A geometric morphometric approach to the study of variation of shovel-shaped incisors.

OBJECTIVES: The scoring and analysis of dental nonmetric traits are predominantly accomplished by using the Arizona State University Dental Anthropology System (ASUDAS), a standard protocol based on strict definitions and three-dimensional dental plaques. However, visual scoring, even when controlled by strict definitions of features, visual reference, and the experience of the observer, includes an unavoidable part of subjectivity. In this methodological contribution, we propose a new quantitative geometric morphometric approach to quickly and efficiently assess the variation of shoveling in modern human maxillary central incisors (UI1). MATERIALS AND METHODS: We analyzed 87 modern human UI1s by means of virtual imaging and the ASU-UI1 dental plaque grades using geometric morphometrics by placing semilandmarks on the labial crown aspect. The modern human sample was composed of individuals from Europe, Africa, and Asia and included representatives of all seven grades defined by the ASUDAS method. RESULTS: Our results highlighted some limitations in the use of the current UI1 ASUDAS plaque, indicating that it did not necessarily represent an objective gradient of expression of a nonmetric tooth feature. Rating of shoveling tended to be more prone to intra- and interobserver bias for the highest grades. In addition, our analyses suggest that the observers were strongly influenced by the depth of the lingual crown aspect when assessing the shoveling. DISCUSSION: In this context, our results provide a reliable and reproducible framework reinforced by statistical results supporting the fact that open scale numerical measurements can complement the ASUDAS method.

A History of Caries in the Middle Ages: Characteristics and Cultural Profiles.

In paleopathology, since the mid-1960s, caries and its characteristics have been studied on medieval teeth by many different teams in Europe, particularly in relation to the dietary and cultural habits of the populations concerned. The aims of this article are to propose a global study of caries within European medieval populations through various parameters such as prevalence, distribution, location, gender, and diet.

Intraoral Ultrasonography for Periodontal Tissue Exploration: A Review.

This systematic review aims to investigate the possibilities of ultrasound imaging in the field of periodontal tissues exploration to visualize periodontal anatomical structures and to assess reliability in clinical evaluation using the PRISMA guidelines. An electronic search through the MEDLINE database was realized to identify studies that have explored ultrasonography in the field of periodontal imaging published from 2000 to March 2022. The search resulted in 245 records; after exclusions, a total of 15 papers were included in the present review. Various publications have shown the possibility of using intraoral ultrasound for a precise exploration of intraoral tissues and to perform measurements of periodontal structures. Studies argue that ultrasounds open the prospect of a complete paradigm shift on the diagnosis and follow-up of periodontal disease. However, there is currently no clinical device dedicated to periodontal ultrasound. This field is still under-studied, and studies are needed to explore the large field of applications from periodontal assessment to treatment reassessment, including surgery. Researchers should focus their efforts to develop special intraoral ultrasound device and explore the possibilities of clinical periodontal applications.

Prevention and repair of orthodontically induced root resorption using ultrasound: a scoping review.

INTRODUCTION: This review summarizes the available recent literature on different mechanisms and parameters of pulsed ultrasound (US) that have been used during orthodontic treatments to prevent and repair root resorption. AREAS COVERED: A literature search was conducted between January (2002) and September (2022) in the following databases: PubMed, Google-Scholar, Embase, and The-Cochrane-Library. After exclusions, a total of 19 papers were included in the present review. The most used US parameters with positive outcomes were frequency of 1.5 MHz, pulse repetition frequency of 1000 Hz, output intensity of 30 mW/cm2, duration of application of 20 min and total number sessions were 14 with a repetition interval of 1 day. The suggested mechanisms induced by US were alteration of cementoblasts, osteoblasts, osteoclasts, alkaline-phosphatase (ALP), runt-related-gene-2 (Runx2), osteoprotegerin (OPG), type-I-collagen (Col-I), C-telopeptide-type-I-collagen (CTX-I), hepatocyte-growth-factor (HGF), bone morphogenetic protein-2 (BMP-2), cyclooxygenase-2 (Cox-2), calcium (Ca2+), receptor activator of nuclear factor-kappa-B ligand (RANKL), and receptor activator of nuclear factor-kappa-B (RANK). EXPERT OPINION: Understanding mechanisms and deciding which parameters of US that can be used during orthodontic treatment to prevent and repair root resorption is a great challenge. This work summarizes all the available data that can aid this process and suggest that US is an effective noninvasive method not only in prevention and repairing of orthodontic induced root resorption but also in accelerating teeth movement.

Recreational Nitrous Oxide Use and Associated Factors among Health Profession Students in France.

The first aim of this study was to investigate the recreational use of nitrous oxide (N2O) among health profession students at Montpellier University (France). The second aim was to identify the factors associated with N2O use. All students in medicine, dentistry, pharmacy and midwifery of the Montpellier University were contacted by email to participate in the survey. The students answered directly online by filling out anonymously a questionnaire including demographic information and questions about N2O, illicit drugs and alcohol use. Ethical approval was granted by the ethics committee of the Montpellier University. The sample comprised 593 students (mean age = 22.3 ± 2.6 yr), with 68.6% of females. Lifetime N2O use was reported by 76.6% and frequent alcohol use by 30.5% of the respondents. The lifetime use of cannabis, 'poppers', cocaine, ecstasy and LSD was 26.8%, 54.6%, 9.6%, 10.1% and 2.0% respectively. In multivariate analysis, the substances significantly associated with lifetime N2O were alcohol drinking and 'poppers' use. With respect to this self-nominated sample, our results indicate that respondents who were alcohol drinkers, were poppers users, follow longer studies, divert medical products for recreational use or were members of a students' corporation had higher odds of lifetime N2O use.

Benefit of Hyaluronic Acid to Treat Facial Aging in Completely Edentulous Patients.

Hyaluronic acid (HA) is widely used in aesthetic medicine for its moisturizing and anti-aging action. This molecule, which is naturally present in the body, has an interesting response to aging, accentuated in totally edentulous patients. While its aesthetic benefits for facial rejuvenation are well-documented, there is a lack of description and investigation on its therapeutic usefulness for edentulous patients. The management of completely edentulous patients is a daily reality in dental practice and requires specific attention. The aesthetic and functional challenge is considerable. The displacement of the bone base, which is often marked, and lack of soft tissue support are sometimes difficult to correct with prosthetic reconstruction. This review aims to present the physiological processes appearing in completely edentulous patients and prosthetic solutions available to recreate oral functions and counteract facial aging. As prosthetic rehabilitations are not fully satisfying for counterbalancing the impression of excessive facial aging, we investigated the applications of HA injection in the perioral area, in order to improve edentulism treatment, and discussed the advantages and disadvantages, compared to other dermal fillers and rejuvenation therapies. Considering the specific situations of edentulous patients, dermal HA injections help to correct uncompensated bone losses and mucous volume losses and appear to be a therapeutically beneficial for treating completely edentulous patients, without the requirement to full rejuvenation therapy.

Using the "One Shot" Concept for Immediate Loading Implant Protocol in Edentulous Patient Rehabilitation with a Fixed Prosthesis: A 6-Year Follow-Up.

Immediate-loaded implants with a fixed prosthesis are a viable option for the restoration of edentulous ridges. Several procedures now allow for the fabrication of immediate-loading provisional and definitive prostheses. However, this complex treatment is not accessible to all patients with budget restrictions. By using a unique master model with a single titanium framework prosthesis can simplify and shorten the treatment, as well as reduce costs. After surgical placement of implant fixtures, an interim prosthesis was fabricated using a laser-welded definitive titanium framework. The prosthesis was fitted intraorally following the immediate loading protocols. The master cast model used to fabricate interim prosthesis was conserved and subsequently used in modifying the final prosthesis. After the healing process and complete soft tissue stability, an impression was made to register the clearance between the gingiva and resin. The light silicone material was directly injected under the prosthesis screwed in the mouth. In the master cast model, the stone was eliminated between the implants and a new plaster was poured to modify the crest profile with the posthealing new shape. With this modified model, it is possible to rehabilitate the denture to the new gingival anatomy in 3 to 4 hours and, if necessary, the tooth rearrangement. This "one shot" concept combines the single definitive titanium welded framework and limited laboratory work with a unique master model thereby decreasing the cost and the time of treatment.