10General treatment of dentofacial deformities Treatment principles1. Correction standard :individual normal occlusion2. Treatment according to the mechanism of malformation Remove the causing
11Treatment principles 4. In line with the growth and development of the law 5. In line with the patients own body's physiological characteristics 6. Appliance design should be simple and practical
12The key to the treatment of crowding is gaining space. How to effectively meet the individual physiological characteristics and keep stable of gained space is the basis for successful treatment.
134 The method of gaining space 1 expansion of the dental arch width1. orthopaedic expansionBranch-type base frame and two forms. To open the palate raphe extended mainly to expand 0.5mm/ day, the cheek teeth to tilt less mobile. Adults need assisted rapid palatal expansion for zygomatic alveolar ridge cortical incision, reducing the resistance to expansion.
17Dental arch expansion ： 1.0mm of Palatal expansion can get 0.7mm spacerelapse rate: 10% - 30%
182. Orthodontic expansion Dental arch expansion Appliance-use activities in the spring or split spring fixed to the expansion of the expansion. Mainly to the buccal tooth inclination mobile. The general availability of gap mm. The application of the tongue by the teeth of the arch to the tilt caused by stenosis.
24Each side can get 4.0mm.As to rely on the activities of the mobile appliance on the crownAnd face-bow to the root of the combined mobile.
25Face-bow to the root is the key to mobile-line traction to the teeth against the center is located at the top, traction generally about 150g, traction time was hours one day. Force of Oral appliance on the crown is about 30 g, required to wear all day.
27lip bumper ：The main role is to use the force of lip vertical mandibular molar (Upright) and molar re-gap (due to early loss of deciduous teeth); to stop the forces of muscular buccal premolar arch area to expand.
283 Reducing circumference treatment ： （1）. IndicationsAdult patients; For the bell-shaped central incisors; Mild anterior crowding; People with little or no dental caries
29（2) treatment Reduce the diameter of the teeth 0 （2) treatment Reduce the diameter of the teeth mm on each side can be reduced Attention to the restoration of the original contact pointRestoration of surface finish Not suitable for patients with a higher rate of caries
30(3) procedures Aligned teeth to normal relations (3) procedures Aligned teeth to normal relations. Determine the number, and the order is from back to front. Separate the contact points. Fine curved nose drilling, fluoride.
314 Extraction : The factors of extraction to consider: The space requirements of Correction The adjustment of the dental arch midline Crowding of the site
32The principle of extraction The first premolar is the first choice Generally, incisors and canines do not consider to extractTeeth extracted should be closed to the crowding site
33Permanent teeth germ should be chceked in Mixed dentition extraction Symmetry extraction
345 The principle of correction of crowding Mild crowding: Mild crowding can be treated by expanding the arch or molar distalization. In the mixed dentition, the leeway space can be used to disarm the crowded dentition.
35Moderately crowded: Non-extraction treatment should be possibly considered in the growing season, like molar distalization. The direction of the face-bow is according to mandibular plane angle and height of 1 / 3 surface
36Moderate crowding: Extraction orthodontic treatment may be considered in the non-growth season. The space obtained by extraction is mainly used to ease the crowded dentition, and the remaining space will enable the posterior teeth to move to mesial. Anchorage control should also be paid attention in the treatment of moderately crowding, especially in maxillary.
37Severe crowding: Extraction treatment should be considered in growing and non-growing season in general. The space obtained by extraction is used to lifting the crowding. Anchorage control is the critical point in severe crowding treatment. Loss of anchorage will lead the failure of treatment.
38Anchorage controlled manner: 1 Anchorage controlled manner: 1. Against the tooth movement by the bending such as tip-back bending . 2. Reducing the friction： such as the single point ligation 3. To increase the number of anchorage teeth： 7 band . 4. Using the opposite jaw to provide anchorage; using II, III type traction. 5. Extraoral anchorage; Top, Pillow, neck. 6. Implant Anchorage
39小结 crowding teeth greater bone smaller Reducing tooth Increasing bone volume massExtraction Expand Reducing diameter Distractionosteogenesis
40Comprehensive space analysis 1 severity of crowding2 protrusion of anteriors3 curve of spee4 mesial drift of anchorage molar5 maxillofacial skeletal patterns6 facial profile7 growth status