Alveolar ridge preservation (ARP) therapy is indicated to attenuate the physiologic resorptive events that occur as a consequence of tooth extraction with the purpose of facilitating tooth replacement therapy. This randomized controlled trial was primarily aimed at testing the efficacy of ARP as compared with unassisted socket healing. A secondary objective was to evaluate the effect that local phenotypic factors play in the volumetric reduction of the alveolar bone. A total of 53 subjects completed the study. Subjects were randomized into either the control group, which involved only tooth extraction (EXT n = 27), or the experimental group, which received ARP using a combination of socket grafting with a particulate bone allograft and socket sealing with a nonabsorbable membrane (dPTFE) following tooth extraction (ARP n = 26). A set of clinical, linear, volumetric, implant-related, and patient-reported outcomes were assessed during a 14-wk healing period. All linear bone assessments (horizontal, midbuccal, and midlingual reduction) revealed that ARP is superior to EXT. Likewise, volumetric bone resorption was significantly higher in the control group (mean ± SD: EXT = −15.83% ± 4.48%, ARP = −8.36% ± 3.81%, P < 0.0001). Linear regression analyses revealed that baseline buccal bone thickness is a strong predictor of alveolar bone resorption in both groups. Interestingly, no significant differences in terms of soft tissue contour change were observed between groups. Additional bone augmentation to facilitate implant placement in a prosthetically acceptable position was deemed necessary in 48.1% of the EXT sites and only 11.5% of the ARP sites ( P < 0.004). Assessment of perceived postoperative discomfort at each follow-up visit revealed a progressive decrease over time, which was comparable between groups. Although some extent of alveolar ridge remodeling occurred in both groups, ARP therapy was superior to EXT as it was more efficacious in the maintenance of alveolar bone and reduced the estimated need for additional bone augmentation at the time of implant placement (ClinicalTrials.gov NCT01794806).

Variation in nasal floor topography has generated both neontological and paleontological interest. Three categories of nasal floor shape (Franciscus: J Hum Evol 44 (2003) 699-727) have been used when analyzing this trait in extant humans and fossil Homo: flat, sloped, and depressed (or "bi-level"). Variation in the frequency of these configurations within and among extant and fossil humans has been well-documented (Franciscus: J Hum Evol 44 (2003) 699-727; Wu et al.: Anthropol Sci 120 (2012) 217-226). However, variation in this trait in Homo has been observed primarily in adults, with comparatively small subadult sample sizes and/or large age gradients that may not sufficiently track key ontogenetic changes. In this study, we investigate the ontogeny of nasal floor shape in a relatively large cross-sectional age sample of extant humans (n = 382) ranging from 4.0 months fetal to 21 years post-natal. Results indicate that no fetal or young infant individuals possess a depressed nasal floor, and that a depressed nasal floor, when present (ca. 21% of the sample), does not occur until 3.0 years postnatal. A canonical variates analysis of maxillary shape revealed that individuals with depressed nasal floors were also characterized by relatively taller anterior alveolar regions. This suggests that palate remodeling at about 3.0-3.5 years after birth, under the influence of tooth development, strongly influences nasal floor variation, and that various aspects of dental development, including larger crown/root size, may contribute to the development of a depressed nasal floor. These results in extant humans may help explain the high frequency of this trait found in Neandertal and other archaic Homo maxillae.

This study quantifies the metacarpal 1 (MC 1) proximal articular surface using three-dimensional morphometrics in extant hominids and fossil hominins (SK 84, cf + Paranthropus robustus/Homo erectus and StW 418, . Australopithecus africanus) to understand which characteristics of the proximal metacarpal 1 are potentially correlated with human manipulative abilities and if they can be used in a paleoanthropological setting. A principal components (PC) analysis was used to compare MC 1 proximal articular surface shape and ANOVA and Tukey's HSD post-hoc tests were conducted to determine differences among groups + Homo is significantly different from nonhuman hominids having a less radioulnarly and dorsovolarly curved articular surface. All nonhuman hominids have more curved articular surface with . Gorilla showing the most curved joint. Moreover, this study highlights the presence of a radially extended surface in . Homo that may be related to the greater thumb abduction in human manipulation activities. Both fossils analyzed show a great ape-like MC 1 proximal articular surface which, associated with recent trabecular and archaeological evidence, may indicate that the ability to make/use stone tools preceded the morphological adaptations associated today with such behavior

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The aims of this study were to compare third‐year dental students’ satisfaction and level of learning in case‐based learning (CBL) versus team‐based learning (TBL) and the resources required in those two methodologies. Level of learning was assessed for both knowledge and application, and resources were defined as student and faculty time and rooms. In academic year 2018‐19, all 68 third‐year dental students in one U.S. dental school were enrolled in two sequential semester‐long courses; the first used CBL, and the second used TBL. After each course, students and faculty facilitators completed surveys, and data from students’ knowledge and application exams were collected. The student surveys asked students to report their satisfaction with the learning methodology (CBL or TBL); the faculty surveys asked the faculty facilitators to report the resources used for each methodology. Forty‐five of 68 students (66%) consented to participate; however, a larger number of students completed surveys in the two semesters (69% for CBL and 87% for TBL). Fourteen of 16 (88%) faculty facilitators completed the CBL survey, and five of the six (83%) completed the TBL survey. Overall, the results showed that students’ satisfaction was higher with CBL than TBL (Mann‐Whitney U = 882.0; p<0.001), and students reported having a better understanding of concepts after CBL than TBL (U = 899.0; p<0.001). The students performed better on knowledge exam items in TBL than CBL (86% vs. 82%) but the same on application items (both 86%). Resource requirements for both methods were extensive, with TBL requiring fewer facilitators and rooms than CBL but requiring more time from both students (2.6 vs. 2.3 hours weekly) and faculty members (2.3 vs. 1.4 hours weekly). In this study, students preferred CBL to TBL but had higher knowledge scores in the TBL course. The resources needed for both CBL and TBL were said to be extensive, with infrastructure use higher for CBL but time for students and faculty higher for TBL.