Orthodontic Treatment would purely depends on the criteria such as Spacing, Crowded, crooked teeth. Basically it may be around 12-18 months with Braces. Cost factor depends on criteria and type of Braces you choose ( Metal, Ceramic, Damon ). Aligners would be expensive then Braces. And Confining to your question
- Age is not an issue until your gums and bone support is fine.
Next Steps
Lateral Cephalogram, OPG X rays
Health Tips
Clinical consultation can give you better idea.