Ball clasps are typically used as auxiliary retention in conjunction with other clasps. They are usually placed tightly into the interproximal embrasure between two posterior teeth. This is usually sufficient to create the retention needed, however it can also be adjusted mesially or distally to engage the undercut of either tooth. This is particularly useful during the exfoliation stage of the mixed dentition. When one primary molar is lost, a simple adjustment will allow you to regain the retention needed to continue on with treatment.