It is better to get your braces done first before your crown. This is because the tooth and gum position will move and it may affect the final crown work. The crown surface may also be damaged during braces work (risk is small) which means that you may need a new crown after braces.
If you want to be treated with subsidy you will need a polyclinic referral letter. However please note that there are no subsidies for any orthodontic treatment. You can be seen by the postgraduate students at NUS for a slightly reduced price for braces if you wanted to.
In terms of wisdom teeth, it is better to consult the orthodontist first prior to extractions as sometimes other teeth may need to be extracted alongside the wisdom teeth.
Hope this helps. Good luck!
