📘 ❞ Orthodontic Removable Appliances ❝ كتاب ــ Sandhya Shyam Lohakare اصدار 2008

عن كتاب Orthodontic Removable Appliances:
Orthodontic
Removable Appliances
Sandhya Shyam Lohakare (Talmale) MDS (Orthodontia)
VSPM Dental College and Research Centre
Digdoh, Hingana
Nagpur, India
JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD
New Delhi . Ahmedabad . Bengaluru . Chennai . Hyderabad
Kochi . Kolkata . Lucknow . Mumbai . Nagpur

Preface
Orthodontics is one of the important clinical branches of dentistry. It starts from the prenatal stage and continues
throughout your life. It is the base of cosmetic dentistry.
Malaligned teeth give ugly look to the face and the smile does not feel heart warming. To correct these
crooked teeth, we are using some mechanical means in the oral cavity. They are called as removable appliances.
Because it is used by the patient, so it is considered as removable.
The other branches of dentistry deals with management of loss of vitality of teeth, enamel chip off, loss of
bone and periodontal tissue for good facial look while smiling. But in orthodontics we are conserving the
whole structure with redirection of tooth of new perfect position.
Removable appliances are the major culprit for preventive, and interceptive and corrective orthodontics.
These appliances are simple to manage, economic and time saver, i.e. there is less time involvement of an
orthodontist.
This book includes all retentive parts, active parts, technique of wire bending, biomechanical considerations,
modification for different malalignments.
I sincerely hope that this book will prove useful for students and practitioners.

Contents
1. History and Review of Literature.................................................................................................................... 1
2. Orthodontic Appliances....................................................................................................................................... 4
3. Biomechanics .......................................................................................................................................................... 7
4. Components of Removable Appliances ....................................................................................................... 11
5. Active Appliances ............................................................................................................................................... 16
6. Passive Appliances ............................................................................................................................................. 49
7. Retentive Component of Appliances ............................................................................................................ 55
8. Plate Construction and Finishing................................................................................................................... 63
9. Practical Management ........................................................................................................................................ 65
Summary ................................................................................................................................................................. 67
Bibliography ............................................................................................................................................................. 69


24. Active components • Springs – Provide extra length of wire to increase range of action and resiliency – Extra length can be provided in the form of coil (s), loop (s) or change configuration to provide extra length of the wire
25. Active component • Wire springs – Spring design • Recommended wire is St. St. round wire (0.5mm) in diameter • The design must ensure adequate springiness and range while keeping acceptable strength • The spring must be guided so that its action is exerted only in the appropriate direction by: – Place the spring in an undercut of the tooth so that it does not slip occlusally during activation – Use a guide to hold the spring in its position during activation – Bond an attachment to the tooth surface to engage the spring
26. Active component • Short labial arch – Constructed from 0.030 inch (0.7 OR 0.8) round St. St. wire – It must contact the middle 1/3 of the labial surface of the teeth 21|12 – Loops should be ½ width of the canine, should extend slightly above the gingival margin – Wire must be closely adapted where it cross the occlusal surface – Palatal retentive arms must be adapted to the contour of the palate.
27. Retentive components • Clasps – Adam’s clasp – C-clasp (Circumferential clasp) – Lingual extension clasp – Ball clasp
28. Adam’s Clasp • The most useful clasp in removable appliances. • It is designed to engage the MB, DB undercuts of posterior teeth. • Advantage, it does not separate teeth and has excellent retention.
29. Fabrication of Adam’s Clasp • Components of Adam’s Clasp • 1- Arrow heads • 2- Bridge • 3- Tags • 4- Retentive parts • It is made of 0.7 mm diameter hard St. St. round wire
30. Adam’s Clasp • Design modifications Long bridge One arrow head Solder a HG tube to the bridge Solder hook to he bridge
31. Adjustment of Adam’s clasp
32. Retentive component • Circumferential clasp – Useful for second molars and canines – Easier to keep it out from occlusal contact – It is only supportive, not as retentive as Adam’s clasp – It can be adequate for a retainer, but not for an active appliance
33. Retentive component • Ball Clasp – – – – It like Adam, extends across the embrasure Uses buccal undercuts for retention Easy to fabricate It is stiff that could not be extended deep into the undercuts
34. Retentive component • Lingual Extension Clasp – It works only from the lingual aspect without crossing the occlusal surface or embrasures – Short loop of (0.4 mm) wire – Can be placed in the first molar second premolar lingual embrasure – Difficult to adjust – Break easily – May cause tissue irritation – Can separate teeth if active – Can be used for retainers, – not for active appliance
35. Acrylic base plate • It is used as a vehicle to carry all Removable Appliance components together. • It is the Anchor tool for tooth movement. • Use self-curing acrylic resin. • Steps in construction (see handouts).
36. Adjunct to fixed orthodontic appliances • Bite plane The horizontal shelf-like part of a bite plate, on which the teeth touch. Bite planes also can be used in a fixed design (i.e. bonded to the teeth, or attached to a palatal arch).
37. To prevent or treat abnormal orofunctional habits Crib An interceptive appliance used for correction of deleterious habits such as a deviating tongue position and/or digit-sucking. A crib consists of a transpalatal [0.036-inch (0.9-mm) or heavier gauge] wire. For removable appliance, the wire is embedded in acrylic base plate supported via retentive means (clasps) or soldered on two maxillary first permanent molar bands (for the fixed appliance). The wire extends toward the anterior palate where it forms a crib-shaped "fence" meant to interfere with the habit. Posterior (lateral) tongue cribs can be used as part of removable appliances in patients with unilateral or bilateral posterior open bite.
38. Space maintainers • To replace prematurely lost deciduous teeth
39. To retain the obtained tooth movement, either by removable or fixed orthodontic appliances
40. Clinical Adjustment • Maxillary removable appliances are more tolerable and successful than the mandibular ones. Because the maxillary removable appliance can provide more stability as the baseplate fits better than lower removable appliances. • During the treatment the adjustments can be performed as follow: • 1- Tightening of clasps as they become loose • 2- Activation of the spring/screws /bows • 3- Trimming of the baseplate (as required)
41. Combined functional and active plate treatment • Growth guidance can be combined with active tooth movement by adding springs or screws with three problems:• Active tooth movement is not the goal of functional appliance therapy. • Long-term stability of arch expansion is questionable VS improving Class II open-bite or deep-bite treatment success. • Two point contact is difficult to be attained using removable appliance for tooth movement.
42. Advantages of Removable Appliance: • More acceptable to the patient ( can be removed on socially sensitive occasions). - They are fabricated in the lab rather than directly in the patient’s mouth, reducing the dentist’s chair time. - Allow some types of growth guidance treatment to be carried out more readily than is possible with fixed appliances.