In addition to orthodontics, teeth straightening can also be done using restorative methods such as veneers and full crowns. Orthodontics, through the use of fixed or invisible braces, encourages the teeth to move slowly and then the alveolar bone is remodeled, thus aligning the teeth and correcting the occlusal relationship between the upper and lower teeth. For mild crowding or tilting of the teeth, a small amount of tooth tissue on the labial side can be abraded, and all-ceramic veneers can be fabricated for bonding. For moderate crowding or proclination, the teeth can be prepared to change the long axis of the teeth, and the fabricated porcelain or all-ceramic crowns can be bonded to the abutment teeth to improve the appearance of the teeth.