Mechanical
Common causes of oral ulceration include rubbing on sharp edges of teeth, fillings, crowns, false teeth (dentures), or braces (orthodontic appliances), or accidental biting caused by a lack of awareness of painful stimuli in the mouth (e.g., following local anesthetic used during dental treatment, which the person becomes aware of as the anesthetic wears off).Eating hard foods (e.g., potato chips) can damage the lining of the mouth. Some people cause damage inside their mouths themselves, either through an absentminded habit or as a type of deliberate self-harm (factitious ulceration). Examples include biting the cheek, tongue, or lips, or rubbing a fingernail, pen, or toothpick inside the mouth. Tearing (and subsequent ulceration) of the upper labial frenum may be a sign of child abuse (non-accidental injury).Iatrogenic ulceration can also occur during dental treatment, where incidental abrasions to the soft tissues of the mouth are common. Some dentists apply a protective layer of petroleum jelly to the lips before carrying out dental work to minimize this.The lingual frenum is also vulnerable to ulceration by repeated friction during oral sexual activity ("cunnilingus tongue"). Rarely, infants can ulcerate the tongue or lower lip with the teeth, termed Riga-Fede disease. Thermal and electrical burn
Thermal burns usually result from placing hot food or beverages in the mouth. This may occur in those who eat or drink before a local anesthetic has worn off. The normal painful sensation is absent and a burn may occur.
Low-set ears are a clinical feature in which the ears are positioned lower on the head than usual. They are present in many congenital conditions. Low-set ears are defined as outer ears positioned two or more standard deviations lower than the population average. Clinically, if the point at which the helix of the outer ear meets the cranium is at or below the line connecting the inner canthi of eyes(bicanthal plane), the ears are considered low set.Low-set ears can be associated with conditions such as:

Down syndrome
Turner syndrome
Noonan syndrome
Patau syndrome
DiGeorge syndrome
Cri du chat syndrome
Edwards syndrome
Fragile X syndrome
Okamoto syndromeIt is usually bilateral, but it can be unilateral in Goldenhar syndrome. See also
LEOPARD syndrome

References


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