Influence of a bite-plane according to Jeanmonod, on bruxism activity during sleep.

One way to look at nocturnal oral parafunction such as bruxism, is using polysomnography. Although in recent years several studies have been carried out, it is almost impossible to compare the respective results because of the lack of standardization in the methodology used. The nocturnal muscular activity of m. Masseter and m. Temporalis Anterior has been registered in 21 patients suffering from bruxism, prior and after treatment with a bite-plane made according to Jeanmonod. A group of five persons without any dental or muscular parafunction has been included as a control. A computer program based on the biomechanical principles of muscle contraction has been developed and was used to analyse the raw electromyography (EMG) signal. The data shows a significant decrease (P = 0.008) in nocturnal parafunctional muscle activity with the bite-plane in situ. The present study shows that by analysing the raw signal obtained via EMG using a specially designed computer program, it becomes possible to isolate the occurrence of parafunctional events in the EMG signal and to study the influence of a given therapy on this EMG signal.

Decreased amount of slow wave sleep in nocturnal bruxism is not improved by dental splint therapy.

OBJECTIVE: To test the efficacy of dental treatment of bruxism on sleep quality, using slow wave sleep as the primary outcome parameter. METHODS: The study design consisted of an open label, unpaired comparison between normals and patients and a paired comparison between pre- and post-treatment patient recordings. Twenty patients suffering from bruxism (13 male, 7 female, mean age 35 years) and 6 normal volunteers (3 male, 3 female, mean age 30 years) participated in the study. Polysomnographic recordings were performed in a sleep laboratory in a general hospital both before and after treatment. The treatment was derived from a model that ascribes bruxism to a dental malocclusion, and consisted solely of dental therapy (Jeanmonood 1988). RESULTS: The untreated bruxism group had worse sleep than normals when comparing slow wave sleep (21% versus 32% slow wave sleep percentage in sleep period time) during the second polysomnographic recording, after one night adaptation. Therapy did not improve sleep quality; bruxism patients showed only minor, non-significant differences in sleep quality when comparing pre- and post-treatment recordings.

[What efforts are being made by dentists in the Flemish region for the limiting of amalgam rejection? A study conducted on a representative sample of 373 Flemish dentists on the subject of amalgam waste: extent of the problem, waste management and foreseeable solutions]. / Quels efforts les dentistes en région flamande font-ils pour limiter les rejets d'amalgame? Une étude réalisée auprès d'un échantillon représentatif de 373 dentistes flamands au sujet des déchets d'amalgame: étendue du problème, gestion des déchets et solutions envisageables.

The great Amalgam debate is also taking place in Flanders (Belgium). Mercury amalgam has been used for dental fillings since the last century. Over that time, questions have occasionally been raised with regard to its safety (mercury vapour given off by the amalgam fillings and the possible dangers that these could cause to the patient and the dentist) and with regard to the ecological impact of amalgam waste. Some materials used to treat dental patients endanger the environment. The most important polluting materials are the heavy metals, in particular mercury. This study investigated the answers to the following research questions: What is the total volume of amalgam that is used in Flemish dentistry and what part ended up in the household waste? How do Flemish dentists manage (store and dispose of) their dental amalgam waste? Are Flemish dentists using any alternatives (amalgam separators or alternative materials for dental fillings) for amalgam? A randomly selected group of 500 dentists working in the Flemish part of Belgium was invited to answer a mail questionnaire. A total of 373 dentists responded (response rate 74.6%), providing a representative sample. Of the 5000 kg amalgam being used in one year in Flemish dentistry, about 1.200 kg is discharged either into the sewage or into the household waste. Furthermore, a supplementary 1.900 kg amalgam (extracted teeth with amalgam fillings or bored out amalgam fillings) is also being discharged either into the sewage or into the household waste. Although dental amalgam is the restorative material most used in Flanders, composite materials are becoming more widely used. Only 5% of the respondents were using an amalgam separator.

[Radiographic waste coming from Flemish dental offices. A survey of a representative sample of 373 Flemish dentists]. / Déchets radiographiques provenant des cabinets dentaires flamands. Une enquête auprès d'un échantillon représentatif de 373 dentistes flamands.

Apart from amalgam, the materials used for dental radiography also endanger the environment. The debate on toxic chemicals in dentistry is focused on the way these radiographic materials (fixator, developer, the small lead plates and the old roentgenograms) are discharged into the environment. This study investigated the answers to the following research questions: What is the total volume of fixator, developer, small lead plates and old roentgenograms that is used in Flemish dentistry and what part ends up in the household waste? How do Flemish dentists manage (store and dispose of) these radiographic materials? A randomly selected group of 500 dentists working in the Flemish part of Belgium was invited to answer a mail questionnaire. A total of 373 dentists responded (response rate 74.6%), providing a representative sample. Of the 2.1 million roentgenograms made yearly in Flemish dentistry only 160,000 are dropped in the household garbage can. About 70% of the 2.2 million small lead plates used yearly in Flemish dentistry is discharged in the household garbage, to end on the rubbish-dump or in the combustion furnace where the lead vapours will poison the surrounding air. Although the storing and the ecological responsible discharging of the pollutants fixator and developer does not pose any problems, most of these products are discharged into the sewage system: about 80% of the 80,000 liter developer and 75% of the 70,000 liter fixator used each year in Flemish dentistry.

[The dilemma of the 2d primary molar]. / Le dilemme de la deuxième molaire de lait.

Extensive carious lesions in primary molars often confront the dentist with a dilemma: extraction or restoration. The primary molar constitutes an important element in the development of the dentition. If extraction is considered, the dentist should be aware of the possible risks towards malocclusion or malposition. In order to understand these consequences a brief summary of normal dentition development is given, followed by a description of factors influencing development of dentition after premature extraction of a second primary molar. Premature extraction causes a disturbance in the eruption of the successor and migration of the neighbouring teeth. The eruption of the bicuspid can be delayed or accelerated according to the stage of root formation. The rate, amount and direction of migration depends on the extracted element, time of loss, spacing or crowding, eruption sequence, dental relationship, intercuspation, interaction of soft tissues and dental arch, supra-occlusion and the leeway space. To conclude the treatment modalities of pulp pathologies in primary molars are outlined. In children with deep carious lesions a treatment plan involves the child's medical history and social development as well as orthodontic, preventive and restorative aspects.