the lower incisors begin to wear down, after five years the canines begin to wear down, after seven years the lower incisors are worn down to a rounded shape, and after ten years or more, the upper incisors are worn down to a rounded shape.
Cats reach adulthood when they grow new fur at 6 months old, enter middle age at 6-7 years old, at which time white whiskers grow on their mouths, and in old age, white fur grows on the back of their heads. 
III. What are some common dental problems in cats?
Generally speaking, more than one-third of cats over three years old have various degrees of dental disease. By the time they are ten years old, most of their teeth have fallen out, which can lead to problems in other parts of their bodies.
The most common dental clinical cases in cats, namely degenerative dental diseases, include the following:
1. Tartar and halitosis
Cats' teeth are prone to tartar buildup, and the process is very similar to that of humans. Tartar is formed from bacteria, saliva, and food debris, and eventually mineralizes to form tartar. Unless cleaned regularly, severe tartar buildup and bad breath will occur. Excessive tartar can cause gingivitis, leading to bone loss around the teeth and eventually exposing the tooth roots. Soon after, when a cat's teeth start to have problems, there are usually only minor external symptoms. By the time loss of appetite occurs, it means that the teeth are already quite painful and have begun to prevent eating.
2. Gum ulceration and broken teeth
Gingival ulcers are also known as "isthmic lesions" (meaning lesions occurring at the junction of the tooth and gum). They usually appear as ulcers along the gum line in young kittens, eventually destroying the entire tooth structure. Once the tooth is damaged, it becomes prone to breakage. In addition, when the ulcer spreads to the root of the tooth, it can lead to root abscesses. Unless it occurs on the upper teeth, it is difficult to detect obvious symptoms.
It is worth noting that some veterinarians may recommend extracting these teeth and filling them, but there is increasing evidence that this method cannot stop the condition from worsening. Therefore, regular dental cleanings and good daily hygiene are the most effective treatments.
Trauma or disease (such as gingival ulcers) can cause teeth to break. If the breakage occurs in the pulp cavity, it will quickly cause pain and inflammation. However, from the outside, you will usually only see that the cat has no appetite, or tilts its head to one side when eating, and avoids chewing food with the painful teeth. Then, due to secondary bacterial infection, it may gradually develop symptoms such as loss of appetite, fever and facial swelling. If it can be detected in the early stage of the disease, a veterinarian can perform repair work. However, most veterinarians currently treat it by extraction.
3. Stomatitis
The causes of feline stomatitis are complex. Currently, it is generally believed that immunodeficiency is one of the causes, while other factors play a stimulating role. These other factors mainly include viral infections such as feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), feline calicivirus (FCV), and feline herpesvirus (FHV); persistent bacterial and fungal infections of the oral cavity; nutritional factors; certain systemic diseases can also cause oral ulcers, such as uremia and diabetes; chronic inflammation caused by trauma, such as irritation from ingesting foreign substances; certain types of oral tumors, such as squamous cell carcinoma and gingival tumors; dental and gingival diseases such as dental caries, dental abscesses, tartar, gingivitis, and gingival hyperplasia; oral ulcers caused by feline eosinophilic granuloma; and malformations of the teeth, hard palate, and pharynx.
If treatment is delayed, it will cause a severe inflammatory response that damages the gum tissue and destroys the teeth. Treatment may include steroid medications, professional dental cleanings at least every three months, and proper daily dental care, which will improve the condition. However, to completely cure the condition, all damaged teeth must be extracted. 
IV. How to maintain dental health
The most important preventative measure is to have your cat's teeth cleaned regularly. Although teeth cleaning requires anesthesia, it can be done in an outpatient setting without hospitalization.
Typically, a veterinarian will first remove plaque and tartar from the surface and roots of the teeth. If diseased or damaged gum tissue is found near the roots, it will be treated appropriately. Then, the teeth will be ground down to smooth the surface and slow down the formation of plaque. Finally, the teeth will be rinsed with an antibiotic solution to prevent infection. This completes the teeth cleaning process, which takes about an hour.
It is important to note that some veterinarians may use only their fingers or tools to scrape away tartar directly from a cat's teeth without anesthesia. This practice can cause serious damage to the adjacent gum tissue, and I do not recommend it.
In principle, veterinarians can solve many special dental problems. For example, root canals can relieve abscesses in the root area, gingival caps can fix exposed roots, and they can be used to assist with malocclusion. However, due to the professional technical requirements, such medical procedures are best performed by professional and experienced veterinary dentists.
When kittens are teething, it's important to carefully check if their baby teeth have fallen out. Unfallen baby teeth can hinder the normal growth of permanent teeth, causing them to become crooked, resulting in malocclusion and food residue buildup. Small dogs are particularly prone to retaining baby teeth, but this is less common in cats.
Harder kibble and chew toys help clean a cat's teeth, but if possible, cats should also be accustomed to having their teeth brushed regularly. Once a kitten is weaned and transferred to its new owner, you can begin to get it used to having its owner check and clean its mouth.
Harder foods with low moisture content, such as dry food and cat biscuits, can help remove plaque from a cat's teeth by rubbing against them. However, real bones from animals like pigs, cows, chickens, and ducks are sometimes chewed into small pieces and swallowed by cats, which can harm their digestive system. Therefore, it's best not to give them real bones as a dental cleaning tool.
In any case, if your cat doesn't receive any effective dental care at home and never has its teeth cleaned or professionally cleaned by a veterinarian, then stubborn tartar will be impossible to remove. Therefore, establishing proper preventative measures is essential; otherwise, it will be too late once your cat has a mouthful of rotten teeth and tartar.
