Cost-effective 3D scanning and printing technologies for outer ear reconstruction: current status

Evaluation of a Structured Light Scanner for 3D Facial Imaging: A Comparative Study with Direct Anthropometry

This study evaluates the accuracy and repeatability of craniofacial measurements with a 3D light scanner, specifically the EINSTAR scanner, in comparison to traditional caliper measurements for facial anthropometry. Eleven volunteers were assessed by two examiners, one experienced and one inexperienced, who performed direct caliper measurements and indirect measurements using the scanner. Results indicated minimal differences between caliper and scanner results, with overall high accuracy and reliability demonstrated by correlation coefficients. Despite the slightly longer scanning time, the benefits of 3D imaging, including detailed surface mapping and virtual modeling, justify its integration into clinical practice, particularly in maxillofacial surgery and craniofacial assessment. Craniofacial measurements obtained with the EINSTAR scanner showed excellent reliability and accuracy, which qualifies this method for clinical and scientific use.

Bioengineering Full-scale auricles using 3D-printed external scaffolds and decellularized cartilage xenograft

Reconstruction of the human auricle remains a formidable challenge for plastic surgeons. Autologous costal cartilage grafts and alloplastic implants are technically challenging, and aesthetic and/or tactile outcomes are frequently suboptimal. Using a small animal "bioreactor", we have bioengineered full-scale ears utilizing decellularized cartilage xenograft placed within a 3D-printed external auricular scaffold that mimics the size, shape, and biomechanical properties of the native human auricle. The full-scale polylactic acid ear scaffolds were 3D-printed based upon data acquired from 3D photogrammetry of an adult ear. Ovine costal cartilage was processed either through mincing (1 mm3) or zesting (< 0.5 mm3), and then fully decellularized and sterilized. At explantation, both the minced and zested neoears maintained the size and contour complexities of the scaffold topography with steady tissue ingrowth through 6 months in vivo. A mild inflammatory infiltrate at 3 months was replaced by homogenous fibrovascular tissue ingrowth enveloping individual cartilage pieces at 6 months. All ear constructs were pliable, and the elasticity was confirmed by biomechanical analysis. Longer-term studies of the neoears with faster degrading biomaterials will be warranted for future clinical application. STATEMENT OF SIGNIFICANCE: Accurate reconstruction of the human auricle has always been a formidable challenge to plastic surgeons. In this article, we have bioengineered full-scale ears utilizing decellularized cartilage xenograft placed within a 3D-printed external auricular scaffold that mimic the size, shape, and biomechanical properties of the native human auricle. Longer-term studies of the neoears with faster degrading biomaterials will be warranted for future clinical application.

Effect of sound-induced vibrations of the pinna on head-related transfer functions: Experimental and numerical investigations

Numerical simulations of head-related transfer functions (HRTFs) conventionally assume a rigid boundary condition for the pinna. The human pinna, however, is an elastic deformable body that can vibrate due to incident acoustic waves. This work investigates how sound-induced vibrations of the pinna can affect simulated HRTF magnitudes. The work will motivate the research question by measuring the sound-induced vibrational patterns of an artificial pinna with a high-speed holographic interferometric system. Then, finite element simulations are used to determine HRTFs for a tabletop model of the B&K 5128 head and torso simulator for a number of directions. Two scenarios are explored: one where the pinna is modeled as perfectly rigid, and another where the pinna is modeled as linear elastic with material properties close to that of auricular cartilage. The findings suggest that pinna vibrations have negligible effects on HRTF magnitudes up to 5 kHz. The same conclusion, albeit with less certainty, is drawn for higher frequencies. Finally, the importance of the elastic domain's material properties is emphasized and possible implications for validation studies on dummy heads 1as well as the limitations of the present work are discussed in detail.

Lower Jaw Full-Arch Restoration: A Completely Digital Approach to Immediate Load

The digital transformation has revolutionized various sectors, including dentistry. Dentistry has emerged as a pioneer in embracing digital technologies, leading to advancements in surgical and prosthetic oral healthcare. Immediate loading for full-arch edentulous dental implants, once debated, is now widely accepted. This case report describes a 74-year-old patient with dental mobility and significant bone loss who was rehabilitated using a Toronto Bridge protocol on four dental implants with immediate loading. Digital planning, surgical guides, 3D printing, and precision techniques were employed. The surgery involved implant placement and prosthetic procedures. The patient reported minimal post-operative discomfort, and after four months, the definitive prosthesis was successfully placed. This case demonstrates the efficacy of immediate loading in complex dental scenarios with digital innovation, resulting in improved patient outcomes. The full digital workflow, including 3D printing and the use of modern materials, enhances the efficiency and predictability of oral rehabilitation, marking a transformative era in dental care. The integration of digital technology in all phases of treatment, from diagnosis to finalization, makes this approach safer, reliable, and efficient, thereby benefiting both patients and clinicians.