Abfraction is the loss of tooth structure from flexural forces. It is hypothesized that enamel, especially at the cementoenamel junction (CEJ), undergo this pattern of destruction by separating the enamel rods.
As teeth flex under pressure, the arrangement of teeth touching each other, known as occlusion, causes tension on one side of the tooth and compression on the other side of the tooth. This is believed to cause V-shaped depressions on the side under tension and C-shaped depressions on the side under compression. This theory of abfraction is specious as these type of enamel lesions are mainly thought to be due to over- zealous brushing. It is noted that these cervical lesions are mainly at the premolar areas and sometimes the first molars and on the buccal side. This is exactly where people put most of the force when they brush. There is a very high correlation between these lesions and patients who are very good brushers as evidenced by their good oral hygiene.