Japan Prosthodontic Society position paper on "occlusal discomfort syndrome".

PURPOSE: Dentists may encounter patients who present with a sense of a malocclusion but in whom no objective findings can be detected. For the patient who insists that there is occlusal discomfort, in the absence of evidence some dentists elect to perform an occlusal adjustment that not only fails to alleviate symptoms, and may, in fact, exacerbate the discomfort. The patient-dentist relationship is then likely compromised because of a lack of trust. STUDY SELECTION: In 2011, the Clinical Practice Guidelines Committee of the Japan Prosthodontic Society formulated guidelines for the management of occlusal discomfort. When formulating clinical practice guidelines, the committee bases their recommendations on information derived from scientific evidence. For "occlusal dysesthesia," however, there are an insufficient number of high-quality papers related to the subject. Therefore, a consensus meeting was convened by the Japan Prosthodontic Society to examine evidence in the Japanese- and English-language literature and generate a multi-center survey to create an appropriate appellation for this condition. RESULTS: As a result of the consensus meeting and survey findings, this condition may be justifiably termed "occlusal discomfort syndrome." CONCLUSIONS: The Japan Prosthodontics Society believes that identification of an umbrella term for occlusal discomfort might serve as a useful guide to formulating clinical practice guidelines in the future. This position paper represents summary findings in the literature combined with the results of a multicenter survey focused on dental occlusal treatment and the condition of patients who present with occlusal discomfort syndrome.

Effect of experimental jaw muscle pain on occlusal contacts.

The aim of the study was measuring the effect of experimental jaw muscle pain on number and position of posterior occlusal contacts. Eleven adult voluntary subjects were enrolled. A lower impression was taken for each subject and two dental casts were obtained from each impression. The study was carried out in a randomised cross-over fashion. Each subject participated in two experimental sessions (30-day interval) in which he/she received an injection in the central part of the right masseter muscle consisting of 0·5 mL of either hypertonic or isotonic saline. Each subject was asked to rate pain intensity on a visual analogue scale. Three occlusal bite checks (polyvinylsiloxane) at the maximal intercuspal position were obtained during the experimental session: the first before the injection, the second between 60 and 90 s after the injection and the third 15 min after the injection. Evaluation of contacts was performed on dental casts with the use of different colours (black for baseline, red for intermediate and green for final contacts). Repeated-measures analysis of variance was used to compare the overall number of contacts among groups and the number of contacts of different colours. No significant difference was found between the overall number of occlusal contacts (P>0·05), but significant differences were found between contacts according to different colours: confirmed (P=0·006), disappeared (P=0·007) and new (P<0·001). Assuming different colours as change in contact position, the overall number of contacts did not change, but the position did. Experimentally induced jaw muscle pain affected the pattern of posterior occlusal contacts.

Stability of anterior open-bite treatment with occlusal adjustment.

INTRODUCTION: In this study, we aimed to evaluate the long-term stability of anterior open-bite treatment with occlusal adjustment and the dentinal sensitivity caused by this procedure in the long term. METHODS: The sample comprised 17 open-bite patients who experienced relapse of the negative vertical overbite after orthodontic treatment and were retreated with occlusal adjustment. The cephalometric changes were evaluated on lateral cephalograms obtained before and after the occlusal adjustment and in the long term (mean, 3.4 years after occlusal adjustment). Dentinal sensitivity was also evaluated before the occlusal adjustment, and 1.35 months, 4.61 months, and 3.4 years later. The cephalometric statuses between the 3 evaluations were compared with analysis of variance (ANOVA) and Tukey tests. The percentages of clinically significant relapse were calculated. To compare dentinal sensitivity at the several stages, nonparametric Friedman and Wilcoxon tests were performed. RESULTS: Statistically significant relapse of anterior open bite occurred in 33.3% of the patients. Those who had the procedure before 21 years of age were most likely to experience relapse. Dentinal sensitivity remained within the normal range in the long term. CONCLUSIONS: Despite the statistically significant relapse of anterior open bite, clinically significant stability was found in 66.7% of the patients.

Evaluation of anterior open-bite treatment with occlusal adjustment.

INTRODUCTION: The purpose of this study was to evaluate the cephalometric and occlusal changes, the functional occlusion, and the dentinal sensitivity of anterior open-bite treatment with occlusal adjustment. METHODS: The sample comprised 20 patients who experienced relapse of the anterior open bite (mean, -1.06 mm). Occlusal adjustment was performed until a positive overbite was established. Cephalometric changes were evaluated on lateral cephalograms taken before and after the occlusal adjustment. The functional occlusion analysis consisted of evaluating immediate anterior and canine guidance and the number of teeth in contact before and after the procedure. Dentinal sensitivity was evaluated before, shortly after, and 4.61 months after the occlusal adjustment. Pretreatment and posttreatment cephalometric changes and the number of teeth in contact were compared with dependent t tests. Percentages of anterior and canine guidance before and after the adjustment procedure were compared with the McNemar test. To compare dentinal sensitivity at several stages, the nonparametric Friedman test was used, followed by the Wilcoxon test. RESULTS: Significant increases in overbite and mandibular protrusion were seen, as were significant decreases in apical base discrepancy, facial convexity, and growth pattern angles. The percentages of immediate anterior and canine guidance increased significantly, as did the number of teeth with occlusal contacts. Dentinal sensitivity increased immediately after the adjustment but decreased to normal levels after 4.61 months. CONCLUSIONS: Occlusal adjustment is a viable treatment alternative for some open-bite patients; it establishes positive vertical overbite and improves the functional occlusion with only transient dentinal sensitivity.

Dental anomaly: dens evaginatus (talon cusp).

Dens evaginatus is a developmental anomaly characterized by the occurrence of an extra cusp shaped as a tubercle projecting from the palatal or buccal surfaces (talon cusp). In the anterior dentition, dens evaginatus is more commonly found in the maxilla and on the palatal surface of the tooth. The authors present a case of dens evaginatus in a maxillary central incisor, in which the evagination was removed and routine endodontic treatment was performed.

Microleakage of fissure sealants after occlusal enameloplasty and thermocycling.

This study evaluated the microleakage of a filled and an unfilled sealant after different occlusal surface treatments. A total of 120 human non carious extracted molars were cleaned with a water slurry of fine flour of pumice using Crescent Snap-On pointed brushes in a slow-speed hand piece. The teeth were divided at random into six groups of 20 teeth each; Group 1 pumice prophylaxis and PrismaShield filled sealant; Group 2 pumice prophylaxis and Delton opaque unfilled sealant; Group 3 treatment with a diamond fissure bur (Sorensen Ponta K.G. 2137 F) and PrismaShield sealant; Group 4 treatment with a diamond fissure bur (Sorensen Ponta K.G. 2137 F) and Delton opaque sealant; Group 5 treatment with a 1/4 round carbide bur and PrismaShield sealant; and Group 6 treatment with a 1/4 round carbide bur and Delton opaque sealant. Before sealant placement, the enamel occlusal surfaces were acid-etched for 30 seconds using disposable brushes, rinsed, and dried. The sealants were light-cured for 40 seconds. Immediately after curing the sealant, 60 teeth were placed in distilled water for 48 hours and 60 teeth were thermocycled (500x, at 5 degrees C - 55 degrees C, dwell time 30 seconds) and evaluated for microleakage. Wilcoxon and Fisher's Exact Test revealed no statistical significant difference in microleakage between the thermocycled and non-thermocycled groups, between the fissure treatment modalities or between the filled and unfilled sealants.

Dens evaginatus from an orthodontic perspective: report of several clinical cases and review of the literature.

The anomaly of dens evaginatus manifests itself as an innocuous-looking tubercle of enamel on the occlusal surface of a premolar tooth. Problems can arise when the tubercle is either worn, ground, or fractured off, resulting in pulpal exposure and possible loss of vitality of the tooth. Orthodontists should be particularly aware of this dental anomaly, which occurs in at least 2% of the Asian and Native Indian population. Premolar extraction cases should be planned to include extraction of the anomalous premolars instead of the normal ones. In addition, the orthodontist should be wary of occlusal changes during treatment or occlusal equilibration that might jeopardize the vitality of teeth with dens evaginatus. Pulp-capping or partial pulpotomy has been postulated as the most reliable form of treatment to prevent loss of vitality of the affected teeth and to allow continued root maturation where necessary.