Mask refinement network for tooth segmentation on panoramic radiographs.

OBJECTIVES: Instance-level tooth segmentation extracts abundant localization and shape information from panoramic radiographs (PRs). The aim of this study was to evaluate the performance of a mask refinement network that extracts precise tooth edges. METHODS: A public dataset which consists of 543 PRs and 16211 labelled teeth was utilized. The structure of a typical Mask Region-based Convolutional Neural Network (Mask RCNN) was used as the baseline. A novel loss function was designed focus on producing accurate mask edges. In addition to our proposed method, 3 existing tooth segmentation methods were also implemented on the dataset for comparative analysis. The average precisions (APs), mean intersection over union (mIoU), and mean Hausdorff distance (mHAU) were exploited to evaluate the performance of the network. RESULTS: A novel mask refinement region-based convolutional neural network was designed based on Mask RCNN architecture to extract refined masks for individual tooth on PRs. A total of 3311 teeth were correctly detected from 3382 tested teeth in 111 PRs. The AP, precision, and recall were 0.686, 0.979, and 0.952, respectively. Moreover, the mIoU and mHAU achieved 0.941 and 9.7, respectively, which are significantly better than the other existing segmentation methods. CONCLUSIONS: This study proposed an efficient deep learning algorithm for accurately extracting the mask of any individual tooth from PRs. Precise tooth masks can provide valuable reference for clinical diagnosis and treatment. This algorithm is a fundamental basis for further automated processing applications.

Application of modified mucogingival surgery in the treatment of gingival recession / 口腔疾病防治

@#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.

Polyetherketoneketone, a high-performance polymer for splinting mobile teeth: A clinical report.

A digital workflow for fabricating a polyetherketoneketone (PEKK) periodontal splint is described. The antibacterial properties of PEKK and the precision and efficiency of digital technology led to the provision of a splint with no adverse effects on oral hygiene or periodontal maintenance during a 2-year follow-up.

Multi-disciplinary treatment of maxillofacial skeletal deformities by orthognathic surgery combined with periodontal phenotype modification: A case report.

BACKGROUND: Maxillofacial deformities are skeletal discrepancies that cause occlusal, functional, and esthetic problems, and are managed by multi-disciplinary treatment, including careful orthodontic, surgical, and periodontal evaluations. However, thin periodontal phenotype is often overlooked although it affects the therapeutic outcome. Gingival augmentation and periodontal accelerated osteogenic orthodontics (PAOO) can effectively modify the periodontal phenotype and improve treatment outcome. We describe the multi-disciplinary approaches used to manage a case of skeletal Class III malocclusion and facial asymmetry, with thin periodontal phenotype limiting the correction of deformity. CASE SUMMARY: A patient with facial asymmetry and weakness in chewing had been treated with orthodontic camouflage, but the treatment outcome was not satisfactory. After examination, gingiva augmentation and PAOO were performed to increase the volume of both the gingiva and the alveolar bone to allow further tooth movement. After orthodontic decompensation, double-jaw surgery was performed to reposition the maxilla-mandibular complex. Finally, implant placement and chin molding were performed to restore the dentition and to improve the skeletal profile. The appearance and function were significantly improved, and the periodontal tissue remained healthy and stable. CONCLUSION: In patients with dentofacial deformities and a thin periodontal phenotype, multi-disciplinary treatment that includes PAOO could be effective, and could improve both the quality and safety of orthodontic-orthognathic therapy.

Periodontitis-related salivary microbiota aggravates Alzheimer's disease via gut-brain axis crosstalk.

The oral cavity is the initial chamber of digestive tract; the saliva swallowed daily contains an estimated 1.5 × 1012 oral bacteria. Increasing evidence indicates that periodontal pathogens and subsequent inflammatory responses to them contribute to the pathogenesis of Alzheimer's disease (AD). The intestine and central nervous system jointly engage in crosstalk; microbiota-mediated immunity significantly impacts AD via the gut-brain axis. However, the exact mechanism linking periodontitis to AD remains unclear. In this study, we explored the influence of periodontitis-related salivary microbiota on AD based on the gut-brain crosstalk in APPswe/PS1ΔE9 (PAP) transgenic mice. Saliva samples were collected from patients with periodontitis and healthy individuals. The salivary microbiota was gavaged into PAP mice for two months. Continuous gavage of periodontitis-related salivary microbiota in PAP mice impaired cognitive function and increased ß-amyloid accumulation and neuroinflammation. Moreover, these AD-related pathologies were consistent with gut microbial dysbiosis, intestinal pro-inflammatory responses, intestinal barrier impairment, and subsequent exacerbation of systemic inflammation, suggesting that the periodontitis-related salivary microbiota may aggravate AD pathogenesis through crosstalk of the gut-brain axis. In this study, we demonstrated that periodontitis might participate in the pathogenesis of AD by swallowing salivary microbiota, verifying the role of periodontitis in AD progression and providing a novel perspective on the etiology and intervention strategies of AD.

Multidisciplinary non-surgical treatment of advanced periodontitis: A case report.

BACKGROUND: Patients with severe periodontitis often require multidisciplinary treatment to achieve healthy periodontal tissue, normal occlusion, and optimal aesthetics. In the present study, we aimed to evaluate the efficacy of multidisciplinary non-surgical treatment in a patient with stage IV/ grade C periodontitis, malocclusion, and dentition defects. CASE SUMMARY: A 47-year-old woman visited our periodontology department due to teeth mobility problems and difficulties chewing food. The patient had no history of drug allergies or systemic disease. Initial therapy involved scaling and root planning with a Gracey scaler and periodontal ultrasonic therapeutic apparatus using a periodontal endoscope (Perioscopy, Zest Dental Solutions, United States) to control the periodontal inflammation prior to treatment. Five months later, orthodontic treatment was then performed to treat occlusion and overall aesthetics. After completion, a Maryland bridge was used to restore Nos. 22, 31, and 41 teeth. Florida probing (Florida probe, United States) was performed every 2-3 mo to evaluate the periodontal condition throughout treatment. Overall, multidisciplinary non-surgical treatment resulted in satisfactory aesthetic results with healthy periodontal tissue and stable occlusion. CONCLUSION: In some patients with stage IV/grade C periodontitis, systematic and sequential non-surgical treatment can provide excellent therapeutic results.

Efficacy of scaling and root planning with periodontal endoscopy for residual pockets in the treatment of chronic periodontitis: a randomized controlled clinical trial.

OBJECTIVES: Residual pockets are a risk factor of periodontitis progression. This study evaluated the efficacy of periodontal endoscopy (PE) during scaling and root planning (SRP) of residual pockets in chronic periodontitis patients after initial periodontal treatment. MATERIALS AND METHODS: A single-blinded, randomized controlled clinical trial was conducted in systemically healthy subjects presenting at least three residual pockets with a probing depth (PD) ≥ 5 mm in each quadrant. Subjects were randomly allocated to one of two trial groups using a computer-generated program: SRP + PE (test group) or SRP alone (control group). Clinical parameters (PD, clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PLI)) were then measured at baseline, 3-, and 6-month follow-up. RESULTS: A total of 1629 sites in 37 patients were examined. Both treatments significantly improved all clinical outcomes (PD, CAL, BOP, and PLI) from baseline to 6 months (P < 0.05), although greater reductions in PD and PLI were observed in the test group at both 3- (PD: 3.45 ± 0.56 vs. 4.14 ± 0.59 mm; PLI: 0.55 ± 0.23 vs. 0.73 ± 0.27) and 6-month follow-up (PD: 3.12 ± 0.63 vs. 4.0 ± 0.68 mm; PLI: 0.49 ± 0.21 vs. 0.72 ± 0.28, respectively; P = 0.001 for PD and P = 0.021 for PLI). No significant differences in CAL or BOP were observed. CONCLUSIONS: SRP + PE resulted in significant reductions in PD and PLI compared to SRP alone in residual pockets with a PD ≥ 5 mm. CLINICAL RELEVANCE: The findings highlight the benefits of SRP + PE, supporting use as an alternative strategy in nonsurgical periodontal treatment.

Clinical presentation and management of drug-induced gingival overgrowth: A case series.

BACKGROUND: We report three patients with drug-induced gingiva overgrowth (DIGO) caused by nifedipine, a calcium channel blocker, who were treated and followed up for 1-3 years. We discussed their symptoms, treatment process, treatment prognosis, and follow-up results. CASE SUMMARY: All the patients had a history of nifedipine treatment to control hypertension. Besides nifedipine, Patient 1 was prescribed immunosuppressant cyclosporine A to control nephritis, which is also implicated in GO. Thus, we assumed that a synergistic effect between the drugs contributed to the severity of Patient 1's condition. This condition has been reported to be more pronounced in patients with periodontitis. In the course of treatment, Patients 1 and 2 did not stop or change drugs. After initial periodontal treatment, periodontal surgery, and later periodontal support and better plaque control, their gingival hyperplasia was well managed and controlled. Under the guidance of a physician, Patient 3 replaced her calcium-channel blocker drug with losartan potassium and hydrochlorothiazide tablets. She received initial treatment without surgery, obtaining a good curative effect. CONCLUSION: Patients' compliance, self-plaque control, and professional periodontal therapy have a vital role in treating and preventing the recurrence of DIGO.

Effects of ultrasonic subgingival scaling and root planing with a periodontal endoscope on the root surface / 口腔疾病防治

Objective @# To evaluate the effects of root calculus residue and root cement preservation by ultrasonic subgingival scaling and root planing (SRP) with or without perioscopy.@*Methods @# Twelve teeth extracted due to severe periodontitis were randomly divided into three groups with four teeth in each group: ① Endoscope-assisted SRP group. The root surfaces of the affected teeth were cleaned with an EMS ultrasonic treatment instrument. ② Traditional SRP group. The affected teeth were treated by ultrasonic subgingival scaling and hand root planing with a Gracey curette. ③ Untreat group. The above operations were performed by the same senior physician. Under local anesthesia, each tooth was scraped for 10 minutes and then extracted. The residual amount of calculus on the root surface after plaque staining was observed and recorded. The thickness of the retained cementum at 1/3 of the root neck was measured.@*Results@# The residual rate of calculus on the root surface was the lowest in the endoscope-assisted SRP group, which was significantly different from the traditional SRP group and the untreated group (P < 0.001). Histological observation showed that the mean residual cementum thickness at 1/3 of the root neck increased gradually from the cemento-enamel junction (CEJ), 2.5 mm below the CEJ and 5 mm below the CEJ. Ultrasound SRP assisted by endoscopy caused less damage to the cementum and preserved the cementum better than traditional subgingival scaling (P < 0.001). @*Conclusion@# Compared with traditional SRP therapy, endoscope-assisted SRP treatment can remove subgingival plaque and calculus more effectively and can better preserve the cementum of the root surface.

[Clinical effects of scaling and root planing with an adjunctive periodontal endoscope for residual pockets: a randomized controlled clinical study].

OBJECTIVE: To evaluate the efficacy of scaling and root planing (SRP) with a periodontal endoscope in the treatment of residual pockets in patients with periodontitis after initial periodontal therapy. METHODS: Patients with residual pockets [probing depth (PD)≥5 mm] were included and randomly assigned to the endoscope group (SRP with a periodontal endoscope) or SRP group (SRP alone). The PD, attachment loss (AL), and bleeding on probing (BOP) of residual pockets were recorded before treatment and at 3 and 6 months after treatment. Data were analyzed with SPSS 20.0 software. RESULTS: Compared with the baseline values, the percentage of PD≥5 mm sites, PD, AL, and BOP (+)% in the endoscope group and SRP group at 3 and 6 months after treatment decreased (P<0.05). Compared with the values at 3 months after treatment, the percentage of PD≥5 mm sites, PD, AL, and BOP (+)% at 3 and 6 months after treatment decreased in the endoscope group (P<0.05), whereas no statistical difference in these values was observed in the SRP group (P>0.05). Compared with those in the SRP group, the percentage of PD≥5 mm sites and PD at 3 and 6 months after treatment and AL and BOP (+)% at 6 months after treatment in the endoscope group decreased (P<0.05). CONCLUSIONS: SRP with a periodontal endoscope shows a better effect in improving the PD, AL, and BOP of residual pockets (PD≥5 mm) in patients with periodontitis after initial periodontal therapy and has advantages in improving the long-term curative effect of this therapy.

Pulp status of teeth in patients with chronic advanced periodontitis.

OBJECTIVE: This study aimed to evaluate the dental-pulp status in patients with chronic advanced periodontitis. MATERIALS AND METHODS: Sixty teeth were extracted from patients with advanced periodontitis. Before extraction, electric pulp tests were conducted to explore the real state of the pulp. According to the height of the residual periodontal membrane, all teeth were divided into two groups: group 1< (3 mm) and group 2 (3-6 mm). Two groups of teeth were sliced and stained with hematoxylin and eosin. The dental-pulp status of histopathologic changes was analyzed. RESULTS: The frequency of pulp necrosis in group 1 was significantly higher than that in group 2 (P<0.05). The frequency of a complete odontoblastic layer, vacuolar degeneration of the odontoblastic layer, pulp edema, and reticular atrophy in group 1 were significantly lower than in group 2 (P<0.05). There were no significant differences in other histopathologic changes. Histopathologic examination compared to the traditional electric pulp testing, revealed that 24.48% of dental pulps showed complete pulp necrosis and 5.75% exhibited normal pulp tissue by histopathology. However, only 9.52% of teeth exhibited no response, and 33.33% displayed responses similar to those of neighboring teeth, suggesting that the electric pulp test cannot completely detect dental-pulp status. CONCLUSIONS: Teeth in patients with chronic advanced periodontitis, exhibited worse pulp conditions with decreased height of the residual periodontal membrane. The results of electric pulp testing were not completely representative of histopathologic results in advanced periodontitis.

In Vivo Detection of Subtle Vertical Root Fracture in Endodontically Treated Teeth by Cone-beam Computed Tomography.

INTRODUCTION: The purpose of this study was to evaluate the diagnostic accuracy of cone-beam computed tomographic (CBCT) imaging in the detection of subtle vertical root fractures (VRFs) in endodontically treated teeth in vivo and to discuss direct and indirect evidence for the diagnosis of subtle VRFs. METHODS: Twenty-nine endodontically treated teeth with suspected VRFs from 29 patients were examined using CBCT imaging. CBCT images were scored based on evaluation of the fracture line and vertical buccopalatal (lingual) bone loss. VRF was diagnosed only when a definite fracture line was detected on CBCT images, and findings of periodontal exploration or surgical extraction were considered the gold standard. The diagnostic sensitivity, specificity, and accuracy were assessed. RESULTS: Of the 29 teeth, 27 were positive and 2 were negative for VRF according to the gold standard. Sensitivity, specificity, and accuracy were 33.3%, 100%, and 37.9%, respectively, based on the direct finding of a fracture line on CBCT images. However, vertical buccopalatal (lingual) bone loss was found in 25 of 27 teeth with VRFs. CONCLUSIONS: Although the accuracy of CBCT imaging for the diagnosis of subtle VRFs in endodontically treated teeth in vivo was poor, vertical buccopalatal (lingual) bone loss is an important indirect sign for the diagnosis of VRFs, which can be found on CBCT images.

[The clinical effect of root amputation in the treatment of periodontal/alveolar abscess].

OBJECTIVE: To study the clinical effect of root amputation in the treatment of periodontal/alveolar abscess teeth with one severe lesion root. METHODS: 30 periodontal/alveolar abscess teeth with one severe lesion root were chosen in the study. After root canal treatment, supragingival scaling, subgingival scaling and root planning, occlusal adjustment were done. Then the teeth were treated by root amputation. The clinical effect was evaluated 3 months, 6 months and 1 year after surgery. RESULTS: One year after surgery, 27 of 30 teeth were successful, 1 mandibular molar occurred root fracture, 1 mandibular molar was removed because of tooth loosening secondary to periodontal damage. 1 patient lost. CONCLUSION: Root amputation is an effective solution of periodontal/alveolar abscess.