@endo苑士良： 有文献称：恒磨牙侧副根管发生率79%。《Dammaschke T, Witt M, Ott K, Scha¨ fer E. Scanning electron microscopic investigation of incidence, location, and size of accessory foramina in primary and permanent molars. Quintessence Int 2004;35:699–705.》
