E h angle

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1. E H ANGLE LAHAN.TP ROLL NO-69 PART 1

2. INTRODUCTION Edward H. Angle (1855-1930) is considered the’ Father of Modern Orthodontics' for his numerous contributions to this speciality . Through his leadership, orthodontics was separated from other branches of dentistry to establish itself as a speciality Angle believed that the whole complement of teeth could be retained and yet good occlusion could be achieved. He thus advocated arch expansion for most patients Angle's contributions include :- classification of malocclusion orthodontic appliances such as Pin and tube and the Edgewise appliance. Angle also started a School of Orthodontics at St. Louis, New London

3. ANGLES SYSTEM OF CLASSIFICATION Edward Angle introduced a system of classifying malocclusion in the year 1899. Angle's classification is still in use after almost 100 years of its introduction due to its simplicity in application. Angle's classification was based on the mesio -distal relation of the teeth, dental arches and the jaws. According to Angle, the maxillary first permanent molar is the key to occlusion ANGLES CLASS I Angle's Class I malocclusion is characterized by the presence of a normal inter-arch molar relation. The mesio -buccal cusp of the maxillary first permanent molar occludes in the buccal groove of mandibular first permanent molar ANGLES CLASS II This group is characterized by a Class II molar relation where the disto -buccal cusp of the upper first permanent molar occludes in the buccal groove of the lower first permanent molar . Angle has sub-classified Class II malocclusions into two divisions

4. A.ANGLES CLASS II,DIVISION I The Class II, division I malocclusion is characterized by proclined upper incisors with a resultant increase in overjet . A deep incisor overbite can occur in the anterior region. A characteristic feature of this malocclusion is the presence of abnormal muscle activity B.ANGLES CLASS II,DIVISION II As in Class II, division I malocclusion, the division2 also exhibits a Class II molar relationship. The classic feature of this malocclusion is the presence of lingually inclined upper central incisors and labially tipped upper lateral incisors overlapping the central incisors. Variations of this form are lingually inclined central and lateral incisors with the canines labially tipped. The patient exhibits a deep anterior overbite. C.ANGLES CLASS II,SUBDIVISION when a Class II molar relation exists on one side and a Class I relation on the other, it is referred to as Class II, subdivision. Based on whether it is a division1 or division 2 it can be called Class II, division 1,subdivision or Class II, division 2, subdivision

5. ANGLES CLASS III This malocclusion exhibits a Class II molar relation with the mesio -buccal cusp of the maxillary first permanent molar occluding in the interdental space between the mandibular first and second molars (fig17.D 826). Class Ill malocclusion can be classified into true Class III and pseudo Class III A.TRUE CLASS III This is a skeletal Class III maloclusion of genetic origin that can occur due to the following causes: A. Excessively large mandible B. Forwardly placed mandible C. Smaller than normal maxilla D. Retropositioned maxilla E. Combination of the above causes The lower incisors tend to be lingually inclined. The patient can present with a normal overjet, an edge to edge incisor relation or an anterior Crossbite

6. B.PSEUDO CLASS III This type of malocclusion is produced by a forward movement of the mandible during jaw closure ,thus it is also called 'postural' or 'habitual' Class III malocclusion. The following are some of the causes of pseudo Class III malocclusion: A. Presence of occlusal prematurity may detiect the mandible forward. B. In case of premature loss of deciduous posteriors ,the child tends to move the mandible forward to establish contact in the anterior region. C. A child with enlarged adenoids C.CLASS III,SUBDIVISION This is a condition characterized by a Class III molar relation on one side and a Class I relation on the other side .

7. DRAWBACK OF ANGLES CLASSIFICATION Although Angle's classification has been used for almost a hundred years now, it still has a number of drawbacks that include: A. Angle considered malocclusion only in the antero-posterior plane. He did not consider malocclusions in the transverse and vertical planes. B. Angle considered the first permanent molars as fixed points in the skull. But this is not found to be so C. The classification cannot be applied if the first permanent molars are extracted or missing D. The classification cannot be applied to the deciduous dentition. E. The classification does not differentiate between skeletal and dental malocclusions. F. The classification does not highlight the etiology of the malocclusion. G. Individual tooth malpositions have not been considered by Angle.

8. ANGLES APPLIANCE E-ARCH APPLIANCE H. Angle introduced the E Arch or the expansion arch in the late 1800's (fig 28.A). The appliance used bands on the molars with an expansion arch threaded to the buccal aspect of the molar bands PIN AND TUBE APPLIANCE In 1912, Edward H. Angle introduced the pin and tube appliance (fig 28.B). The appliance consisted of bands with a vertical tube placed on all teeth. The arch wire carried soldered pins that inserted into the vertical tubes. Tooth movement was achieved by altering the placement of these pins RIBBON ARCH APPLIANCE In 1925, Edward H. Angle introduced the ribbon arch appliance (fig 28.C). This was the first appliance to use a true bracket having a vertical slot facing occlusally. Angle used gold arch wires and lock pins with this technique. The ribbon arch technique enabled rotation control as well as bucco -lingual and inciso -gingival tooth movement. However mesio -distal tipping movements were considered difficult with this technique

9. EDGEWISE APPLIANCE Angle's last contribution to orthodontics was the introduction of the edgewise technique in 1928. He devised a metal bracket having a rectangular slot The slot received a rectangular arch wire of 0.022" x 0.028"dimension. The wire is inserted into the bracket with the narrow dimension placed occluso -gingivally. This mode of insertion of the wire is called edgewise and therefore the technique was called edgewise technique. The unique feature of having a rectangular arch wire in a rectangular slot enabled control of tooth movement in all the three planes of space ADVANTAGES- 1. Ability to move teeth in all three planes of space 2. Good control over the tooth movement 3. Bodily tooth movement is possible. 4. Precise finishing is possible DISADVANTAGE- 1.The need to apply heavy forces. 2. The need for complex wire bending 3. Increased friction between the arch wire and the bracket. 4. The need for extraoral forces for anchorage. 5. Difficulty to open deep bites.

10. ANGLES SCHOOL OF ORTHODONTICS Angles also started a school of orthodontics at st. Louis, new landon established in 1899.the school taught its students orthodontics over a period of 3-6 weeks. 183 students graduated until it closed in 1927. some of the notable students are Cecil c.Steiner , Charles A.Hawley , Charles H.Tweed , Frank E.Shelden , Copeland Shelden etc …

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