Balkwill's angle, occlusal plane, mandibular shape, and curve of Spee.

OBJECTIVE: This study proposes a cephalometric method to determine an individual radius of the curve of Spee in cases of occlusal prosthetic rehabilitation. METHODS: A retrospective study was conducted on 469 lateral cephalograms. Statistical analysis was performed. Correlations were computed using simple regression, Z tests, paired t-tests, and one-way repeated measures ANOVA. RESULTS: Regression calculations supported a link between the radius of the curve of Spee and occlusal plane inclination, Balkwill's angle, mandibular parameters (MP), with MP = corpus - ramus + Bonwill height. Based on MP, data that are accessible even in the absence of teeth, a regression formula can be proposed to provide an individualized estimation of the radius of the Spee curve (RCS): RCS = 0.624 * MP + 26.583. CONCLUSION: This study proposes an individualized estimation of the RCS from only skeletal mandibular parameters: the length of the ramus, length of the corpus, and the Bonwill height.

Occlusal devices in France: An assessment of professional practice.

STATEMENT OF PROBLEM: Whether recommendations for the use of occlusal devices are made uniformly in terms of indications, designs, and wearing time is unclear. Different recommendations may lead to different clinical outcomes. PURPOSE: The purpose of this survey was to assess the professional practice of dental surgeons in France regarding the use of occlusal devices. MATERIAL AND METHODS: A 26-question cross-sectional survey was sent to a panel of French dentists via the County Councils of the Dental Order. The questionnaire concerned the amount of occlusion-related treatment, the use of an anterior deprogramming device, stabilization splint, and anterior repositioning appliance, and the patient follow-up as well as the drawbacks of using an occlusal device as a therapeutic solution. The statistical tests used in the study were the chi-square test and the Yate correction for continuity. RESULTS: A total of 771 responses were received. Invasive options were still reported as being used as a first-line treatment for temporomandibular disorder, although a statistical difference was found between experienced and recently graduated practitioners, with recent graduates preferring noninvasive options as first-line treatment. Also, the results showed that anterior deprogramming devices were not used or that their application, particularly the length of treatment, was unfamiliar to practitioners. The anterior repositioning appliance seems to be used, but only a few practitioners integrate it into their practice. In general, about one-third of dentists appear to have a good knowledge of occlusion-related treatments, in particular, the use of occlusal devices. CONCLUSIONS: The results indicated that only 20% to 30% of practitioners have good knowledge of contemporary occlusion-related practice. There is a need for the standardization of practice and improved education for practitioners in the use of occlusal devices.

[Focus on the occlusal failure]. / Regards sur l'insuccès occlusal.

The success is evidenced by the longevity of aesthetic and functional therapeutic result. The occlusal «postorthodontic¼ failure could result in dental instability, functional discomfort, dental or musculo-articular complaint. Analysis of the occlusion research potential occlusal pathogenic dysfunction listed in stabilizing (shimming), centering and guiding anomalies. The large capacity of tolerance of the masticatory system makes it difficult to define the border between physiology and pathology but it is necessary to have benchmarks that can be summarized as follows: - shimming: occlusal contact of mesio-lingual cusp of the first maxillary molars (in Class I, II or III) and occlusal contacts between the canines antagonists; - centering: no transversal deflected occlusion between maximal Intercuspation (ICP) and occlusion in Centric Relation (RCP); - guiding: absence of posterior interference, absence of anterior interference (locking).

Optimal placement of the two anterior implants for the mandibular All-on-4 concept.

The novelty of the All-on-4 concept for a mandibular implant-supported fixed dental prosthesis is the inclination of the posterior implants. Typically, the anterior implants are placed lingually relative to the canine/incisor teeth and perpendicular relative to the occlusal plane. According to the laws of elementary biomechanics, the long axis of the implant unit should be aligned to the axis of the occlusal loading forces during clenching in the maximal intercuspal position. When several implants are connected by a prosthesis, the mean axis of the overall occlusal loading must be taken into account. The objective of this report was to propose a different position for anterior implants by tilting them labially to counterbalance the distal inclination of the posterior implants.