Hello mam..
There is no age restriction for braces treatment...you can proceed with orthodontic treatment...The cost of the orthodontic treatment varies with the type of braces used..
If it is a metal braces the cost will be Rs.25,000
If it is a tooth coloured ceramic the cost will be Rs.35,000
Black spot on your teeth may be due to stains and deposits or due to Dental caries...
Complete clinical examination is necessary to rule out the cause and management
Next Steps
kindly visit dentist for furthur clinical examination and management