CONTACT POINTS DISTRIBUTION ACCORDING TO THE ARTICULATOR TYPE: SEMIADJUSTABLE VERSUS NON ADAPTABLE VERSUS DIGITAL

Objectives. To analyze the location and intensity of occlusal contact points using three types of articulators: non adjustable, semiadjustable and digital with aiming at improving the diagnostic and treatment options in dental medicine. Material and method. For analyzing the distribution of contact points, the casts of a patient were mounted in the non adjustable and semiadjustable articulator. Intraoral scanning was performed using an intraoral scanner (Trios 3Shape) and reviewed in a virtual articulator. Occlusion obtained by the three methods was compared to the clinical situation. Results. Contact points in maximum intercuspation, propulsion and lateral movements were analyzed. The points obtained by using the non adjustable articulator have been less intense and more unprecise. By digitizing the contact points, the image becomes more accurate and sharp. Discussion. The semiadjustable articulator reproduces the contact points which are consistent with the clinical situation. Major differences occur when using the non adjustable articulator, which has a limited capacity of reproducing the clinical movements, therefore the marks are non consistent with the real clinical situation. The digital articulator seems promising in terms of eccentric movements. Conclusions. However performing an articulator may be, the clinical maximum intercuspation will never be fittingly reproduced, due to the fact that articulators are rigid systems, whereas the oral cavity has an elasticity, resulting from the mandible, teeth and periodontal ligaments. Virtual articulators need to be further developed for more accurate results.

Anatomical and histological structure of the cavy’s teeth as a basis for diagnosis of dental diseases

The cavy’s dentition can be shortly described as diphyodont, heterodont, and hypselodont. Histologically, each tooth consists of enamel formed of 4 layers of cells, which together form an apical bud, dentin formed by odontoblasts, and dental cementum. The facies lingualis of incisors is covered with classical acellular cementum, whereas a few circular islands of cementum pearls occur on facies labialis. There are 3 types of cementum in cheek teeth: acellular cementum, cementum pearls, and cartilage-like cementum. Constant tooth growth is ensured by an open pulp cavity within the apex. Periodontal ligaments that are part of the desmodontium are responsible for anchoring teeth in the alveolus.

Comparison of the Effects Caused by Three Different Mandibular Advancement Devices on the Periodontal Ligaments and Teeth for the Treatment of Osa: A Finite Element Model Study

AIM: The purpose of this study is to compare the stress effects developed on the periodontal ligaments and teeth by three different types of mandibular advancement devices (MADs) using a finite element method (FEM) analysis. Introduction: Obstructive sleep apnea (OSA) is a disease with a high prevalence and, in recent years, the use of MADs as an alternative or support treatment to the continuous positive airway pressure (CPAP) has spread. Their use finds relative contraindications in the case of partial edentulism and severe periodontal disease. Given the widespread of periodontal problems, it is essential to know the effects that these devices cause on the periodontal ligament of the teeth. Materials and methods: Starting from the computed tomography (CT) scan of a patient’s skull, 3D reconstructions of the maxilla and mandible were implemented. Three different MADs were prepared for the patient, then 3D scanned, and lastly, coupled with the 3D models of the jaws. The devices have two different mechanics: One has a front reverse connecting rod (OrthoapneaTM), and two have lateral propulsion (SomnodentTM and HerbstTM). A FEM analysis was performed to calculate the stress applied on periodontal ligaments, on every single tooth and the displacement vectors that are generated by applying an advancement force on the mandible. Results: HerbstTM and SomnodentTM devices present very similar stress values, mainly concentrated on lateral teeth, but in general, the forces are very mild and distributed. The maximum stresses values are 3.27 kPa on periodontal ligaments and 287 kPa on teeth for SomnodentTM and 3.56 kPa on periodontal ligaments and 302 kPa on teeth for HerbstTM. OrthoapneaTM has, instead, higher and concentrated stress values, especially in the anterior maxillary and mandibular area with 4.26 kPa and 600 kPa as maximum stress values, respectively, on periodontal ligaments and teeth. Conclusions: From the results, it is concluded that devices with a bilateral mechanism generate less and more distributed stress than an anterior connecting rod mechanism. Therefore, they may be advisable to patients with compromised periodontal conditions in the anterior area.

Periostin: Immunomodulatory Effects on Oral Diseases

Periostin is a microcellular adapter protein. It plays a wide range of essential roles during the development and in immunomodulation. Periostin is a prominent contributor during the process of angiogenesis, tumorigenesis, and cardiac repair. It is expressed in periodontal ligaments, tendons, skin, adipose tissues, muscle, and bone. This is a protein-based biomolecule that has the diagnostic and monitoring capability and can potentially be used as a biomarker to detect physiological and pathological conditions. The aim of the present review was to explore the periostin morphology and associated structural features. Additionally, periostin’s immunomodulatory effects and associated biomarkers in context of oral diseases have been discussed.

Biomaterial-Based Approaches for Regeneration of Periodontal Ligament and Cementum Using 3D Platforms

Currently, various tissue engineering strategies have been developed for multiple tissue regeneration and integrative structure formations as well as single tissue formation in musculoskeletal complexes. In particular, the regeneration of periodontal tissues or tooth-supportive structures is still challenging to spatiotemporally compartmentalize PCL (poly-ε-caprolactone)-cementum constructs with micron-scaled interfaces, integrative tissue (or cementum) formations with optimal dimensions along the tooth-root surfaces, and specific orientations of engineered periodontal ligaments (PDLs). Here, we discuss current advanced approaches to spatiotemporally control PDL orientations with specific angulations and to regenerate cementum layers on the tooth-root surfaces with Sharpey’s fiber anchorages for state-of-the-art periodontal tissue engineering.