2007 ICD-9-CM Procedure 20.49 Other mastoidectomy 20.49 is a specific code that can be used to specify a procedure 20.49 contains 8 index entries View the full Volume 3 20.* hierarchy 20.49 also known as: Atticoantrostomy Mastoidectomy: NOS modified radical Index entries containing 20.49: Antrectomy mastoid 20.49 Atticoantrostomy (ear) 20.49 Atticoantrotomy (ear) 20.49 Excision lesion (local) mastoid (bone) 20.49 mastoid -- see also Mastoidectomy 20.49 Mastoidectomy (cortical) (conservative) 20.49 complete (simple) 20.41 modified radical 20.49 radical 20.42 modified 20.49 simple (complete) 20.41