Ear Prosthesis for Postburn Deformity

Evaluation of the accuracy of digital and conventional implant-level impression techniques for maxillofacial prosthesis

Objectives

This study aims to evaluate the accuracy of digital impression making based on trueness and precision measurements of dental implants placed in maxillofacial lesions to produce Maxillofacial prosthesis substructures.

Methods

Two intra-oral scanners (Trios 3 and CS 3700) and one Desktop scanner (open technology) were examined in this study. A Model of a patient with a lesion in the ear region was created as a reference. The reference model was scanned by each scanner 10 times. Standard Tessellation Language files were provided from each scanner and were examined in terms of Trueness and Precision aspects.

Results

In Distance 1, in the one-way analysis of variance test, there was a significant difference between the three scanners. The Trios group has less deviation than the Open Technology group (P = 0.015) compared with the CareStream (CS) group that showed more deviation (P < 0.000). There is a statistically significant difference in distance 2 among scanners. The Trios group showed more deviation as compared with the Open Technology group (P < 0.000). While this deviation is not statistically significant compared with the CS group (P = 0.0907). Open Technology Group compared with the CS group also has less deviation in distance 2, which has been statistically significant (P < 0.000). The preparation of a precise model of maxillofacial lesions is still difficult for some Intraoral scanners.

Conclusion

There were significant statistical differences in Trueness and Precision among scanners. Used scanners can be applied as an alternative to conventional impression methods.

Tissue engineering of human ear pinna

Auricular deformities (Microtia) can cause physical, social as well as psychological impacts on a patient's wellbeing. Biofabrication of a complex structure such as ear pinna is not precise with currently available techniques. These limitations can be overcome with the help of tissue engineering. In this article, the authors presented molding and three dimensional (3D) printing to generate a flexible, human size ear pinna. The decellularization of goat ear cartilage protocol and bioink alkaline digestion protocol was followed to yield complete removal of all cellular components without changing the properties of the Extra Cellular Matrix (ECM). Decellularized scaffold used in molding technology and 3D printing technology Computer-Aided Design /Stereolithography (CAD/STL) uses bioink to construct the patient-specific ear. In vivo biocompatibility of the both ear pinnae showed demonstrable recellularization. Histology and scanning electron microscopy analysis revealed the recellularization of cartilage-specific cells and the development of ECM in molded and 3D printed ear pinna after transplantation. Both the techniques provided ideal results for mechanical properties such as elasticity. Vascular Associated Protein expression revealed specific vasculogenic pattern (angiogenesis) in transplanted molded pinna. Chondrocyte specific progenitor cells express CD⁹⁰⁺ which highlighted newly developed chondrocytes in both the grafts which indicated that the xenograft was accepted by the rat. Transplantation of molded as well as 3D ear pinna was successful in an animal model and can be available for clinical treatments as a medical object to cure auricular deformities.