Answer
Wa `alaykum As-Salamu waRahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
If putting veneers is simply a cosmetic procedure, it is not permissible or desirable. If, however, it is a corrective procedure intended to correct a deformity, then it is permissible.
In responding to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
If putting veneers is simply a cosmetic procedure, it is not permissible or desirable. If, however, it is a corrective procedure intended to correct a deformity, then it is permissible.
Having said this, however, I must caution you against resorting to this procedure simply for cosmetic purposes; for to do so for mere cosmetic reasons is akin to mutilation of the creation of Allah.
If, on the other hand, it is considered a deformity and your teeth alignment causes you emotional and psychological harm as it invites jeers and laughs, then that is a genuine reason for undertaking such a corrective surgery.
The Prophet Muhammad (peace be upon him) told Aishah: “You are allowed to remove what is objectionable and causing harm!” One of the accepted principles of jurisprudence states, “harm/injury shall be averted”.
There are also precedents from the Prophet (PBUH) in the sources that he allowed his companions to resort to corrective procedures in case of broken teeth and noses.
Almighty Allah knows best.