Maltese dogs are pretty hardy dogs but yes they're indeed more prone to health problem than other dogs are.
Common health problems that Maltese dogs face more than other dogs are, Leg problems, Bladder Stones, Tooth problems, Bad Breath, Eye Problems and ear problems.
Maltese dogs are a pretty healthy dog breed though so I wouldn't worry too much. Just make sure to have your Maltese dog checked up at the vet more often than other dogs and your dog should just be fine.