Mutational analysis of candidate genes in 24 amelogenesis imperfecta families

Amelogenesis imperfecta (AI) is a heterogeneous group of inherited defects in dental enamel formation. The malformed enamel can be unusually thin, soft, rough and stained. The strict definition of AI includes only those cases where enamel defects occur in the absence of other symptoms. Currently, there are seven candidate genes for AI: amelogenin, enamelin, ameloblastin, tuftelin, distal-less homeobox 3, enamelysin, and kallikrein 4. To identify sequence variations in AI candidate genes in patients with isolated enamel defects, and to deduce the likely effect of each sequence variation on protein expression and structure, families with isolated enamel defects were recruited. The coding exons and nearby intron sequences were amplified for each of the AI candidate genes by using genomic DNA from the proband as template. The amplification products for the proband were sequenced. Then, other family members were tested to determine their genotype with respect to each sequence variation. All subjects received an oral examination, and intraoral photographs and dental radiographs were obtained. Out of 24 families with isolated enamel defects, only six disease-causing mutations were identified in the AI candidate genes. This finding suggests that many additional genes potentially contribute to the etiology of AI.     

Clinical evaluation of patients with temporomandibular joint implants

PURPOSE: An undetermined number of patients with temporomandibular joint (TMJ) symptoms have been treated with intra-articular disc implants composed of Teflon ethylene/propylene or Teflon polytetrafluoroethylene and aluminum oxide (Proplast-Teflon; Vitek, Houston, TX). These implants have shown the potential to fragment in situ resulting in nonbiodegradable particles that stimulate a giant cell reaction and lead to degeneration of local structures, pain, and limitation of mandibular opening. We examined the possible relationship between TMJ implants and persistent pain, responses to sensory stimuli, quality of life, and systemic immune dysfunction. PATIENTS AND METHODS: This case series (32 patients) were referred from university-based orofacial pain centers and private practices from across the United States. Laboratory and clinical assessments evaluated orofacial pain symptoms, neurologic function, clinical signs and symptoms of rheumatologic disease, physical function, systemic measures of immune function, and behavioral measures. RESULTS: We found that TMJ implant patients appeared to have altered sensitivity to sensory stimuli, a higher number of tender points with a diagnosis of fibromyalgia, increased self-report of chemical sensitivity, higher psychologic distress and significantly lower functional ability. Systemic illness or autoimmune disease was not evident in this series of TMJ implant patients. CONCLUSIONS: Significant problems were noted on clinical assessment of TMJ implant patients. This is a US government work. There are no restrictions on its use.     

Evaluation of the adjunctive benefits of platelet-rich plasma in subantral sinus augmentation

Subantral sinus augmentation is often necessary to permit placement of endosseous implants. Recent efforts to improve wound healing have focused on autogenous sources of bioactive mediators, such as platelet-rich plasma (PRP), which offer the potential to enhance the biological activity of bone replacement grafts. The purpose of this randomized, single-blinded, controlled study was to compare bone formation after subantral maxillary sinus augmentation with freeze-dried bone allograft (FDBA) plus PRP versus FDBA plus resorbable membrane. Ten patients underwent bilateral maxillary subantral sinus augmentation, with sites within subjects randomized to receive FDBA plus PRP or FDBA plus membrane. Core biopsy specimens were obtained 4.5 to 6 months after the grafting procedure at time of implant placement. Histomorphometric analysis revealed a significantly higher percentage of vital tissue in sinuses after treatment with FDBA and PRP (78.8 +/- 8.3) than with FDBA and membrane (63.0 +/- 15.7). Moreover, the percentage of bone formation in sinuses augmented with the combination of FDBA plus PRP (33.3 +/- 11.3) was nonsignificantly (P 相似文献   

The effectiveness of computer-aided learning in teaching orthodontics: a review of the literature.

INTRODUCTION: The purposes of this review were to evaluate the effectiveness of computer-aided learning (CAL) in orthodontic education, to make evidence-based recommendations for the use of CAL in orthodontics, and to develop guidelines for conducting comparative trials to evaluate CAL as a mode of learning in orthodontic education. METHODS: Medline, the Cochrane Library Database, ERIC, CINAHL, LISA, Psycinfo, and IPA were searched for randomized controlled trials evaluating the effectiveness of CAL in orthodontics. Outcome measures included objectively measured posttest scores on multiple choice, written, or oral tests; performance on a clinical procedure or clinical interview; time spent on CAL programs to learn the material presented; and responses to questionnaires conveying participants' attitudes toward various modes of learning. RESULTS: Four randomized controlled trials comparing CAL with conventional teaching fulfilled the inclusion criteria and met the cutoff quality assessment checklist (QAC) score of > or = 8. Each study was assessed for quality by 2 independent reviewers. The validity and strength of the selected studies were assessed by using a QAC for an educational intervention. CONCLUSIONS: The controlled trials of CAL in orthodontics that met our QAC cutoff score of 8 were split, with 2 showing that CAL enjoyed a significant advantage over conventional teaching, 1 showing no difference, and 1 showing that the conventional tutorial method was better. More high-quality trials evaluating the effectiveness of CAL in orthodontics are needed. CAL programs in orthodontics elicit mostly positive responses and attitudes from students toward learning.     

Apical root resorption is associated with comprehensive orthodontic treatment but not clearly dependent on prior tooth characteristics or orthodontic techniques

SYSTEMATIC REVIEW CONCLUSION: Increased incidence and severity of external apical root resorption (EARR) occurred in patients undergoing comprehensive orthodontic therapy, especially when therapy involved higher levels of force than those commonly used for orthodontic tooth movement. CRITICAL SUMMARY ASSESSMENT: Results from a high-quality systematic review of 11 randomized clinical trials (RCTs) suggests that EARR has a multifactorial etiology; is associated with comprehensive orthodontics; supports the clinical use of light forces, especially during intrusion of teeth; and requires higher-quality research. EVIDENCE QUALITY RATING: Limited.     

Tooth whitening: current status

This article reviews the history of tooth whitening and its rapid evolution and briefly discusses tooth whitening agents and protocols. The active ingredients and mode of action during the whitening process are explained. The factors affecting the speed of whitening and its final results are discussed, as well as adverse effects and safety precautions. Protocols are explained in detail, and the predicted outcomes, including those for tetracycline-stained teeth, are covered.     

Evaluation of sedation failure in the outpatient oral and maxillofacial surgery clinic.

PURPOSE: Our goal was to report on the incidence of sedation failures in our outpatient oral surgery clinic. Sedation failure is the inability to complete a procedure under intravenous sedation. There is very little in the oral surgery literature on this subject. MATERIALS AND METHODS: Proper Institutional Review Board approval was obtained from the appropriate governing body for this project. The medical records of 539 intravenous sedation patients treated at the Oral and Maxillofacial Surgery Clinic at our institution were retrospectively evaluated to determine the incidence of failed sedation. Patients sedated with midazolam and fentanyl were placed in group A. There were 323 patients in group A. We placed patients sedated with midazolam, fentanyl and methohexital into group B. There were 216 patients in group B. The gender, medical history, type of procedure being performed, amount of drug given, and the patient's vital signs throughout the procedure were recorded. RESULTS: There were 9 failed sedations with a rate of 1.6% (9/539); 3 in group B (1%) and 6 in group A (2%). Five of our failures were undergoing multiple tooth extractions. Two of the failures were undergoing surgical removal of impacted third molars. Two patients underwent mandibular fracture reduction. Failure was attributed to increased agitation and combativeness, uncontrolled hypertension, tachycardia and desaturation. CONCLUSION: The mandible fracture population and multiple teeth extraction patients had higher rates of failure than other groups. This may be the result of procedure length, type of procedure, or a preoperative anxiety and attitude toward treatment expressed by the patient making sedation unpredictable. Level of training and experience of the practitioner may contribute to sedation failure. These results allow us to develop a prospective study protocol of outpatient sedation and to quantify more detailed information about preoperative anxiety, medical status, and social history than we had available during our chart review. More specific conclusions may help us determine if certain patient populations are at a higher risk for failed sedations.     

An in vitro comparison of bacterial leakage of three common restorative materials used as an intracoronal barrier

The purpose of this in vitro study was to evaluate quantitatively the effectiveness of three different restorative materials used as an intracoronal barrier to prevent microleakage of endodontically treated teeth. Fifty-five extracted human single-canal teeth were used in this study. The teeth were endodontically prepared and obturated. Forty-five teeth were randomly assigned to three experimental groups: group 1: sealed with Ketac-Cem (3M ESPE, St Paul, MN) (n = 15), group 2: sealed with Clearfil Protect Bond/Clearfil AP-X (Kuraray, New York, NY) (n = 15), and group 3: sealed with Maxcem (Kerr, Orange, CA) (n = 15). Ten teeth were also randomly assigned to a negative control group (n = 5) and a positive control group (n = 5). Microleakage was tested by using a sterile two-chamber bacterial method and Enterococcus faecalis was used as a microbial marker. Samples were incubated aerobically at 37 degrees C for 120 days. Bacterial leakage was determined by change in turbidity in the medium. Statistical analysis was performed using a Wald chi-square test. No significant difference (p > 0.05) in bacterial leakage was found between the three experimental groups tested. All positive controls leaked within 60 days and broth of the negative control group remained clear throughout the entire experimental period.     

The Periodontitis and Vascular Events (PAVE) pilot study: adverse events

BACKGROUND: During the last 15 years, a substantial number of population-based, clinical, laboratory, and animal studies have been published that reported findings on the relationship between periodontal disease and cardiovascular disease. The Periodontitis and Vascular Events (PAVE) pilot study was conducted to investigate the feasibility of a randomized secondary prevention trial to test whether treatment of periodontal disease reduces the risk for cardiovascular disease. This article describes the occurrence of adverse events during the pilot study. METHODS: The PAVE pilot study was a multicenter, randomized trial comparing periodontal therapy to community dental care. Baseline and follow-up clinic visits included a periodontal examination; blood, subgingival plaque, and crevicular fluid specimen collection; and medical and dental histories. Telephone follow-up contacts were scheduled to occur 3 months after randomization and every 6 months thereafter to assess adverse events or endpoints. RESULTS: Cardiovascular adverse events occurred with similar frequency (23 versus 24 [P = 0.85] in the community control and the treatment groups, respectively). There were 15 serious adverse events (SAEs) with a non-significantly higher percentage occurring in the community care group (6.6% versus 3.3%; P = 0.19). A time-to-event analysis of patterns of SAEs indicated that subjects in the periodontal therapy group tended to be less likely to experience an SAE over the entire 25 months of the study. CONCLUSION: For those individuals who remained in the study, it appears that provision of periodontal scaling and root planing treatment to individuals with heart disease resulted in a similar pattern of adverse events as seen in the community care group, which also received some treatment.