Sir can i straighten my front teeth by applying manual pressure ? is there any side effect or some kind of precaution to be taken ? ??

Self treatment: Trying to straighten your teeth manually simply won't work and even if you were able to make slight improvement, the teeth won't stay in place. Seek qualified Orthodontic treatment or accept what you have. Orthodontists have years of training and experience and special appliances and materials to achieve their goals.

Bad idea: As you have no control over the exact force and vector to which it is applied, manual pressure to move teeth is not recommended. Furthermore, if you have gum disease you can cause serious complications including but not limited to, tooth loss. See a Dentist for a consultation.

No: No chance of success, You can damage or loosen teeth. See orthodontist.

No: Teeth are moved by applying a low amount of pressure over a long period of time. So unless you were going to stay up all night every night and apply pressure you cant do it. Plus you wouldn't know exactly what direction the pressure needed to be applied in.

You're 16: It will take about another dozen years of training to know where to apply force without causing supporting tissue damage, how much force to apply, and how to create the appropriate space to accommodate the straightened teeth. Please don't do damage to yourself. This isn't a DIY project, or Home Depot would have a tooth straightening kit to sell you. Please see a qualified Orthodontic Specialist

Not recommended: See an orthodontist who is a specialist and has 2-3 years of additional education, and is an expert in straightening your teeth and choosing the best treatment option for your smile and your function.