7mm overjet, about 4-5 cm overbite...Braces?

Braces alone will not fix your problem. To have this large of an overjet and overbite means you have several problems: your upper jaw is underdeveloped, your lower jaw is retruded, your teeth are more than likely crowded and you over close.There are basically three ways to fix your problem: 1) extract teeth to create space then use braces to straighten the teeth. The problem with this approach is that you will be left with an upper and lower jaw that are still underdeveloped and a a retruded lower jaw. Your teeth will be straight, your overjet and overbite may be fully corrected but underdeveloped dental arches and retruded lower jaw can lead to a myriad of dental and medical problems; including compromised facial aesthetics, TMJ Dysfunction and sleep apnea. 2) you can develop the upper and lower jaws and surgically move the lower jaw forward. This is a far better approach to treatment as it resolves all of your concerns. However, surgery is expensive and invasive. 3) you can develop the upper and lower arches and move the lower jaw forward with an appliance. This takes more time but is less expensive and much less invasive. The development of the upper and lower jaws can not be accomplished with braces but is done with removable appliances that are comfortable and non intrusive.Good luck!