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steiner's analysis and wit's appraisal-1.pptx
- 1. STEINER’S ANALYSIS AND WITS APPRAISAL ASHITHA J Final Year Part -1 200020808 1
- 2. CONTENTS ■ Introduction ■ Steiner’s analysis - skeletal analysis - dental analysis - soft tissue analysis ■ Drawbacks of Steiner's analysis ■ Wits appraisal ■ Drawbacks of wits appraisal ■ Conclusion ■ Reference 2
- 3. INTRODUCTION ■ Cephalometrics was introduced in 1934 by Hofrath in Germany and Broadbent in the United States. ■ The term cephalometrics is used to describe analysis and measurements made on the cephalometrics radiographs. ■ Used as a clinical tool for the study of malocclusion and underlying skeletal disproportions. ■ Previously unsuspected anomalies in the cervical spine or degenerative changes in the vertebrae are also revealed in a cepahlometric radiograph. 3
- 4. STEINER’S ANALYSIS ■ Developed and promoted by Cecil Steiner in the 1950s. ■ Considered the first of the modern cephalometrics analysis. ■ Reference plane in Steiner’s analysis is sella nasion plane. ■ Colour coding used in Steiner’s analysis - red : maxillary teeth green: mandibular teeth brown: all those parameter related to mandible black: all the other lines ■ It includes skeletal analysis, dental analysis and soft tissue analysis. 4
- 5. Skeletal analysis ■ Keeping the S-N plane as reference the anteropsterior apical base relationship of maxillary and mandible to each other and to the anterior cranial base can be determined. ■ MAXILLA - SNA angle Mean SNA reading is (82±2 ) degree. ± 5
- 6. ■ Mandible - SNB angle Mean angular reading is (80±2) degree. ■ Relationship of maxilla to mandible - ANB angle Mean angular reading is 2 degree. Skeletal analysis (Contd.) 6
- 7. Skeletal analysis (Contd.) ■ Occlusal plane angle Mean angular reading is 14 degree. ■ Mandibular plane angle Denotes growth pattern of an individual. Mean value is 32 degree. 7
- 8. Dental analysis ■ Maxillary incisor position Upper incisor to N-A : linear - 4 mm angular - 22 degree ■ Mandibular incisor position Lower incisor to N-B : linear - 4 mm angular - 25 degree ■ Interincisal angle Mean value is 132 degree. 8
- 9. Soft tissue analysis ■ Steiner’s S line 9
- 10. DRAWBACKS OF STEINER’S ANALYSIS ■ ANB angle is affected by rotation of jaws and length of the cranial base. ■ Clockwise rotation of jaws - increased ANB angulation. ■ Counterclockwise rotation of jaws - decreased ANB angulation. ■ Short cranial base results in backward position of nasion in relation to jaws - increased ANB angulation. ■ Long cranial base forward position of nasion - decreased ANB angulation. ■ ANB angle is also affected by the vertical height of the face. ■ As vertical height increases distance between nasion, point A and B increase thus ANB angulation decreases. 10
- 11. WITS APPRAISAL ■ Alexander Jacobson found that measurements from the cranial base are inconsistent in estimating anteropsterior jaw relation. ■ He developed Wits analysis to overcome the drawbacks of Steiner’s analysis. ■ It was developed in University of Witwatersrand. ■ It was developed primarily to study the interrelationship of maxilla and mandible anteropsteriorly. 11
- 12. WITS APPRAISAL (Contd.) Landmarks used in Wits analysis ■ Functional occlusal plane ■ AO point ■ BO point 12
- 13. DRAWBACKS OF WITS APPRAISAL ■ Wits analysis is influenced by the dentition both horizontally and vertically. ■ Horizontally dependent upon the inclination of occlusal plane. ■ Clockwise rotation of occlusal plane positions AO behind BO. Counterclockwise rotation of occlusal plane positions BO behind AO. ■ Vertically influenced by the vertical position of the incisors. ■ This approach fails to distinguish skeletal discrepancies from problems caused by displacement of the dentition and it does not specify which jaw is at default if there is a skeletal problem. 13
- 14. CONCLUSION ■ In Steiner’s analysis, • skeletal component tries to relate upper and lower jaw to skull and to each other. • dental component tries to relate upper and lower incisors to each other and to their respective jaws. • soft tissue component tries to understand the lower facial profile • the most common measurement used is ANB angle which is dependent upon rotation of jaws and length of cranial base. ■ In Wits appraisal, • this method is used to overcome the limitations of ANB as an indicator of jaw discrepancy • the main landmark used is the functional occlusal plane but the measurements are highly dependent upon the inclination of occlusal plane. • therefore Wits appraisal of jaws should be combined with other methods to judge the anteroposterior relationship. 14
- 15. REFERENCE ■ Contemporary Orthodontics - 5th edition - William. R. Proffit. ■ Textbook of Orthodontics - 2nd edition - S. Gowri Shankar. ■ Orthodontics Prep Manual for Undergraduates 3rd edition - Sridhar Premkumar. ■ Orthodontics the Art and Science - 5th edition - S. I. Bhalajhi 15