LABIAL BOW.pptx orthodontics required for bds

Labial bow orthodontics slide share

1. labial bows

2. Labial bows are the active components of the removable orthodontic appliances. 1 Introduction They are used mainly for overjet reduction. It also act as an auxiliary aid for providing anterior retention Wide variety of labial bows are available for use in orthodontics Labial bows are used in both upper and lower arches

3. Basic design of Labial bow It consists of 3 parts , namely: 1. Horizontal bow portion 2. Vertical loops 3. Retentive Arms

4. Indications • Closure of spaces mesial to canines. • Minor overjet reduction. • A component of retention appliance. • Minor incisor alignment. • Incorporated with other springs for retention.

5. s Commonly used Labial bows Long labial bo w Soldered labial bow Mill’s retrator Rickett’s retention bow Split labial bow High labial bow with apron springs Reverse loop labial bow Short labial bow Robert’s retractor Fitted labial bow

6. SHORT LABIAL BOW Short labial bows are made from . 0.6 mm round stainless steel wire for retraction , 0.7mm for retention, 0.9-1mm for reinforcement. labial bow is constructed in such a way that the horizontal labial portion is adopted to the labial surface of anterior teeth and the bow contacts the labial surface of most prominent anterior teeth and extends from canine to canine. Horizontal arm ends in two vertical U shaped loops on either side. In retraction labial loop the anterior loop starts between the lateral incisor and canine. In retentive labial bow the anterior limb starts at the middle third of canine. The distal vertical arms of the U loop extend as retentive arm between the canine and first premolar before getting embedded in the acrlic base plate. The U loops should be formed 2mm past the gingival margins and should also be taken to keep it away from the frenal or muscle attachments. Care is taken to see that the labial bow remains at the junction of middle and incisal third of labial surface of anterior teeth if used for retraction. If used for retention, the labial bow should be adapted in the middle third.

7. DISADVANTAGES. Idowu Koyenikan Active part is very rigid. The range of action is minimum. Labial bow exerts high pressure over a small range. Buccal drift of canine happens sometimes. RETRACTION SHORT LABIAL BOW RETENTION SHORT LABIAL BOW

8. LONG LABIAL BOW Long labial bow is similar to that of short labial bow except it extends from one first premolar to opposite first premolar. Distal arm of U loop extends between two premolars and ends as the retentive arm in acrylic plate. It can be used as an active and retentive component of removable appliance. It can be used in active or passive mode. Active labial bow- used to close the minor anterior spaces, overjet reduction It is also used to close spaces distal to canine. It can be used as guidance wire during canine retraction using palatal retractor. Long labial bow also serves as a retainer after the end of fixed orthodontic treatment, particularly in first premolar extraction cases.

9. SHORT LABIAL BOW LONG LABIAL BOW

10. SPLIT LABIAL BOW There are two types, 1. Used for retraction of incisors 2.Used for closure of median diastema. Both types are made from 0.7mm or 21gauge stainless steel wire.

11. SPLIT LABIAL BOW USED FOR RETRACTION Split labial bow was designed by Bass and Robinson. One of the main drawbacks of labial bow is its rigidity. The flexibility of the labial bow can be increased by dividing the labial bow so that there are two buccal arms. This split labial bow is reasonably effective for retraction of incisors but care must be taken during adjustment to preserve the correct curve and not to flatten off the arch anteriorly. This is achieved by adjusting the bow at the ‘U’ loops, rather than at the horizontal arms. Rotations or minor individual tooth movements are difficult to control with a split bow.

12. SPLIT LABIAL BOW FOR MEDIAN DIASTEMA CLOSURE In this type, the free ends of the labial bow crossover each other. The arms should be parallel to each other. The free end of one bow crosses the opposite central incisors and is hooked on to the distal aspect of the central incisor. In the same way, opposite side bow is fabricated. Drawback of this is it is useful only for closure of median diastema and not effective in overjet correction. Activation is by closure of the loop by 1 mm.

13. REVERSE LABIAL BOW This is also called reverse loop labial bow and is made up of 0.7 mm of SS wire extending from one canine to other caine at the middle third of labial surfaces. As a longer span of wire is incorporated the bow exhibit increased flexibility. The activation of labial bow is done in two steps 1. The U loops is opened- This results in lowering of the labial bow in the incisal region. 2. A compensatory bend is the made at the base of the U loop to maintain proper level of the bow. In short reverse labial bow, the retentive arm is in between the canines and lateral incisor In case of long reverse labial bow, the retentive arm is in between two premolars. This design relatively increases the horizontal portion of the bow and as a result of a longer span of wire the bow exhibit increased flexibility.

14. FITTED LABIAL BOW The bow is adapted to the contours of the labial surface of individual teeth The labial bow is placed at the middle thirds The U Loop is usually smaller compared to conventional labial bows. This offers good retention of proclined upper incisors. A 0.7mm 21gauge stainless steel wire is used. Adjustments can be made for proper fit of the appliance. It cannot be used for any active movements They are used as retainer at the completion of fixed orthodontic therapy.

15. ROBERTS RETRACTOR It was designed by GH ROBERT. It is a flexible bow made of 0.5mm diameter or 23gauge stainless steel wire. It is used for retraction of 4 incisors and when the overjet is greater than 4mm. Roberts retractor consists of 2 sleeved canine retractors joined together forming an apron spring. The length of the bow should be long enough to be able to control the lateral incisor. The coil is placed at the point of the emergence of the wire from the sleeve and the size of the coil should be minimum of 3mm. A helix of about 3mm diameter is incorporated in a V shaped loop which tends to increase the wire length and flexibility. It is used in treating severe anterior proclination with overjet above 4mm and especially in adult patients and in peridontally compromised teeth where very light forces are required.

16. FITTED LABIAL BOW ROBERTS RETRACTOR

17. PARTS OF ROBERTS RETRACTOR 1.Horizontal bow portion 2.Vertical arm 3. Coil 4.Retentive arm reinforced with sleeve. HORIZONTAL BOW PORTION Adapted to the labial surface of incisors. Instead of a regular loop, it incorporates a 3mm internal diameter helix at the base of the loop mesial to the canine. VERTICAL ARM Anterior vertical arm extends distal to the lateral incisor and should be parallel to the root of canine. The distal vertical arm continues as retentive arm between canine and first premolar.

18. COIL Activation is done by closing the coil at the anterior vertical limb so that the horizontal portion is displaced palatally . DISADVANTAGES Not well tolerated by the patients and cannot be given in lower arch as the sulcus is shallow.

19. MILLS RETRACTOR Also termed as extended labial bow Made of 0.7mm or 21 gauge hard stainless steel wires It is an alternative for Robert's retractor It has got loops and these loops consist of horizontal and vertical compartment. USES:- 1.Reduction of large overjet 2.Alignment of irregular CI 3.Flexible because this incorporates extensive loops

20. DISADVANTAGES 1.less comfortable 2.complex design 3.More prone to distortion during use, therefore needs regular follow ups. If patient continously use distorted bow, abnormal forces may be generated

21. HIGH LABIALBOW WITH APRON SPRINGS It consist of a heavy stainless steel wire of 0.9mm thickness that extends into buccal vestibule relieved in the areas of labial and buccal frenum. Apron spring made of 0.4mm wire is attached to high labial bow and both ends are soldered to the wire. Apron spring can be designed for retraction of 1 or more teeth. This type of labial bow is highly flexible and thus used in cases of large overjet. As very light forces are generated they can be used in adult patients and periodontally involved teeth. Apron spring is the active component that is activated by bending it towards the teeth. As it is highly flexible activation of uptp 3mm at a time can be done. It approaches the tooth from gingival side. Its range of action is long and force decay is less.

22. DISADVANTAGES Construction is difficult Needs soldering May cause soft tissue injury

23. REFERENCE TEXTBOOK OF ORTHODONTICS- SRIDHAR PREMKUMAR ORTHODONTICS THE ART AND SCIENCE- S I BHALAJHI TEXTBOOK OF ORTHODONTICS- SANDEEP GOYAL TEXTBOOK OF ORTHODONTICS- S GOWRI SANKAR