ABSTRACT
The crosstalk between the nerve and stomatognathic systems plays a more important role in organismal health than previously appreciated with the presence of emerging concept of the "brain-oral axis". A deeper understanding of the intricate interaction between the nervous system and the stomatognathic system is warranted, considering their significant developmental homology and anatomical proximity, and the more complex innervation of the jawbone compared to other skeletons. In this review, we provide an in-depth look at studies concerning neurodevelopment, craniofacial development, and congenital anomalies that occur when the two systems develop abnormally. It summarizes the cross-regulation between nerves and jawbones and the effects of various states of the jawbone on intrabony nerve distribution. Diseases closely related to both the nervous system and the stomatognathic system are divided into craniofacial diseases caused by neurological illnesses, and neurological diseases caused by an aberrant stomatognathic system. The two-way relationships between common diseases, such as periodontitis and neurodegenerative disorders, and depression and oral diseases were also discussed. This review provides valuable insights into novel strategies for neuro-skeletal tissue engineering and early prevention and treatment of orofacial and neurological diseases.
Subject(s)
Humans , Bone and Bones , Nervous System , Stomatognathic SystemABSTRACT
Multiple signaling pathways are involved in the regulation of cell proliferation and differentiation in odontogenesis and dental tissue renewal, but the details of these mechanisms remain unknown. Here, we investigated the expression patterns of a transcription factor, Krüppel-like factor 6 (KLF6), during the development of murine tooth germ and its function in odontoblastic differentiation. KLF6 was almost ubiquitously expressed in odontoblasts at various stages, and it was co-expressed with P21 (to varying degrees) in mouse dental germ. To determine the function of Klf6, overexpression and knockdown experiments were performed in a mouse dental papilla cell line (iMDP-3). Klf6 functioned as a promoter of odontoblastic differentiation and inhibited the proliferation and cell cycle progression of iMDP-3 through p21 upregulation. Dual-luciferase reporter assay and chromatin immunoprecipitation showed that Klf6 directly activates p21 transcription. Additionally, the in vivo study showed that KLF6 and P21 were also co-expressed in odontoblasts around the reparative dentin. In conclusion, Klf6 regulates the transcriptional activity of p21, thus promoting the cell proliferation to odontoblastic differentiation transition in vitro. This study provides a theoretical basis for odontoblast differentiation and the formation of reparative dentine regeneration.
Subject(s)
Animals , Mice , Cell Differentiation/physiology , Cell Proliferation , Odontoblasts/metabolism , Odontogenesis , Tooth GermABSTRACT
Objective To construct a geometric skull model by using three-dimensional reconstruction, computer tomography scanning and rapid prototyping technology and evaluate its significance in treatment of complex oral and maxillofacial deformities. Methods A cranial and a goldenhar syndrome patient with complex oral and maxillofacial deformities bone received continuous volumetric scanning of skull and the data acquisition was done by an electron computed tomography, by which reconstruction was performed and the obtained images saved as STL files. Then the data were input into rapid prototyping machine to make three-dimensional geometric model. Direct measurement, designation and surgery simulation could be done on this three-dimensional model. Then the mandibular mirror physical model was manufactured using rapid prototyping according to the normal side. Results A computer-aided model according to CT data could represent the three-dimensional anatomic structures and their relationships precisely. The replica exhibited dimensional errors ranging 0.02 mm to 0.53 mm. Which provided strong basis for accurate understanding of disease status and reasonable surgical plans and helped improve the curative effect of surgery. Conclusion Rapid prototyping can help surgeons in many ways for therapy of the complex oral and maxillofacial deformities.
ABSTRACT
<p><b>OBJECTIVE</b>To study the adaptive alterations of elastic fibers in the bilaminar zone (BZ) of rabbit temporomandibular joint (TMJ) following disc displacement.</p><p><b>METHODS</b>Twenty-eight Japanese white rabbits were used in this study. The right temporomandibular joints of 20 of 28 rabbits were subjected to the surgical procedure of anterior disc displacement (ADD). Four rabbits in the surgical group were sacrificed at 2, 4, 6, 8 and 12 weeks after operation. Their temporomandibular joints were studied histochemically.</p><p><b>RESULTS</b>Elastic fibers were reduced in number and ran irregularly in the superior lamina of BZ from ADD rabbits. The jungly elastic fibers (EFs) could still be seen at 2 weeks after operation. At 4 weeks, the number of EFs decreased significantly; EFs lost their jungly arrangement and were shaped like rough dots, of which the arrangement and the lengths were different. Six weeks after operation, many EFs were replaced by distorted, uneven, non-oriented fine EFs, distributed unevenly and some thick or fine EFs that ran irregularly. The number of EFs decreased further and their arrangement was more deranged at 8 weeks. At 10 and 12 weeks, EFs in the superior lamina of BZ were similar to those at 8 weeks.</p><p><b>CONCLUSION</b>Our results show that EFs lost their function as well as their distribution and arrangement after disc displacement.</p>