Autologous temporomandibular joint reconstruction independent of exogenous additives: a proof-of-concept study for guided self-generation

Joint defects are complex and difficult to reconstruct. By exploiting the body's own regenerative capacity, we aimed to individually generate anatomically precise neo-tissue constructs for autologous joint reconstruction without using any exogenous additives. In a goat model, CT scans of the mandibular condyle including articular surface and a large portion of the ascending ramus were processed using computer-aided design and manufacturing. A corresponding hydroxylapatite negative mold was printed in 3D and temporarily embedded into the transition zone of costal periosteum and perichondrium. A demineralized bone matrix scaffold implanted on the contralateral side served as control. Neo-tissue constructs obtained by guided self-generation exhibited accurate configuration, robust vascularization, biomechanical stability, and function. After autologous replacement surgery, the constructs showed stable results with similar anatomical, histological, and functional findings compared to native controls. Further studies are required to assess long-term outcome and possible extensions to other further applications. The absence of exogenous cells, growth factors, and scaffolds may facilitate clinical translation of this approach

Bioengineered human tissue regeneration and repair using endogenous stem cells

We describe a general approach to produce bone and cartilaginous structures utilizing the self-regenerative capacity of the intercostal rib space to treat a deformed metacarpophalangeal joint and microtia. Anatomically precise 3D molds were positioned on the perichondro-periosteal or perichondral flap of the intercostal rib without any other exogenous elements. We find anatomically precise metacarpal head and auricle constructs within the implanted molds after 6 months. The regenerated metacarpal head was used successfully to surgically repair the deformed metacarpophalangeal joint. Auricle reconstructive surgery in five unilateral microtia patients yielded good aesthetic and functional results. Long-term follow-up revealed the auricle constructs were safe and stable. Single-cell RNA sequencing analysis reveal early infiltration of a cell population consistent with mesenchymal stem cells, followed by IL-8-stimulated differentiation into chondrocytes. Our results demonstrate the repair and regeneration of tissues using only endogenous factors and a viable treatment strategy for bone and tissue structural defects.</p

Classification of congenital thumb hypoplasia and deformity

Background: Congenital thumb deformities account for one-third or more of all cases of congenital hand deformity. However, the current classification schemes of congenital thumb hypoplasia are no longer adequate due to their lack of adaptability to increasing knowledge in the field. Hence, a modified system with the potential to adapt to ongoing advances in knowledge and understanding is desperately needed. Methods: Based on the photographs collected from thousands of cases of congenital deformities of the hand and upper limb over multiple decades in our department, we subdivided thumb hypoplasia according to the variables of morphological characteristics, anatomical structures, functional status, the relationship between thumb deformity and hand deformity, the relationship between congenital hand deformity syndrome and thumb hypoplasia, and the selection of treatment methods. Results: A total of 10 types were presented, which were elucidated with nomenclatures as well as pathological feature and symptoms. Conclusion: This modified system may shed additional light on the classification of congenital thumb anomalies, which will assist in a more effective selection of treatment modalities and offers significant benefits to both patients and practice

Nasal valve angle or nasal valve groove: Which is more suitable to describe a normal anatomic structure?

The size of the nasal valve angle is often used to assess nasal ventilation. A larger angle of the nasal valve is believed to be more conducive for ventilation, and a small angle is considered unfavorable. However, in more than 30 years of clinical practice, we have experienced that some patients with a normal nasal valve angle have relatively severe subjective or objective nasal ventilation obstruction. By studying the computed tomography data of these patients, we found that the tips of their nasal valves were at a sharp angle, while those of healthy individuals were in an arc shape. A sharp angle at the tip of the nasal valve, therefore, is a risk factor for obstructed nasal ventilation. Herein, we propose that the term “nasal valve groove” may be a more appropriate descriptor for the normal internal nasal valve anatomy, and we hope that more rhinoplasty surgeons will pay attention to how the shape of the tip affects nasal ventilation

Using the parietal branch of superficial temporal vessels: A good approach to total ear replantation

Although ear reconstruction is a mature procedure, emergency microsurgical replantation has still been regarded as the optimal treatment for ear amputation due to its cost-effectiveness and aesthetically pleasing results. Successful microsurgical ear replantation is rare because of the difficulty in identifying suitable vessels for anastomosis. We describe two cases of total ear microsurgical replants using the parietal branch of the superficial temporal vessels (STV) as the recipient vessels. The STV parietal branch was dissected up to a sufficient length after thorough debridement, and the amputated ears were revascularized using end-to-end anastomosis. Our experience shows that the parietal branch of the STV is an ideal recipient vessel option for total ear replantation