Signs and symptoms
Talon cusp will show physical signs of the irregular dental formation of the teeth and cause other symptoms of the disease that could possibly lead to dental problems in the future, depending on severity of the deformity. Most commonly, the extra cusp is located on the lingual surface, giving a three-pronged appearance. Rarely, however, the extra cusp may be situated on the facial surface, or there may be extra cusps on both lingual and facial surfaces. There may be a deep groove between the talon cusp and the rest of the tooth. The extra cusp typically contains pulp tissue. When viewing talon cusp from the occlusal, the projection will appear "x-shaped", as well as appears conical, and mimic the shape of an eagles talon.Symptoms of talon cusp include:

Interference with occlusion or bite
Irritation of soft tissues and tongue
Accidental cusp fracture
Susceptible to dental caries

Cause
The cause of talon cusp is unknown. The anomaly can occur due to genetic and environmental factors but the onset can be spontaneous. Prevention is difficult because the occurrence happens during the development of teeth. Talon cusp affects men and women equally, however the majority of reported cases are of the male gender. Individuals of Asian, Arabic, Native American and Inuit descent are affected more commonly. Talon cusp is also highly observed in patients with orofacial digital II syndrome and Rubinstein Taybi syndrome. Other anomalies that occur with talon cusp can include peg laterals, supernumerary teeth, dens envaginatus, agenesis and impaction.
Treatment is not required for those with skin spots, but some individuals with BRBNS may want treatment for cosmetic reasons or if the affected location causes discomfort or affects normal function. Incidence
Blue Rubber Bleb Nevus Syndrome affects males and females in equal numbers. According to a review of literature, 20% of patients with BRBNS were from the United States, 15% from Japan, 9% from Spain, 9% from Germany, 6% from China, and 6% from France; and a lower number of cases from other countries. This indicates that any race can be affected by BRBNS. See also
Bart syndrome
List of cutaneous conditions

References
Further reading
Bean WB (1958). Vascular spiders and related lesions of the skin. Springfield, Illinois: Charles C.Thomas. pp. 178–85. External links

Blue rubber bleb nevus; Bean syndrome at NIHs Office of Rare Diseases