Computational technology for nasal cartilage-related clinical research and application

An overview of nasal cartilage bioprinting: from bench to bedside

Nasal cartilage diseases and injuries are known as significant challenges in reconstructive medicine, affecting a substantial number of individuals worldwide. In recent years, the advent of three-dimensional (3D) bioprinting has emerged as a promising approach for nasal cartilage reconstruction, offering potential breakthroughs in the field of regenerative medicine. This paper provides an overview of the methods and challenges associated with 3D bioprinting technologies in the procedure of reconstructing nasal cartilage tissue. The process of 3D bioprinting entails generating a digital 3D model using biomedical imaging techniques and computer-aided design to integrate both internal and external scaffold features. Then, bioinks which consist of biomaterials, cell types, and bioactive chemicals, are applied to facilitate the precise layer-by-layer bioprinting of tissue-engineered scaffolds. After undergoing in vitro and in vivo experiments, this process results in the development of the physiologically functional integrity of the tissue. The advantages of 3D bioprinting encompass the ability to customize scaffold design, enabling the precise incorporation of pore shape, size, and porosity, as well as the utilization of patient-specific cells to enhance compatibility. However, various challenges should be considered, including the optimization of biomaterials, ensuring adequate cell viability and differentiation, achieving seamless integration with the host tissue, and navigating regulatory attention. Although numerous studies have demonstrated the potential of 3D bioprinting in the rebuilding of such soft tissues, this paper covers various aspects of the bioprinted tissues to provide insights for the future development of repair techniques appropriate for clinical use.

Approach to Major Nasal Reconstruction: Benefits of Staged Surgery and Use of Technology

This article reviews special considerations in complex nasal defects including treatment of adjacent subunit defects, timing of repair with radiation, reconstruction in patients with prior repairs or recurrent disease, and the role of prosthetics. The role of technological advances including virtual surgical planning, 3 dimensional printing, biocompatible materials, and tissue engineering is discussed.

The evolution of robotics: research and application progress of dental implant robotic systems

The use of robots to augment human capabilities and assist in work has long been an aspiration. Robotics has been developing since the 1960s when the first industrial robot was introduced. As technology has advanced, robotic-assisted surgery has shown numerous advantages, including more precision, efficiency, minimal invasiveness, and safety than is possible with conventional techniques, which are research hotspots and cutting-edge trends. This article reviewed the history of medical robot development and seminal research papers about current research progress. Taking the autonomous dental implant robotic system as an example, the advantages and prospects of medical robotic systems would be discussed which would provide a reference for future research.

Usefulness of T2-Weighted Images with Deep-Learning-Based Reconstruction in Nasal Cartilage

OBJECTIVE

This study aims to evaluate the feasibility of visualizing nasal cartilage using deep-learning-based reconstruction (DLR) fast spin-echo (FSE) imaging in comparison to three-dimensional fast spoiled gradient-echo (3D FSPGR) images.

MATERIALS AND METHODS

This retrospective study included 190 set images of 38 participants, including axial T1- and T2-weighted FSE images using DLR (T1WIDL and T2WIDL, belong to FSEDL) and without using DLR (T1WIO and T2WIO, belong to FSEO) and 3D FSPGR images. Subjective evaluation (overall image quality, noise, contrast, artifacts, and identification of anatomical structures) was independently conducted by two radiologists. Objective evaluation including signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) was conducted using manual region-of-interest (ROI)-based analysis. Coefficient of variation (CV) and Bland-Altman plots were used to demonstrate the intra-rater repeatability of measurements for cartilage thickness on five different images.

RESULTS

Both qualitative and quantitative results confirmed superior FSEDL to 3D FSPGR images (both p < 0.05), improving the diagnosis confidence of the observers. Lower lateral cartilage (LLC), upper lateral cartilage (ULC), and septal cartilage (SP) were relatively well delineated on the T2WIDL, while 3D FSPGR showed poorly on the septal cartilage. For the repeatability of cartilage thickness measurements, T2WIDL showed the highest intra-observer (%CV = 8.7% for SP, 9.5% for ULC, and 9.7% for LLC) agreements. In addition, the acquisition time for T1WIDL and T2WIDL was respectively reduced by 14.2% to 29% compared to 3D FSPGR (both p < 0.05).

CONCLUSIONS

Two-dimensional equivalent-thin-slice T1- and T2-weighted images using DLR showed better image quality and shorter scan time than 3D FSPGR and conventional construction images in nasal cartilages. The anatomical details were preserved without losing clinical performance on diagnosis and prognosis, especially for pre-rhinoplasty planning.

ChatGPT for shaping the future of dentistry: the potential of multi-modal large language model

The ChatGPT, a lite and conversational variant of Generative Pretrained Transformer 4 (GPT-4) developed by OpenAI, is one of the milestone Large Language Models (LLMs) with billions of parameters. LLMs have stirred up much interest among researchers and practitioners in their impressive skills in natural language processing tasks, which profoundly impact various fields. This paper mainly discusses the future applications of LLMs in dentistry. We introduce two primary LLM deployment methods in dentistry, including automated dental diagnosis and cross-modal dental diagnosis, and examine their potential applications. Especially, equipped with a cross-modal encoder, a single LLM can manage multi-source data and conduct advanced natural language reasoning to perform complex clinical operations. We also present cases to demonstrate the potential of a fully automatic Multi-Modal LLM AI system for dentistry clinical application. While LLMs offer significant potential benefits, the challenges, such as data privacy, data quality, and model bias, need further study. Overall, LLMs have the potential to revolutionize dental diagnosis and treatment, which indicates a promising avenue for clinical application and research in dentistry.

Obturator Manufacturing for Oronasal Fistula after Cleft Palate Repair: A Review from Handicraft to the Application of Digital Techniques

An oronasal fistula (ONF) is an abnormal structure between the oral and nasal cavities, which is a common complication of cleft palate repair due to the failure of wound healing. When some patients with ONF are unsuitable for secondary surgical repair, the obturator treatment becomes a potential method. The objectives of the obturator treatment should be summarized as filling the ONF comfortably and cosmetically restoring the dentition with partial function. The anatomy of patients with cleft palate is complex, which may lead to a more complex structure of the ONF. Thus, the manufacturing process of the obturator for these patients is more difficult. For performing the design and fabrication process rapidly and precisely, digital techniques can help, but limitations still exist. In this review, literature searches were conducted through Medline via PubMed, Wiley Online Library, Science Direct, and Web of Science, and 122 articles were selected. The purpose of this review was to introduce the development of the obturator for treating patients with ONF after cleft palate repair, from the initial achievement of the obstruction of the ONF to later problems such as fixation, velopharyngeal insufficiency, and infection, as well as the application of digital technologies in obturator manufacturing.

Surgical design and application of alar cartilage positioning and repositioning in correcting cleft lip nose deformity

Correction of nasal deformity is integral to modern cleft lip repair, and high risk of postoperative relapse remains a technical hurdle to overcome. The authors previously presented internal fixation of alar cartilage based on Chinese nasal morphology and lateral columella tissue increment for the correction of unilateral cleft nose deformity. Through the application and review of these techniques, the authors developed a new technique named alar cartilage positioning for primary cleft nose correction, or alar cartilage repositioning for secondary cases. Here, we introduce the theoretical foundation and preliminary experience in using this new technique.

Shape Prediction of Nasal Bones by Digital 2D-Photogrammetry of the Nose Based on Convolution and Back-Propagation Neural Network

In rhinoplasty, it is necessary to consider the correlation between the anthropometric indicators of the nasal bone, so that it prevents surgical complications and enhances the patient's satisfaction. The penetrating form of high-energy electromagnetic radiation is highly impacted on human health, which has often raised concerns of alternative method for facial analysis. The critical stage to assess nasal morphology is the nasal analysis on its anthropology that is highly reliant on the understanding of the structural features of the nasal radix. For example, the shape and size of nasal bone features, skin thickness, and also body factors aggregated from different facial anthropology values. In medical diagnosis, however, the morphology of the nasal bone is determined manually and significantly relies on the clinician's expertise. Furthermore, the evaluation anthropological keypoint of the nasal bone is nonrepeatable and laborious, also finding widely differ and intralaboratory variability in the results because of facial soft tissue and equipment defects. In order to overcome these problems, we propose specialized convolutional neural network (CNN) architecture to accurately predict nasal measurement based on digital 2D photogrammetry. To boost performance and efficacy, it is deliberately constructed with many layers and different filter sizes, with less filters and optimizing parameters. Through its result, the back-propagation neural network (BPNN) indicated the correlation between differences in human body factors mentioned are height, weight known as body mass index (BMI), age, gender, and the nasal bone dimension of the participant. With full of parameters could the nasal morphology be diagnostic continuously. The model's performance is evaluated on various newest architecture models such as DenseNet, ConvNet, Inception, VGG, and MobileNet. Experiments were directly conducted on different facials. The results show the proposed architecture worked well in terms of nasal properties achieved which utilize four statistical criteria named mean average precision (mAP), mean absolute error (MAE), R-square (R²), and T-test analyzed. Data has also shown that the nasal shape of Southeast Asians, especially Vietnamese, could be divided into different types in two perspective views. From cadavers for bony datasets, nasal bones can be classified into 2 morphological types in the lateral view which “V” shape was presented by 78.8% and the remains were “S” shape evaluated based on Lazovic (2015). With 2 angular dimension averages are 136.41 ± 7.99 and 104.25 ± 5.95 represented by the nasofrontal angle (g-n-prn) and the nasomental angle (n-prn-sn), respectively. For frontal view, classified by Hwang, Tae-Sun, et al. (2005), nasal morphology of Vietnamese participants could be divided into three types: type A was present in 57.6% and type B was present in 30.3% of the noses. In particular, types C, D, and E were not a common form of Vietnamese which includes the remaining number of participants. In conclusion, the proposed model performed the potential hybrid of CNN and BPNN with its application to give expected accuracy in terms of keypoint localization and nasal morphology regression. Nasal analysis can replace MRI imaging diagnostics that are reflected by the risk to human body.

Short-term surgical outcomes in patients with unilateral complete cleft lip and palate after presurgical nasoalveolar molding therapy: A three-dimensional anthropometric study

OBJECTIVE

This brief research report aimed to evaluate the short-term efficacy of presurgical nasoalveolar molding (PNAM) therapy on the nasolabial morphology three dimensionally in patients with non-syndromic complete unilateral cleft lip and palate (UCLP).

METHODS

Thirty-six patients with non-syndromic complete unilateral complete cleft lip and palate were enrolled retrospectively and categorized into 2 groups: 18 patients who had received PNAM treatment (PNAM group) and 18 age-matched patients who have not receive PNAM treatment (no PNAM group) from 2017 to 2021. The average starting age for PNAM therapy was 18.33 days, and the average PNAM treatment duration was 99.08 days. Twelve nasolabial parameters were measured to compare the postsurgical outcomes of two groups.

RESULTS

In PNAM groups, cleft width, vertical distance between double Crista philtri and columellar deviation were reduced compared to that in no PNAM group. And nostril height was larger than that in no PNAM group. The differences between two groups were statistically significant (p < .05). There were no statistical differences in columellar length, nostril width and bi-alar width between two groups. However, the nostril width on cleft side in PNAM group was decreased by an average of 1.1 mm.

CONCLUSION

Our result indicated that PNAM therapy decreased cleft width and vertical distance between Crista philtri. It also increased nasal symmetry by decreasing columellar deviation, increasing nostril height.

Inspiration After Posterior Pharyngeal Flap Palatoplasty: A Preliminary Study Using Computational Fluid Dynamic Analysis

Posterior pharyngeal flap palatoplasty (PPF) is one of the most commonly used surgical procedures to correct speech, especially for patients suffering from velopharyngeal insufficiency (VPI). During PPF, surgeons use the catheter to control the lateral velopharyngeal port on each side. Airway obstruction and sleep apnea are common after PPF. To understand the air dynamics of the upper airway after PPF, we used computational fluid dynamics (CFD) to demonstrate the airflow. In our previous study, we have revealed the expiration process of the upper airway after PPF and shown the features of how PPF successfully restores the oral pressure for speech. In this study, we focus on examining the inspiration process. Normal airway structures were included. For the normal velopharyngeal structure, one cylinder was applied to each model. For recapitulating the velopharyngeal structure after PPF, two cylinders were used in each model. The ports for borderline/inadequate closure, which can help the oral cavity get the required pressure, were chosen for this study. A real-time CFD simulation was used to capture the airflow through the ports. We found that the airflow dynamics of the upper airway's inspiration were dependent on the velopharyngeal structure. Although the airflow patterns were similar, the velocities between one-port and two-port structures were different, which explained why patients after PPF breathed harder than before and suggested that the one-port structure might be a better choice for secondary VPI reconstruction based on the CFD analyses.

Radiopaque Chitosan Ducts Fabricated by Extrusion-Based 3D Printing to Promote Healing After Pancreaticoenterostomy

Long-term placement of non-degradable silicone rubber pancreatic duct stents in the body is likely to cause inflammation and injury. Therefore, it is necessary to develop degradable and biocompatible stents to replace silicone rubber tubes as pancreatic duct stents. The purpose of our research was to verify the feasibility and biological safety of extrusion-based 3D printed radiopaque chitosan (CS) ducts for pancreaticojejunostomy. Chitosan-barium sulfate (CS-Ba) ducts with different molecular weights (low-, medium-, and high-molecular weight CS-Ba: LCS-Ba, MCS-Ba, and HCS-Ba, respectively) were soaked in vitro in simulated pancreatic juice (SPJ) (pH 8.0) with or without pancreatin for 16 weeks. Changes in their weight, water absorption rate and mechanical properties were tested regularly. The biocompatibility, degradation and radiopaque performance were verified by in vivo and in vitro experiments. The results showed that CS-Ba ducts prepared by this method had regular compact structures and good molding effects. In addition, the lower the molecular weight of the CS-Ba ducts was, the faster the degradation rate was. Extrusion-based 3D-printed CS-Ba ducts have mechanical properties that match those of soft tissue, good biocompatibility and radioopacity. In vitro studies have also shown that CS-Ba ducts can promote the growth of fibroblasts. These stents have great potential for use in pancreatic duct stent applications in the future.

Three-dimensional reconstruction of systematic histological sections: application to observations on palatal shelf elevation

Normal mammalian secondary palate development undergoes a series of processes, including palatal shelf (PS) growth, elevation, adhesion and fusion, and palatal bone formation. It has been estimated that more than 90% of isolated cleft palate is caused by defects associated with the elevation process. However, because of the rapidly completed elevation process, the entire process of elevation will never be easy to clarify. In this article, we present a novel method for three-dimensional (3D) reconstruction of thick tissue blocks from two-dimensional (2D) histological sections. We established multiplanar sections of the palate and tongue in coronal and sagittal directions, and further performed 3D reconstruction to observe the morphological interaction and connection between the two components prior to and during elevation. The method completes an imaging system for simultaneous morphological analysis of thick tissue samples using both synthetic and real data. The new method will provide a comprehensive picture of reorientation morphology and gene expression pattern during the palatal elevation process.