You may not think of straightening teeth as a necessary procedure, but it is much harder to clean teeth that overlap because there are more places for bacteria and plaque to accumulate. This, in turn, leads to cavities or periodontal disease.
Correcting overbites, under bites and misaligned jaws has more importance than just aesthetics. Leaving these issues uncorrected can lead to gum damage, difficulty in speaking and chewing, unnecessary wear and damage on teeth, jaw pain and even sleep apnoea.