1. STUDY MODELBASING AND TRIMMING PRESENTED BY SUSNA SARAH PAUL DEPT. OF ORTHODONTICS

2. CONTENTS INTRODUCTIONSTUDY MODELSBASINGTRIMMING OF MAXILLARY CASTTRIMMING OF MANDIBULAR CASTCONCLUSION 3. Orthodontic diagnosis deals with recognition of the various characteristics of the malocclusion. Diagnostic aids fall into two categories -Essential Diagnostic Records -Supplemental Diagnostic Records 4. ESSENTIAL DIAGNOSTIC AIDSSUPPLEMENTAL DIAGNOSTIC AIDS1)CASE HISTORY.1)SPECIALIZED RADIOGRAPHS2)CLINICAL EXAMINATION.2)ELECTROMYOGRAPHY.3)STUDY MODELS.3)HAND-WRIST RADIOGRAPHS.4)RADIOGRAPHS4)ENDOCRINE TESTS.5)FACIAL PHOTOGRAPHS.5)BMR ESTIMATION.6)OCCLUSOGRAMS. 5. According to Proffit, these records fall into three categories:I. Teeth and oral structures II.Evaluation of facial proportion III.Occlusal evaluation 6. STUDY MODELS Orthodontic study models are essential diagnostic records, which are accurate plaster reproductions of the teeth and their supporting soft tissues and which help to study the occlusion and dentition from all the three dimensions. 7. Purpose of Making Study Models 1) Valuable in planning treatment as threedimensional records of patients dentition. 2) Occlusion can be visualized from all aspects. 3) Provide a permanent record at the start of therapy.. 4)nature and severity of the malocclusion. 5)explain the treatment plan and progress.. 6)transfer records. 8. Steps in construction of study models. 1.Impression making. 2.Taking a wax bite. 3.Disinfection of the impression. 4.Casting the impression. 5.Basing and trimming. 6.Finishing and polishing. 7.Care of the study models. 9. BASING 10. RUBBER MOULD BASE FORMERS 11. TRIMMING OF MODELS 12. Template or degree plate 13. Squaring tool and angle guide (Tsquare) 14. TRIMMING OF MAXILLA 15. TRIMMING OF MANDIBLE 16. 13 mmANATOMICAL PORTIONARTISTIC PORTION3:1 17. 60mm70mm55mm 18. CONCLUSION Models accurately reproduce the teeth and their surrounding soft tissues. Models are to be trimmed so that they are symmetrical and pleasing to the eye. Models are to be trimmed so that they meet the measurements and angles as proposed for trimming them. Models are to have a clean, smooth, bubble free surfaces with sharp angles where the cuts meet.