Supplementary material BMJ Open Table S1 Extent of reproduction of anatomical features in digital and 3D printed model of the skull bone specimens. Digital Digital Anatomic feature print Anatomic feature print model model Parietal foramen (for Frontal bone P P A A emissary vein) Superior Coronal suture A A Lambda A A of the Bregma A A Lambdoid suture P NR skull Parietal bone P P Occipital bone P P Sagittal suture NR NR Mastoid notch (for Maxilla P P P P digastric muscle) Occipital groove (for Incisive fossa P P P P occipital artery) Jugular fossa (jugular Palatine process P P P P foramen in its depth) Intermaxillary suture NR NR Mastoid foramen NR NR Zygomatic process P P Parietal bone P P Zygomatic bone P P Occipital bone P P Frontal bone P P Hypoglossal canal P P Inferior of Sphenoidal bone P P Occipital condyle P P the skull Pterygoid process P P Condylar canal and fossa P P Hamulus NR A Basilar part P P Pterygoid fossa P P Pharyngeal tubercle P P Lateral plate P P Foramen magnum NR NR Greater wing P P Inferior nuchal line P P Foramen ovale P P External occipital crest P P Foramen spinosum LP NR Superior nuchal line P NR External occipital Spine P P P P protuberance Temporal bone P P Palatine bone P P Li Q-Y, et al. BMJ Open 2020; 10:e034900. doi: 10.1136/bmjopen-2019-034900 Supplementary material BMJ Open Zygomatic process P P Horizontal plate P P Articular tubercle P P Greater palatine foramen P NR Mandibular fossa P P Pyramidal process P P Styloid process P P Lesser palatine foramina NR A Petrotympanic fissure P P Posterior nasal spine P P Carotid canal P P Choanae P P (external opening) Tympanic canaliculus NR A Vomer P P External acoustic P P Ala P P meatus Groove for Mastoid process P P pharyngotympanic P P (auditory, eustachian) tube Stylomastoid NR NR Foramen lacerum P P foramen Petrous part P P Frontal bone P P Ethmoidal bone P P Glabella P P Orbital plate P P Supra-orbital notch P P Perpendicular plate P P (foramen) Orbital surface P P Middle nasal concha P NR Anterior Nasal bone P P Inferior nasal concha P NR of the Lacrimal bone P P Vomer P P skull Orbital surface of frontal Zygomatic bone P P P P bone Orbital surface of lesser Frontal process P P P P wing of sphenoidal bone Orbital surface P P Superior orbital fissure P NR Temporal process P P Optic canal (foramen) P P Li Q-Y, et al. BMJ Open 2020; 10:e034900. doi: 10.1136/bmjopen-2019-034900 Supplementary material BMJ Open Zygomaticofacial Orbital surface of greater A A P P foramen wing of sphenoidal hone Orbital surface of Maxilla P P P P zygomatic bone Zygomaticofacial Zygomatic process P P A A foramen Infra-orbital foramen P P Inferior orbital fissure P NR Alveolar process P P Infra-orbital groove P P Anterior nasal spine P P Supra-orbital notch P P Posterior and Anterior Coronal suture A A NR A ethmoidal foramina Orbital plate of Parietal bone P P P P ethmoidal bone Nasion P P Lacrimal bone P P Sphenoidal bone P P Fossa for lacrimal sac P P Orbital process of Lesser wing P P P P palatine bone Orbital surface of Greater wing P P P P maxilla Temporal bone P P lnfra-orbital foramen P P Glabella P P Asterion A A Alveolar process P P Pterygomaxillary fissure P P Temporal process P P Inferior orbital P P Zygomatic arch P P Infratemporal surface of P P Temporal fossa P P Alveolar foramina A A Lateral of Temporal bone the skull P P Tuberosity of maxilla P P squamous part Zygomatic process P P Infratemporal crest P P Lateral plate of pterygoid Articular tubercle P P P P process Supramastoid crest P P Pterygoid hamulus NR A External acoustic P P External acoustic meatus P P Li Q-Y, et al. BMJ Open 2020; 10:e034900. doi: 10.1136/bmjopen-2019-034900 Supplementary material BMJ Open meatus Mastoid process P P Mandibular fossa P P Lambdoid suture P NR Articular tubercle P P Occipital bone P P Sphenopalatine foramen P P Atlas of Human Anatomy, 6th edition (edited by Frank H. Netter, MD) was used as a reference book for anatomical annotations, with all listed anatomical features observed on in original bone specimens. Abbreviations: P: present distinctly, LP: lost partly, NR: not well-resolved. Li Q-Y, et al. BMJ Open 2020; 10:e034900. doi: 10.1136/bmjopen-2019-034900 Supplementary material BMJ Open Table S2 Sample points’ deviation distribution and average deviation of 3D comparison between specimens and 3D printed models. Femur Rib Total Total >=Min <Max >=Min <Max Points % Points % Out of Lower Critical 193 0.1031 Out of Lower Critical 59 0.0164 -2.0000 -1.5000 42 0.0224 -2.0000 -1.5000 310 0.0861 -1.5000 -1.0000 387 0.2067 -1.5000 -1.0000 406 1.1279 -1.0000 -0.5000 4985 2.6630 -1.0000 -0.5000 36183 10.0443 -0.5000 0.5000 165449 88.3881 -0.5000 0.5000 299947 83.2638 0.5000 1.0000 8978 4.7962 0.5000 1.0000 8944 2.4828 1.0000 1.5000 3928 2.0986 1.0000 1.5000 6741 1.8713 1.5000 2.0000 2136 1.1411 1.5000 2.0000 978 0.2715 Out of Upper Critical 1087 0.5807 Out of Upper Critical 3012 0.8361 Total 187185 100.0000 Total 360237 100.0002 Average Positive Average Positive Deviation 0.2523 0.3619 Deviation Average Negative Average Negative -0.1180 -0.3845 Deviation Deviation Cervical vertebra Skull Total Total >=Min <Max >=Min <Max Points % Points % Out of Lower Critical 0 0.0000 Out of Lower Critical 4797 0.2392 -2.0000 -1.5000 1 0.0007 -2.0000 -1.5000 1709 0.0852 -1.5000 -1.0000 0 0.0000 -1.5000 -1.0000 3311 0.1651 -1.0000 -0.5000 34 0.0231 -1.0000 -0.5000 82859 4.1315 -0.5000 0.5000 146810 99.7195 -0.5000 0.5000 1718475 85.6858 0.5000 1.0000 374 0.2540 0.5000 1.0000 168402 8.3968 1.0000 1.5000 3 0.0020 1.0000 1.5000 13610 0.6786 1.5000 2.0000 0 0.0000 1.5000 2.0000 4019 0.2004 Out of Upper Critical 1 0.0007 Out of Upper Critical 8369 0.4173 Total 147223 100.0000 Total 2005554 99.9999 Average Positive Average Positive Deviation 0.0853 0.2522 Deviation Average Negative Average Negative -0.0683 -0.1945 Deviation Deviation Li Q-Y, et al. BMJ Open 2020; 10:e034900. doi: 10.1136/bmjopen-2019-034900 Supplementary material BMJ Open Table S3 Sample points’ deviation distribution and average deviation of 3D comparison between digital models and 3D printed models. Femur Rib Total Total >=Min <Max >=Min <Max Points % Points % Out of Lower Critical 2030 0.2817 Out of Lower Critical 0 0.0000 -2.0000 -1.5000 7 0.0010 -2.0000 -1.5000 5 0.0014 -1.5000 -1.0000 16 0.0022 -1.5000 -1.0000 2847 0.7897 -1.0000 -0.5000 584 0.0810 -1.0000 -0.5000 22353 6.2005 -0.5000 0.5000 716715 99.4490 -0.5000 0.5000 325333 90.2424 0.5000 1.0000 1037 0.1439 0.5000 1.0000 8018 2.2240 1.0000 1.5000 139 0.0193 1.0000 1.5000 1953 0.5417 1.5000 2.0000 120 0.0167 1.5000 2.0000 1 0.0003 Out of Upper Critical 38 0.0053 Out of Upper Critical 0 0.0000 Total 720686 100.0001 Total 360510 100.0000 Average Positive Average Positive 0.1330 0.2730 Deviation Deviation Average Negative Average Negative -0.1622 -0.3334 Deviation Deviation Cervical vertebra Skull Total Total >=Min <Max >=Min <Max Points % Points % Out of Lower Critical 0 0.0000 Out of Lower Critical 1232 0.0614 -2.0000 -1.5000 2 0.0014 -2.0000 -1.5000 520 0.0259 -1.5000 -1.0000 0 0.0000 -1.5000 -1.0000 627 0.0313 -1.0000 -0.5000 5 0.0034 -1.0000 -0.5000 19089 0.9520 -0.5000 0.5000 147014 99.8418 -0.5000 0.5000 1962660 97.8834 0.5000 1.0000 225 0.1528 0.5000 1.0000 6337 0.3160 1.0000 1.5000 0 0.0000 1.0000 1.5000 4015 0.2002 1.5000 2.0000 0 0.0000 1.5000 2.0000 2532 0.1263 Out of Upper Critical 1 0.0007 Out of Upper Critical 8087 0.4033 Total 147247 100.0001 Total 2005099 99.9998 Average Positive Average Positive Deviation 0.0524 0.1561 Deviation Average Negative Average Negative -0.0783 -0.1633 Deviation Deviation Li Q-Y, et al. BMJ Open 2020; 10:e034900. doi: 10.1136/bmjopen-2019-034900.