Bone defect repair caused by trauma, congenital malformation, tumor, infection or systemic diseases remains the focus of attention in regeneration medicine. Recent advances in osteoimmunology indicate that immune cells and...

Periodontitis is a chronic infectious disease caused by bacterial irritation. As an essential component of the host immunity, macrophages are highly plastic and play a crucial role in inflammatory response. An appropriate and timely transition from proinflammatory (M1) to anti‐inflammatory (M2) macrophages is indispensable for treating periodontitis. As M2 macrophage‐derived exosomes (M2‐exos) can actively target inflammatory sites and modulate immune microenvironments, M2‐exos can effectively treat periodontitis. Excessive endoplasmic reticulum stress (ER stress) and unfolded protein response (UPR) are highly destructive pathological characteristics during inflammatory periodontal bone loss. Although melatonin has antioxidant and anti‐inflammatory effects, studies focusing on melatonin ER stress modulation remain limited. This study fabricates engineered M2‐exos loading with melatonin (Mel@M2‐exos) for treating periodontitis. As a result, M2‐exos drive an appropriate and timely macrophage reprogramming from M1 to M2 type, which resolves chronic inflammation and accelerated periodontal healing. Melatonin released from Mel@M2‐exos rescues the osteogenic and cementogenic differentiation capacity in inflammatory human periodontal ligament cells (hPDLCs) by reducing excessive ER stress and UPR. Injectable gelatin methacryloyl (GelMA) hydrogels with sustained‐release Mel@M2‐exos accelerate periodontal bone regeneration in rats with ligation‐induced periodontitis. Taken together, melatonin engineering M2 macrophage‐derived exosomes are promising candidates for inflammatory periodontal tissue regeneration.

: Parry-Romberg syndrome (PRS) refers to a relatively rare dysfunction disease that is characterized by chronic progressive maxillofacial atrophy, especially one side of facial skin, subcutaneous tissue, muscle, and bone. According to the atrophy degree of skin, subcutaneous tissue, and skeleton in the area innervated by the trigeminal nerve, PRS can be classified into mild, moderate, and severe. In general, cases with different severity have specific treatment regimens. For mild and moderate cases, soft tissue augmentation techniques are the optimal strategy for aesthetic reconstruction. In this study, the authors report a 19-year-old female with severe PRS. Considering the severity of the case, a combined surgical and orthodontic treatment was performed, which was involved in alveolar bone augmentation, preoperative and postoperative orthodontic treatment in combination with orthognathic surgery, medpor filling of zygomatic and maxillary complex, free fat grafting, as well as angulus oris and lip trimming. Comprehensive treatment is recommended for severe cases with extensive atrophy of soft tissue and craniofacial bone, obvious deviation of the chin and occlusal plane.