Is it permissible to close the gap between the front teeth?

Cosmetic procedures performed to remove a defect or deformity are permissible, such as in the case of Arfajah ibn As'ad's injured nose, for which the Prophet, peace and blessings be upon him, permitted him to wear a nose made of gold. Ibn 'Uthaymeen mentioned that cosmetic surgery to remove a defect is permissible, whereas excessive cosmetic surgery to enhance beauty is forbidden. Furthermore, a large gap between the teeth is considered a defect that may be corrected. Al-Nawawi indicated that what is forbidden are procedures done to seek beauty, but there is no objection to them for treatment or to correct a defect. The Permanent Committee for Scholarly Research and Ifta' issued a fatwa (definition) permitting the leveling of long teeth if they cause harm.