<prompt> Thistle-tube appearance is a characteristic feature of:Radicular dentin dysplasiaCoronal dentin dysplasiaAmelogenesis imperfectaDentinogenesis imperfecta  <response>: Radiographic features of type II coronal dentin dysplasia:The permanent teeth exhibit an abnormally large pulp chamber in the coronal portion of the tooth, often described as thistle-tube in shape, and within such areas radiopaque foci resembling pulp stones may be found.Ref: Shafers textbook of oral pathology 7th edition page 57 