Since 1990, the ADA has defined oral and maxillofacial surgery as "the specialty of dentistry which includes the diagnosis, surgical and adjunctive treatment of diseases, injuries and defects involving both the functional and esthetic aspects of the hard and soft tissues of the oral and maxillofacial region. Oral and Maxillofacial Surgeons in the US and many other nations have 4 to 7 years of hospital based residency training following the 4 year dental curriculum and receipt of the DDS or DMD degree. They treat conditions, defects, injuries, and esthetic aspects of the mouth, teeth, jaws, and face. It involves caring for patients who have problem wisdom teeth, facial pain, and misaligned jaws. Oral and maxillofacial surgeons also treat accident victims suffering facial injuries, offer reconstructive and dental implant surgery, and care for patients with tumors and cysts of the head and neck. This category includes informational and educational sites involved with all aspects of oral and maxillofacial surgery.