Playing wind instruments as a potential aetiologic cofactor in external cervical resorption: two case reports

AIM: To present two cases of external cervical resorption (ECR) on maxillary incisors, in which the primary aetiologic factor is suggested to be pressure trauma by frequently playing wind instruments. SUMMARY: The exact aetiological spectrum of ECR is still poorly understood. For resorption to occur, a defect in the cementum layer (trigger) is a likely prerequisite. Whilst the mechanism for continuation (stimulus) is still unclear, knowledge of potential predisposing factors is important in assessing patients at risk. Pressure generated by playing wind instruments could present an aetiological factor in ECR because it affects the cervical region of the root surface. The cases that are presented may confirm this hypothesis and the extent of resorption defects is shown by cone-beam computer tomography (CT) and micro-focus CT imaging techniques.     

口腔扁平苔藓基因遗传学的研究进展

口腔扁平苔藓(OLP)的确切病因和发病机制目前尚不明确,对其病因尚未有一种可以完全解释其发病机制的假说,可能是多种因素共同作用的结果。近年来,陆续有OLP家族发病的报道以及关于OLP分子遗传学的研究,认为遗传因素是OLP的一个发病因素。目前已知多种与OLP易感性有关的遗传因素,包括人类DNA错配修复系统基因(MMR)、p53基因及其与家族蛋白、线粒体DNA、(RNA)。国内外学者对关于OLP遗传相关性已做了一定的研究,取得了很大的进展。通过研究多种细胞因子的基因多态性、核糖核酸,有利于从遗传方面阐述OLP的病因和发病机制,有利于对OLP相关联区域的精准定位,进一步找出关键基因,进一步阐明OLP的分子病理机制,并对其进行功能分类,也有利于对OLP的预防、早期诊断、直接有效靶向治疗和防复发以及药物研发提供重要价值。本文从基因、基因多态性、核糖核酸三方面对OLP遗传相关性的研究作一综述。     

Erosion: guidelines for the general practitioner

Tooth surface loss by erosion presents a challenge to the general practitioner in terms of identification of patients at risk, differential diagnosis from attrition and abrasion, evaluation of aetiological and modifying factors in Individual patients and in the clinical management of a progressively destructive pathological process. The guidelines presented in this paper, based on current research findings, were developed in the Department of Cariology, Karolinska Institute, Stockholm, to provide dentists with routines suitable for use in general practice.     

Orofacial granulomatosis: review on aetiology and pathogenesis

Orofacial granulomatosis (OFG) is considered as an uncommon disease and nomenclature of the disease was subjected to debate for a long time. Although various aetiological agents such as food substances, food additives, dental materials and various microbiological agents have been implicated in the disease process its precise pathogenesis is yet to be elucidated. Delayed type of hypersensitivity reaction appears to play a significant role, although the exact antigen inducing the immunological reaction varies in individual patients. However, evidence for the role of genetic predisposition to the disease is sparse. The underlying immunological mechanism appears to show some similarities between OFG and Crohn's disease, emphasizing the need for more comparative studies of the two entities. Therefore, we propose the term idiopathic OFG as a better term for those cases restricted to oral region without any identifiable known granulomatous disease and the diagnosis should not be changed until the patient develops systemic manifestations of a specific granulomatous condition. This review attempts to discuss the role of different aetiological agents and certain aspects of pathogenesis of OFG.     

Assessment of adverse reactions to prosthodontic materials

In 1978 five cases of so-called hypersensitivity reactions to Scutan and two to Impregum were reported (Dahl, 1978). The aim of the present study was to assess whether hypersensitivity or cell-mediated immune reactions were associated with the adverse clinical reactions in these patients or in others who had experienced the same reactions. Epicutaneous patch testing and lymphocyte transformation tests were carried out in a total of 13 individuals. The findings were difficult to interpret, because there was no consistent association between skin reactions and cell-mediated immune responses in subjects with suspected allergies. Other possible reasons for the reactions originally recorded were therefore discussed. It was concluded that adverse reactions associated with immune-mediated, delayed type hypersensitivity reactions may be elicited by prosthodontic materials, but other pathogenic mechanisms and aetiological factors responsible for the reactions observed should also be considered.     

Effectiveness of periodontal therapies on the treatment of different aetiological factors induced gingival overgrowth in puberty

OBJECTIVES: The aim of the present study was to compare oral improvement achieved by different periodontal therapies (surgical and non-surgical) for different aetiological factors induced gingival overgrowth in 60 subjects (mean age +/- SD = 12.33 +/- 1.05 years; age range = 12-15 years). METHODS: Subjects received oral hygiene instructions, scaling, surgical treatment (if necessary) and periodontal maintenance therapy. Clinical parameters were taken at baseline, after initial treatment and after periodontal surgery. RESULTS: The decrease in the clinical index values after all treatments compared to the initial values is found to be statistically significant (P < 0.05). Although there was a statistically significant difference in all aspects of the clinical index values of the study groups after initial treatments, for drug-induced gingival overgrowth subjects full improvement was seen only after periodontal surgery. CONCLUSION: Attention to plaque control and removal of local irritants is very important for the gingival health of the patients in puberty. In puberty, plaque-induced gingival overgrowth can be treated with plaque removal. However, these approaches alone do not prevent drug-induced gingival overgrowth and surgical therapy often becomes the treatment of choice.     

Stem cells and the repair of radiation‐induced salivary gland damage

Oral Diseases (2011) 17 , 143–153 Hyposalivation underlying xerostomia after radiotherapy is still a major problem in the treatment of head and neck cancer. Stem cell therapy may provide a means to reduce radiation‐induced hyposalivation and improve the quality of life of patients. This review discusses the current status in salivary gland stem cell research with respect to their potential to attenuate salivary gland dysfunction. Knowledge on the embryonic development, homeostasis and regeneration after atrophy of the salivary glands has provided important knowledge on the location of the salivary gland as well as on the factors that influence proliferation and differentiation. This knowledge has helped to locate, isolate and characterize cell populations that contain the salivary gland stem cell, although the exact tissue stem cell is still unidentified. The role that stem/progenitor cells play in the response to radiation and the factors that can influence stem/progenitor induced proliferation and differentiation are discussed. Finally, the mobilization and transplantation of stem cells and supportive cells and their potential to attenuate radiation‐induced salivary gland damage are discussed. Based on the major advances made in the field of stem cell research, stem cell‐based therapy has great potential to allow prevention or treatment of radiation‐induced hyposalivation.     

Medication-related osteonecrosis of the jaw: A literature review

BackgroundAntiresorptive agents such as bisphosphonates and denosumab, as well as angiogenesis inhibitors, may induce medication-related osteonecrosis of the jaw (MRONJ). However, the exact mechanisms of MRONJ are unclear and definitive treatment strategies have not yet been developed. Moreover, the aging population requiring antiresorptive agents and angiogenesis inhibitors has been increasing worldwide. Therefore, the aim of this literature review was to introduce the latest information on MRONJ. The epidemiology, triggering factors, risk factors, drug holiday, pathoetiology and treatment strategies for each drug-induced ONJ were investigated by conducting a PubMed search.HighlightThe prevalence and incidence of ONJ were very low. Some mechanisms of ONJ have been identified, although they were not definitive. Novel treatment strategies have been proposed in basic and clinical research. Several factors, including age and the administration duration of bisphosphonates, are risks for the development of bisphosphonate-related ONJ (BRONJ). Dental implant therapy and peri-implantitis could become risk factors of BRONJ, regardless of the onset timing of bisphosphonates. No reliable information about ONJ induced by denosumab and angiogenesis inhibitors was found.ConclusionCaution should be taken when dental treatment including implant therapy is performed in patients receiving bisphosphonates, denosumab, and angiogenesis inhibitors. There is limited scientific evidence regarding the relationship between MRONJ and older age. Further ONJ-related research on the aging population is required to manage the treatment of such diseases in older people in the future.     

Discuss the role of microorganisms in the aetiology and pathogenesis of periapical disease

The literature indicates that microorganisms have a critical role in the aetiology and pathogenesis of apical periodontitis. The advancement in microbiological study methods has allowed for the identification of newer species associated with the disease process. At our current understanding, however, the exact roles of specific microorganisms in apical periodontitis are not fully understood but the poly‐microbial aetiology of the disease appears to be supported by the literature. The endodontic microbiota is comprised of a subset of microbiota present in the oral cavity, consisting of predominantly anaerobic bacterial species, some fungal and viral species. The pathogenesis of apical periodontitis is essentially the result of a complex interplay between bacterial and host factors, giving rise to a range of presentations depending on the balance of the interaction. The role of endodontic microbiota in the initiation and persistence of apical periodontitis means that the mainstay of endodontic treatment is the elimination of such bacteria. A challenge to the resolution of apical periodontitis after treatment lies in the inadequacy of treatment protocol in completely eradicating the pathogenic species and the inherent ability of certain species to survive the treatment. This issue should be the focus of future research as we continually search for more predictable treatment methods of achieving the resolution of apical periodontitis.     

A review of 47 cases of unerupted maxillary incisors

Objectives. To study the prevalence of aetiological factors associated with unerupted maxillary incisors and to follow the outcome of treatment in a study of 47 cases.
Design . A retrospective study.
Setting . The Dental Department, St Luke's Hospital, Malta, the School Dental Clinic of Malta and the private practices of two orthodontists in Malta.
Sample and methods . Forty-seven patients with a total of 53 unerupted maxillary incisors were classified according to the aetiological factors causing non-eruption. The relative prevalence of the various aetiologies were ascertained, and the outcome after treatment was recorded to assess the efficacy of the treatment methods being used.
Results . The most common cause of lack of eruption was the presence of supernumerary teeth (47% of patients). The other 53% of cases were distributed more or less equally between the remaining aetiological factors, which were odontomes (9%), dilacerations (9%), tooth germ malposition (12%), crowding (4%), one case of a calcifying odontogenic cyst (2%) and one case of trauma to the preceding deciduous tooth (2%). The aetiology of 15% of cases could not be ascertained. Once supernumerary teeth were removed, maxillary incisors usually erupted successfully with the help of conventional treatment methods such as surgical exposure and orthodontics. A relatively large number of incisors that failed to erupt due to other aetiological factors had to be extracted.
Conclusions . Maxillary incisors that fail to erupt due to the presence of supernumerary teeth have a better prognosis than unerupted incisors with less common aetiologies.     

Bacteriotherapy and probiotics' role on oral health

Oral infections constitute some of the most common and costly forms of infections in humans. The concept of microbial ecological change as a mechanism for preventing dental disease is an important one while altered microbial ecology may lead to dental disease. New methods such as probiotic approaches (i.e. whole bacteria replacement therapy) to eliminate pathogenic members of the microbiota can be investigated. Bacteriotherapy is an alternative and promising way to combat infections by using harmless bacteria to displace pathogenic microorganisms. Probiotics are one of these new agents which are widely used for their therapeutic action. Limited research is available showing that some probiotic cultures may help dental improvement. Present paper focuses on possible oral benefits of probiotics.     

Orofacial sensitivity reactions and the role of dietary components. Case reports

Dietary components have proven to be important aetiological factors in orofacial sensitivity reactions such as plasma cell gingivitis and orofacial granulomatosis. The use of elimination diets to identify these dietary antigens can be instrumental in both diagnosis and effective treatment for these disorders.     

Opinions and attitudes of the UK's GDPs and specialists in oral surgery, oral medicine and surgical dentistry on oral cancer screening

OBJECTIVE: To survey two broad areas of oral cancer awareness and management of patients at risk of oral cancer by specialists in oral surgery, oral medicine, surgical dentistry and general dental practitioners (GDPs) in the UK. The first of these included knowledge and awareness of aetiological factors, changing patterns of disease, and screening/detection programmes including their effectiveness. The second included oral cancer detection methods, advice on avoidance of high-risk activity and self-examination, and referral pattern of GDPs. DESIGN AND METHOD: A pretested, 44-item questionnaire, a covering letter, a brief outline of the research protocol and return, stamped envelope were mailed in March 2003. A sample of 200 GDPs whose names were obtained from the General Dental Council's main list and 305 dental specialist names obtained from specialist's list in surgical dentistry, oral medicine and oral surgery were selected randomly. Information on oral cancer awareness and practice, screening practice and education was obtained. RESULTS: The response rate was 66.9%. The knowledge of the dental specialists was consistent with that in reports of current aetiological studies on oral cancer. However there were gaps in the GDP's knowledge and ascertainment of oral cancer risk factors. Over 70% of the dental specialists provided counselling advice on the risks of tobacco and alcohol habits compared with 41.2% of GDPs. More GDPs (52.4%) than specialists (35.4%) believed that oral cancer screening on a national basis would be effective in decreasing the mortality of oral cancer. Over 95% of all respondents used a visual examination for oral cancer screening and 89.9% of all respondents strongly believed that visual screening is effective in the early detection of oral cancer. CONCLUSION: The results showed that GDPs had knowledge gaps in their awareness of oral cancer risk factors and the application of preventive measures. Most dental health providers in the UK perform visual screening of the oral mucosa for their patients. Opinion was equivocal as to whether a nationally based screening programme similar to cervical cancer would be effective in improving the mortality and morbidity of oral cancer.     

Dental plaque biofilm in oral health and disease

Dental plaque is an archetypical biofilm composed of a complex microbial community. It is the aetiological agent for major dental diseases such as dental caries and periodontal disease. The clinical picture of these dental diseases is a net result of the cross-talk between the pathogenic dental plaque biofilm and the host tissue response. In the healthy state, both plaque biofilm and adjacent tissues maintain a delicate balance, establishing a harmonious relationship between the two. However, changes occur during the disease process that transform this 'healthy' dental plaque into a 'pathogenic' biofilm. Recent advances in molecular microbiology have improved the understanding of dental plaque biofilm and produced numerous clinical benefits. Therefore, it is imperative that clinicians keep abreast with these new developments in the field of dentistry. Better understanding of the molecular mechanisms behind dental diseases will facilitate the development of novel therapeutic strategies to establish a 'healthy dental plaque biofilm' by modulating both host and microbial factors. In this review, the present authors aim to summarise the current knowledge on dental plaque as a microbial biofilm and its properties in oral health and disease.     

Non-surgical periodontal therapy: An update on current evidence

Periodontal disease is an inflammatory condition that involves a complex interaction between pathogenic bacteria, environmental and acquired factors and host related factors. Till recently periodontal treatment was directed primarily towards reduction of bacterial load by subgingival debridement of root surfaces and modification of environmental risk factors. The current paradigm of periodontal disease stresses greater role of host-mediated inflammatory response in tissue destruction characteristic of periodontal disease. Various therapeutic modalities have been developed adjuvant to mechanical periodontal therapy. The use of laser and photodynamic therapy show great promise but their effectiveness has still not been conclusively proven. Chemotherapeutic agents, either systemic and local antimicrobials or host modulating drugs, played pivotal role in better and more predictable management of periodontal disease. The present review focuses on the best available evidence, for the current management of the chronic periodontal patients, gathered from systematic reviews and meta-analysis of mechanical non surgical periodontal therapy (NSPT) (subgingival debridement, laser therapy and photodynamic therapy) and the adjunctive chemotherapeutic approaches such as systematic and local antibiotics and antiseptics, subgingival pocket irrigation and host modulation therapies. The review also attempts to briefly introduce future developments in some of these modalities. At the end, the review summarizes the analysis of the current evidence that suggests that thorough subgingival debridement remains the mainstay of NSPT and that adjunct use of chemotherapeutic agents may offer better management of clinical parameters in periodontitis patients.     

The sequential hypothesis of impaction of maxillary canine – A hypothesis based on clinical and radiographic findings

The aetiology of impacted maxillary canines remains obscure. Numerous researchers have focused on identifying specific and non-specific aetiological factors responsible for canine displacement. Currently, the two most popular hypotheses that have gained consensus worldwide are the guidance theory and the genetic theory. However, no single hypotheses, can completely explain the aetiology of impaction of maxillary canines. This retrospective study was used to develop and postulate the aetiology of both buccally and palatally impacted maxillary canines. The study was conducted on a sample of 533 patients for whom the pattern and distribution of the impacted maxillary canines, sex differences, the dental age of the patients, dental anomalies and various geometric measurements which were made on the panoramic radiographs were recorded. Based on these findings, the sequential hypothesis of impaction of the maxillary canine was postulated. The hypothesis states that both buccally and palatally impacted canines have similar aetiological factors leading to their impaction. It is suggested that genetic mechanisms strongly influence the potential of the maxillary canine to be impacted and the guidance from the lateral incisor and the stage of development plays a vital role in determining the ultimate position of the impacted canine.     

The use of CO2 laser in the treatment of oral white patches: outcomes and factors affecting recurrence

Laser therapy has been a favoured treatment regime for oral leukoplakia since the mid 1980s. There is no information in the literature regarding factors affecting outcomes in patients with oral leukoplakia. Forty-three patients (mean age 60.3+/-13.6 years) with 73 primary oral leukoplakia were assessed for outcome and factors affecting survival. Dysplastic lesions were found in the majority of patients. The male to female ratio was 1.7:1 with 74% ex- or current smokers, 27% consuming alcohol and 31% continuing to smoke after treatment. The mean observation time was 47.2+/-28.2 months (range 2-102 months). Disease-free survival was 55.4% at 3 years that dropped to 33.9% after 5 years. The malignant transformation rate was 7.3%. No significant prognostic factors were found on univariate analysis but alcohol consumption (P=0.034) and previous malignancy (P=0.018) were found to be significant prognostic indicators using multivariate analysis. Continuation to smoke approached significance (P=0.061). Similar disease-free survival and malignant transformation rates with minimal complications were found as compared to the literature. Recommendations for minimizing recurrence are presented. Long-term follow up and removal of aetiological factors, such as smoking and alcohol, are advised.     

Factors increasing the caries risk of second primary molars in 5‐year‐old Dutch children

International Journal of Paediatric Dentistry 2010; 20: 151–157 Background. Caries is still a prevalent condition in 5‐year‐old children. At present, knowledge regarding some aetiological factors, like deciduous molar hypomineralization (DMH), is limited. Aim. To investigate aetiological factors both directly and indirectly associated with caries in second primary molars. Design. Of 974 children invited to participate in the study, 386 children were examined clinically with visual detection of caries. Only carious lesions determined to have reached the dentine were recorded. Information about tooth brushing frequency, education level of the mother, and country of birth of mother and child, was collected by means of a multiple‐choice questionnaire. Parents of 452 children filled in the questionnaire. Complete clinical and questionnaire data were available for 242 children. Statistical analysis of the effect of the independent variables was undertaken using the Pearson’s chi‐squared test. Results. Deciduous molar hypomineralization (P = 0.02) and the country of birth of the mother (P < 0.001) were positively associated with caries prevalence. Conclusions. Deciduous molar hypomineralization and the country of birth of the mother play a role in the prevalence of dental caries. These aetiological factors associated with childhood dental caries need to be investigated further in longitudinal clinical trials.     

不同消毒方法对感染根管内粪肠球菌抗菌性的研究现状

粪肠球菌属于人体的正常菌群,但在根管治疗后持续感染和再感染的根管中常被检出,此菌是导致根管治疗失败的主要致病菌。目前,根管治疗中常规的机械预备和根管冲洗方法并不能完全清除已定植于根管中的粪肠球菌。本文就几种临床根管消毒方法对粪肠球菌的抑菌作用方面做一综述。     

Osteoradionecrosis of the jaws as a side effect of radiotherapy of head and neck tumour patients--a report of a thirty year retrospective review

This retrospective study aimed to demonstrate the incidence and the aetiological factors involved in osteoradionecrosis (ORN) in a group of 830 head and neck tumour patients who received radiotherapy between 1969 and 1999.The data showed an over all incidence of 8.2% and a 3-fold higher incidence for men than for women. Osteoradionecrosis was most commonly located in the body of the mandible. Concerning the risk factors, a negative influence was shown for advanced tumours, segmental resections of the mandible and pre-/post-radiation tooth extractions. Tooth extractions were found to be responsible for 50% of all cases. The osteoradionecroses were observed significantly earlier in patients who received pre-surgical radiotherapy than those who received post-surgical radiotherapy. Combined pre-surgical radio- and chemotherapy significantly hastened the appearance of osteoradionecrosis compared to pre-surgical radiotherapy alone. Only 40% of patients with osteoradionecrosis could be healed completely by means of surgery and antibiotic medication. Hyperbaric oxygenation (HBO) therapy was performed only in individual cases.The data suggest that osteoradionecrosis has a multifactorial aetiology. Therefore, a very close follow-up of tumour patients and a strict prophylactic management are required.