Table 1.
Details of the embryonic period
| O'Rahilly stage | Section plane | CR length (mm) | Embryo | Results |
|---|---|---|---|---|
| 13 | T | 6 | OY-4 | Presumptive stapedial area |
| 14 | T | 7 | GV-4 | Appearance of the stapedial anlage |
| 15 | T | 8 | PT-11 | |
| 16 | T | 9 | BOT-9 | Relationship between the stapedial artery and the stapedial anlage. Appearance of the interhyale |
| 16 | T | 10.75 | CIV-3 | |
| 17 | T | 12 | MAR-12 | Delimitation of the parts of the stapedial anlage |
| 17 | T | 13 | GV-6 | |
| 17 | T | 13.6 | FAUS-6 | |
| 18 | T | 14.5 | GV-8 | |
| 18 | T | 15 | NO | |
| 18 | T | 16 | CIV-2 | Chondrogenesis phase. Start of involution of the stapedial artery |
| 19 | F | 17 | ESC-14 | |
| 19 | T | 17 | PA | |
| 19 | T | 18 | MAR-2 | |
| 20 | F | 18.5 | PT-5 | Delimitation of the ossicular anlages. Cartilaginous phase. Disappearance of the stapedial artery |
| 20 | S | 19 | PR | |
| 20 | S | 20 | BR-3 | |
| 20 | T | 20 | Be-1 | |
| 20 | F | 21.5 | AR | |
| 21 | F | 22 | GV-6 | |
| 21 | S | 22 | GV-7 | |
| 22 | F | 26 | PT-10 | Delimitation of the interhyale |
| 22 | F | 26.5 | GI-4 | |
| 23 | F | 28 | BR-4 | Anlage of the stapedial muscle tendon |
| 23 | T | 28.5 | BR-2 |