There are some things to be aware of regarding Maltese (and other toy breeds) mouths and teeth. Maltese, due to downsizing from their larger breed counterparts, have unique problems that are not generally seen in bigger dogs.
Larger breeds start getting their first puppy teeth at around 4 weeks of age and, in fact, have begun weaning at this age. Maltese are much further behind. Often the canines don't begin poking through until about 5 weeks of age, with molars and incisors erupting at about 6-7 weeks. Because of this, Maltese puppies often do not being weaning until about 6 weeks of age and do not begin eating reliably until 9-10 weeks of age. This is one reason why a toy breed should never be sold at a young age, i.e., before 12 weeks of age.
Maltese adult teeth are very slow to come in. Most breeds start losing baby teeth at 3-½ months of age. By contrast, Maltese often don't start until closer to 5 months of age. Vets are always amazed to still see mouths without their full complement of adult teeth at 5 months!
It is important to watch the mouths of puppies as their adult teeth come in. It is quite common to notice a puppy having difficulty eating during this time due to swollen gums and loose teeth. Softening their food can help through this period, and giving them something to gnaw on can help loosen the teeth. For example, you can saturate a wash cloth with water, twist it, and freeze it for a homemade teething ring. Massaging the gums may also help.
Many puppies don't lose their baby teeth (particularly the canines) in a timely manner and will need to have them extracted. For Maltese who have gone to pet homes, those teeth can be removed when they are spayed or neutered (after 6 months of age). It is important to get the baby teeth out as food can become trapped and tarter can begin to build up. For dogs destined for the show ring, if it looks like the mouth is overcrowded with adult and baby teeth, it would be wise to get the baby teeth out sooner than later to prevent the adult teeth from becoming misaligned.
One disappointment occasionally seen in the Maltese is when the bite “goes off” and results in an undershot (reverse scissors) bite. When this happens, the pup is placed as a pet as this is an inherited condition and not desired for breeding or show. A note for pet owners: There is no cause for worry about buying a puppy with an undershot bite. Many breeds are purposely bred to have undershot bites and have no problems eating, etc.
Once the adult teeth are in, it can't be stressed enough to start a regimen to keep the teeth clean. These smaller dogs have more problems with periodontal disease than large breed dogs or those with lots of room between their teeth. They are also prone to tarter buildup, gingivitis and early tooth loss. If the teeth are bad enough, bacteria can travel from the mouth to other parts of the body such as the heart, kidney or liver. There are many ways to look after the teeth—brushing (this is the best), dental rinses, dental chews, T/D diet, etc. Even then, Maltese may require periodic cleaning under anesthesia. Like humans, some Maltese are blessed with good teeth while others require regular maintenance. This goes for show dogs, too. There is nothing worse than showing a dog with dirty teeth. Judges are not impressed and it may even count against the dog if the competition is keen!