Table 1 Patient, tumor, and treatment characteristics
| Characteristic |
All patients (n = 616) (%) |
Non-ORNJ (n = 570) (%) |
ORNJ (n = 46) (%) | P value |
|---|---|---|---|---|
| Patient-related factors | ||||
| Age, years [median (range)] | 65 (23–89) | 65.5 (23–89) | 64.5 (37–82) | 0.2460 |
| Sex | ||||
| Male | 513 (83) | 473 (83) | 40 (87) | |
| Female | 103 (17) | 97 (17) | 6 (13) | 0.6810 |
| History of smoking | ||||
| No | 464 (75) | 133 (23) | 7 (15) | |
| Yes | 140 (23) | 426 (75) | 38 (83) | 0.2710 |
| Missing | 12 (2) | 11 (2) | 1 (2) | |
| History of alcohol use | ||||
| No | 150 (24) | 139 (24) | 11 (24) | |
| Yes | 449 (73) | 416 (73) | 33 (72) | 1.0000 |
| Missing | 17 (3) | 15 (3) | 2 (4) | |
| Diabetes mellitus | ||||
| No | 507 (82) | 470 (82) | 37 (80) | |
| Yes | 101 (16) | 93 (16) | 8 (17) | 0.8350 |
| Missing | 8 (1) | 7 (1) | 1 (2) | |
| Performance status | ||||
| 0 | 180 (29) | 161 (28) | 19 (41) | |
| 1 | 286 (46) | 272 (48) | 14 (30) | |
| 2 | 83 (13) | 76 (13) | 7 (15) | |
| 3 | 13 (2) | 13 (2) | 0 (0) | 0.0968 |
| Missing | 54 (9) | 48 (8) | 6 (13) | |
| Pre-RT dental evaluation | ||||
| No | 128 (21) | 118 (21) | 10 (22) | |
| Yes | 488 (79) | 452 (75) | 36 (78) | 0.8510 |
| Pre-RT tooth extraction | ||||
| No | 393 (64) | 368 (65) | 25 (54) | |
| Yes | 223 (36) | 202 (35) | 21 (46) | 0.2020 |
| Post-RT tooth extraction | ||||
| No | 567 (92) | 533 (94) | 34 (74) | |
| Yes | 49 (8) | 37 (6) | 12 (26) | < 0.0001 |
| Tumor-related factors | ||||
| Tumor site | ||||
| OPC | 169 (27) | 147 (26) | 22 (48) | |
| OC | 161 (26) | 143 (25) | 18 (39) | |
| HPC | 226 (37) | 223 (39) | 3 (7) | |
| NPC | 42 (7) | 40 (7) | 2 (4) | |
| CUP | 18 (3) | 17 (3) | 1 (2) | 0.0001 |
| T-stage | ||||
| T0–2 | 370 (60) | 338 (59) | 32 (70) | |
| T3–4 | 246 (40) | 232 (41) | 14 (30) | 0.2110 |
| Nodal status | ||||
| Negative | 131 (21) | 123 (22) | 8 (17) | |
| Positive | 485 (79) | 447 (78) | 38 (83) | 0.5790 |
| Treatment-related factors | ||||
| Pre-RT surgery | ||||
| No | 378 (61) | 354 (62) | 24 (52) | |
| Yes | 238 (39) | 216 (38) | 22 (48) | 0.2090 |
| Pre-RT mandible surgery | ||||
| No | 565 (92) | 526 (92) | 39 (85) | |
| Yes | 51 (8) | 44 (8) | 7 (15) | 0.0908 |
| Induction chemotherapy | ||||
| No | 563 (91) | 520 (91) | 43 (93) | |
| Yes | 53 (9) | 50 (9) | 3 (7) | 0.7870 |
| Concurrent chemotherapy | ||||
| No | 172 (28) | 167 (29) | 5 (11) | |
| Yes | 444 (72) | 403 (71) | 41 (89) | 0.0059 |
| RT technique | ||||
| 3D-CRT | 448 (73) | 409 (72) | 39 (85) | |
| IMRT | 168 (27) | 161 (28) | 7 (15) | 0.0593 |
| Total radiation dose, Gy [median (range)] | 69.96 (50–75) | 69.96 (50–75) | 69.96 (50–70) | 0.5210 |