<prompt> Overdentures are indicated over retained roots instead of extracting them and making complete dentures because:To preserve the alveolar boneTo allow proprioception from the periodontal ligament of remaining teethCarrier for patient to adjustAll of the above  <response>: Advantages of overdentures:Ridge preservationProprioceptionSuperior patients acceptanceOpen palate possibleDefinitive vertical stop for denture baseSupport, stability and retention are improvedLess trauma to supporting tissuesFewer post insertion problems than a conventional complete dentureConversion to complete dentureIncreased biting force pacer FJ, Bowman DC. Occlusal force discrimination by denture patients. J Prosthet Dent 1975; 33: 602-9Physiological advantage. 