Recent advances in diagnostic aids /certified fixed orthodontic courses by Indian dental academy


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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit ,or call

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Recent advances in diagnostic aids /certified fixed orthodontic courses by Indian dental academy

  1. 1. RECENT ADVANCES IN DIAGNOSTIC AIDS INDIAN DENTAL ACADEMY Leader in continuing dental education
  2. 2. • Sure smile (computer assisted diagnosis and treatment) • EMG • Finite element modeling and analysis
  3. 3. Sure smile Computer assisted diagnosis and treatment
  4. 4. Clinical procedure • Oroscanner
  5. 5.
  6. 6. • The image is reference independent, meaning the image capturing process is not affected by movement of patient or scanner. • Scanner is placed in mobile care smile cart and that rolls from chair to chair.
  7. 7.
  8. 8. • A full oral scan is taken and integrated with the conventional; photographs and x rays and entered into the electronic patients record.
  9. 9. • Once the process is complete the teeth can be moved in 3 dimensions with the software controls.
  10. 10. • 3D viewing of the model like frontal, lateral, posterior or occlussal views or different perspective using navigation tools.
  11. 11. • The teeth can also be viewed as individual arches.
  12. 12. • The operator can diagnose and plan the treatment with tools to measure tooth and arc dimensions and symmetric and asymmetric arc forms.
  13. 13. • A 3D coronal cross section like a 3D cat scan is also available for evaluation of 3rd order relationships.
  14. 14. • The clinicians plans treatment based on the parameters such as midline, occlussal plane and arc dimensions, multiple plans are stimulated for comparison.
  15. 15. Target occlusion
  16. 16. • The operator can manipulate by moving the teeth with mouse or selected menus. • You can extract or reduce the teeth mesially or distally to simulate interproximal disking.
  17. 17. • The changes in x, y and z co-ordinates can be done in individual case to show case difficulty and treatment changes. • Inter arch contacts and relations ,such as over bite and over jet ,can be viewed with a cutting plane tool ,which displays interproximal or an transverse view anywhere along the arch.
  18. 18.
  19. 19. • After the target occlusion the digital bracket placement system and geometric calculation of the wires and forces exerted and their impact on teeth can be assessed. • The operator can based on the forces and amount of tooth movement required can decide the optimum treatment plan.
  20. 20.
  21. 21. • Any errors in bracket positioning and arch wire selection can be detected and changed during any phase of the treatment.
  22. 22. Advantages • Reduce errors in treatment planning and appliance management. • Reduce undesirable toot movements ,bracket placement errors, errors in wire selection, bending and adhesive thickness are all reduced.
  23. 23. Advantages • It provides image capturing, 3D visualization of the tools from diagnosis, monitoring and patient communication, along with precision appliances that can help the orthodontist deliver truly customized treatment in a patient centered practice.
  24. 24. Accuracy of the system • Oro Scanner • Digital Bracket Placement • Wire Bending
  25. 25. Electromyography
  26. 26. • Electromyography is defined as the recording and study of the intrinsic skeletal muscle by means of surface or needle electrodes . • Electromyography is the instrument used. • The structural basis of EMG is the motor unit.
  27. 27. Motor Unit Potential • During each twitch of the muscle fibre, a minute electrical potential is generated, which is dissipated into the surrounding tissues. • The duration may be there for 2 –3 millisecond or 4 millisecond.
  28. 28. • Majority of the motor unit potential have an amplitude of around 5mv. • Einthoven first discovered a muscle contraction gives a idiomuscular current.This is referred to as an action potential.the current is so small that it has to be amplified several hundred times. • Using electromyography one can get a relatively accurate picture of the muscle activity under diverse functional conditions.
  29. 29. Technique • Two types of electrodes are mainly used – • Surface electrodes ( skin) • Needle electrodes
  30. 30. Needle electrode • Superior to surface electrodes and produce better Electromyograms. • Lesser technical artifacts • Distance between muscle and electrode is constant • May cause infection and is painful
  31. 31. Surface electrodes • non invasive and reduced risk of infection • Possibility of loosening of electrodes while nerve stimulation. • Errors in variation between distance of muscle an electrodes.
  32. 32. • Important guideline for adequate needle insertion is to observe and palpate the scale while test maneuver is done. • It is important to test the insertion by asking the patient to contract the muscle being tested. • If the needle is correctly placed this maneuver should produce correct and crisp action potential.
  33. 33.
  34. 34. Drawbacks • Impossible to know how much activity of the muscle being missed. • Movement cannot be inferred from electromyography alone, because antagonistic muscles may be working synergistically to produce movement or provide stabilization.
  35. 35. Electromyography in orthodontics. • Muscles of importance ( figure )
  36. 36. EMG activity in class II div 1 • Graber points out – class I -normal muscle activity (except open bite ) class II div 1 – abnormal muscle activity class II div 2 – compensatory muscle activity.
  37. 37. Pancherz study • Class II div I patients . • Recordings were made in patients in maximal biting in centric occlusion during chewing.
  38. 38. Results • Using maximal biting class II exhibited less EMG activity in the masseter and temporalis than controls • During chewing class II showed less muscle activity in EMG than in controls in masseter • For temporal muscles no differences were found • The impaired muscle activity fond in class II cases may be attributed to Diverging dentofacial morphology and unstable occlussal conditions.
  39. 39. • Moyers investigated EMG in children in class II div I and concluded that there was dysplasia in function in the temporal muscle in habitual occlusion and at rest. • He asserted this as an etiologic factor for post normal occlusion.
  40. 40. Functional appliances • James Mcnamara (jr) studied change in muscle activity in functional appliance treatment. • During first few hours after functional treatment – no change • Distinct change after first few weeks.
  41. 41. • Decrease in activity of the posterior-temporalis • Increase in activity if the masseter muscle and the lateral pterygoid muscle. • As the experiments progressed the pterygoid response decreased and the gradual return to pre treatment levels occurred.
  42. 42. • Lacouture et al ( AJO DO 1997) • Three types of appliances – Herbst, twin block and the Frankel. • To test the lateral pterygoid hypotheses.
  43. 43. • Ingervall and Thuer ( AJO DO 1991) • Muscle activity during first year of treatment during activator therapy • No decrease in degree of activity of the posterior temporal muscle.
  44. 44. Class III subjects • Deguchi and Iwaara (Angle Orthod 1998) • It is believed that there is decrease in co-ordination between the masseter and temporalis muscles in treatment of open bite. • The integrated activity of the masseter and the temporal muscle activity in class III less than normal occlusion subjects
  45. 45. Electromyographic activity during swallowing • Winders et al (Angle Orthod) buccal and lingual musculature do not contract during swallowing unless there is an anterior open bite and anterior skeletal dysplasia.
  46. 46. Electromyographic activity during swallowing In tongue thrust habit there is increase in genioglossus activity and hypertrophy of the tongue muscles (EMG activity increases during hypertrophy).
  47. 47. Effect from pain in orthodontic treatment on EMG activity • Goldreich et al (AJO DO 1994) Reduction ion muscle activity Ngan et al (Ang Orthod 1997 )
  48. 48. Lip and cheek activity in sucking habits • Ahlgeren et al 1997 • Increase in mentalis activity • Buccinator muscle was less evident.
  49. 49. Cleft lip and palate patients Li et al (Cleft Palate Craniofac 1998 ) In unilateral ceft lip an palate activity - a higher activation levels of temporalis and masseter in rest position - Lower potential function of masseter in temporalis and masseter - In harmonious activity of the muscles during movements
  50. 50. Finite element modeling
  51. 51. • Originated from advances in aircraft structural analysis. • Clough in 1960 first coined the term finite. • Zienkewic and Chung published the first book in 1967.
  52. 52. Definition • Technique of discrediting a continuum into simple geometric shapes elements enforcing material properties and governing relationships on these elements giving due consideration to loading and boundary conditions which results in set of equations ,the solution which gives approximate behavior of the continuum.
  53. 53. Applications • Stress and vibration analysis Ex – automobile,aircraft,aerospace • Field analysis • Ex – heat flux, fluid flux, seepage etc
  54. 54. Role of computers • With the advances in computer technology and CAD system complex problems can be modeled with relative ease. • Alternative configurations can be tried/analyzed on the computer before the first prototype is built. Ex – design and development of the first Boeing 747 aircraft.
  55. 55. Advantages • Model irregularly shaped bodies easily • Handle general load conditions without difficulty • Model bodies composed of several different materials because the element equations are evaluated individually. • Handle united numbers and kind of boundary conditions .
  56. 56. • Vary the sizes of elements to make it use small elements wherever necessary • Induce dynamic efforts • Handle non collinear behavior existing with large deformations and non linear materials.
  57. 57. Computer programs • • • • • • Algor Ansys Cosmos/m Stardyne Images 3D Sap 90
  58. 58. Finite element analysis software • • • • There are three basic componentsPreprocessor ( step 1 ) Processors ( step 2 to 4 ) Post processor ( step 5 )
  59. 59. Methods of finite element generation • • • • • • Single node and element generation. Digitizing input Pattern generation Duplication Region generation Dragging generation
  60. 60. Applications in Orthodontics
  61. 61. • Finite element model of apical force distribution from orthodontic tooth movement David et al (Angle Orthodontist 2001)
  62. 62. • 3 D finite element analysis orthodontic forces in periodontal tissue Lu et al (Angle orthodontist 1999)
  63. 63. • 3 D finite element analysis of mandible and tmj during distraction osteogenesis Kofod et al (j craniofac surg 2005)
  64. 64. • Anchorage effects of palatal osteointegrated mini implants Chen et al (Angle Orthodontist 2005)
  65. 65. • Used for appliance selection and analysis of orthodontic mechanics • To determine the center of resistance and center of rotation • To evaluate canine retraction by sliding mechanics
  66. 66. Thank you For more details please visit