2020 Vol.28(11): 681–688    [Abstract] ( )    [RICH HTML ] ( )   [PDF 913 KB ]( )

Orthodontic treatment for dentofacial deformity is fundamental throughout the entire management process of cleft lip and palate. Orthodontist is one of those who are indispensable in the comprehensive multidisciplinary cleft team. Cleft lip and palate patients have unique dentofacial characteristics which makes the treatment goals and strategies different from those of other patients in different stages. For newborns with cleft lip and palate, the main treatment includes presurgical orthopedics. For patients in their primary dentition stage, the treatment mainly focuses on the prevention of bad oral habits and severe malocclusion. For those in their mixed dentition stage, the treatment mainly consists of dentition preparation for alveolar bone grafting and skeletal growth modification. For patients in their permanent dentition stage, treatment strategies include orthodontic camaflouge treatment, combined orthodontic-orthognathic approach and segmental alveolar distraction osteogenesis. In addition to routine orthodontic treatment, orthodontists should pay special attention to managing the compliance of cleft lip and palate patients with unique psychological characteristics. By summarizing the state-of-art cleft lip and palate orthodontic care in the multidisciplinary team, this review aims to involve more orthodontic clinicians to join in the modern biopsychosocial medical practice of cleft lip and palate team approach and to improve the standard of care for cleft lip and palate patients.

2020 Vol.28(11): 689–697    [Abstract] ( )    [RICH HTML ] ( )   [PDF 1377 KB ]( )

Transverse maxillary deficiency is a common malocclusion in the clinic. Palatal expansion techniques are commonly used in the treatment of maxillary transverse deficiency. Traditional palatal expansion techniques have good effects on the treatment of children and adolescents whose palatal suture has not yet closed, but the effects on adult patients are unsatisfied. New palatal expansion techniques, such as miniscrew-assisted rapid palatal expansion and surgical-assisted maxillary expansion, have increased the age-related indications for palatal expansion, and their bone expansion effect has been strengthened. With the development of CAD/CAM technology and 3D printing technology, techniques such as Invisalign and personalized appliances have been developed and have promising application prospects. To provide references for the clinical treatment of maxillary transverse deficiency, palatal expansion techniques are reviewed from the following aspects: mechanism and indications, expansion pattern, traditional and new palatal expansion appliances, stability and retention of palatal expansion, outlook of future expanders, etc.

2020 Vol.28(11): 698–704    [Abstract] ( )    [RICH HTML ] ( )   [PDF 5567 KB ]( )

Abstract Objective Exploring the effects of susceptibility genes on aggressive periodontitis during its occurrence and development lays a foundation for further research on its genetic pathogenesis. Methods Medical history and clinical indicators were collected from monozygotic twins with generalized aggressive periodontitis. Susceptibility genes were detected by polymerase chain reaction-restriction fragment length polymorphisms, and the exon gene components were analyzed by whole-exome sequencing. Results The severity of generalized aggressive periodontitis in the twins was different (P < 0.05). Florida diagnosis results showed that the younger sister’s explored clinical depth (probing depth, PD) and clinical attachment loss (CAL) were higher than those for the elder sister, but her clinical bleeding index (bleeding on probing, BOP) was lower than that of the elder sister. In addition, their responses to periodontal basic treatment were different (P < 0.05). After treatment, the improvement of CAL and decline in BOP were more obvious in the elder sister, and the proportion of different periodontal pocket depths in the elder sister decreased after treatment, while the decrease was slighter in the younger sister. Genetic tests revealed that the twins had the same genotypes at target susceptibility genes (IL-1β-511, IL-1β+3953, TNF-α-308, FcγR-IIIb, VDR, and ER) and differential exon gene components, and that the suspected differential genes, e.g. ZFPM1, PTH2, ZFYVE16, and LY6G6C, might be related to their phenotypic differences. Conclusion These monozygotic twins had different phenotypes of generalized aggressive periodontitis. Their shared susceptibility genes increased the risk of disease, and their different genetic mutations affected the phenotype of the disease.

2020 Vol.28(11): 705–709    [Abstract] ( )    [RICH HTML ] ( )   [PDF 1566 KB ]( )

Objective To investigate changes in the three-dimensional position of the maxillary canine during the distal movement of the maxillary first molar by a mini-implant combined with a CD appliance. Methods Ten typodont models of class II malocclusion were selected, and one side was randomly chosen as the experimental group. The CD appliance was bonded to the maxillary canine and first molar of the experimental group, and 1.2 mm stainless steel wire was bent as the anchorage, which was fixed on the model to simulate mini-implants implanted in the zygomatic alveolar ridge. Then, 180 g orthodontic force was applied to the canine of the experimental group; the other side was recognized as the control group and was not used for strengthening. Six mini-implants were implanted in different parts of the model and used as a reference before and after the experiment. The models were placed in an incubator and heated at 56 ℃in a water bath for 2 min. The models were scanned before and after thermostatic water bath treatment with a 3-shape scanner. Then, the digital models were overlapped through the reference points, and the positions of the canines and first molars were measured before and after the experiment. Results The sagittal movement distance of the first molar in the experimental group was ( 0.25 ± 0.33) mm, and the vertical movement distance was (0.25 ± 0.28 )mm, which was significantly different from the control group (P P > 0.05). There was no significant difference in the root position of the first molar in the experimental group (P > 0.05). The lateral and vertical displacement distances of the maxillary canine crown in the experimental group were (4.03 ± 2.11) mm and (1.86 ± 1.01) mm, respectively, which were significantly different from those in the control group (P P > 0.05). In the experimental group, there was no significant difference in the position of the apex of the maxillary cusp (P > 0.05). Conclusion Our in vitro study showed that the maxillary canines inclined buccally accompanied by a small amount of intrusion during molar distalization by a mini-implant combined with a CD appliance.

2020 Vol.28(11): 710–713    [Abstract] ( )    [RICH HTML ] ( )   [PDF 1293 KB ]( )

Objective To evaluate the effect of 3D-printed oval root canal preparation by using small field-of-view cone beam CT (CBCT) combined with computer-aided technologies.Methods An extracted tooth with a suitable single oval canal was selected by small field-of-view CBCT scanning. Three-dimensional (3D)-printed resin teeth were obtained based on the CBCT data after data conversion and processing. 50 general dentists were selected to prepare the oval root canal of the resin teeth with X-Gold rotary Ni-Ti instruments. Small field-of-view CBCT was applied to scan the oval root canals before and after preparation. Then, computer-aided technologies were used to calculate and compare these CBCT data, analyzing the effects of oval root canal cleaning as well as the root canal deviation by 3D reconstruction and rendering of the images.Results Among the 50 cases, the mean unprepared area of the oval root canal wall was（56.20 ± 11.91）% and the mean maximum deviation distance of the root canal was（0.140 ± 0.041）mm. There was no correlation between root canal cleanliness and deviation (r=0.18, P=0.212).Conclusion Combined with small field-of-view CBCT and computer-aided technology, we can effectively quantitatively evaluate the root canal preparation effect.

2020 Vol.28(11): 714–717    [Abstract] ( )    [RICH HTML ] ( )   [PDF 809 KB ]( )

Objective To explore the potential association between particular living habits and recurrent aphthous ulcers (RAU), and provide some references for RAU prevention among the young and middle-aged. Methods The multistage random sampling method was adopted to select 850 young and middle-aged people in Nanjing. The disease status and living habits of young and middle-aged people with RAU in Nanjing were investigated by a questionnaire, and the influencing factors were analyzed by univariate and multivariate logistic regression analysis. Results The prevalence of RAU was 20.5% among 799 individuals, including 357 men and 442 women. The risk of RAU at medium and low stress levels was 0.533 times and 0.419 times that at high stress levels, respectively (P > 0.05), indicating that high stress was an independent risk factor for RAU. The risk of RAU in patients with low exercise levels was 1.513 times that in patients with high exercise levels (P > 0.05), indicating that high exercise levels were a protective factor for RAU. There were no statistically significant differences in age, sex, smoking, drinking or bedtime (P < 0.05). Conclusion Multivariate logistic regression showed that mental stress and physical activity were independent influencing factors for the development of RAU. The living habits of RAU patients and RAU susceptible populations should be treated with corresponding interventions to prevent RAU.

2020 Vol.28(11): 718–722    [Abstract] ( )    [RICH HTML ] ( )   [PDF 1185 KB ]( )

Objective To explore the influence of marital status on the survival of patients with buccal mucosa squamous cell carcinoma (BMSCC) and to provide a scientific basis for risk assessment and nursing decisions for these patients. Methods A total of 1 006 BMSCC participants were identified in the Surveillance, Epidemiology, and End Results(SEER) database. Kaplan-Meier analysis was used to evaluate the effect of marital status (married, unmarried and unhappily married) on the survival of patients with buccal squamous cell carcinoma. The independent prognostic effect of marital status was further determined by univariate and multivariate Cox proportional hazard regression analysis.Results Marital status was an independent prognostic factor for BMSCC patients (P=0.001). Married patients had the best survival, while separated/divorced/widowed patients had the worst survival (HR=1. 445, P=0.001), and never married patients had an intermediate risk (HR=1.297, P=0.040).Conclusion Marital status was an independent prognostic factor for BMSCC patients. Unmarried and unhappily married patients had worse survival, which suggests that we should pay more attention to patients’ marital status, especially unmarried and unhappily married patients.

2020 Vol.28(11): 723–727    [Abstract] ( )    [RICH HTML ] ( )   [PDF 1662 KB ]( )

Objective To investigate the diagnosis, treatment and prognosis of nonodontogenic periapical lesions and to provide a reference for clinical diagnosis and treatment. Methods A case of a patient with right upper molar pulp with apical penetration and local occlusion admitted to the West China Stomatological Hospital of Sichuan University was retrospectively analyzed, and the curative effect of microapical surgery and pith preservation was also analyzed. Results The imaging features of tooth 16 showed periradicular radiolucency combined with local radiopaque lesions around the distal buccal apical area. Endodontic microsurgery was performed under local anesthesia. Soft tissue coverage was observed in the distal buccal apical area during the surgery, and no radiopaque tissue was detected. The distal buccal root apex was cut by 3 mm, and mineral trioxide aggregate was used for root-end backfilling. The postoperative pathological results revealed fibrous connective tissue. One-week recall X-ray examination showed tight root-end backfilling and no periradicular radiolucency; an electrical test of pulp vitality showed positive results. The four-year follow-up showed that there was no discoloration in tooth 16 and no significant difference in thermal and electrical tests of pulp vitality compared with control teeth. Combining the clinical manifestations, imaging features, surgical exploration results and pathological reports, the case was most likely to be cemental hypoplasia. Through the literature review, the treatment and healthy pulp preservation of such cases by endodontic microsurgery under the premise of preserving teeth has not been reported.Conclusion For maxillary posterior teeth with periapical lesions but healthy pulp, accurate estimation of pulp status, endodontic microsurgical exploration and application of bioactive materials can achieve vital pulp preservation while removing the lesions.

2020 Vol.28(11): 728–732    [Abstract] ( )    [RICH HTML ] ( )   [PDF 790 KB ]( )

With the rapid development of implant technology, implant restoration is a conventional treatment option for adult patients with tooth loss. Severe dental lesions, trauma, tumors, abnormal development and other reasons can cause dental defects and even dentition loss in children and adolescents. There has been hesitation to perform implant therapy for growing children because of the growth period; thus, little is known about the outcomes of the osseointegration procedure in young patients. Therefore, this article reviews the current literature to discuss the use of dental implants in children and adolescents. According to current studies, orthodontic treatment or transitional restoration should be undertaken based on the characteristics of the children and adolescents. Implant surgery should be performed after the end of the peak growth period. For patients with severe dentition defects, relevant criteria should be established before implant surgery to evaluate the effect of implant therapy in children and adolescents. The patients should be treated with a multidisciplinary, staged and long-term treatment approach. Most of the recent literature consists of case reports and short-term studies. There is an urgent need for more studies in this field with long-term follow-up.

2020 Vol.28(11): 733–738    [Abstract] ( )    [RICH HTML ] ( )   [PDF 1382 KB ]( )

Oral lichen planus (OLP) is a chronic inflammatory disease of the mucosa, some of which will develop into oral squamous cell carcinoma (OSCC). However, the pathogenesis of OLP remains unknown, but autoimmunity has been suggested as a potential cause. MicroRNAs (miRNAs), which are small noncoding RNAs, have been reported to be involved in a series of physiological events as well as the progression of diseases. The evidence indicates that miRNAs may be highly related to both the initiation and malignant progression of OLP. MiR-146a, miR-26b, miR-155, miR-19a and miR-125a are able to trigger OLP by regulating autoimmunity, and miR-137, miR-125b, and miR-27b may accelerate the carcinogenesis of OLP. These miRNAs may be potential targets for prognosis and treatment. Subsequent studies are expected to focus on a more comprehensive exploration of the role of miRNAs in OLP (including specific action pathways and other OLP-related miRNAs), as well as the potential for miRNAs to predict the treatment outcome of OLP. This review provides an updated summary of the roles of miRNAs in OLP to provide new ideas and approaches to OLP research.

2020 Vol.28(11): 739–743    [Abstract] ( )    [RICH HTML ] ( )   [PDF 821 KB ]( )

In recent years, many researchers have devoted themselves to the application of photodynamic therapy (PDT) in root canal disinfection, as conventional root canal disinfection methods have failed to achieve the optimal effect. Some clinicians have also applied PDT to root canal disinfection. PDT is expected to have a better effect than traditional root canal disinfection. This paper reviews the research progress on the mechanism, effect, influencing factors and limitations of PDT in root canal disinfection. Current research suggests that differences in the type and status of the bacteria, photosensitizers, light sources, operating environment and methods all affect the efficacy of root canal disinfection of PDT. Most of the research into PDT for root canal disinfection finds that it is effective, nontoxic, advantageous to dental pulp regeneration and comfortable for the patient, as well as lacking an excitant; however, its bactericidal effect is inferior to that of sodium hypochlorite. At present, it cannot replace traditional chemical washing but is a promising auxiliary method. The design of the photosensitizer, the energy dose of the light source and the optimal irradiation time need to be determined by further experiments, and more clinical verification is needed before its application in root canal therapy.

2020 Vol.28(11): 744–748    [Abstract] ( )    [RICH HTML ] ( )   [PDF 830 KB ]( )

Dental caries detector is a kind of diagnostic tool specifically designed for dental professionals to detect and monitor the early occurrence and development of dental caries. They are widely used in the clinic because of their advantages of rapid detection, flexible applications, ease of carrying, intuitive detection results and lack of pain for the patient. However, due to the different types and principles of the instruments produced by various instrument manufacturers, the clinical application range, sensitivity and specificity of test results also show significant differences. In terms of the current clinical application effects, although the DIAGNOdent caries detector has the widest range of clinical use, the accuracy of its detection results needs to be improved because it is affected by factors such as pigments and dental materials. The Canary System caries detector can effectively avoid the interference of the above factors, but its classification of the degree of caries is not clear. The DIAGNOcam caries detector can effectively detect early caries, but it has low reliability for occlusal caries detection. The existing dental caries detectors on the market can be used only as clinical auxiliary tools, and the accuracy of the detection results and comprehensiveness of the detection range need further improvement. With the application of the new multispectral near-infrared scanning fiber endoscope (NIR-SFE) and high-frequency ultrasound imaging (HFUS) in the detection of dental caries, a more efficient and accurate diagnosis of dental caries is possible in the future. To this end, we still need to continue exploring new technology to help clinicians complete the early diagnosis and treatment of dental caries to improve the quality of life of their patients.