Rheumatoid arthritis is an autoimmune‐mediated inflammatory disease, which is characterized by chronic synovitis, progressive bone destruction and reduced mobility. Aryl hydrocarbon receptor (AhR), a ligand‐dependent transcription factor, has been shown to regulate the differentiation, activation and apoptosis of various cells involved in rheumatoid arthritis. The ligands of AhR such as tetrachlorodibenzo‐p‐dioxin, benzo[a]pyrene and 3,3′‐diindolylmetheane are able to inhibit osteoclastogenesis and attenuate arthritis in mice. However, the long‐term use of these compounds is associated with severe side effects, which limit their use as therapeutic agents in animals or humans. There is an urgent need to search for new AhR ligands that are effective and safe. This MiniReview discusses the potential therapeutic value of the AhR ligands derived from natural products.

Objective: Surgical navigation-guided removal of foreign bodies in the craniomaxillofacial region has been proven to be an effective method. However, there have been some unsuccessful patients due to reduced navigation accuracy or complicated and undetectable anatomy. This article summarizes the experience and proposes some solutions to achieve better results. Study design: Two solutions were proposed to optimize the surgical navigation procedure: using a 3-dimensionally printed customized mandible retainer to indirectly maintain the consistency of the foreign body's visual images of preoperative planning and intraoperative navigation and importing real-time endoscopic imaging during surgery to provide vision under complex anatomy. Two patients were selected for each method. Results: The foreign bodies were successfully and minimally invasively removed in all patients assisted by optimized surgical navigation. During follow-up at 3 to 6 months postoperatively, no complications were found. Conclusion: Improving navigation accuracy and providing real vision might be effective at compensating for insufficient navigation due to navigation positioning errors or the interference of imperceptible and complicated anatomy.

Objective: Orthognathic surgery is an effective method to correct the dentomaxillofacial deformities. The aim of the study is to introduce the robot-assisted orthognathic surgery and demonstrate the accuracy and feasibility of robot-assisted osteotomy in transferring the preoperative virtual surgical planning (VSP) into the intraoperative phase. Methods: The CMF robot system, a craniomaxillofacial surgical robot system was developed, consisted of a robotic arm with 6 degrees of freedom, a self-developed end-effector, and an optical localizer. The individualized end-effector was installed with reciprocating saw so that it could perform osteotomy. The study included control and experimental groups. In control group, under the guidance of navigation system, surgeon performed the osteotomies on 3 skull models. In experimental group, according to the preoperative VSP, the robot completed the osteotomies on 3 skull models automatically with assistance of navigation. Statistical analysis was carried out to evaluate the accuracy and feasibility of robot-assisted orthognathic surgery and compare the errors between robot-assisted automatic osteotomy and navigation-assisted manual osteotomy. Results: All the osteotomies were successfully completed. The overall osteotomy error was 1.07 ± 0.19 mm in the control group, and 1.12 ± 0.20 mm in the experimental group. No significant difference in osteotomy errors was found in the robot-assisted osteotomy groups (P = 0.353). There was consistence of errors between robot-assisted automatic osteotomy and navigation-assisted manual osteotomy. Conclusion: In robot-assisted orthognathic surgery, the robot can complete an osteotomy according to the preoperative VSP and transfer a preoperative VSP into the actual surgical operation with good accuracy and feasibility.