Tooth Structure and Replacement of the Triassic Keichousaurus (Sauropterygia, Reptilia) From South China

The small-sized sauropterygian Keichousaurus hui was one of the most abundant marine reptiles from the Triassic Yangtze Sea in South China. Although Keichousaurus has been studied in many aspects, including the osteology, ontogeny, sexual dimorphism, and reproduction, the dentition of this marine reptile was only briefly described in external morphology. In this study, we provide new information on Keichousaurus tooth implantation, histology, and replacement based on a detailed examination of well-preserved specimens collected in the past decades. The tooth histology has been investigated for the first time by analyzing cross-sections of premaxillary teeth and the tooth attachment and implantation have been further revealed by X-ray computed microtomography. We refer the tooth replacement of Keichousaurus to the iguanid replacement type on the basis of the observed invasion of small replacement tooth into the pulp cavity of the functional tooth. Given the resemblance to other extinct and modern piscivorous predators in the morphology and structure of teeth, Keichousaurus might mainly feed on small or juvenile fishes and some relatively soft-bodied invertebrates (e.g., mysidacean shrimps) from the same ecosystem.

Functional tooth units and masticatory ability in elderly population

Introduction: The elders are the ones that most often experience tooth loss which affects masticatory function. Masticatory function can be evaluated subjectively through masticatory ability assessment. The masticatory function is influenced by the number of posterior occluding pairs; this also may be called as functional tooth units (FTUs). The purpose of this study was to describe FTUs and masticatory ability in the elderly. Methods: This research was a descriptive study with a cross-sectional study design. Subjects were taken by purposive sampling technique. The study was conducted in the Lebakgede Sub-district, Bandung City. Data mentioned were obtained by conducting interviews regarding data on subject characteristics and questionnaires of masticatory ability, as well as examining the oral cavity to obtain FTUs data. Results: Subjects obtained were 74 people consisting of 63 women (85.14%) and 11 men (14.86%). Based on the results, the average age of the research subjects was 68.49 years, and those with good masticatory ability status were 26 elderly (35.14%) with an average FTU value of 5.9 while 48 elderly (64.86%) had poor masticatory ability status with an average FTU score of 1.5, even 31 subjects (41.89%) had a zero FTU score. Conclusion: The majority of the elderly in this research mostly had a low total FTUs score which means that the masticatory ability status in the elderly tended to be poor.

The Association between Malnutrition and Oral Health in Older People: A Systematic Review

The aim of this systematic review was to examine the association between malnutrition and oral health in older people (≥ 60 years of age). A comprehensive systematic literature search was performed in four databases (PubMed, CINAHL, Dentistry and Oral Sciences Source, and Embase) for literature from January 2000 to May 2020. Both observational and intervention studies were screened for eligibility. Two reviewers independently screened the search results to identify potential eligible studies, and assessed the methodological quality of the full-text studies. A total of 3240 potential studies were identified. After judgement for relevance, 10 studies (cross-sectional (n = 9), prospective cohort (n = 1)) met the inclusion criteria. Three studies described malnourished participants as having fewer teeth, or functional (tooth) units (FTUs), compared to well-nourished participants. Four studies reported soft tissue problems in malnourished participants, including red tongue with blisters, and dry or cracked lips. Subjective oral health was the topic in six studies, with poorer oral health and negative self-perception of oral health in malnourished elderly participants. There are associations between (at risk of) malnutrition and oral health in older people, categorized in hard and soft tissue conditions of the mouth, and subjective oral health. Future research should be focused on longitudinal cohort studies with proper determination of malnutrition and oral health assessments, in order to evaluate the actual association between malnutrition and oral health in older people.

Associations between the composition of Functional Tooth Units and nutrient intake in older men: The Concord Health and Ageing in Men Project

Objective: Inadequate nutrient intakes have been linked with poor dentition in older adults. The aim of this study was to investigate the associations between composition of Functional Tooth Units (FTUs) and nutrient intakes in older men. Design: A cross-sectional study with a standardized validated diet history assessment and comprehensive oral health assessments. FTUs were categorised by dentition type; (i) Group A (Natural FTUs Only) (ii) Group B (Natural and Replaced FTUs) and (iii) Group C (No Natural FTUs). Attainment of Nutrient Reference Values (NRVs) for 16 micronutrients was incorporated into a Micronutrient Risk variable, dichotomised 'good’ (≥12) or 'poor’ (≤11), and for 7 macronutrients into a Macronutrient Risk variable, dichotomised 'good’ (≥5) or 'poor’ (≤4). Setting: Subjects selected from the local Sydney geographical areas. Participants: Community dwelling older men (n=608). Results: 32% (n=197) of participants were categorized as Group A, 27% (n=167) as Group B and 40% (n=244) as Group C. In adjusted logistic regression analysis being in Group C, compared to Group A, was associated with intakes below NRV recommendations for fibre (OR:2.30, 95%CI 1.30 - 4.05). Adjusted analysis also showed that men in Group C, compared to Group A, were more likely to have poor intake of macronutrients (OR:2.00, 95%CI 1.01 – 3.94). Conclusions: Our study shows statistically significant associations between composition of FTUs and poor macronutrient intakes. Maintaining natural pairs of occluding FTUs may be important for attaining adequate nutrient intakes in older men.

Tooth wear development in the Australian Aboriginal dentition from Yuendumu: A longitudinal study

The analysis of dental wear, at both the microscopic and macroscopic scale, is one of the most widely used tools in archeology and anthropology to reconstruct the diet and lifestyle of past human populations. Biomechanical studies have indicated that tooth wear helps to dissipate the mechanical load over the crown surface, thus reducing the risk of tooth fracture. To date, there are only a few studies that have examined functional tooth wear variation in modern humans. Here we propose to study masticatory efficiency through the use of the Occlusal Fingerprint Analysis method, a well-developed digital approach that allows the reconstruction of the occlusal dynamics occurring during mastication. The aim of this study is to provide the first longitudinal quantitative data of molar and premolar macrowear patterns within a functional context. We examined the mixed and permanent dentition of one Australian Aboriginal child (from ages 8 to 17) from Yuendumu, using high-resolution surface scans of dental casts including both upper and lower arches. Our results suggest that the occlusal macrowear patterns of this individual did not significantly change through time. Occlusal contact parameters such as functional area, inclination and direction remain relatively unaltered throughout childhood and adolescence, indicating little change in the masticatory function of this individual. The functional tooth wear pattern in this individual did not change longitudinally indicating the degree of masticatory efficiency has most probably remained unaltered.

Eruption of Bioengineered Teeth: A New Approach Based on A Polycaprolactone Biomembrane

Obtaining a functional tooth is the ultimate goal of tooth engineering. However, the implantation of bioengineered teeth in the jawbone of adult animals never allows for spontaneous eruption due mainly to ankylosis within the bone crypt. The objective of this study was to develop an innovative approach allowing eruption of implanted bioengineered teeth through the isolation of the germ from the bone crypt using a polycaprolactone membrane (PCL). The germs of the first lower molars were harvested on the 14th day of embryonic development, cultured in vitro, and then implanted in the recipient site drilled in the maxillary bone of adult mice. To prevent the ankylosis of the dental germ, a PCL membrane synthesized by electrospinning was placed between the germ and the bone. After 10 weeks of follow-up, microtomography, and histology of the implantation site were performed. In control mice where germs were directly placed in contact with the bone, a spontaneous eruption of bioengineered teeth was only observed in 3.3% of the cases versus 19.2% in the test group where PCL biomembrane was used as a barrier (p < 0.1). This preliminary study is the first to describe an innovative method allowing the eruption of bioengineered tooth implanted directly in the jawbone of mice. This new approach is a hope for the field of tooth regeneration, especially in children with oligodontia in whom titanium implants are not an optimal solution.

A Prospective Analysis of the Correlation Between Postoperative Pain and Vital Pulp Therapy

Vital pulp therapy (VPT) is a viable treatment option for carious teeth with exposed pulps. To our knowledge, no study has examined the correlation between postoperative pain and the outcome of VPT on asymptomatic permanent teeth. The aim of this study was to examine whether odontogenic pain experienced after VPT on asymptomatic teeth with a carious pulp exposures is correlated with the progression of pulpal disease into a more inflamed or necrotic state. Direct pulp caps or partial pulpotomies using a tricalcium silicate (MTA Angelus, Angelus, Londrina, Brazil) were performed on asymptomatic permanent teeth using a standardized protocol. Patients were contacted at 24 h, 1 week, and 3 months following treatment and data was collected on post-operative pain and analgesic intake using a standardized questionnaire. At 6 months after treatment, an in-person clinical exam was performed which included standard vitality tests along with exposure of a periapical radiograph. Success was defined as an asymptomatic, functional tooth without any clinical or radiographic pathology. Data was analyzed using logistic regression. VPT was successful in 84.3% of patients at the 6 months timepoint. The percentage of patients that experienced pain at 24-h, 1 week, and 3-month time periods was 38, 22, and 12%, respectively. Pain at 3 months was significantly correlated with decreased outcome (p = 0.028). This data suggests that postoperative pain in the first 3 months after VPT is predictive of a poor treatment outcome.

A New Basal Hadrosaurid (Dinosauria: Ornithischia) From the Latest Cretaceous Kita-ama Formation in Japan: the Rise of Hadrosaurs

Here we describe a partial hadrosaurid skeleton from the marine Maastrichtian Kita-ama Formation of the Izumi Group in Japan as a new taxon, Yamatosaurus izanagii gen. et sp. nov. Our phylogenetic analysis demonstrates it belongs to the Hadrosauridae, composed of Hadrosaurus foulkii + (Yamatosaurus izanagii + (Saurolophinae + Lambeosaurinae). Yamatosaurus izanagii is unique in having only one functional tooth/row in the middle of the dentary dental battery and complete absence of the branched ridges on the occlusal surfaces. The coracoid lacks a biceps tubercle as in non-hadrosaurid hadrosauroids, suggesting its presence is a key feature for the clade of Saurolophinae and Lambeosaurinae. The evolutionary rate analysis further supports that shoulder and forelimb features, which are likely to be involved in locomotion, are important for the early evolution of Hadrosauridae. Our biogeographic analyses show that the basal Hadrosauridae was widely distributed in Asia and Appalachia, and the clade of Saurolophinae and Lambeosaurinae originated in Asia. The contemporaneous occurrence of basal (Yamatosaurus izanagii) and derived (Kamuysaurus japonicus) hadrosaurids during the Maastrichtian in Japan is the first record in Asia. Because of a long geographical distance between these localities, they may not co-exist but show some level of provinciality.

Hubungan Kehilangan Gigi Sebagian Terhadap Status Gizi dan Kualitas Hidup di UPT Pelayanan Sosial Lanjut Usia Binjai Tahun 2020

Kehilangan gigi sebagian pada lansia dalam waktu yang lama dan tidak digantikan dengan gigi palsuakan menyebabkan penurunan fungsi mastikasi yang akan menyebabkan penurunan pada status gizi dankualitas hidupnya. Penelitian ini bertujuan untuk mengetahui hubungan antara kehilangan gigi sebagianterhadap status gizi dan kualitas hidup lansia yang tinggal di UPT Pelayanan Sosial Lanjut Usia Binjaipada tahun 2020. Jenis penelitiannya adalah deskriptif analitik dengan rancangan cross sectional. Sampelpenelitian adalah 67 lansia. Penelitian dilakukan dengan melakukan pemeriksaan rongga mulut,pengukuran berat dan tinggi badan dan pengisian kuesioner GOHAI. Analisis data menggunakan uji Chi-Square. Hasil penelitian menunjukkan terdapat hubungan antara kehilangan gigi sebagian terhadap statusgizi dan kualitas hidup lansia di UPT Pelayanan Sosial Lanjut Usia Binjai Tahun 2020 berdasarkanjumlah gigi yang ada dan jumlah functional tooth units (FTUs) di rongga mulut p=0,0001 (p0,05).Jumlah gigi yang ada dan jumlah functional tooth units (FTUs) di rongga mulut berhubungan penurunankemampuan mastikasi dan menyebabkan status gizi dan kualitas hidup pada lansia.

Rationale for the use of a design of Emax CAD on an endodontically treated tooth. Clinical case

Elimination of aesthetic and functional tooth disorders is one of the most popular areas in the daily practice of a dentist. The desire to achieve an ideal aesthetic result plays an important role in the choice of material for restoration. Replacing lost tooth tissues in aesthetically demanding patients is a very difficult task, for the dentist and for the restoration material.