Jean-Daniel Orthlieb

Gouttières occlusales. Mise au point

Occlusal splint are defined as intra-oral devices mostly indicated to modify the occlusal relationship between maxillar and mandibular dental arches. Among the different shapes of occlusal splint, an updating seemed necessary to the authors. The main indications for occlusal splint are represented by temporomandibular disorders and teeth protection. Occlusal splints are usually made of hard resin and are, generally, carried on the mandibular jaw. Total occlusal splint are preferable to partial occlusal splint, except in some emergent cases. The smooth occlusal splints are needed for musculo-articular disorders when the indentated splints are reserved for mandibular repositioning in articular temporomandibular joint disorders.

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.

Mise au pointGouttières occlusales. Mise au pointOcclusal splint: State on the art

Occlusal splint are defined as intra-oral devices mostly indicated to modify the occlusal relationship between maxillar and mandibular dental arches. Among the different shapes of occlusal splint, an updating seemed necessary to the authors. The main indications for occlusal splint are represented by temporomandibular disorders and teeth protection. Occlusal splints are usually made of hard resin and are, generally, carried on the mandibular jaw. Total occlusal splint are preferable to partial occlusal splint, except in some emergent cases. The smooth occlusal splints are needed for musculo-articular disorders when the indentated splints are reserved for mandibular repositioning in articular temporomandibular joint disorders.

Disc displacement without reduction: a retrospective study of a clinical diagnostic sign

Objective: The purpose of this retrospective study is to evaluate a clinical diagnostic sign for disc displacement without reduction (DDWR), the absence of additional condylar translation during opening compared with protrusion. Method: Thirty-eight electronic axiographic and magnetic resonance imaging (MRI) examinations of the TMJ were analyzed in order to compare the opening/protrusion ratio of condylar translation between non-painful DDWR and non-DDWR. Result: According to the Mann-Whitney U test, the opening/protrusion ratio in non-painful DDWR differs significantly from non-DDWR (p < 0.0001). Discussion: Among non-painful DDWR, there is no additional condylar translation during opening in comparison with protrusion, and this is probably also the case for DDWR without limited opening, which is a subtype that has not been validated by the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Comparative condylar palpation can analyze this sign, and therefore, further comparative investigations between MRI and clinical examination are needed to validate the corresponding clinical test.

Focus on the occlusal failure

The success is evidenced by the longevity of aesthetic and functional therapeutic result. The occlusal «postorthodontic» 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).

Rapid orthodontic extrusion of a subgingivally fractured incisor

Figure 2. Extrusion after 1 week. A subgingivally fractured incisor presents a restorative challenge. Orthodontic eruption is a good alternative to crown lengthening for restoring the biological width, maintaining the alveolar bone, and restoring esthetics. The technique requires a hook to serve as the attachment system, fixed to the fractured tooth root, and an anchorage bar to allow movement of the root. The bar should not interfere with the occlusion, should be directly above the hook, and should ensure stabilization of the anchored teeth. The elastic provides the force. The forces must be vertically directed along the long axis of the tooth. With sufficient force, the periodontal fibers are ruptured. Therefore, tooth movement is rapid, and there is no movement of the periodontal tissues. The eruption described required 1 week.

The Good, the Bad, and the T.M.J.

The Temporo-Mandibular-Joint, or TMJ, is a complex anatomic structure with a specific function. It provides the mandible with a broad capacity to move while simultaneously assuring condylar stability no matter what the position of the mandible may be, maintaining throughout a visco-elastic potential for absorbing constraints. All of these qualities are in a large measure intimately related to the structure and the form of the articular disc and the union or cohesion between that disc and the condyle. The flexibility of the fibro-cartilaginous structure, the large surface area of the synovial membrane, and the great volume of investing fluid that characterize this joint embody it with its capacities of resilience, or reservoir of visco-elasticity for modeling and re-modeling and underline the importance of movement in its trophic exchanges.