4- A brief history & overview of treatment mechanics 2.pptx

This presentation is very important to dentist to treat, malocclusion!

1. A brief history & overview of treatment mechanics presented by:Dr.basina Hashimi

2. fundamentals Orthodontic treatment mechanics are determined by 4 elements Bracket selection Bracket positioning Arch wire selection Force level

3. The work of Andrew Father of preadjusted bracket system Original straight-wire appliance Based on science He measured 120 non-orthodontic normal cases No special anchorage control measures Bracket positioning was based on the center of the clinical crown

4. Continue… Various arch form were used Difficulties encountered due to heavy force and increased tip in anterior brackets Consequently deepening of anterior bite, with creation of lateral open bite

5. Continue… He recommended wide range of brackets He recommended the bellow chart in his treatment

6. The work of Roth Roth recommended a single appliance system He also use center of clinical crown for bracket positioning Roth had use wider arch form for canine tip

7. The work of McLaughlin, Bennet & Trevisi Their treatment mechanics recommendations included Accurate bracket positioning Lacebacks and bendbacks Light archwire forces Sliding mechanics on .19 x .025 steel rectangular wire With light .014 finishing wire

8. Overview of the MBT treatment philosophy The following elements make up the MBT treatment philosophy Bracket selection Versatility of the bracket system Accuracy of bracket positioning Light continuous force The .022 versus .018 slot Anchorage control early in treatment

9. Continue… Group movement The use of three arch form One size of rectangular steel wire Archwire hook Methods of archwire ligations Awareness of tooth size discrepancies Persistence in finishing

10. Bracket selection Brackets are the heart of the high quality treatment A range of brackets are available Standard metal Mid-sized brackets Clear brackets

11. Continue…. The exact bracket specifications are important The orthodontist time is more valuabel These bracket system can save the chair time in finishing stage

12. Versatility of the bracket system The system full name is “ MBT versatile +

13. Accuracy of bracket positioning Every effort should be made to ensure accuracy Its part of the technique to reposition if necessary as treatment progresses Gauge and bracket-positioning charts are recommended

14. Light continuous forces The authors believe this is the most effective way to move teeth Being comfortable to the patient Minimizing the threat to anchorage Light force is important at the start of treatment upon antero-posterior(A/P) anchorage

15. Continue…. Its not possible to exactly quantify the term “light force” Traditionally force in range bellow 200 gm were referred to as light force and above 600 gm to heavy Essentially there is need for orthodontist to use thin, flexible wires in opening stages

16. Continue… Avoid too frequent archwire changes Recognize the sign of excess force Tissue blanching Patient discomfort Unwanted tooth movements

17. Continue… Later in treatment during sliding mechanics light continuous force are applied using active tie backs with rigid .019/.025 steel working wire In the finishing stages .014 steel .016 HANT wires

18. The .022 versus .018 slot The MBT system seems to perform best in the .022 form , cause The larger slot allows more freedom of movement for the starting wire Helps to keep force light

19. Continue… Later in treatment the steel rectangular working wire .019/.025 perform well , cause This wire do not shows deflection and bending But .018 are more flexible and shows bending and deflection

20. Anchorage control early in treatment The main threat to anchorage in the opening stages of treatment comes from anterior bracket tip (A/P control) The changes in tip (reduced tip) and light force results in reduced anchorage needs The following methods helps in anchorage needs in opening stages ( till working wire stage )

21. Continue… Lacebacks This assist control of canine crowns in premolar extraction cases, and in some non-extraction cases. This allows space for anterior crowded teeth This allow to retrocline the anterior , not to procline

22. Continue… Benbacks This help to prevent mesial movement of the anterior teeth, which is undesirable in most cases, Class II/1 Note: Bendbacks and lacebacks are normally continued throughout tooth leveling and aligning until the rectangular steel wire stage

23. Group movement Where possible teeth are managed in groups (consolidation) Canines are retracted with lacebacks until crowded teeth are aligned As a group of six or eight

24. The use of three arch forms The tapered Has the narrowest intercanine width and is obviously indicated for patient with narrow arch form The square arch form This is indicated in cases with broad arch form and cases that require expansion of the molar region

25. Continue… Currently , the recommended technique is to create an individualized form for all patient based on tapperd, ovoid and square

26. One size of rectangular steel wire Only one size of rectangular steel wire is used in normal treatment There is approximately 10o slop between the .019 x .025 wire and .022 slot

27. Archwire hooks The SS wire had normally an archwire hook The average hook positions are 36 – 38 mm in upper arch 26 mm in lower

28. Methods of archwire ligation In opening stage the author favor elastomeric modules But, where the wire is not completely seated in the bracket slot , its beneficial to fully tie

29. Awareness of tooth size discrepencies For upper lateral (build up) For lower incisors ( enamel slicing)

30. Persistence in finishing In finishing cases light wire and archwire bends are frequently required Time should be use in finishing and settling using technique Bracket repositioning Using of settling elastics Building up of discrepancies in tooth size

31. Thank you