Role of primary cilia and Hedgehog signaling in craniofacial features of Ellis-van Creveld syndrome.

Ellis-van Creveld syndrome (EvC) is an autosomal recessive genetic disorder involving pathogenic variants of EVC and EVC2 genes and classified as a ciliopathy. The syndrome is caused by mutations in the EVC gene on chromosome 4p16, and EVC2 gene, located close to the EVC gene, in a head-to-head configuration. Regardless of the affliction of EVC or EVC2, the clinical features of Ellis-van Creveld syndrome are similar. Both these genes are expressed in tissues such as, but not limited to, the heart, liver, skeletal muscle, and placenta, while the predominant expression in the craniofacial tissues is that of EVC2. Biallelic mutations of EVC and EVC2 affect Hedgehog signaling and thereby ciliary function, crucial factors in vertebrate development, culminating in the phenotypical features characteristic of EvC. The clinical features of Ellis-van Creveld syndrome are consistent with significant abnormalities in morphogenesis and differentiation of the affected tissues. The robust role of primary cilia in histodifferentiation and morphodifferentiation of oral, perioral, and craniofacial tissues is becoming more evident in the most recent literature. In this review, we give a summary of the mechanistic role of primary cilia in craniofacial development, taking Ellis-van Creveld syndrome as a representative example.

Effect of Cathodic Arc Plasma Deposition on Shear Bond Strength between Palladium Cobalt Chromium Coated with Titanium Nitride and Titanium Aluminium Nitride with Ceramic.

BACKGROUND: The success of esthetic ceramo-metal restoration is strongly influenced by its bond strength. The success of ceramo-metal restoration is subjective to its bond strength. AIM AND OBJECTIVES: The aim of this study is to evaluate the shear bond strength between palladium-based cobalt chromium (Co-Cr) alloy coated with titanium nitride (TiNi) and titanium aluminum nitride with feldspathic ceramics. MATERIALS AND METHODS: According to the International Organization for standardization 9693; technical report 1,140,640 samples were prepared using Palladium-based Co-Cr alloy with ×4 vertical projection resting on 5 mm diameter base. The samples were divided into Group: A (control), Group: B (Sandblasted), Group: C (TiNi coated), and Group: D (titanium aluminum nitride coated by cathodic arc plasma deposition, following which feldspathic ceramic application was performed. Shear bond test was performed using universal testing machine and surface analysis was performed using scanning electron microscope. RESULTS: The mean shear bond strength for Group A was 172.994 ± 3.739 N, Group B 209.485 ± 5.913 N, Group C 176.536 ± 4.780 N, and Group D 260.576 ± 16.351 N. Comparison within the groups was made using one-way ANOVA, and multiple group comparisons were made using Tukey's honestly significant difference Post hoc test where the P < 0.001was considered statistically significant. CONCLUSION: Palladium based Co-Cr alloy coated with titanium aluminum nitride by cathodic plasma arc deposition showed maximum shear bond strength with feldspathic ceramic compared to noncoated, sandblasted, and TiNi coated alloy.