Thermo-Mechanical Behaviour of Human Nasal Cartilage

Challenges in Nasal Cartilage Tissue Engineering to Restore the Shape and Function of the Nose

The repair of nasal septal cartilage is a key challenge in cosmetic and functional surgery of the nose, as it determines its shape and its respiratory function. Supporting the dorsum of the nose is essential for both the prevention of nasal obstruction and the restoration of the nose structure. Most surgical procedures to repair or modify the nasal septum focus on restoring the external aspect of the nose by placing a graft under the skin, without considering respiratory concerns. Tissue engineering offers a more satisfactory approach, in which both the structural and biological roles of the nose are restored. To achieve this goal, nasal cartilage engineering research has led to the development of scaffolds capable of accommodating cartilaginous extracellular matrix-producing cells, possessing mechanical properties close to those of the nasal septum, and retaining their structure after implantation in vivo. The combination of a non-resorbable core structure with suitable mechanical properties and a biocompatible hydrogel loaded with autologous chondrocytes or mesenchymal stem cells is a promising strategy. However, the stability and immunotolerance of these implants are crucial parameters to be monitored over the long term after in vivo implantation, to definitively assess the success of nasal cartilage tissue engineering. Here, we review the tissue engineering methods to repair nasal cartilage, focusing on the type and mechanical characteristics of the biomaterials; cell and implantation strategy; and the outcome with regard to cartilage repair. Impact statement Nasal septal cartilage is key to the cosmetic and function of the nose. To repair important damage to the nasal septum, current surgical techniques are complex and limited by graft source availability. Conversely, tissue engineering is a promising strategy to reproduce the dimensions and mechanical properties of the nose without causing donor site morbidity. This approach, however, remains overlooked for the reconstruction of the nasal septum compared with other cartilaginous tissues. This review describes the specific challenges associated with nasal cartilage repair and the pioneering studies leading to advances in the growing field of nose tissue engineering.

Evaluating the Outcomes of Closed Reduction of Different Types of Nasal Bone Fractures

This study was conducted to evaluate the outcomes of closed reduction of different types of nasal bone fractures depending on time between onset of injury and reduction and comparing the outcomes of early closed reduction (within 6 h) of nasal bone fracture with late closed reduction (after 2 weeks). A hospital based Prospective cohort type of study was conducted among cases of nasal bone fracture attending the outpatient department of Otorhinolaryngology at Chettinad Hospital and Research Institute, Chennai during the months of August 2021 to January 2022. A total of 54 participants were included in the study. Primary outcome was to assess the effectiveness of closed reduction of different types of nasal bone fractures postoperatively. The second objective was to compare the outcomes of early closed reduction (within 6 h) of nasal bone fracture with late closed reduction (after 2 weeks). Using chi square test, the association of factors such as age, sex, mode of injury, external framework deformity, type of fracture and treatment was analyzed with outcome measures such as post op degree of deviation, arch irregularity, malalignment, bony irregularity, bony displacement, olfactory disturbances and result. We analyzed the sample data statistically and measured the outcomes which showed that post operatively after undergoing closed reduction, some degree of deviation was present in 17(31.48./.), arch irregularity present in 12(22.2./.), malalignment in 11(20.37./.), bony irregularity in 24(44.44./.), bony displacement in 19(35.19./.), olfactory disturbances in 2(3.70./.). Comparing the outcome factors between early and late reduction, we found that the outcome was better in early closed reduction when compared with late closed reduction. Among the 54 patients studied, the results of closed reduction were found to be excellent in 27(50./.), Fair in 16(29.63./.), Good in 10(18.52./.) and poor in 1(1.85./.) We could thus conclude from this study that early closed reduction of nasal bone fracture gave better results than a late closed reduction in terms of post operative deformity, arch irregularity, malalignment, bony irregularity, bony displacement and olfactory disturbances.

Septal Advancement Flap: Preserving, Restructuring, and Reshaping the Nasal Tip Contour with a Novel Flap

Tip support and the tip's exact final position-rotation and projection-remain a main concern among rhinoplasty surgeons. The available options can be classified into two groups: septal extension graft (variations including tongue-in-groove) and columellar strut (with all its variations). There is still the possibility of nasal tip ligament(s) preservation-namely the interdomal ligament, when anchoraged cephalically to the anterior septal angle preserving the tip support. Including this panoply of solutions, the author has identified some challenges with insufficient outcome. Based on engineering concepts, a novel septal flap was developed to facilitate a preferred tip position and shape. The septal advancement flap (SAF) is a rotational-advancement flap of the superior and caudal aspects of the cartilaginous septum that enables the surgeon to create stable and accurate tip shape and position. This flap was designed following the spare roof technique B sequence, although it can be completed along with any technique of structure or preservation rhinoplasty.

Properties of the Nasal Cartilage, from Development to Adulthood: A Scoping Review

OBJECTIVE

Nasal septum cartilage is a hyaline cartilage that provides structural support to the nasal cavity and midface. Currently, information on its cellular and mechanical properties is widely dispersed and has often been inferred from studies conducted on other cartilage types such as the knee. A detailed understanding of nasal cartilage properties is important for several biological, clinical, and engineering disciplines. The objectives of this scoping review are to (1) consolidate actual existing knowledge on nasal cartilage properties and (2) identify gaps of knowledge and research questions requiring future investigations.

DESIGN

This scoping review incorporated articles identified using PROSPERO, Cochrane Library (CDSR and Central), WOS BIOSIS, WOS Core Collection, and ProQuest Dissertations and Theses Global databases. Following the screening process, 86 articles were considered. Articles were categorized into three groups: growth, extracellular matrix, and mechanical properties.

RESULTS

Most articles investigated growth properties followed by extracellular matrix and mechanical properties. NSC cartilage is not uniform. Nasal cartilage growth varies with age and location. Similarly, extracellular matrix composition and mechanical properties are location-specific within the NSC. Moreover, most articles included in the review investigate these properties in isolation and only very few articles demonstrate the interrelationship between multiple cartilage properties.

CONCLUSIONS

This scoping review presents a first comprehensive description of research on NSC properties with a focus on NSC growth, extracellular matrix and mechanical properties. It additionally identifies the needs (1) to understand how these various cartilage properties intersect and (2) for more granular, standardized assessment protocols to describe NSC.

Spare Roof Technique Versus Component Dorsal Hump Reduction: A Randomized Prospective Study in 250 Primary Rhinoplasties, Aesthetic and Functional Outcomes

BACKGROUND

Most Caucasian aesthetic rhinoplasty patients complain about having a noticeable hump in profile view. Taking the integrity of the middle vault into consideration, there are 2 ways to dehump a nose: the structured technique and the preservation technique.

OBJECTIVES

The aim of this study was to compare the aesthetic and functional outcomes of 2 reduction rhinoplasty techniques.

METHODS

We performed a prospective, randomized, interventional, and longitudinal study on 250 patients randomly divided into 2 groups: the component dorsal hump reduction group (CDRg) (n = 125) and the spare roof technique group (SRTg) (n = 125). We utilized the Utrecht Questionnaire for Outcome Assessment in Aesthetic Rhinoplasty. Patients answered the questionnaire before the surgery, and at 3 and 12 months after surgery. In addition, we utilized a visual analog scale (VAS) to score nasal patency for each side.

RESULTS

Analyses of the preoperative and postoperative aesthetic VAS scores showed a significant improvement in both groups, from 3.66 to 7.00 (at 3 months) to 7.35 (at 12 months) in the CDRg, and from 3.81 to 8.14 (at 3 months) to 8.45 (at 12 months) in the SRTg. Analyses of postoperative means of aesthetic VAS scores showed a significant improvement in both groups over time. However, aesthetic improvement was higher in the SRTg than in the CDRg at both 3 (P < 0.001) and 12 months (P < 0.001) postsurgery. Analyses of the mean functional VAS scores showed a significant improvement with both techniques, with a better result for the SRTg.

CONCLUSIONS

The SRT is a reliable technique that can help deliver consistently better aesthetic and functional results than CDR for reduction rhinoplasty in Caucasian patients with a dorsal hump.

LEVEL OF EVIDENCE: 2