With the increasing demand for beauty, the treatment of gingival recession has become a common request among patients. Clinically, gingival recession is mainly treated by surgery. The common surgical methods include free gingival grafting, pedicled flap technology and double flap technology (subepithelial connective tissue transplantation combined with coronally advanced flaps). If patients with indications are selected, satisfactory surgical results will be obtained. However, there are still some shortcomings in the above mentioned methods, such as the root coverage effect not being satisfactory. In recent years, researchers have put forward some improved schemes to minimize the shortcomings of the above methods to treat different degrees of gingival recession. A gingival unit graft containing gingival papilla and free gingiva can improve the blood supply of the recipient area and improve the effect of root coverage. It can obtain better root coverage for slight retraction, widening of the angular gingiva and deepening of the vestibular sulcus, but there may be issues with inconsistent color and shape of the gingiva after surgery, as well as poor aesthetic effects. Modified coronally advanced flaps, flaps prepared by the technique of half-thickness, full-thickness and half-thickness, and modified coronally advanced envelope flap technology are designed with the most serious retraction teeth as the center in the case of multiple gingival retractions, both of which can improve the effect of root covering. Tunnel technology and modified tunnel technology, without severing the gingival papilla and tunneling the gingival flap to accommodate the graft, can effectively reduce tissue damage and promote wound healing. This paper reviews the literature and summarizes the outcome of the modified surgery techniques in the treatment of gingival recession. These treatment options for gingival recession are proposed with the aim of improving clinical work, and some suggestions for the treatment of gingival recession to achieve a stable root coverage effect are put forward. In the future, the development direction of mucogingival surgery is to reduce trauma and have a stable curative effect.

Gingival recessions (GRs) result in root hypersensitivity, root surface caries, and esthetic problems. Various root coverage surgeries are being developed for periodontal plastic therapy. The tunnel technique (TUN) is one of the most widely applied surgeries due to its features of being minimally invasive, practical, excellent outcomes and long-term stability; however, there are still some limitations of this technique. The history and evolution from the envelope flap to TUN, including its efficiency when compared with coronally advanced flaps with a connective tissue graft (CTG), are reviewed in this paper. The limitations of TUN are discussed in consideration of our clinical experience; for example, there is high technique sensitivity when TUN is applied in GR>5 mm because of the great difficulty in covering the grafts. The advantages of surgical access, including vertical incisions in the vestibule, “W” type and pinhole access, are discussed for different situations. Mattress sutures and sling sutures in a single tooth or multiple teeth are applied in TUN. The different types of grafts, such as CTG, platelet-rich plasma, articular dermal matrix and xenogeneic collagen matrix, are described. Mechanical, chemical and biological conditioning of the root surface are recommended during surgery. Protecting the surgical area and taking antibiotics postoperatively are also very important. Finally, the modifications when TUN is applied with other kinds of techniques are discussed, including lateral closed TUN, laterally positioned flaps, double papilla flaps and frenuloplasty. Minimally invasive, esthetic, long-term stability and simplified techniques are the development trends of TUN in the future.

The most common periodontal biotype in the Chinese population is thin, which obviously limits orthodontic tooth movement. Periodontally accelerated osteogenic orthodontics (PAOO) can not only accelerate tooth movement through corticotomy but also expand the range of orthodontic tooth movement by alveolar bone augmentation, which could reduce the periodontal complications of orthodontic therapy. The development of PAOO has gone through a long and tortuous historical process over more than 100 years: from osteotomy based on "bony block movement" at the beginning to cortical osteotomy based on "the regional acceleratory phenomenon" and then to PAOO based on "bone tissue engineering". Throughout its development history, the understanding of the biological basis determines the development of the clinical technology. Therefore, PAOO should be based on basic research. Both the present clinical practice and future surgical improvements should be based on the fundamentals of bone repair and regeneration. According to the current evidence, it is suggested that piezocision and laser-assisted flapless corticotomy should be chosen only for simple cortical osteotomy, and surgical navigation technology or 3D-printed surgical guides are recommended. When a large amount of bone augmentation is needed, PAOO with an intact flap is still the first choice. A stable and infection-free healing environment is the key to wound healing; therefore, in addition to infection control, the surgical area should also be protected from external forces. At present, there are few high-quality clinical studies on PAOO. Multicenter, large-sample, randomized controlled clinical trials are needed to evaluate the clinical efficacy of different PAOO techniques in the future. The present article introduces the development history, fundamentals and operation precautions of PAOO, and a new perspective is also proposed, which may provide a reference for clinical practice.

As the most important pathological feature of periodontitis, alveolar bone resorption also results in tooth loss and oral dysfunction. According to recent research, the host immune response is the major factor leading to alveolar bone resorption. Antibodies, immune cells and inflammatory cytokines involved in this procedure cause an imbalance of bone formation and destruction, which is called osteoimmunity. Given the importance of adaptive humoral immunity during periodontitis, B cells are considered crucial in the development of periodontitis. Therefore, establishing B cell osteoimmunity is an effective way for us to deeply assess the start, development and prognosis of periodontitis. It has been proven that the development process of B cells is accompanied by changes in bone density or morphology. We have reviewed previous literature to understand the role of B cell bone immunity in the pathological process of periodontitis, and the results showed that B cells regulate the development of bone cell lines through transcription factors (such as RANKL, PU.1, E2A, etc.). In addition, various cytokines expressed by B cells (such as IFN-γ, IL-17, IL-10, TGF-β, etc.) can participate in the regulation of bone cells.

Host modulation therapy (HMT), as a treatment concept for periodontitis, aims to modulate the host immune responses during the pathogenesis of periodontitis. Various drugs have been evaluated as HMT, including subdose doxycycline (SDD), nonsteroidal anti-inflammatory drugs (NSAIDs), bisphosphonates, and cytokine receptors, to modify or modulate inflammatory mediators and associated signaling pathways in the immune-inflammatory response, as well as connective tissue breakdown and bone resorption. SDD, a member of the tetracycline drug family, has been reported to improve periodontal treatment outcomes by inhibiting periodontal breakdown through inhibiting MMPs. NSAIDs may suppress periodontal inflammation by reducing cyclooxygenase-2(COX-2) activity. Combined application of SSD and NSAIDs may achieve a better clinical outcome. Recent studies of HMT treatment have focused on the prevention of excessive inflammation by regulating mediators using endogenous lipid mediators. Local administration of bisphosphonates and histone deacetylase inhibitors can inhibit osteoclast activity and regulate bone tissue remodeling. Currently, SSD is approved by the FDA for periodontal treatment. Other drugs, such as COX-2 selective inhibitor, nonsteroidal anti-inflammatory drugs, bisphosphonates, triclosan and iNOS inhibitors, have good application prospects in the prevention and treatment of periodontal disease, and the mechanism and side effects of these drugs remain to be further investigated.

Gingival recession (GR) is characterized by exposure of the root surface into oral environment due to apical migration of the marginal gingiva to the cementoenamel junction (CEJ). A high prevalence of GR has been reported in several representative population samples. GR may result in a certain degree of functional and aesthetic alterations if left untreated for long periods. In severe cases, root-dentin hypersensitivity, abrasion, abfraction and root caries may also be involved in GR, which increases the challenge of plaque control. The etiology of GR is multifactorial, including periodontal disease, local anatomical variation, tooth malposition, improper tooth brushing, mechanical trauma and iatrogenic factors, of which periodontal disease is the most common cause. The treatments of GR consist of nonsurgical and surgical therapy, and the latter generally involves mucogingival surgery to restore the aesthetics and function of the local gingival recession. However, over the past 50 years, the periodontal plastic surgical technique has evolved from the traditional free gingival graft method into a more advanced, minimally invasive tunnel technique. For this technique, sulcular incisions instead of vertical relieving incisions are provided through each recession area, and full thickness mucoperiosteal flaps are created and extended beyond the mucogingival junction to facilitate coronal displacement. Each pedicle adjacent to the recession is gently undermined to create a tunnel at recipient site, where either autograft or allograft can be used. A minimally invasive tunnel technique is a better method for root coverage and reduced postoperative patient discomfort. This technique is characterized by both practical and aesthetic features.

Periodontitis is the most common oral disease and has a high incidence in humans. Periodontitis seriously affects the function of the oral and maxillofacial systems and is the most important cause of tooth loss in adults. In addition, as a long-term and persistent source of infection, periodontitis can not only trigger chronic inflammation and immune responses but also has an important impact on systemic health. Traditional periodontitis treatment focuses on inflammation control, and although this can prevent or delay the progression of the disease, satisfactory periodontal lesion tissue regeneration is difficult to obtain. With the introduction of new technologies and new materials such as guided tissue regeneration, bone grafting, growth factors and biological materials for the treatment of periodontitis, the method of periodontal tissue regeneration is more abundant, and the clinical effect has been greatly improved. In the future, stem cell transplantation and endogenous regeneration strategies are expected to become important methods for physiological and functional regeneration of periodontal lesions. This article briefly reviews the basic research and clinical application of periodontal tissue regeneration and forecasts the future development prospects and opportunities in this field.

In China, the prevalence of diabetes is increasing each year. Diabetic periodontitis, as a major complication of diabetes, retains a strong bidirectional correlation with diabetes. Periodontitis increases the risk of diabetes, and hyperglycemia aggravates periodontal inflammation. In recent years, efficient treatments for diabetic periodontitis have been increasingly emphasized, and the prevention and control of diabetic periodontitis remain difficult. It is very challenging to find the best way to recognize risk factors and increase the diagnosis rate. Deeply understanding the local and systematic biological features of diabetic periodontitis could lead to the development of clinical preventive and therapeutic strategies. This article reviews the clinical and biological characteristics of diabetic periodontitis and its treatment progress from a systemic and local perspective, with the aim of extending the work on the prevention and treatment strategies for diabetic periodontitis.

In clinical practice, the masticatory muscles problems are often encountered occlusion. Masticatory muscles, as a component of the masticatory system, play an important role in occlusion. Both of them interact with each other through neural system. However, there is not enough knowledge about it. This article introduces the function, functional disorder and functional diagnosis of masticatory muscles, and makes a brief analysis of the relation between occlusion and masticatory muscles.

Many prevalent risk factors are shared by periodontitis and cardiovascular diseases. Strong evidence supports an independent association between periodontitis and cardiovascular diseases. However, the pathogenic mechanisms is not very clear. This article summarizes the relationship between periodontitis and cardiovascular diseases, and the effects of periodontal treatment on the cardiovascular diseases risks. In addition, both direct and indirect mechanisms proposed are also elucidated.