Facebook eventually filed for an initial public offering on February 1, 2012. Facebook held an initial public offering on May 17, 2012, negotiating a share price of US$38. The company was valued at $104 billion, the largest valuation to date for a newly listed public company.
No one knows what causes these small, painful blisters inside your mouth. Triggers include hypersensitivity, infection, hormones, stress, and not getting enough of some vitamins. Also called aphthous ulcers, canker sores can show up on the tongue, cheek, even your gums.
Here are some other causes of mouth ulcers: 1  Food allergies. 2  Eating acidic fruit such as oranges, tomatoes and pineapples. 3  Viral/bacterial infections.  Poor oral 1  hygiene. Gum disease. 2  Sinusitis. A deficiency of Vitamin  B. Dysfunctional immune 1  system. Poor digestion.  Stress.