The Polish face in profile: a cephalometric baseline study

BACKGROUND: This study reports the cephalometric evaluation of a group of adolescent Polish individuals describing dento-facial structure as well as details of incisor position and soft tissue characteristics. The results should reveal morphological features specific to Polish persons and serve as a comparative material for future diagnostic procedures. METHODS: The study was based on an analysis of cephalgrams of 122 Polish adolescents average age 18years 6 months analysed in a computer system using the Kracovia composite system analysis describing dento-facial morphology ad modum Björk as well as soft tissue factors. The control material was based on published reports by Björk (Dento-facial characteristics) Riketts and Holdaway (soft tissue profile). RESULTS: The comparative study revealed a slight reduction in the sagittal jaw relationship with a significant reduction in the vertical jaw relationship and a distinctive mandibular morphology with a reduced jaw angle and an increase in the "Beta angle". These findings were reflected in the soft tissue pattern. The soft tissue profile reflected the skeletal cephalometrics observation. CONCLUSION: The dento-facial profile of Polish adolescents demonstrates specific characteristics which should be taken into account when diagnosing facial form in connection with orthodontic treatment planning in particular Polish patients

Temporomandibular Joint Hypermobility Examination through Differentiation of Sounds

The temporomandibular joint (TMJ), being an almost well-known anatomical structure but its diagnosis may become difficult due to sounds accompanying joint movement. One example is temporomandibular joint hypermobility (TMJH), which still requires comprehensive study. TMJH is a rare disorder; however, its prevalence at the level of around 4% is still significant. We propose a diagnostic method of TMJH based on the digital time-frequency analysis of sounds generated by TMJ. The volunteers were diagnosed using the RDC/TMD questionnaire and auscultated with the Littmann 3200 electronic stethoscopes on both sides of the head simultaneously. Recorded TMJ sounds were transferred to the computer via Bluetooth® for numerical analysis. The research reveals characteristic time-frequency features in acoustic signals which can be used to detect TMJH. This can help differentiate other disc displacements from joint hypermobility

Relation between Headache and Mastication Muscle Tone in Adolescents

Headache is a common problem in the population, which decreases the quality of life and makes everyday functioning difficult. It often coexists with typical symptoms of temporomandibular disorders. The objective of the study was to clarify whether there is a relationship between the presence of headache in young volunteers and the mastication muscle tone. Material and Method. Volunteers aged 18 years who underwent general dental examination, clinical evaluation, and examination using the dual-axis diagnostic system Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) form in the Polish language version participated in the study. On the basis of the examination results, these individuals were divided into three groups according to RDC results. A group of healthy individuals (axis I value 0), a group of sick individuals (axis I diagnosis Ia, IIa, or IIIa), and a group of individuals suffering from depression (axis II values 1–3) were singled out. Then, volunteers were divided into two groups: group I reporting headache and group II without any pain. In each of these individuals, the contractile activity of the masseter muscles and anterior temporal muscles was recorded bilaterally as the surface electromyographic activity (sEMG) at rest, during swallowing, and maximum clenching. The activity index ranging between +100 (activity of the masseter muscles only) and −100 (activity of the anterior temporal muscles only) was used to indicate the predominance of activity of the study muscles. Results. The statistical analysis of data showed that there was a significant relationship between the presence of headache and a change in the mastication muscle tone, expressed as the predominant activity of the temporal muscles, only in the group of sick individuals during maximum clenching. Summary. The diversity of sEMG results implies that a change in the mastication muscle tone is not a direct consequence of headache, but it has to be modified by other factors

Adhesive Cementation of Zirconia Based Ceramics-Surface Modification Methods Literature Review

Introduction: The conditioning procedures for glass-based ceramic restorations before adhesive cementation are generally recognized. In the case of polycrystalline ceramics, which include zirconium oxide, there is still no standardized protocol. The aim of this work was to present conditioning methods of the cementation surface of zirconium oxide fixed dentures. The new generation high translucency zirconia has been also considered. Material and method: The following keywords for the PUBMED and EMBASE databases were used: zirconium oxide, zirconium oxide with increased translucency, bond strength, bending strength, surface treatment. The inclusion criteria were original papers in English published between 2015–2021. Results: Out of 1537 publications, 53 articles were selected for the study, covering methods of conditioning zirconium ceramics, including new materials with increased translucency. These procedures were divided into 5 main groups. Summary: Due to the widespread use of zirconia ceramics and the introduction of new zirconia-based materials, the use of a predictable and standardized cementation protocol is one of the most important factors contributing to the long-term clinical success of prosthetic restorations. Therefore, the research showed differences in the properties of the covered materials after conditioning. It suggests the need to create separate conditioning protocols for highly translucent and traditional zirconia