Diagnostic considerations for Class II treatment with TADs Shingo Kuroda, DDS, PhD / Tokushima, Japan Establishment of proper anchorage must be one of the most important keys to achieve successful results in treating Class II patients. In this decade, emergence of temporary anchorage devices (TADs) has completely changed the treatment strategy, providing sufficient 1, 2 anchorage without patient compliance. In this lecture, I would like to introduce effective usage of TADs in Class II treatment and discuss the diagnostic considerations. Usage of TADs in Class II patients can be classified into two categories. One is the alternative use of traditional anchorage devices for extraction cases. By utilizing TADs, patients 3 could get better results without uncomfortable extraoral appliances. Furthermore, we can choose the extraction site according to the condition of the tooth, not to the strength of the anchorage unit. Another one, use of TADs makes it possible to distalize the maxillary dentition simply, and expands application of non-extraction treatment. Even with the interradicular screws, the 4 maxillary molars could be distalized by 3 mm on average. Interestingly, the mandibular plane angle was not increased during the distalization. Moreover, our recent study demonstrated newly bone formation on the maxillary sinus induced by mechanical stress, suggests the maxillary 5 distal tooth movement might be a safe procedure in the view of bone physiology. On the other hand, not all the Class II patients could be treated without extraction. It might be closely related with the discrepancies between the tooth materials and jaw bones, especially in the mandible. Not only the sagittal but also the vertical discrepancies could be improved with TADs. Patients with severe gummy smile have been treated with an orthognathic surgery because 6 absolute incisor intrusion was considered difficult. Meanwhile, the recent development of TADs 7 makes it considerably possible to intrude the incisors without any undesirable counteractions. The most evolutionary change in Class II treatment with TADs must be the treatment of anterior openbite. 8-10 Absolute molar intrusions and the succeeding mandibular counter-clockwise rotation are quite effective to increase reduced overbite. As a result, the patients could be treated without surgery even though they have a negative overbite of less than -5 mm. Conclusively, TADs enhance the quality of Class II treatment with simple mechanics. References 1. Kuroda S et al. Root proximity is a major factor for screw failure in orthodontic anchorage. Am J Orthod Dentofacial Orthop. 2007;131(4 Suppl):S68-73. 2. Kuroda S et al. Clinical use of miniscrew implants as orthodontic anchorage: success rates and postoperative discomfort. Am J Orthod Dentofacial Orthop. 2007;131(1):9-15. 3. Kuroda S et al. Class II malocclusion treated with miniscrew anchorage: comparison with traditional orthodontic mechanics outcomes. Am J Orthod Dentofacial Orthop. 2009;135(3):302-9. 4. Yamada K, Kuroda S et al. Distal movement of maxillary molars using miniscrew anchorage in the buccal interradicular region. Angle Orthod. 2009;79(1):78-84. 5. Kuroda S et al. Mechanical stress induces bone formation in the maxillary sinus in a short-term mouse model. Clin Oral Investig. 2013;17:131-7. 6. Kuroda S et al. Severe Class II malocclusion with facial asymmetry treated with intraoral vertico-sagittal ramus osteotomy and LeFort I osteotomy. Am J Orthod Dentofacial Orthop. 2009;135(6):809-19. 7. Ishihara Y, Kuroda S et al. Deep overbite correction with intrusion of the mandibular incisors using miniscrew anchorage. Am J Orthod Dentofacial Orthop, 2013, in press. 8. Kuroda S et al. Treatment of severe anterior open bite with skeletal anchorage in adults: comparison with orthognathic surgery outcomes. Am J Orthod Dentofacial Orthop. 2007;132(5):599-605. 9. Kuroda S et al. Anterior open bite with temporomandibular disorder treated with titanium screw anchorage: evaluation of morphological and functional improvement. Am J Orthod Dentofacial Orthop. 2007;131(4):550-60. 10. Kuroda S et al. Severe anterior open-bite case treated using titanium screw anchorage. Angle Orthod. 2004 ;74(4):558-67.