These lesions generally occur around the cervical areas of the dentition. Signs and symptoms
Abfraction lesions will generally occur in the region on the tooth where the greatest tensile stress is located. In statements such as these there is no comment on whether the lesions occur above or below the CEJ. One theory suggests that the abfraction lesions will only form above the CEJ. However, it is assumed that the abfraction lesions will occur anywhere in the cervical areas of affected teeth. It is important to note that studies supporting this configuration of abfraction lesions also state that when there is more than one abnormally large tensile stress on a tooth two or more abfraction lesions can result on the one surface.When looking at abfraction lesions there are generally three shapes in which they appear, appearing as either wedge, saucer or mixed patterns. Wedge and saucer shaped lesions are the most common, whereas mixed lesions are less frequently identified in the oral cavity. In reference to figure 1, wedge shaped lesions have the sharpest internal line angles and saucer/mixed shaped lesions are either smooth internally, or a variety. Clinically, people with abfraction lesions can also present with tooth sensitivity in the associated areas. This occurs because as the abfraction lesions appear, dentine/cementum is exposed. The dentine and cementum are less dense than tooth enamel and therefore more susceptible to sensation from thermal/mechanical sources. Causes
As abfraction is still a controversial theory there are various ideas on what causes the lesions.
Café au lait spots, or café au lait macules, are flat, hyperpigmented birthmarks. The name café au lait is French for "coffee with milk" and refers to their light-brown color. Café au lait lesions with rough borders ("coast of Maine") may be seen in McCune-Albright syndrome. In contrast, Café au lait lesions of neurofibromatosis have smooth borders ("coast of California").They are caused by a collection of pigment-producing melanocytes in the epidermis of the skin.These spots are typically permanent and may grow or increase in number over time.Café au lait spots are often harmless but may be associated with syndromes such as neurofibromatosis type 1 and McCune–Albright syndrome. Cause
Café au lait spots can arise from diverse and unrelated causes:
Ataxia–telangiectasia
Basal cell nevus syndrome
Benign congenital skin lesion
Bloom syndrome
Chédiak–Higashi syndrome
Congenital melanocytic naevus
Fanconi anemia
Gaucher disease
Hunter syndrome
Jaffe–Campanacci syndrome
Legius syndrome
Maffucci syndrome
They can be caused by vitiligo in the rare McCune–Albright syndrome. Multiple mucosal neuroma syndrome
Having six or more café au lait spots greater than 5 mm in diameter before puberty, or greater than 15 mm in diameter after puberty, is a diagnostic feature of neurofibromatosis type I (NF-1), but other features are required to diagnose NF-1. Familial multiple cafe-au-lait spots have been observed without an NF-1 diagnosis. Noonan syndrome
Silver–Russell syndrome
Tuberous sclerosis
Watson syndrome
Wiskott–Aldrich syndrome

Diagnosis
Diagnosis is visual with measurement of spot size. The number of spots can have clinical significance for diagnosis of associated disorders such as Neurofibromatosis type I.