Tetrasomy 18p is a genetic condition that is caused by the presence of an isochromosome composed of two copies of the short arm of chromosome 18 in addition to the two normal copies of the chromosome. It is characterized by multiple medical and developmental concerns. Signs and symptoms
Tetrasomy 18p causes a wide range of medical and developmental problems. Congenital anomalies
Cardiac anomalies are the most common congenital malformation in individuals with tetrasomy 18p. However, there is no pathognomatic heart defect associated with the condition. Patent ductus arteriosus is the most common defect. Septal defects (ventricular septal defects and atrial septal defects) are also common, as are patent foramina ovalia. Other cardiac anomalies include mitral valve regurgitation,  mitral valve prolapse, bicuspid pulmonary valve, hypoplastic transverse aortic arch, tricuspid valve regurgitation, right ventricular hypertrophy, and pulmonic stenosis. In males, cryptorchidism is common. Abnormal genitalia in females is not a common feature. Renal abnormalities have been reported in a minority of patients. Horseshoe kidney and bladder diverticuli have been reported. Other abdominal malformations, including pyloric stenosis and hernias, have also been reported, though they are present in only a minority of patients.Orthopedic anomalies also occur relatively frequently, with hip dysplasia being the most common orthopedic issue. Clubfoot and rocker bottom feet have also been reported.Myelomeningocele is another known feature associated with tetrasomy 18p. Neonatal complications
Neonatal complications (apart from congenital anomalies) are common.
Cracked tooth syndrome (CTS) is where a tooth has incompletely cracked but no part of the tooth has yet broken off. Sometimes it is described as a greenstick fracture. The symptoms are very variable, making it a notoriously difficult condition to diagnose. Classification and definition
Cracked tooth syndrome could be considered a type of dental trauma and also one of the possible causes of dental pain. One definition of cracked tooth syndrome is "a fracture plane of unknown depth and direction passing through tooth structure that, if not already involving, may progress to communicate with the pulp and/or periodontal ligament." Signs and symptoms
The reported symptoms are very variable, and frequently have been present for many months before the condition is diagnosed. Reported symptoms may include some of the following:

Sharp pain when biting on a certain tooth, which may get worse if the applied biting force is increased. Sometimes the pain on biting occurs when the food being chewed is soft with harder elements, e.g. seeded bread. "Rebound pain" i.e. sharp, fleeting pain occurring when the biting force is released from the tooth, which may occur when eating fibrous foods. Pain on biting
Pain when grinding the teeth backward and forward and side to side. Sharp pain when drinking cold beverages or eating cold foods, lack of pain with heat stimuli. Pain when eating or drinking sugary substances.