I am often asked about bite proof muzzles and the answer is that all muzzles are designed to prevent dogs from biting, some offering more protection than others. However very few companies, if any, will declare a muzzle bite proof as nothing is infallible.
The more enclosed a muzzle is, the more protection they are going to offer, however this often means they may be heavier, or not as good for running off lead due to reduced airflow through the muzzle which means it is warmer for them to wear.
As an owner you need to assess the risk, and a reactive dog on lead is under your close control so the muzzle is secondary to you moving the dog out of the way, and in these situations a basket style muzzle is often good enough.
Something else to consider is the ability to feed treats, and the ability for the dog to be able to drink. Dogs can drink in all of our muzzles, (in some cases the muzzle needs to be submerged into the water), however some styles make it more difficult or impossible to feed treats which may be important if the dog is in training.
Basket muzzles should always be the first choice for off lead running, and activities such as canicross, bikejor and lure coursing, however in some circumstances the dog may need a box muzzle to keep them and others safe.
A box muzzle offers more protection from their teeth and are also used to help prevent scavenging, which can be life threatening for some dogs. Any muzzle will hinder scavenging and a basket muzzle may be enough to hinder the dog and give you time to call them off, a determined scavenger who is making themselves ill may need a box muzzle that puts a physical barrier between them and the item they are trying to eat.
It is also important to take into consideration how much the muzzle interferes with the dogs sense of smell, and to a certain degree sight. A dogs sense of smell is vitally important to them exploring and experiencing their world, and the basket muzzles will allow them to do this better than the more enclosed box muzzles.