Bruxism is excessive teeth grinding and jaw clenching during the N2 stage of non-rapid eye movement sleep. Risk factors include stress, young age, aggressive or hyperactive personalities, tobacco, caffeine, and methamphetamine
or ecstasy. Symptoms are usually absent, but may include hypersensitive teeth, aching jaw muscles, headaches, tooth wear, damage to dental restorations (e.g. crowns and fillings) and damage to teeth. Diagnosis is usually by clinical examination, or sleep studies in selected cases. Treatment depends on the underlying diagnosis and may include mouth guards, dental correction, stress management, behavior therapy, muscle relaxants
, or Botox injections (for severe cases).