What is the primary effect of a lingual appliance on mandibular teeth?

The primary effect of a lingual appliance on mandibular teeth is tipping labially. When a lingual appliance is placed on the back (lingual) side of the teeth, it exerts forces that can lead to the labial tipping of the mandibular incisors. This happens because the appliance is designed to apply pressure to specific teeth to achieve desired movements, and in many cases, this often results in the anterior teeth moving toward the labial position.

While other effects may occur, such as those related to occlusal stability or aesthetics, they are secondary factors that may not be the primary focus of the appliance's design or functionality. For instance, although enhancing aesthetic appearance and facilitating better oral hygiene are considerations in orthodontic treatment, the immediate and most direct mechanical result of using a lingual appliance is the consistent tipping of the teeth in the direction of the applied force.