3. Teeth straightening
There are two ways to straighten teeth, either cosmetically or with orthodontics - the area of dentistry concerned with the prevention and correction of irregularities of the teeth.
What's it for?: For people with crowded teeth, crooked teeth or tilting teeth. All these problems can trap food which can lead to gum disease and tooth decay.
Stars who have opted for this treatment are Victoria Beckham, Sienna Miller, Kate Beckinsale, Daniel Radcliffe
• Cosmetic teeth straightening
How it works: The patient is given a local anaesthetic. The dentist uses an electrosurge unit - a surgical device which uses heat to remove fragments of gum - to reshape the gum and suit the shape of new veneers. The teeth are drilled ready to receive the new veneers. Each veneer is then bonded to the front of the tooth.
How long does it take?: Three appointments. Surgery takes one hour.
How long does it last?: Between two and five years.
Cost: From around £600.
How it works: A metal or tooth-coloured brace is fitted inside the whole of the mouth. Over time, the wires between each tooth push or pull the teeth to straighten them out.
How long does it take?: From one to three years, with follow up appointments every four to eight weeks.
How long does it last?: It varies from case to case, but the patient is advised to wear a retainer - otherwise the teeth can start to drift back to their original position.
Cost: From around £5,000.