Chinese Journal of Dental Research, 02/2015

Oral cancer is an aggressive disease with a high incidence in both males and females in Asia and ranks as the first of all malignancies in India. The relatively high prevalence rate of oral cancer in Asia is mainly due to the fact that a high percentage of the population are smokers or chew betel nut. They comprised the so called 'high risk population' of oral cancer. Meanwhile, epidemiological surveys showed a much lower 5-year survival rate in patients with advanced TNM stage III and IV oral cancer than those in the earlier stage I and II disease after treatment. Therefore, it is important to identify and treat precancerous lesions and oral cancer at early stages. In this article, we describe the expert consensus contributed by outstanding clinicians and scientists at the 11th Asian Congress of Oral & Maxillofacial Surgery (ACOMS) and we highlight the importance of oral cancer screening by various conventional and novel methods based on scientific research. Keywords: Asia, betel nut, oral cancer, screening, smoking

Objective: To provide an overview of internal organ involvement (IOI) in immunoglobulin G4-related sialadenitis (IgG4-RS) patients, with a focus on the prevalence and clinical features of IOI, the analysis of serum IgG4 levels in patients with or without IOI, and the usefulness of positron emission tomography (PET) for examination of the whole body. Methods: A systematic search was performed using PubMed, CNKI, Wanfang Data and CQVIP databases. Results: A total of 99 articles, including 493 IgG4-RS cases, were analysed in this study. The male-to-female ratio was 1.57:1 and the mean age was 61.67 years. IOI was observed in 71.6% patients, including lesions of the pancreas (38.5%), the biliary system and liver (17.8%), distant lymphadenopathy (20.3%), the respiratory system (15.6%), the urinary system (12.0%) and retroperitoneal fibrosis (11.4%). The lesions could occur homeochronously or metachronously with IgG4-RS. The serum IgG4 levels in the IOI-positive and IOI-negative groups were 1,131 ± 952 mg/dL and 659 ± 843 mg/dL, respectively (P 0.01). The prevalence of IOI and the number of involved internal organs between the PET and the non-PET groups showed no significant difference (P = 0.399 and P = 0.823, respectively), but were significantly higher in the PET group, amongst patients whose first symptom or chief complaint was salivary gland swelling (P = 0.002 and P = 0.001, respectively). Conclusion: IOI is common in IgG4-RS and almost every organ can be affected. High levels of serum IgG4 represent a potential indicator of IOI. Furthermore, PET is a useful tool for evaluation of the whole body. Keywords: IgG4-RD, IgG4-RS, internal organ involvement, serum IgG4 level, PET

Objective: To investigate the effects of the multi-glycosides of Tripterygium wilfordii (GTW) on Sjögren's syndrome (SS) in the non-obese diabetic (NOD) mouse model. Methods: Twenty-seven 8-week-old, female NOD mice were divided into the GTW group, the hydroxychloroquine (HCQ) group, and control (normal saline) group, and received corresponding treatment for 16 weeks. The treatment-induced changes in stimulated total saliva flow rate (STFR), level of serum anti-SSA/SSB, ratio of regulatory T (Treg) cells, histology of the submandibular gland (SMG) and the gene expression profile that is related to inflammation and autoimmunization were evaluated. Results: Compared to the untreated (control) mice, STRF, SMG index and Treg/CD4+ cell ratio were significantly higher, whereas anti-SSA, anti-SSB and lymphoid foci were remarkably lower in GTW-treated mice. HCQ-treated mice showed similar results except SMG index was not different from the untreated mice. NOD mice showed 19.03% altered gene expression with maturation from the age of 8 weeks to 24 weeks. Treatment with HCQ and GTW reduced the change in gene expression to 13.09% and 7.14%, respectively. Conclusion: GTW is as effective as HCQ in the treatment of Sjögren's syndrome in the NOD mouse model. Keywords: multi-glycoside of Tripterygium wilfordii, NOD mouse model, Sjögren's syndrome

Objective: To evaluate the relationship between caries and malocclusion in the early and late mixed dentition in a population of children of Chinese migrant workers in Shanghai. Methods: Dental charts were obtained for 646 children in the mixed dentition, aged between 6 and 13 years old. The decayed, missing, and filled teeth (DMFT) index and interproximal tooth structure lost due to caries (ITSLC) were evaluated. Results: In the early mixed dentition, overbite was more likely to be ideal in subjects with DMFT > 0. In the late mixed dentition, crowding in both arches was greater in subjects with DMFT > 0. In the total sample, crowding in the lower arch only was greater in subjects with DMFT > 0. In the early mixed dentition, upper crowding was lower in subjects with ITSLC in the upper arch and in both arches and the rate of anterior crossbite was higher in subjects with ITSLC in the upper arch. In the late mixed dentition, overjet was more likely to be ideal in subjects with ITSLC in the upper arch and upper crowding was greater in subjects with ITSLC in both arches. In the total sample, overjet was more likely to be ideal in subjects with ITSLC in the upper arch and lower crowding was greater in subjects with ITSLC in both arches. Conclusion: A relationship exists between caries and malocclusion, and between ITSLC and malocclusion, and some relationships may change with dental age. Keywords: Dental caries, DMFT, early mixed dentition, late mixed dentition, malocclusion

Objective: To investigate the effects of the closed-eruption technique on impacted immature maxillary incisors. Methods: The contour and position of the gingival margin, root development, and pulp status were evaluated in 50 impacted immature maxillary incisors immediately after treatment and 2 years later. Results: Chronic periapical periodontitis and trauma of the primary teeth were the main causes of impacted immature maxillary incisors. The average treatment time was 11 months. After treatment, the contour of the impacted incisor gingival margin, which had already erupted, conformed with the contralateral incisors; the gingival margin positions of 34 (68%) impacted incisors were the same as those of the contralateral incisors but the other 16 (32%) were more apical. All roots developed normally; pulp vitality was normal and conformed with the contralateral incisor change into a period. Three (6%) impacted incisors were slightly labially inclined because the dilacerated part of their roots was too long. Conclusion: The closed-eruption technique is an effective method of treating impacted immature maxillary incisors. Keywords: closed-eruption technique, immature incisor, impacted maxillary incisor

Objective: To modify the conventional straight elevator with a unique and innovative design in respect to approach and accessibility during extraction for patients with abrasions around corners of the mouth and with thick buccal mucosa, without causing overstretching of angles of the mouth. Methods: The shank of the straight elevator in the shape of a 'U' was modified, giving it a shape similar to 'P' in the English alphabet hence it is named the P Elevator. The P elevator utilises a 'U' shaped bend in the shank of the conventional straight elevator making space for the buccal soft tissues and the angle of the mouth, to accommodate properly in the 'U' shank. The application of this elevator in the successful removal of third molars is described. Results: Two hundred patients underwent extraction of third molars with the P elevator including 166 patients with disimpaction of all third molars, 23 patients with abrasion around the angle of the mouth, and 11 patients with thick buccal mucosa. Satisfactory results were obtained in all the cases with no postoperative complications. Conclusion: The P elevator permits prudent, meticulous, innovative and proficient extraction of third molars in patients with thick buccal mucosa and abrasions around the angle of the mouth, without overstretching the corners of the mouth. We introduce novel applications of the P elevator in third molar extraction that provide substantial advantages over a conventional straight elevator. Keywords: abrasions of angles of the mouth, elevators, thick buccal mucosa, third molar extraction, overstretching of corners of the mouth