Labial bow Functions , Constructions , Types & Indications.

It's a brief Presentation about Labial bows; used in orthodontic appliances.

1. Labial bow Presented by: M.R. Vatankhah Assistant professor: Dr. H. M.Sadeghi

2. What is a labial bow? A labial bow is the most notable component of a retainer so patients are very sensitive to the look and feel of it . Labial bows or the active component of the removable orthodontics appliances.  The principle function of the bow is to retrude the anterior teeth. Labial bow is an essential component of removable orthodontic appliances.

3. Functions It can be either passive OR active . It can also be used for retentive purposes . They exist in two groups: With U-loops & without U-loops.

4. Types Short labial bow Long labial bow Roberts retractor Reverse labial bow Begg’s labial bow Mills labial bow Fitted labial bow High labial bow with apron springs Split labial bow

5. Components The incisor segment. Vertical loops. The o cclusal or cross over section. The retentive ends. Vertical loop Retentive end

6. Placement of the incisor segment Active bow Passive bow (below the HOC) 0.6 or 0.7 mm 0.9 or 1 mm

7. Construction

8. Short labial bow 0.7 mm (A)

9. Fabrication of S.L.B. Labial segment of wire is placed at the J. of the incisal and middle third. Vertical segment starts from mesial third of canine , should be perpendicular to the incisor segment and should be away from gingiva . Occlusaly it passes between canine and premolar . Retentive ends adapted to the lingual or palatal side.

10. Activation Compressing the U-loop by 1mm.

11. Long labial bow 0.7 mm (A) 0.9 mm (P)

12. Fabrication & Activation of L.L.B. Same as short labial bow, BUT: Occlusaly it passes between two premolars . Also activated by compressing of the U-loop.

13. Retractors function; Canine retraction for example An example for retractor’s function; canine retractor

14. Roberts retractor 0.5 OR 0.6 mm Excellent retraction bow

15. Fabrication Labial segment of wire is placed at the J. of the incisal and middle third. Extends only two thirds of the MD width of the lateral incisors. A coil of 3mm internal diameter placed mesial to canine. Distal part is supported in a SS tubing.

16. Activation It is activated by closing the coil OR giving palatal bend at emergence of the coil.

17. Reverse labial bow 0.7 mm This is too stiff for effective incisor retraction ; and the stability ratio is poor .

18. Fabrication U-Loops are placed distal to the canine. The free ends of the U-loops are adapted occlusally between the premolar and canine.

19. Activation First the U-loop is opened this results in lowering of the labial bow in the incisor region . A compensatory bend is given at the base of the loop

20. Begg’s labial bow wrap around, around the globe bow 0.9 mm

21. Fabrication Consists of labial wire that extends till the last erupted molar. U-loop is incorporated at the premolar and molar area to close the band spaces. Advantage: because there is no cross-over wire between the canine and premolar, it eliminates the risk of space opening up .

22. Mill’s retractor extended labial bow 0.7 mm

23. In this labial bow: Extensive looping of the wire → Flexibility↑ & Range of action↑ Patient acceptance : poor Design: complex

24. Fitted labial bow 0.7 mm

25. High labial bow with apron spring 0.9 mm

26. T his labial bow: Is very similar to a Roberts retractor Highly flexible Light force

27. Fabrication A heavy base arch of 0.9 to 1mm wire extends into the buccal sulcus, with vertical arms incorporated and relived in the areas of labial frenum . Apron springs are the active components which are attached to the base arch by winding a few turns in horizontal arms. made of 0.4mm wire is attached to the high labial bow.

28. Activation Bending the upright arms of the apron spring towards the teeth. (3mm activation at a time) Disadvantages: Difficulty in construction & Tissue injury .

29. Split labial bow 0.7 mm

30. T his labial bow: Used for retraction; effective for incisors retraction. Used for median diastema closure; in this type, the free ends of labial bow meet each other. Not effective for overjet reduction Activation is same as short labial bow.

31. References Contemporary orthodontics, proffit’s 2013 JSS university official website & presentations. Alam , Mohammad Khursheed . "REMOVABLE APPLIANCE .“ Luther, Friedy , and Zararna Nelson-Moon.  Orthodontic retainers and removable appliances: Principles of design and use . John Wiley & Sons, 2012 . Indiandentalacademy.com http://www.dent-wiki.com/dental_technology/labial-bow/

32. Thanks for your attention Presented by: M.R. Vatankhah Assistant professor: Dr. H. M.Sadeghi