Wits apprasial /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 www.indiandentalacademy.com ,or call
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Wits apprasial /certified fixed orthodontic courses by Indian dental academy

  1. 1. WITS APPRAISAL INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. Influence of occlusal plane inclination on ANB & Wits assessments of anteroposterior jaw relationships www.indiandentalacademy.com
  3. 3. Introduction  Angular measurements are geometrically sensitive & can give false results.  ANB angle is used to determine the anteroposterior maxillomandibular relationships.  It varies with the extension & inclination of cranial base.  Routinely, ANB angle & Wits appraisal are the most common cephalometric tool for assessing AP jaw discrepancies. www.indiandentalacademy.com
  4. 4.  ANB & Wits are related to vertical features.  There is influence of the occlusal plane angle & facial height on the ANB assessment. www.indiandentalacademy.com
  5. 5. Aim  The primary purpose of this study were to verify whether ANB & Wits assessments show consistent results in patients with high & low occlusal plane angles & to determine whether specific cranial base features have an important geometric influence in the assessment. www.indiandentalacademy.com
  6. 6. Materials & Methods  The sample consisted of 122 patients, 44 males & 78 females.  Their mean age at the initial records was 13.5 (+/- 5.3 yrs).  The sample included the following types of malocclusions  29 Class I  82 Class II div 1  7 Class II div 2  4 Class III www.indiandentalacademy.com
  7. 7. Criteria for selection of cases  The samples were selected based on consecutive chronological orthodontic patients started from 1995 to 2003, who were treated & had standardized initial & final records taken ( cephalo –lateral radiographs).  Patients with cranio-facial deformities were rejected. www.indiandentalacademy.com
  8. 8.     All patients received treatment from the same orthodontist. Patients were treated by straight wire fixed appliance, 0.018” slot brackets & molar bands. Headgears and lip bumpers were used when appropriate. Pretreatment (T1) & pretreatment (T2) lateral cephalograms were taken from the same cepahalostat. www.indiandentalacademy.com
  9. 9.  Orthodontic treatment was performed a) Without extraction in 99 patients. b) With maxillary & mandibular extraction in 11 patients. c) With maxillary premolar extractions in 10 patients. d) With mandibular premolar extractions in 2 patients. www.indiandentalacademy.com
  10. 10.  Cephalometric landmarks were identified and traced on acetate paper by the orthodontist.  All landmarks were digitized & all measurements were computed by usind DFPlus software. www.indiandentalacademy.com
  11. 11. Landmarks  Basion, Sella, Nasion, ANS, Point-A, Point-B, Gonion, Gnathion, Menton  The occlusal plane was formed by the half-distance point between the incisal edges of the maxillary incisors & the mesial cuspid tips of the mandibular bilateral first molars. www.indiandentalacademy.com
  12. 12. Cephalometric landmarks www.indiandentalacademy.com
  13. 13. Measurements  a. b. c. d. e. f. g. h. i. j. The following measurements were computed S-N NSB ANB Wits S-Go N-me SNOP Y-axis AP proportion Anterior proportion www.indiandentalacademy.com
  14. 14.  To calculate for systemic & random errors, a sub-sample of 5 randomly selected radiographs was retraced & redigitzed.  Systematic errors was not statistically not significant.  Random method errors, ranged from 0.5mm for S-Go to 1.0mm for Wits & from 0.3° for Y-axis to 1.2° for NSBa. www.indiandentalacademy.com
  15. 15. Cephalometric measurements Wits appraisal www.indiandentalacademy.com
  16. 16. Statistical method  All data were computed with SPSS software.  Paired t-test were performed to evaluate treatment changes.  Pearson product moment correction coefficients were calculated between T1 & T2 variables.  Based on the descriptive statistics of the total sample, 2 occlusal plane angle groups were constituted. www.indiandentalacademy.com
  17. 17.  The median of 15.3° for SNOP angle divided the patients into high & low occlusal plane.  The median of 73mm for the S-N distance divided the patients into short and long anterior cranial base sub groups.  The median of 123.4° for NSBa angle divided the patients into small & large cranial base angle subgroups. www.indiandentalacademy.com
  18. 18. High occlusal plane angle www.indiandentalacademy.com Normal occlusal plane
  19. 19. Short www.indiandentalacademy.com anterior cranial base Normal anterior cranial base
  20. 20. Results Variable n Mean T1 SD Mean T2 SD Mean diff SD P S-N 122 72.4 3.8 74.0 3.8 1.6 2.2 .01 SNBa 122 123.5 5.1 123.3 5.3 -0.2 2.3 .26 ANB 122 3.8 2.5 2.8 2.3 -1.1 1.8 .01 Wits 122 2.1 4.1 1.3 2.9 -0.8 2.7 .01 S-Go 122 73.9 6.8 79.2 5.9 5.3 5.0 .01 N-Me 122 118.5 8.4 124.2 7.8 5.8 6.2 .01 SNOP 122 14.9 4.2 14.1 4.0 -0.8 3.2 .01 Y-axis 122 85.0 3.8 85.4 3.8 0.4 1.7 .01 AP proportion 122 0.62 0.04 0.63 0.04 0.01 0.02 .01 Ant proportion 122 0.43 0.02 0.43 0.02 0.01 0.02 .30 Descriptive statistics for all patients at T1 & T2 are shown. Paired t test showed Significant differences for variables, except SNBa & anterior www.indiandentalacademy.com proportion
  21. 21.  There was a significant Pearson product moment correlation between ANB & Wits for T1 & T2 data.  The lowest were found between ANB & Wits when comparing T1 & T2. Variable ANB T1 Wits T1 ANB T2 Wits T2 ANB T1 - - - - Wits T1 0.76 - - - ANB T2 0.72 - - - Wits T2 0.65 0.74 0.71 - www.indiandentalacademy.com
  22. 22. Sub group Variable n Difference P Short anterior cranial base ANB T1 & ANB T2 38 1.1 .01 Wits T1 & Wits T2 38 0.1 .95 ANB T1 & ANB T2 21 1.4 .01 Wits T1 & Wits T2 21 0.3 .64 ANB T1 & ANB T2 36 1.3 .01 Wits T1 & Wits T2 36 -0.2 .72 ANB T1 & ANB T2 23 1.1 .01 Wits T1 & Wits T2 23 0.6 .41 Long anterior cranial base Small cranial base angle Large cranial base angle Paired t test between ANB & Wits (T1 & T2) for high occlusal plane angle group www.indiandentalacademy.com
  23. 23. Sub group Variable n Difference P Short anterior cranial base ANB T1 & ANB T2 29 0.9 .05 Wits T1 & Wits T2 29 1.1 .07 ANB T1 & ANB T2 34 0.9 .01 Wits T1 & Wits T2 34 1.6 .01 ANB T1 & ANB T2 28 0.5 .23 Wits T1 & Wits T2 28 0.6 .31 ANB T1 & ANB T2 35 1.3 .01 Wits T1 & Wits T2 35 2.0 .01 Long anterior cranial base Small cranial base angle Large cranial base angle Paired t test between ANB & Wits (T1 & T2) for low occlusal plane angle group www.indiandentalacademy.com
  24. 24.  Paired t tests were applied between T1 & T2 data for ANB & Wits assessment in the high occlusal plane angle & low occlusal plane angle.  In the high occlusal plane angle group, the statistically significant differences between T1 & T2 by ANB assessment were not seen in the Wits assessment foe all groups .  In the low occlusal plane angle group, the statistically significant difference between T1 & T2 shown by ANB assessment were confirmed by the Wits assessment for the long anterior cranial base & large cranial base angle group. www.indiandentalacademy.com
  25. 25. A statistically significant difference was practically confirmed by ANB & Wits assessment for short anterior cranial base but not confirmed by both assessments for the cranial base angle group . www.indiandentalacademy.com
  26. 26. Discussion  The most common doubts of the clinical orthodontist revolve around 2 major questions  Does the patient have a skeletal malocclusion?  If so, to what degree?  Although ANB & wits are cephalometric tools widely applied to evaluate AP relationship, there is a significant lack of certainty.  Consequently, there is an intensive search for new & better cephalometric & noncephalometric diagnostic resource to assess jaw discrepancies. www.indiandentalacademy.com
  27. 27.  This research is needed because vital orthodontic decisions depend on correct assessments.  Literature provide new formulas to assess skeletal discrepancies, but further research is required on traditional measurements, such as ANB & Wits is still necessary.  The normal range of ANB angle is 2°+/- 3°.  The wits distance should be 0mm in females & -1mm in males with skeletal class I relationship. www.indiandentalacademy.com
  28. 28.  Geometric effects causes the occlusal plane angle to modulate the ANB & Wits assessments.  This study attempted to identify agreement or disagreement between ANB & Wits assessments in high & low occlusal plane angle groups, controlling for anterior cranial base size & cranial base angulation subgroups.  The general view of treatment effects shows growth effects on the anterior cranial base but no significant change in the cranial base angle. www.indiandentalacademy.com
  29. 29.  ANB & Wits significantly decreased with treatment because 3/4th of the patients had class II malocclusion at T1, orthodontic mechanics were intended to decrease the initial ANB angle.  Vertical growth occurs in posterior & anterior facial heights, however, the AP proportion is increased.  ANB & Wits assesses the same problem but have fair correlations.  These results show at least 1 assessment has a weakness per se. www.indiandentalacademy.com
  30. 30.  There was clearly a lack of consistency between them in the high occlusal plane angle group.  It is suggested that, in high occlusal plane angle group, ANB might have overestimated AP positioning of the jaws or Wits have underestimated AP positioning of the jaws.  In contrast, in the low occlusal group the statistically significant difference between T1 & T2 of the ANB assessment were confirmed by wits assessment for the long anterior cranial base subgroup & large cranial base angle subgroup. www.indiandentalacademy.com
  31. 31. Conclusion  ANB & Wits have important drawbacks although they are routinely used in clinical orthodontics.  Our results show a tendency for lack of consistency between ANB & Wits assessment in high occlusal plane angle patients & a lack of certainty in at least one measurement.  In the low occlusal plane angle patients, both assessments were consistent. www.indiandentalacademy.com
  32. 32. Reference  Longitudinal changes in the ANB & Wits appraisal : clinical implications –(AJODO 93 Aug) Samir E. Bishara, Julie A. Fahl, Larry C. Peterson.  This study suggests that the ANB angle changes significantly with age , while Wits appraisal indicates that the relationship between points A B does not change significantly with age.  Correlation coefficients shoed that the ANB angle & Wits appraisal are significantly correlated. www.indiandentalacademy.com
  33. 33.  Relation of Wits appraisal to ANB angle Järvinen AJODO 1988 Nov (432 - 435):  In this study the hypothesis was that the relationship between the ANB angle and the Wits appraisal could be declared by measuring individual variations in their reference systems and by constructing a model of regression between them and the parameters describing the reference systems. www.indiandentalacademy.com
  34. 34. Thank you www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com

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