Do intraoral scanning technologies affect the trueness of dental arches with crowding, diastema, and edentulous spaces? A clinical perspective.

Objectives: To evaluate the trueness of dental arches digitised by two intraoral scanning (IOS) technologies from patients presenting crowding, diastema, and bilateral posterior edentulous space with tilted molar.

Methods: Conventional impressions and dental stone models were generated from three patients presenting the aforementioned dental arch conditions. These models were digitised on a desktop scanner, and the resulting mesh was used as reference.

Acceleration of conduction velocity linked to clustering of nodal components precedes myelination.

High-density accumulation of voltage-gated sodium (Nav) channels at nodes of Ranvier ensures rapid saltatory conduction along myelinated axons. To gain insight into mechanisms of node assembly in the CNS, we focused on early steps of nodal protein clustering. We show in hippocampal cultures that prenodes (i.

Axonal cell-adhesion molecule L1 in CNS myelination.

Of the axonal signals influencing myelination, adhesion molecules expressed at the axonal surface are strong candidates to mediate interactions between myelinating cells and axons. The recognition cell-adhesion molecule L1, a member of the immunoglobulin superfamily has been shown to play important roles in neuronal migration and survival, and in PNS myelination. We have investigated the role of axonally expressed L1 in CNS myelination.

Axonal signals in central nervous system myelination, demyelination and remyelination.

Axonal signals are key players in central nervous system myelination. During development, the onset of myelination depends on a balance between positive and negative axonal signals. Among negative signals are inhibitory adhesion molecules that need to be removed from the cell surface for the myelination process to proceed.

The transmembrane semaphorin Sema4D/CD100, an inhibitor of axonal growth, is expressed on oligodendrocytes and upregulated after CNS lesion.

Semaphorins are a family of secreted and membrane-bound proteins, known to regulate axonal pathfinding. Sema4D, also called CD100, was first isolated in the immune system where it is involved in B and T cell activation. We found that in the mouse, Sema4D is expressed in cells throughout the CNS white matter, with a peak during the myelination period.