How long does it take to close a 5mm open bite with braces?

Orthodontic : Could be 2 to 3 years depending on other issues such as crowding and malpositioning of teeth. If your bite is bad enough, surgery could be required to completely fix your problem. Don't concern yourself with getting fixed fast. Moving teeth too fast can cause serious problem like loss of part of the tooth roots or recession of the gums

Hard to say: without seeing your overall condition and bite. Its highly likely that other issues are also getting addressed during your treatment. That said, I would plan on about 2 years in braces. Much of this, BTW will also depend on your compliance-- elastic wear will be critical in both being effective and getting done sooner rather than later.

Cause?: Is open bite dental, skeletal, or both? Is your problem only vertical, or do you also have front-to-back or side-to-side problems. You don't need a computer, you need an Orthodontic Specialist. Go see a Pro (initial exam usually free). Don't try to self-diagnose, see an expert.

Depends...: An open bite is frequently due to poor tongue rest position between the front teeth instead in the roof of the mouth. This needs to be addressed by an orofacial myologist, or any orthodontic correction will ultimately fail. Orthodontic correction will be necessary to correct the bite and close the open bite. Time frames depend mainly on patient cooperation. In severe cases, surgery is required

Average 2 years: Average full band orthodontic braces is about 2 years.

2 years on average: It all depends how the rest of your bite is. If you need to expand the roof of your mouth as well it will take much longer. On average, orthodontic treatment requires 2 years.

Depends: The best thing you want to do is visit an orthodontist for a consultation. 5mm openbite could correct in a few months with a habit breaking appliance that doesn't cost anything, to being a very complicated situation that would require jaw surgery. So, there is no real one answer to your question. It really depends on the cause, nature and severity of the situation.

Open bit???: No orthodontic specialist can properly answer this question w/o comprehensive orthodontic records. I would also need to diagnose the etiology (cause) of the open bite. In many instances, the issue causing the open bite needs to be address prior to placing braces (tongue thrust, airway issues, digit habit). Only an orthodontic specialist can give you the answers AFTER a consultation.