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Maxillary sinus is located in the maxilla bone with the largest volume in all sinuses and is closest to the roots of maxillary posterior teeth, especially the mesiobuccal root of the maxillary second molar. The thickness of the normal maxillary sinus mucosa is about 1 mm. When stimulated or infected, it shows thickening of the mucosa. Periodontitis is one of the most common oral diseases in human beings, and the complex root anatomy of the maxillary molars aggravates the difficulty of inflammation control. Severe periodontitis of maxillary molars without effective treatment can affect the maxillary sinus, increasing the possibility of the mucosa thickening, and is also one of the reasons for the occurrence of odontogenic maxillary sinusitis (OMS). There are many different schemes for the treatment of OMS caused by severe periodontitis of maxillary molars. Extraction of teeth with severe periodontal disease without retention value or successful periodontal treatment can significantly reduce the thickness of maxillary sinus mucosa. For the patients with uncontrollable sinusitis by using drug treatment and eliminating odontogenic causes, or ones with severe symptoms, periodontal treatment and endoscopic sinus surgery can be combined to effectively control the periodontitis related maxillary sinusitis.

Cultivating dental general doctors who practice standardized periodontal diagnosis and treatment techniques is conducive to the prevention and control of periodontal diseases and the improvement of oral health of our population. Manual supragingival scaling is the most important basic skill of basic periodontal treatment, and it is the basic periodontal diagnosis and treatment technique that every oral general practitioner should know. This article starts from why manual supragingival scaling is important and how to standardize the teaching and training of manual supragingival scaling, and begin with the first chapter of basic periodontal diagnosis and treatment training, to provide reference for promoting the standardized development of periodontology teaching in China.

In patients with periodontitis, due to problems of periodontal tissue infection as well as soft and hard tissues defects, it may lead to implant infection, gingival papilla loss, soft tissue recession and poor coordination with adjacent teeth. For such patients, periodontal infection should be actively controlled before dental implant therapy. In consideration of insufficient soft and hard tissues, alveolar ridge preservation and soft tissue augmentation procedure can be used to preserve or increase soft and hard tissues as much as possible. Multi-disciplinary treatment is often needed for occlusion problems and coordination with adjacent tooth. Periodontal maintenance treatment of implants and natural teeth is also necessary after implant therapy. This paper discussed these risk factors and strategies for prevention and control, in order to provide some clinical guidances for the implant treatment of periodontitis patients.

Objective: To evaluate the survival rate, success rate, soft tissue conditions and marginal bone level changes of implants following micro crestal flap-alveolar ridge preservation at molar extraction sockets with severe periodontitis, compared to natural healing. Methods: From March 2015 to January 2017, patients scheduled for molar extraction as a consequence of severe periodontitis and planned implant-retained prostheses from Department of Periodontology Peking University School and Hospital of Stomatology were selected. A total of 40 molar extraction sockets from 40 patients received implant placement following micro crestal flap-alveolar ridge preservation or natural healing. The front consecutive 20 teeth were assigned to the natural healing group, and the back ones were assigned to the micro crestal flap-alveolar ridge preservation (MCF-ARP) group. The superstructures were placed 6 months later. Within 2 weeks (baseline) and 1, 2 and 3 years after implant crown restoration, modified plaque index, probing depth, modified bleeding index and keratinized tissue width were recorded every six months. Parallel periapical radiographs were taken to evaluate the peri-implant marginal bone level and to calculate marginal bone loss. Independent sample t test or Mann-Whitney U test were used to compare the differences in the above clinical and imaging indicators between the two groups. Results: The implant survival rate and success rate of the two groups were both 100% (20/20). There were no significant differences in the modified plaque index, probing depth, modified bleeding index, buccal keratinized tissue width and marginal bone loss between two groups at 1, 2 and 3 years after implant crown restoration (all P> 0.05). Marginal bone loss was 0.22 (0.14, 0.34) mm in the natural healing group and 0.21 (0.12, 0.30) mm in the MCF-ARP group at a 3-year post-loading evaluation. Conclusions: Within the limitations of the present study, implants placed at ridge preserved and naturally healed molar extraction sockets with severe periodontitis demonstrate comparable clinical outcomes at a 3-year post-loading evaluation.

Subepithelial connective tissue or free gingival grafts are often used in traditional mucogingival surgery to treat gingival recession and keratinized gingival insufficiency. However, due to the disadvantages of autologous soft tissue grafts, such as the preparation of the second surgical site, the limited amount of tissue in the donor site, and postoperative discomfort for patients, the research on autologous soft tissue substitute materials has attracted extensive attention. A variety of donor-substitute materials from different sources are currently used in membranous gingival surgeries, including platelet-rich fibrin, acellular dermal matrix, xenogeneic collagen matrix, etc. This paper reviews the research progress and application of several different types of substitute materials in soft tissue augmentation for natural teeth, providing a reference for the application of autologous soft tissue substitutes in clinical gingival augmentation surgery.

The number of patients with periodontal disease in China is large, and the ratio of doctors to patients is seriously imbalanced, especially in the insufficient number of periodontal specialists and periodontal teachers. Strengthening the cultivation of professional postgraduates in periodontology can effectively solve this problem. This paper summarizes the experiences of Peking University School and Hospital of Stomatology in the teaching of periodontal postgraduate students for more than 30 years, in cluding teaching objectives formulation, teaching resources allocation and enhancement of the quality control system of clinical teaching, for ensuring that the periodontal professional postgraduates could reach the expected level after training. This formed the current "Peking University Model". There are both opportunities and challenges in clinical teaching of periodontal postgraduates in domestic stomatology community. The authors hope that the continuous exploration and improvement of this teaching system will promote the vigorous development of clinical teaching for the postgraduates majoring in periodontology in China.

Peri-implantitis (PI) has been defined as an inflammatory lesion of the mucosa surrounding an endosseous implant and with progressive loss of supporting peri-implant bones. In recent years, histopathological differences between PI and periodontitis of natural teeth had been described in animal experiments and a certain number of human experiments. In this paper, we review the histopathological differences between PI and periodontitis reported in the existing literature and try to find the differences in the occurrence and progression of these two diseases. Overall, inflammatory cell infiltrate (ICT) is more extensive in PI than in periodontitis, extending to the alveolar ridge, with dense infiltration of plasma cells, lymphocytes, macrophages, polymorphonuclear leukocytes and a greater number of osteoclasts in the connective tissue, but with less vascular density within ICT than in periodontitis. In addition, foreign bodies are found in PI lesions. The histopathological differences between the two diseases in terms of inflammatory infiltration, vascularity, bone loss, and foreign bodies could partially explain the more rapid progression of PI than periodontitis, suggesting that PI should be taken seriously by physicians. Early diagnosis and treatment are essential to control the progression of PI. In addition, targeted therapy against specific inflammatory cells may become a new direction for PI treatment; reducing titanium particles released into peri-implant tissue by friction or electrochemical corrosion may help to prevent PI.

The standardized training of specialist doctors is an important part of medical education after graduation and it is the only way to train clinicians to diagnose and treat the specialist diseases independently by using a standardized and high-quality way. The prevalence of periodontal disease and the proportion of patienets with severe and advanced periodontitis in our country are high and the diagnosis and treatment process for the periodontal disease are complicated. There is an urgent need to expand the team of periodontal specialists capable of the specialized treatment. The training of periodontal specialists in our country has just started. The present article summarizes the exploration and practice of periodontal specialist training in Peking University School and Hospital of Stomatology in the past five years, including the establishment of training bases, formulation of clear training goals, strict implementation of training rules, strengthening of process quality control to ensure the trainees could reach the expected standard of periodontal specialist after training. Through the summary of the previous stage practice, the authors hope to explore and establish a periodontal specialist training system in line with our country's national conditions and further to promote and accelerate the pace of nationwide periodontal specialist training system.

Gingival papilla deficiency may cause dental plaque stagnation and food impaction, and may also affect the appearance and pronunciation when occurs in the upper anterior teeth. It has become a common concern of patients and doctors. The aetiological factors of gingival papilla deficiency were complex. Various surgical or non-surgical treatments have been reported. This paper reviews and analyzes the current research progress on the factors and treatment methods of gingival papilla deficiency in domestic and foreign studies, summarizes the factors associated with the gingival papilla deficiency and summarizes the corresponding treatment strategy, so as to provide reference for clinical and research works.

Objective: To evaluate the factors associated with the gingival papilla deficiencies of different degrees between maxillary anterior teeth showing alveolar ridge absorption. Methods: A total of 64 gingival papillae between maxillary anterior teeth of 14 patients with periodontitis, who received periodontal treatment and regular review in the Department of Periodontology, Peking University School and Hospital of Stomatology from June 2019 to December 2019, were observed in the present study. Indices were measured by using standardized clinical photographs and cone-beam CT images. The correlations between the gingival papilla deficiencies of different degrees and the distance from contact point to bone crest (CP-BC), the distance from proximal cemento-enamel junction to bone crest (pCEJ-BC), interproximal distance between roots (RD), the width of bone crest (BCW) and the height of gingival papilla (PH) were evaluated. Statistical analyses such as t -test, ANOVA, Pearson correlation coefficient and so on were conducted. Results: The rate of maxillary anterior gingival papilla completely filled the adjacent spaces between anterior teeth was 28% (18/64) and the rate of gingival papilla with deficiencies was 72% (46/64). The mild, moderate and severe deficiencies were 36% (23/64), 27% (17/64) and 9% (6/64) respectively. When CP-BC≥7.0 mm or pCEJ-BC≥4.5 mm, only moderate or severe deficiencies appeared. However, when CP-BC<5.0 mm or pCEJ-BC<1.5 mm, only completely filled adjacent tooth space or mild deficiency appeared. There was a strong positive correlation between CP-BC and pCEJ-BC. The Pearson correlation coefficient was 0.812 ( P <0.01), and the linear fitting coefficient was 0.93 ( R 2 =0.659) (64 gingival papillae). There was no significant difference of RD for gingival papilla deficiencies of different degrees between maxillary anterior teeth ( P >0.05). BCW at the crest level increased slightly with the increase of the degree of gingival papilla deficiency, and the difference was statistically significant between completely filled adjacent tooth space and moderate or severe deficiency ( P <0.05). However, PH at the crest level decreased slightly with the increase of the degree of gingival papilla deficiency, and the difference was statistically significant between completely filled adjacent tooth space and moderate or severe deficiency ( P <0.05). Conclusions: When the alveolar ridge is absorbed, the rate of deficiency is significantly higher than the completely filled adjacent tooth space. The gingival papilla deficiencies of different degrees between maxillary anterior teeth are mainly associated with the absorption of bone crest.

Minimally invasive surgery develops rapidly in the periodontal treatments, especially in the periodontal regenerative treatment, in recent years. It supplements, to a certain extent, the insufficiency of the conventional periodontal regenerative treatment. The minimally invasive surgery has many advantages such as enhancing the healing process, reducing surgical chair time and minimizing patient discomfort, etc. It has been proved to improve the clinical effect and provide additional benefits compared to conventional approaches. At present, there are many studies on minimally invasive techniques used in tooth extraction or implant placement in China, but there are few reports on the application of periodontal minimally invasive surgical techniques. Thus based on the reviews of the literatures, this article describes the applications, advantages, indications, microsurgical instruments of minimally invasive periodontal surgery on the treatment of intrabony defect, including various minimally invasive surgical procedures. The review also demonstrates the therapeutic effects and research progress of minimally invasive periodontal surgery combined with biomaterials used in the treatments of intrabony defect. The present article may also provide reference for clinicians applying minimally invasive surgeries to treat intrabony defects.

Recently the model of cultivating stomatology talents for postgraduate education in China is primarily specialized education. The aim of the present study was to construct a multidisciplinary grand rounds series based on presentation and commentary for diagnosis and treatment plan of clinical cases, in order to improve the clinical competence of postgraduate students from various dental disciplines for resolving the clinical problems. The grand rounds series was designed for postgraduate students of periodontology, with the combination of the advantages of the international dentistry education experience and Chinese characteristics. This study focused on designing and exploring the multidisciplinary grand rounds series based on complicated periodontal clinical cases, and also on analyzing and evaluating the effectiveness of the series by questionnaire investigation for both teachers and students. The results of the preliminary investigation showed that postgraduate students had positive view on the form and content of the teaching rounds. However, more analysis is needed for further evaluation.

Objective: To compare the efficacies of two training protocols, i.e. the multimedia instruction and the conventional method, in periodontal surgery teaching for undergraduate students. Methods: One hundred and twenty-three dental undergraduates in their pre-clinical training course were recruited and divided into two groups according to the learning grade matching principle: the experimental group (multimedia instruction, 60 students) and the control group (conventional method, 63 students). The teaching aim was to train the students gingivectomy and periodontal flap surgery by using the pig jaws. The conventional teaching method of teacher-demonstrating and student-practicing was used in the control group, and the practice time of the students' for each surgery was 45 minutes. A standardized teaching video combined with the teachers' explanations of the key steps was used in the experimental group. The students' practice time for each surgery was 60 minutes. The efficacy of teaching protocol was evaluated by the teachers according to the scoring criteria set by the teaching group. Results: In gingivectomy training, accuracy of fixed points, angle of postoperative gingival margin and morphology of gingiva of the experimental group were better than those of the control group. The experimental group also had more complete and continuous excised gingivae and more thorough adjacent gingival removal. The total scores of the experimental group were significantly higher than those of the control group (92.8±2.6 vs. 89.9±3.7, P< 0.05). In periodontal flap surgery training, the experimental group operated the blade around the shape of the tooth better in internal bevel incision than the control group. Additionally, the incision position of internal bevel incision, periosteal integrity after flapping and flap depth of the experimental group were better than those of the control group. Besides, the experimental group had smoother flap edge and more thorough debridement. The total scores of the experimental group were significantly higher than those of the control group (92.2±4.1 vs. 89.2±4.4, P< 0.05). Conclusions: The teaching efficacy of multimedia instruction was better than that of the conventional method. Its value needs to be further tested in future teaching practice.

To provide references and recommendations about periodontal professionals training for our country by introducing American training mode of clinical postgraduate students of periodontology. Based on ground visits and surveys of University of Washington School of Dentistry's postdoctoral program in periodontics, the professional training mode and its characteristics which adapt to the development trend of American periodontology were summarized and concluded. The discussion is in the following three parts: the overall status of postgraduate education of periodontology in the United States, the training mode of the clinical postgraduate students of periodontology at University of Washington School of Dentistry, and the observation of the American Academy of Periodontology's annual conferences. This kind of training mode supervised by the American Dental Association, giving priority to clinical practice and emphasizing cultivating the multidisciplinary comprehensive ability are worth learning. Meanwhile, the development trend of periodontology in the United States which pay increasing attention to carry out implant therapy with periodontal features and the adaptive training mode of clinical postgraduate students of periodontology also deserves our deep reflection and can be used for reference.

Objective: To explore the training pattern of periodontal probing practice so as to improve the accuracy of probing depth measurements of undergraduate students. Methods: Sixty-two undergraduate dental students in their pre-clinical training course were divided into two groups (31 students in each group): the reform group and the control group. The students in reform group learned and practiced periodontal probing by using transparent gingiva models for 30 minutes, and using conventional periodontal probing models for further 90 minutes in two sessions. The total practicing time was 2 hours. The students in control group learned and practiced periodontal probing using conventional periodontal probing models only for 1 hour of practicing time. After the training, new conventional periodontal probing models were used to evaluate the accuracy of probing depth measurements of the students in the two groups. The probing depths of Ramfjord index teeth were recorded by the students and were compared with the results of an experienced teacher ' s measurements. Results: The percentage of absolutely consistent sites in the reform group (63.4% [708/1 116]) was significantly higher than that of the control group (60.0% [670/1 116]) ( P= 0.012). In both reform group and control group, the percentages of absolutely consistent sites of the incisors (reform group: 69.1% [257/372], control group: 65.9% [245/372]) were significantly higher than those of the molars (reform group 58.9% [219/372], control group 54.3% [202/372])( P< 0.01), meanwhile, the percentages of absolutely consistent sites of the buccal-lingual sites (reform group: 88.7% [330/372], control group: 80.4% [299/372]) were significantly higher than those of the interproximal sites (reform group: 50.8% [378/744], control group: 49.9% [371/744])( P< 0.01). Conclusions: The comprehensive reform of periodontal probing training could improve the accuracy of probing depth measurement of the undergraduate students. During the pre-clinical practice, probing training in the molar areas and the interproximal sites should be reinforced.

Objective: To observe the long-term clinical treatment outcome and the influencing factors of the outcome for the teeth receiving modified crown lengthening surgery combined with root canal treatment and post-core crown restoration. To summarize the clinical guidelines of modified crown lengthening surgery in selection of indications and for mulation of treatment planning. Methods: Fifty-seven patients with a total of 67 teeth receiving modified crown lengthening surgery combined with root canal treatment and post-core crown restoration for at least a 6 months' follow-up period between July 2004 and July 2013 were recruited in this retrospective study by phone call interviews. The patients' clinical outcomes were evaluated by the combination of clinical examination, radiograph and questionnaire regarding patient-reported outcome of the last follow up (≥9 months post modified crown lengthening surgery and ≥6 months after definite crown restorations). All of the treated teeth were classified into two groups, group A (teeth with good clinical treatment outcome) and group B (teeth with poor clinical treatment outcome), based on the defined criteria including patients' satisfaction with the function and esthetics of the teeth and absence of periodontal, endodontic and prosthodontic complications. The potential influencing factors of clinical treatment outcome were also determined by Logistic regression analysis. Results: Vertical root fracture in 1 tooth was found on its periapical film and the tooth was deemed hopeless. Thus, the survival rate is 99% (66/67) for the multidisciplinary treatment approach. Seventy-two percent (48/67) of the teeth achieved good clinical treatment outcome and 28% (19/67) of the teeth developed one or several complications. In group B (teeth with poor clinical treatment), 16 out of teeth exhibited periodontal complications with bleeding on probing (BOP) positive mostly found. Logistic regression analysis demonstrated that plaque control ( OR= 21.392, P= 0.014), edge form ( OR= 7.610, P= 0.011), and smoking experience ( OR= 7.315, P= 0.018) were the risk factors influencing the clinical treatment outcome of modified crown lengthening surgery combined with root canal treatment and post-core restoration. Conclusions: Modified crown lengthening surgery combined with root canal treatment and post-core restoration has a good and stable clinical effect in the observational time of 6-114 months. Plaque control, smoking status and edge form of the tooth appeared to be the influencing factors of this multidisciplinary treatment approach.

Objective: To construct three-dimensional finite element models with modified crown lengthening surgery and post-core restoration in management of various crown-root fracture types, to investigate the intensity and distribution of stressin models mentioned above, and to compare and analyze the indications of traditional and modified crown lengthening surgeries from the mechanic point of view., Methods: Nine three-dimensional finite element models with modified crown lengthening surgery and post-core restoration were established and analyzed by micro-CT scanning technique, dental impression scanner, Mimics 10.0, Geomagic studio 9.0 and ANSYS 14.0 software. The von Mises stress of dentin, periodontal ligament, alveolar bone, post and core, as well as the periodontal ligament area and threshold limit value were calculated and compared with the findings of traditional crown lengthening models which had been published earlierby our research group., Results: The von Mises stress intensity of modified crown lengthening models were: dentin>post>core>alveolar bone>periodontal ligament. The maximum von Mises stress of dentin(44.37-80.58 MPa)distributed in lingual central shoulder. The periodontal ligament area of the modified crown lengthening surgery was reduced by 6% to 28%, under the same crown-root fracture conditions, the periodontal ligament area of modified crown lengthening models was larger than that of the traditional crown lengthening models. In modified crown lengthening surgery models, the von Mises stress of periodontal ligament of B3L1m, B3L2m, B3L3m models exceeded their limit values, however, the von Mises stress of periodontal ligament of the B2L2c, B2L3c, B3L1c, B3L2c, B3L3c models exceeded their limit values in traditional crown lengthening surgery models., Conclusions: The modified crown lengthening surgery conserves more periodontal supporting tissues, which facilitates the long-term survival of teeth. The indication of modified crown lengthening surgery is wider than traditional method. The maxillary central incisors with labial fracture at gingival margin level and with palatal fracture at or below the alveolar crest level are not the indication of the crown lengthening surgery.

Objective: To classify the relationship of the sagittal root positions of the maxillary anterior teeth to their respective osseous housings, and to measure the thickness of facial and palatal alveolar bone by cone-beam computed tomography (CBCT)., Methods: Twenty-three subjects [9 male, 14 female, mean age: (24.5 ± 1.6) years] who fulfilled the inclusion criteria were involved in this study. The CBCT images were evaluated and the relationship of the sagittal root position of the maxillary anterior teeth to its associated osseous housing was recorded as Kan's Class 1, 2, 3, 4. The facial and palatal alveolar bone thickness at three locations:2 mm apical to crest level, mid-root level and apical level, was measured respectively., Results: Ninety seven point one percent(134/138)of the anterior maxillary teeth were classified as Class 1. Only 2.9% (4/138) were Class 4.Occurrences of > 2 mm thickness of maxillary facial alveolar bone were found 2.2% (6/276 sites) at 2 mm apical to crest level and mid-root level in the sample of maxillary anterior teeth., Conclusions: The majority of the anterior maxillary teeth roots were positioned close to the labial cortical plate. Most tooth sites in the anterior maxilla had a thin facial bone wall.

Objective: To investigate the features of the fill of interdental spaces by gingival papillae and the associated factors., Methods: Fifteen volunteers with healthy gingiva were involved in this study. The height and thickness on the alveolar crest level of 62 maxillary anterior papilla were measured radiographically with cone-beam computed tomography (CBCT) scans. A standardized periodontal probe with Williams markings was used for measurements of the papilla width on the alveolar crest level., Results: When the papilla was complete fill interdentally, the mean height of papillary tissue on the alveolar crest level (equal to contact point-bone crest) was (3.67 ± 0.51) mm. The mean thickness of papilla on the alveolar crest level was (8.38 ± 0.75) mm. The papilla height had a positive correlation with papilla thickness (r = 0.433, P < 0.001)., Conclusions: The cone-beam computed tomography can be used for clear visualization of the papilla profile and the measurements of papilla height and thickness. Thicker and wider tissue was associated with an increased likelihood of having a complete papilla fill.

Objective: To investigate the accuracy of probing depth measurements of undergraduate students in department of periodontology and analyze the cause of measurement errors., Methods: Thirty-eight dental students from Peking Universty School and Hospital of Stomatology who began their periodontal clinical practice for the first time were recruited. According to principle of clinical teaching, after the students recorded the probing depth of 1-2 periodontitis patients using Williams periodontol probe, an experienced teacher checked the probing depth. The measurements of interproximal sites of Ramfjord index teeth (6 14 41 6) were used as the data of this study. According to the probing depth discrepancies between teacher and the students, all the probing sites were divided in three levels: absolutely consistent sites (probing depth measured by teacher and by student was completely consistent), almost consistent sites (the depth discrepancy between teacher and student was 1 mm), inconsistent sites (the depth discrepancies between teacher and student ≥ 2 mm)., Results: The accuracy of probing depth measurements of students decreased with the deepening of probing depth, and the accuracy of probing depth measurements in molar teeth was significantly lower than incisor teeth [58.8% (261/444) vs.73.1% (339/464), P < 0.01]. The main factor associated with the accuracy of probing depth measurements in interproximal sites was the probe's inability to get into gingival col, which accounted for 70.7% (87/123) of the total inconsistent sites., Conclusions: The correct angle of insertion of the probe in interproximal sites should be reinforced during the course of pre-clinical education of periodontal probing. More attention should be paid to check the probing depth of deep pockets and molar teeth during the clinical practice of undergraduate students.

Objective: To observe the effect of modified surgical crown lengthening procedure and discuss the factors which could affect the periodontal health of the operated teeth., Methods: Seventeen patients, a total of 20 teeth, who received the modified crown lengthening surgery were recruited in a retrospective study (1 - 6 years). The periodontal status of the operated teeth was compared with the adjacent and the contralateral natural teeth respectively., Results: One out of seventeen patients appeared root fracture after surgery, one patient wasn't satisfied with the color of the molar's metal crown, other fifteen patients were satisfied with the esthetics and function of the teeth. The sites where probing depth was 4 mm just accounted for 4% (5/120) of the operated teeth, and the probing depth of the other sites was less than or equal to 3 mm. Although 83% (33/40) of buccal and lingual sites of the teeth exhibited various degrees of bleeding index, the periodontal indices of the operated teeth and the adjacent teeth. The position of the crown margin had a significantly negative correlation with the bleeding index (r = -0.742), and the plaque index was moderately correlated with the bleeding index (r = 0.480)., Conclusions: The modified surgical crown lengthening indicated a good effect, which could be an alternative method to save the residual crown and root. The position of crown margin might be the main factor which influences the periodontal health of the teeth.

Objective: To investigate the smile esthetic elements of Chinese Han-nationality female based on high definition (HD) digital camera with computer-image measuring technique., Methods: HD digital camera was used to capture spontaneous smile process combined with computer-image measuring technique to establish the analysis method of smile. Ninety-nine Han-nationality female with normal gingiva, aged from 20 to 30 years were recruited. The lip-incisor edge distance, gingival display were measured. The data was statistically analyzed., Results: A standard and objective method to analyze spontaneous smile was established. Forty-three percent (43/99) of the subjects studied were classified as having a high smile and average smile respectively, 13% (13/99) as having a low smile. Gingival display accounted for (1.34 ± 0.98) mm in high smile type., Conclusions: Average smile and high smile type were most common in the Chinese Han-nationality female studied.

Objective: To establish a convenient, objective and applicable method to assess gingival biotype using periodontal probing., Methods: A total of 66 maxillary anterior teeth from 14 volunteers (6 males, 8 females) with healthy gingiva, aged from 20 to 30 years, were recruited in this study. The gingival biotypes were evaluated by whether or not the outline of the periodontal probe was clear inside the gingiva. Gingival thickness of the cemento-enamel junction (CEJ) in upper anterior teeth was measured by cone-beam CT (CBCT)., Results: The method of periodontal probing-assessed gingival biotype had good consistency and repeatability. The result of probing-assessed gingival biotype was consistent with that obtained by CBCT. The mean thickness of gingiva in thin, compromised and thick gingival biotype was (1.02 ± 0.20), (1.28 ± 0.25) and (1.46 ± 0.25) mm. These differences were significant for all three comparisons (P = 0.001, respectively)., Conclusions: Periodontal probing-assessed gingival biotype is a simple, relatively objective and suitable method for clinical examination.

Objective: To measure the width of keratinized gingiva and attached gingiva of anterior dental arch in order to establish reference guidance for periodontal surgery., Methods: A total of 120 healthy Chinese Han-nationality volunteers aged 20 - 30 years with healthy gingival tissue were recruited. The width of anterior labial dental arch, keratinized gingiva of gingival zenith, depth of gingival sulcus, and the width of coronal-apical keratinized gingiva of interdental papilla were measured respectively and the data were statistically analyzed., Results: The width of keratinized gingiva and attached gingiva at gingival zenith varied for each individual and tooth location, ranging up to (5.6 ± 1.3) mm in the anterior maxillary region and (4.5 ± 1.1) mm in the anterior submandibular region. The width decreased over the canine and first premolar and increased slightly over the second premolar. The width of keratinized gingiva at interdental papilla ranged from (6.2 ± 1.3) mm to (8.9 ± 1.4) mm in the maxilla and from (5.8 ± 1.0) mm to (7.6 ± 0.9) mm in the mandible. The narrowest width of keratinized gingiva at interdental papilla was located over central incisors., Conclusions: There is a variation of width on labial keratinized gingiva of anterior dental arch of Han nationality youth among different individuals and tooth locations.

Objective: To investigate the clinical results of non-surgical periodontal treatment of generalized aggressive periodontitis in a Chinese population., Methods: Nineteen patients aged (24. 5 +/- 4.1) years with generalized aggressive periodontitis were included in this prospective study. All subjects received scaling and root planing and were clinically monitored every 2 months for 6 months. The clinical parameters, including probing depth (PD), bleeding on probing (BOP), attachment loss (AL) and mobility, furcation involvement of molars were recorded at baseline, 2, 4 and 6 months after treatment. White blood cells, neutrophil percentage, triglyceride of 7 patients were detected at baseline and 6 months after treatment., Results: At baseline, the mean PD of patients was (5.1 +/- 2.1) mm, the percentage of BOP positive sites was 98.0% and mean AL was (3.9 +/- 1.9) mm. At 6 months after treatment, the mean pocket depth reduction was 2.0 mm, the percentage of BOP positive sites reduced to 11.9% and 0.6 mm attachment level was gained. Incisors showed greater PD reduction than molars, the baseline PD had predictive effect on PD reduction, deep sites showed greater PD reduction than shallow sites. There was a statistically significant decrease of neutrophil percentage at 6 months after treatment [(65.7 +/- 9.9)% vs. (55.4 +/- 9.3)%, P < 0.05]., Conclusions: Non-surgical treatment is effective for the generalized aggressive periodontitis and every 2 months SPT is necessary for maintenance. Further surgical treatment or repeated SRP is recommended for molars.

Objective: To observe two-year natural progression of chronic periodontitis in mild, moderate and advanced periodontitis patients., Methods: The periodontal status of 169 untreated chronic periodontitis patients aged from 22 to 64, were examined for two years. Periodontal measurements were performed on all teeth except the third molars and 6 sites examined for each tooth. Probing depth (PD), attachment loss (AL), and bleeding on probing (BOP) were measured at baseline, one year, and two year by a same experienced periodontist. Forty-five patients were diagnosed as having mild periodontitis, 87 with moderate, and 37 with advanced periodontitis. The changes of attachment level in these three group patients were analyzed. The site with change of AL greater than 3 mm (DeltaAL > or = 3 mm) were defined as periodontal disease activity (PDA) sites. The occurrence of PDA in three groups was compared., Results: (1) The average AL levels at 1 year and at 2 year were greater than that at baseline in mild, moderate and advanced periodontitis. (2) The percentage of sites with AL > or = 1 mm in three groups all increased from baseline to 1 year and to 2 year. (3) The occurrence of periodontal disease activity increased significantly from mild (0.14% at site level, 15.56% at subject level), moderate (0.39%, 29.89%) to advanced (0.73%, 43.24%) periodontitis patients. (4) The mean baseline AL and PD levels in active sites were greater than that in inactive sites (PD: 3.03 +/- 0.45 vs. 2.87 +/- 0.38, P < 0.05; AL: 2.25 +/- 0.93 vs. 1.77 +/- 0.90, P < 0.01)., Conclusion: Untreated advanced periodontitis patients were the risk population for further periodontal breakdown.

Objective: To analyze the relationship between Helicobacter pylori (Hp) in oral cavity and the Hp infection in stomach., Methods: 102 patients with gastric Hp infection and periodontitis were enrolled in this study. DNA was extracted from subgingival plaques, mouthwashes and stomach mucosa samples by using the glass-milk (SiO2) purification method. To identify the presence of Hp in these samples, PCR (polymerase chain reaction) was carried out, and two pairs of oligonucleotide primer were used to amplify a portion of gene urease C and gene cag A of Hp., Results: The rate of Hp detected in oral cavity was significantly higher in patients with positive Hp in stomach (43.1%, n=58) than in those with negative Hp in stomach (22.7%, n=44, P<0.05). After the treatment for gastric Hp infection for 4 weeks, the eradication rate of Hp in stomach was lower, but only slightly in patients with positive oral Hp (16/25, 64%) than in those with negative oral Hp (24/33, 72.7%). However, this difference became apparent (36.0% vs 63.6%, P<0.05) after one year of the treatment., Conclusions: The effectiveness of the eradication therapy for gastric Hp infection is affected by the presence of Hp in oral cavity. Oral colonization of Hp may imply that there is a risk of the relapses of gastric and duodenal Hp infection and ulcer after the antibiotics treatment for the eradication of Hp.