The relative increase in percentage of CD8+ T cells, caused by a reduction in numbers of CD4+ T cells may be implicated in RAS-type ulceration in HIV infection. Mucosal barrier
The thickness of the mucosa may be an important factor in aphthous stomatitis. Usually, ulcers form on the thinner, non-keratinizing mucosal surfaces in the mouth. Factors which decrease the thickness of the mucosa increase the frequency of occurrence, and factors which increase the thickness of the mucosa correlate with decreased ulceration.The nutritional deficiencies associated with aphthous stomatitis (vitamin B12, folate, and iron) can all cause a decrease in the thickness of the oral mucosa (atrophy).Local trauma is also associated with aphthous stomatitis, and it is known that trauma can decrease the mucosal barrier. Trauma could occur during injections of local anesthetic in the mouth, or otherwise during dental treatments, frictional trauma from a sharp surface in the mouth such as broken tooth, or from tooth brushing.Hormonal factors are capable of altering the mucosal barrier. In one study, a small group of females with aphthous stomatitis had fewer occurrences of aphthous ulcers during the luteal phase of the menstrual cycle or with use of the contraceptive pill. This phase is associated with a fall in progestogen levels, mucosal proliferation and keratinization. This subgroup often experiences remission during pregnancy. However, other studies report no correlation between aphthous stomatitis and menstrual period, pregnancy or menopause.Aphthous stomatitis is more common in people who smoke, and there is also a correlation between habit duration and severity of the condition.
The digital images would show a tooth with talon cusp as if it were "double teeth".When looking at a radiograph some features to look for would be location, edge, shape and number. The location would be on an anterior tooth, the edge would be clear and well defined and can be seen even by the naked eye, and the shape would appear "talon-like" over the top portion or crown of the affected tooth. There could potentially be one, two or multiple protrusions depending on the type of cusp. Talon cusp can fall under three categories: Type I, Type II and Type III. They are created based on the cusp formation shape and length of extension. Type I - Talon: The additional cusp or talon projects from the palatal surface of a primary or permanent anterior (front) tooth that extends at least half of the distance from the cemento enamel junction to the incisal edge. Type II - Semi Talon:  The semi talon cusp measures about 1mm or more in length but extends less than half of the distance seen in Type I Talon. Type III - Trace Talon:  The projection originates from the cingulum (also known as the "cervical third") of the root and is enlarged or prominent in any form (conical, bifid or tubercle-like)Since many cases of Talon cusp go unreported, it is hard to draw linkage maps but it is safe to assume that dental formation is influenced by genetic factors.