To achieve reverse tipping of a tooth, the moment of force (Mf) must be:

To achieve reverse tipping of a tooth, it is necessary for the moment of force (Mf) to be less than the moment of resistance (Mc). In orthodontics, tipping refers to the movement of a tooth around its center of resistance. Reverse tipping specifically involves tilting the crown of the tooth in a direction opposite to the direction of the applied force.

When the moment of force is less than the moment of resistance, the tooth will move in the desired direction without tipping too far. This is crucial because an unbalanced moment would lead to excessive tipping, which can result in undesirable tooth movements or damages to the surrounding periodontal structures. Therefore, maintaining a lower Mf in relation to Mc ensures controlled and precise tooth movement, facilitating effective treatment outcomes.

In summary, achieving reverse tipping is effectively governed by ensuring that the moment of force is appropriately less than the moment of resistance, which allows for the desired tooth movement without unwanted effects.