Canker sores are the most common and non-contagious form of mouth sores. These sores can be caused due to various reasons and are scientifically known as Aphthous ulcers. Burning sensations, tingling or a pain inside the mouth is an indication towards ulcers. Medically speaking these are white or yellow lesions circled by an inflamed, red border that occur on the mucus membranes inside the mouth. Although the actual cause of these ulcers remains unknown, still the doctors can predict ce...