A 10 year old male patient complains of a gap between his upper front teeth. Intra-oral examination reveals a midline diastema of 2 mm, for which a removable appliance with finger springs was given. What type of anchorage is seen with this appliance?

A small but unesthetic diastema (2 mm or less) can be closed in the early mixed dentition by tipping the central incisors together. A maxillary removable appliance with clasps, fingersprings, and possibly an anterior bow will successfully complete this type of treatment. Reciprocal anchorage: Reciprocal tooth movement is produced when two teeth or resistance units of equal size pull against each other, as in this example of the reciprocal closure of a maxillary midline diastema. Simple anchorage: Resistance of the anchorage unit to tipping. Closure of a midline diastema can be accomplished with a removable appliance and fingersprings to tip the teeth mesially. Intramaxillary anchorage: When the anchor units and the reactive units are in the same arch.