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.
Many researchers argue that this is inaccurate as they contend that the abfraction lesion is a multifactorial (has many causative factors) lesion with other factors such as abrasion or erosion. This controversy around the causative factors, along with the recency of the lesion classification, are some of the reasons why many dental clinicians are looking at the lesion with some scepticism. More research is needed to fully clear up the controversy surrounding the abfraction lesion. See also
Tooth wear
Abrasion
Attrition
Bruxism
Erosion

References

Summit, James B., J. William Robbins, and Richard S. Schwartz. Fundamentals of Operative Dentistry: A Contemporary Approach. 2nd edition. Carol Stream, Illinois, Quintessence Publishing Co, Inc, 2001. ISBN 0-86715-382-2. Lee, WC. ; Eakle, WS. (1984). "Possible role of tensile stress in the etiology of cervical erosive lesions of teeth". Journal of Prosthetic Dentistry. 52 (3): 374–380. doi:10.1016/0022-3913(84)90448-7. PMID 6592336.