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If policy makers wish to encourage members of a population to take a socially beneficial action, should they reward those who take the desired behavior or punish those who do not? This article develops a model that facilitates both utilitarian and majoritarian perspectives on the use of incentives and disincentives in public policy. An asymmetry arises between the two types of policy: as incentives grow, higher shares of the population take the beneficial action and earn the reward, driving administrative costs up; as disincentives grow, however, smaller shares of the population fail to take the desired action, requiring fewer fines and exerting downward pressure on administrative costs. Domains that favor inducing high (low) shares of the population to take a desired behavior thus indirectly favor the use of disincentives (incentives). Distributive implications amplify this tendency, such that majoritarian influence on policy making tends to generate stronger disincentives and weaker incentives than are efficient. [ABSTRACT FROM AUTHOR]

Malocclusions are common in modern populations. Yet, as the study of occlusion requires an almost intact dentition in both the maxilla and mandible, searching for the ultimate cause of malocclusion is a challenge: relatively little ancient material is available for research on occlusal states. The Qafzeh 9 skull is unique, as its preserved dentition allowed us to investigate the presence and manifestations of malocclusion. The aim of this study was thus to examine the occlusal condition in the Qafzeh 9 specimen in light of modern knowledge regarding the etiology of malocclusion. We revealed a pathologic occlusion in the Qafzeh 9 skull that probably originated in the early developmental stage of the dentition, and was aggravated by forces applied by mastication. When arch continuity is interrupted due to misalignment of teeth as in this case, force transmission is not equal on both sides, causing intra-arch outcomes such as mesialization of the teeth, midline deviation, rotations and the aggravation of crowding. All are evident in the Qafzeh 9 skull: the midline deviates to the left; the incisors rotate mesio-buccally; the left segment is constricted; the left first molar is buccally positioned and the left premolars palatally tilted. The inter-arch evaluation revealed anterior cross bite with functional shift that might affect force transmission and bite force. In conclusion, the findings of the current study suggest that malocclusion of developmental origin was already present in early anatomically modern humans (AMH) (the present case being the oldest known case, dated to ca. 100,000 years); that there is no basis to the notion that early AMH had a better adjustment between teeth and jaw size; and that jaw-teeth size discrepancy could be found in prehistoric populations and is not a recent phenomenon.

Scholars find a clear link between a state's election to a rotating membership on the United Nations Security Council (UNSC) and increased receipt of foreign aid, especially that provided by the United States. Most researchers view this finding as evidence of Washington's attempts to buy the votes of rotating members of the UNSC. If this is the case then it raises serious concerns about the legitimacy of UNSC decisions. However, while current statistical tests show an association between US foreign aid and holding one of the rotating seats on the UNSC, they do not establish the underlying causal mechanism. We seek to do so by generating theoretically motivated hypotheses about the relationship between relative voting congruence with the United States and the receipt of US foreign aid. Leveraging natural variation from the rotating structure of nonpermanent UNSC members, we uncover a causal relationship consistent with the claim that the United States uses foreign aid to procure support for its positions on the UNSC. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Although the maxillary tuberosity (MT) is a major growth site of the maxilla, its time-related growth was not fully investigated. The objectives of the study were to evaluate the MT growth from 6 to 20 years of age defining the peak growth age and to assess time-related indicators. Design: Panoramic radiographs from 189 patients were divided in a cross-sectional study into six age groups. A special panoramic analysis was developed including 18 parameters and 3 time-related indicators, i.e., chronological age, crown/root development stages of the maxillary second (M 2) and third (M 3) molars and eruption stages. Results: From 6 to 20 years, the MT vertical growth was 5.17-fold greater than the horizontal. The horizontal growth covered 36% of the maxillary growth but was inadequate to secure space for third molar eruption despite a 51% increase in MT area. MT peak growth was between 8 and 9 years and 10–11 year. During these 14 years, the maxillary length increased by pneumatisation of the maxillary sinus (86%), growth of the MT (36%) and decrease of the anterior maxillary region (−22%). Of the 18 examined parameters, 83% showed dependency to the combination chronological age with M 2, M 3 crown/root development stage and 72% to the combination chronological age with M 2, M 3 eruption stage. Conclusion: MT growth peak occurs with initiation of root development of M 2 and shortly before M 2 eruption (8–9 years to 10–11 years). Dental time-related indicators adjunct with the chronological age provide an effectual system to define MT growth potential. [ABSTRACT FROM AUTHOR]

Malocclusions are common in modern populations. Yet, as the study of occlusion requires an almost intact dentition in both the maxilla and mandible, searching for the ultimate cause of malocclusion is a challenge: relatively little ancient material is available for research on occlusal states. The Qafzeh 9 skull is unique, as its preserved dentition allowed us to investigate the presence and manifestations of malocclusion. The aim of this study was thus to examine the occlusal condition in the Qafzeh 9 specimen in light of modern knowledge regarding the etiology of malocclusion. We revealed a pathologic occlusion in the Qafzeh 9 skull that probably originated in the early developmental stage of the dentition, and was aggravated by forces applied by mastication. When arch continuity is interrupted due to misalignment of teeth as in this case, force transmission is not equal on both sides, causing intra-arch outcomes such as mesialization of the teeth, midline deviation, rotations and the aggravation of crowding. All are evident in the Qafzeh 9 skull: the midline deviates to the left; the incisors rotate mesio-buccally; the left segment is constricted; the left first molar is buccally positioned and the left premolars palatally tilted. The inter-arch evaluation revealed anterior cross bite with functional shift that might affect force transmission and bite force. In conclusion, the findings of the current study suggest that malocclusion of developmental origin was already present in early anatomically modern humans (AMH) (the present case being the oldest known case, dated to ca. 100,000 years); that there is no basis to the notion that early AMH had a better adjustment between teeth and jaw size; and that jaw-teeth size discrepancy could be found in prehistoric populations and is not a recent phenomenon. [ABSTRACT FROM AUTHOR]

Introduction: The military includes lower extremity amputees requiring arthroplasty; however, there is little literature on this population. The primary aim of this study was to report demographics and clinical factors in amputees who undergo total hip or knee arthroplasty (THA/TKA) in the Military Health System (MHS). Second, patient-reported outcome measures (PROMs) are reported., Methods: The Military Data Repository was queried for patients with lower extremity amputations and TKA or THA between 1 October 2014 and 12 October 2020. The medical records were reviewed and patients were contacted to complete PROMs. Mean follow-up for TKA and THA was 5.5 and 2.5 years, respectively., Results: Nineteen TKAs (76%) and eight THAs (28%) were performed in 25 patients. Mean age of TKA and THA patients at the time of arthroplasty was 57 years old. A majority of TKA (68%) and THA (57%) patients underwent amputations secondary to trauma. Nearly all TKAs were performed on the contralateral side to the amputation (95%), while half of THAs were performed on the ipsilateral side (50%). Two THAs (29%) were revised due to periprosthetic fractures, whereas six TKAs (32%) were revised or reoperated on due to infection. Ten TKA patients completed PROMs. The mean score on Knee Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) was 41.8 and Patient-Reported Outcomes Measurement Information System Global-10 (PROMIS-10) was 41.6 (Global Physical Health) and 49.6 (Global Mental Health)., Conclusions: Most TKAs were performed on the contralateral limb, suggesting increased demand on the joint. The most common indication for amputation and post-TKA complication was trauma and infection, respectively. KOOS JR may not accurately capture the outcomes of this population, or they simply do worse. However, PROMIS-10 scores were similar to the non-amputee population, suggesting that the PROMIS-10 may be more useful than the KOOS JR., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To examine the ability of a removable thermoplastic appliance (RTA) to adsorb hygienic solutions and inhibit bacterial growth and to examine the efficacy of three hygiene protocols in reducing bacterial biofilm adherence to RTA., Materials and Methods: Solution adsorption and bacterial growth inhibition were examined in vitro using paper vs RTA discs. Subsequently, 11 patients treated with RTA (mean age, 29.1 ± 4.7 years) were assigned into a sequence of three hygiene protocols: regular RTA brushing (baseline), immersion RTAs in chlorhexidine mouthwash (CHX), and using a vibrating bath with cleaning solution (VBC). For each patient, 12 upper RTAs were examined (2 baseline RTAs, 5 CHX RTAs, and 5 VBC RTAs), for a total of 132 RTAs. All RTAs were stained with gentian violet, and biofilm presence was measured using a photodensitometer., Results: The RTA discs did not adsorb CHX or cleaning solution. The later agent did not show antibacterial features. Baseline RTAs showed significant biofilm adherence (P < .001) on the posterior palatal side of the aligner and on the anterior incisal edge. CHX and VBC hygienic protocols significantly (P < .001) reduced baseline biofilm adherence by 16% and 50%, respectively. Hygienic improvement was maintained over 140 days when CHX and VBC were used. However, VBC was three times more efficient than CHX., Conclusions: This study highly recommends the use of a VBC protocol. Biofilm deposits on the RTA, especially on incisal edges and attachment dimples, could lead to inadequate tooth/RTA and attachment/RTA overlap and consequently impair tooth alignment.

Objective: To examine the ultimate accuracy of bracket placement in labial vs lingual systems and in direct vs indirect bonding techniques., Materials and Methods: Forty pretreatment dental casts of 20 subjects were selected. For each dental cast, four types of bracket placement were compared: labial direct (LbD), labial indirect (LbI), lingual direct (LgD), and lingual indirect (LgI). Direct bonding was performed with the casts held in a mannequin head. Labial brackets were oriented with a Boone gauge, and lingual brackets were oriented with the Lingual-Bracket-Jig System. Torque error (TqE) and rotation deviation (RotD) were measured with a torque geometric triangle and a toolmaker's microscope, respectively. Both torque and rotational measurements were evaluated statistically as algebraic and absolute numeric values, using analysis of variance with repeated measures., Results: Absolute TqE and RotD were significantly (P < .001) higher in direct than in indirect bonding techniques higher in both the labial and lingual bracket systems by twofold and threefold, respectively (LbD = 7.26 degrees , 1.06 mm; vs LbI = 3.02 degrees , 0.75 mm; LgD = 8.42 degrees , 1.13 mm; vs LgI = 3.18 degrees , 0.55 mm). No statistically significant difference was found between labial and lingual systems for the same bonding technique. Maxillary incisors demonstrated the largest RotD angle (eg, right lateral: 12.04 degrees ). A distal off-center RotD was predominant in the mandibular dentition., Conclusions: Labial and lingual systems have the same level of inaccuracy. For both systems, indirect bonding significantly reduces absolute TqE and RotD. The TqE found can cause transverse discrepancy (scissors or crossbite) combined with disclusion with antagonist teeth. The RotD found can result in irregular interproximal contact points.