Primary molars are a determining factor in the development of occlusion. Given their importance, when restorative treatment is not feasible and a primary molar must be extracted, the practitioner should keep in mind the risk of losing space, and the consequent malocclusion. Preservation of the space can eliminate or reduce the need for prolonged orthodontic treatment. For that reason, there are various kinds of space maintainers and the pediatric dentist must decide which one to utilize, on the basis of general and local factors related to the child. In the selection of a treatment option for space maintenance, the greatest complications occur when the first permanent molar has not yet erupted. A large variety of appliances have been devised to deal with this situation. This article proposes the use of a removable space maintainer that is open on one end and can be employed to guide the first permanent molar, maintaining the integrity of the mucous membrane and serving as a prosthetic appliance, preventing the complications and contraindications often caused by sub-gingival maintainers.
Convergence Towards the End Space for Random Walks on Schreier Graphs
