Research Spotlight

Ribot Trafí, F., García Bartual, M., García-Nos, E., Altamirano Enciso, A.J., Nevgloski, A.J. and Wang, Q. (2020). “Another interpretation of Homo antecessor.” J Anthropol Sci 98.

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We conclude that the remains of TD6.2, attributed to H. antecessor, should be classified as H. erectus, because they share an almost identical midfacial morphology. In contrast to what has been reported in a large number of publications, the depression in the zygomatic process of the maxilla of ATD6-69 and ATD6-58 is not a canine fossa. The depression in these fossils is located laterally to the infraorbital foramen, so it is actually the zygomaxillary fossa or Oschinsky‘s fossa. The area below the infraorbital foramen is flat or slightly convex with no trace of cupping, more similar to that of the hominins of the European middle Pleistocene. The origin of European H. erectus is an African story and its arrival in Europe from North Africa might been through the Strait of Gibraltar or the Alboran Sea. [No abstract; excerpt from article].

Zhang, W., Zhang, Q., McSweeney, K., Han, T., Man, X., Yang, S., Wang, L., Zhu, H., Zhang, Q. and Wang, Q. (2020). “Violence in the first millennium BCE Eurasian steppe: Cranial trauma in three Turpan Basin populations from Xinjiang, China.” Am J Phys Anthropol Dec 11. [Epub ahead of print].

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OBJECTIVES: Violence affected daily life in prehistoric societies, especially at conflict zones where different peoples fought over resources and for other reasons. In this study, cranial trauma was analyzed to discuss the pattern of violence experienced by three Bronze to early Iron Age populations (1,000-100 BCE) that belonged to the Subeixi culture. These populations lived in the Turpan Basin, a conflict zone in the middle of the Eurasian Steppe. METHODS: The injuries on 129 complete crania unearthed from the Subeixi cemeteries were examined for crude prevalence rate (CPR), trauma type, time of occurrence, possible weapon, and direction of the blow. Thirty-three injuries identified from poorly preserved crania were also included in the analyses except for the CPR. Data was also compared between the samples and with four other populations that had violence-related backgrounds. RESULTS: Overall, 16.3% (21/129) of the individuals showed violence-induced traumatic lesions. Results also indicated that most of the injuries were perimortem (81.6%), and that women and children were more involved in conflict than the other comparative populations. Wounds from weapons accounted for 42.1% of the identified cranial injuries. Distribution analysis suggested no dominant handedness of the attackers, and that blows came from all directions including the top (17.1%). Wounds caused by arrowheads and a special type of battle-ax popular in middle and eastern Eurasian Steppe were also recognized. DISCUSSION: A comprehensive analysis of the skeletal evidence, historical records, and archeological background would suggest that the raiding to be the most possible conflict pattern reflected by the samples. The attackers were likely to have been nomadic invaders from the steppe (such as the Xiongnu from historical records), who attacked the residents in the basin more likely for their resources rather than territory or labor force.

Revilla-León, M., Morillo, J.A., Att, W. and Özcan, M. (2020). “Chemical Composition, Knoop Hardness, Surface Roughness, and Adhesion Aspects of Additively Manufactured Dental Interim Materials.” J Prosthodont Dec 8. [Epub ahead of print].

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PURPOSE: To measure the chemical composition, Knoop hardness, surface roughness, and composite bond strength of additive manufactured (AM) and conventional interim materials. MATERIAL AND METHODS: Disks were prepared using conventionally (CNV group) and additively manufactured (AM group) materials: CNV-1 (Protemp 4; 3M ESPE), CNV-2 (Anaxdent new outline dentin; Anaxdent), AM-1 (FreePrint temp; Detax), AM-2 (E-Dent 400 C&B MFH; Envisiontec), AM-3 (NextDent C&B MFH; 3D Systems), and AM-4 (Med620 VEROGlaze; Stratasys). Each group was subdivided into 3 subgroups (n = 20) for analyzing Knoop hardness (KHN), chemical composition, superficial roughness (Ra), and composite shear bond strength. The first subgroup was exposed to a microhardness test. Subsequently, EDAX analysis was selected to analyze the chemical composition. The second subgroup was selected to measure the superficial roughness (Ra) using a contact profilometer. The third subgroup was used to measured composite shear bond strength using a universal testing apparatus. A digital microscope was used to analyze the fracture mode. The Shapiro-Wilk test showed normally distributed data. One-way ANOVA and post hoc Sidak tests were selected (α = 0.05). RESULTS: Major variances in chemical composition were observed among the specimens. Significant differences in Knoop hardness (p < 0.001) and surface roughness (p < 0.001) were detected. The AM-4 (13.45 ± 2.93 KHN), the CNV-2 (13.35 ± 5.84 KHN), the AM-2 (13.03 ± 3.29 KHN), and the AM-1 (12.55 ± 2.93 KHN) groups obtained the highest Knoop hardness values, followed by the AM-3 and the CNV-1 groups (p < 0.05). The AM-1 group (1.88 ± 1.11 Ra) obtained the highest surface roughness values among the groups, followed by the AM-3 group (0.90 ± 0.14 Ra) (p < 0.05). However, no significant differences in shear bond strength values were found between the groups ranging from 23.18 ± 8.88 MPa to 33.29 ± 9.17 MPa (p = 0.061). All the groups showed a cohesive mode of failure. CONCLUSIONS: The AM interim materials tested had significant chemical composition variations compared to conventional materials. For the mechanical properties evaluated, the AM materials obtained appropriate mechanical properties for use as an interim dental restoration. However, further studies are required to evaluate more extensively its mechanical properties and verify their applicability in the oral cavity, clinical behavior, and biocompatibility.

Pérez-Giugovaz, M.G., Mosier, M. and Revilla-León, M. (2021). “An additively manufactured intraoral scan body for aiding complete-arch intraoral implant digital scans with guided integration of 3D virtual representation.” J Prosthet Dent Jan 4;S0022-3913(20)30712-5. [Epub ahead of print].

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This article describes a polymeric additively manufactured intraoral scan body that facilitates a complete-arch intraoral implant digital scan and guides the superimposition procedures between the facial and digital scans comprising the patient’s 3D virtual representation. Furthermore, this novel intraoral scan body can be modified for the patient’s specific arch dimensions, enhancing patient comfort and facilitating digitizing.

Aman, H.M., Alenezi, A., Ducic, Y. and Reddy, L.V. (2020). “Secondary Reconstruction of the Zygomaticomaxillary Complex.” Semin Plast Surg 34(4): 254-259.

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Zygomaticomaxillary (ZMC) fractures are the second most common facial fractures after nasal bone fractures. The zygoma, with its location and multiple points of articulations, lends itself to both facial structure and esthetics. Secondary ZMC deformities are complications of inadequate primary correction, delayed repair, or lack of repair. Secondary revisions of ZMC aim to correct ZMC displacement and projection and to address orbital discrepancies. Extensive correction involving significant orbital and malar defects requires zygomatic repositioning osteotomies and would greatly benefit from the utilization of virtual surgical planning, intraoperative navigation, and imaging. Minor corrections in malar projection can be corrected by onlay grafting and soft tissue augmentation and resuspension. Isolated or minor orbital corrections can be managed by autogenous or alloplastic material to restore lost orbital volume and anatomy.