FACEMASK CHINCUP SEMINAR[1].pptx

Chincup and facemask biomechanics and application
class 3
reverse pool headgear

1. P R E S E N T E D B Y – Dr. J FACEMASK AND CHINCUP

2. INTRODUCTION HISTORICAL BACKGOUND FACEMASK AND ITS TYPES CHIN CUP CONCLUSION

3. Facial mask is effective in most developing Class III patients, because the appliance system affects virtually all areas contributing to Class III.

4. History A reverse pull head gear basically consists of a rigid extra-oral framework which takes anchorage from the chin or forehead or both for the anterior traction of the maxilla using extra-oral elastics which generate large amounts of force upto 1 kg or more . Although the facial mast was developed over 100 years ago. Hickham claims he was the first to use a reverse headgear. However, this modality was made popular by Delairc around the same time. This approach was used infrequently until reintroduced by Delaire in the late 1960s for the treatment of cleft patients. Interest in the facial mask in the United States later was stimulated by Petit through his studies conducted at Baylor University

5. Components of Orthopedic Facial Mask Therapy   The component of facial mask appliance 1) Facial Mask Chin cup Forehead cap Metal frame 2) Intra-oral appliance Bonded maxillary splint 3) Heavy elastic  

6. . Frontal view of the Petit facial mask. Note that the elastics converge on and attach to the crossbow immediately adjacent to the central support bar. The positions of the forehead & chin pads are adjustable The lateral view of the orthopedic facial mask. Note the downward direction of pull of the elastics. The direction of the pull can be adjusted by raising or lowering the crossbar, however, the elastics must not interfere with the functional of the lips.

7. Types of facemask Protraction head gear by ' Hickham Face mask of Delaire

8. Petit type of face mask

9. New Maxillary Protractor: Developed by Dr. Conte. This reverse headgear exerts a selective propulsive force on the maxilla with no deleterious effect on the T.M.J. Because the appliance has got only one point of resistance, (i.e. from the patient frontal bone). There wont be any compression force against the mandible. So it can be used in whom a retrusive mandibular force could be harmful to the joint. Indication: Appliance is comfortable to wear. In patient with Class III malocclusion with maxillary deficiency. Not suitable for patient with ideal maxilla and excessive mandibular growth

10. Indications:   1 . It can be used in a growing patient having a prognathic mandible and a retrusive axilla. It aids in pulling the maxillary structures forward and pushing the mandibular structures backward. 2. It can be used for bending the condylar neck for stimulating temporomandibular joint adaptations to posterior displacement of the chin. 3. It can also be used for selective rearrangement of the palatal shelves in cleft patients. 4. I can be used in correction of post-surgical relapse after osteotomies (or uncontrolled post-surgical adaptations). 5. It can be used to treat certain accessory problems associated with nose morphology such as lateral deviations.

11. Treatment Effects Produced by Facial Mask Therapy: Correction of CO-CR discrepancy. This correction is immediate and usually is observed in pseudo Class III patients. Maxillary skeletal protraction. Usually 1 – 3 mm of forward movement of the maxillary is observed. Forward movement of the maxillary dentition. Lingual tipping of the lower incisors. This tipping often occurs as a pre-existing anterior crossbite is being corrected. Backward rotation of the mandible is relation to the cranial base. In instances in which the patient begins treatment with a short or neutral lower anterior facial height, this change obviously is advantageous. In instances in which a patient has a long lower anterior facial height at the beginning of treatment, this treatment effect may be undesirable. Favorable changes in mandibular growth, at least over the short – term. Condylar growth in a forward direction can be associated with reduced increments in mandibular length.  

12. According to Proffit : Clinical Management of Facemask Treatment. Generally , it is better to defer maxillary protraction until the permanent first molars have erupted and can be incorporated into the anchorage unit. Following palatal expansion or in conjunction with it, a facemask that obtains anchorage from the forehead and chin (Fig.24) is used to exert a forward force on the maxilla via elastics that attach to a maxillary appliance. To resist tooth movement as much as possible, the maxillary teeth should be splinted together as a single unit. The maxillary appliance can be banded, bonded, or removable. A removable plastic splint that covers the occlusal surfaces of the teeth often is satisfactory. Multiple clasps combined with plastic that extends over the incisal edges usually provide adequate retention.

13. 12 Forward traction against the maxilla typically has three effects: (1) some forward movement of the maxilla, the amount depending to a large extent on the patients age; (2) forward movement of the maxillary teeth relative to the maxilla; and (3) downward and backward rotation of the mandible because of the reciprocal force placed against the chin.

14. T he orthope d i c fa c i a l m ask s y st e m component: has 3 b a s i c Facial mask, Bonded maxillary splint and Elastics.

15. The facial mask is an extraoral device It consists of 2 caps which contact the soft tissue in the forehead and chin regions.

16. The pads are made up of acrylic and are lined with a soft closed-cell foam that is non-absorbent, easily cleaned and replaceable. The pads are connected by a midline framework made from a round, contoured length of 0.25” stainless steel with nuts on each end.

17. T h e p o s i t i o n s o f t h e p a d s a r e a d j u s t a b l e t h r o u g h t h e loosening and tightening of a set screw. T h e m i d l i n e f r a m e w o r k a l s o ca n b e b e n t t o c o n f o r m better to the outline of the face of the individual patient.

18. In the center of the midline framework is a crossbar made from 0.075” stainless steel that is secured to the main framework by a set screw. It allows the position of the crossbar to be adjusted vertically. The ends of the crossbar are contoured for patient’s safety.

19. T h e s p l i n t i s a c t i v a t e d o nc e p e r d a y un t i l t h e d es ir e d increase in transverse width has been achieved. I n p a t i e n t s - n o i n c r e a s e i n t r a n s v e r s e d i m e n s i o n is desired - activated for 8-10 days To disrupt the maxillary sutural system To promote maxillary protraction.

20. the facial mask - full time basis for 4-6 months, and then it can be worn on a night-time only basis for an additional period of time. Maintaine oral hygine . Visite within 3-5 weeks .

21. The facial mask is secured to the face by stretching elastics from the hooks on the maxillary splint to the crossbow of the facial mask. Heavy forces are generated, usually through the use of a sequence of elastics, ultimately resulting in a 18oz force being generated by 5/16” elastics. Lighter forces may be used during the break-in period, but forces should be increased as the patient adjusts to the appliance

22. A t th e ti m e of th e deli v e r y - 3/8 ” - 8 oz e l as t i cs f i rst 2 weeks After 2 weeks - ½”. 14oz e. Maximum force i s d e li v ered thr o u gh the u se of 5 /1 6” elastics.

23. Developed in 1960 by Delaire Design was squarish and with rigid metal framework

24. o f c h i n c u p a n d Consists f o r e he a d vertical midline c a p w it h s i ng l e rod from r unn i n g in chin to forehead cap

25. Facial mask especially when combined with a maxillary anchorage unit can produce one or more of the following treatment effects: Correction of CO-CR discrepancy. This correction is immediate and usually observed in pseudo class 3 patients. Maxillary skeletal protraction. Usually 1-2mm of forward movement of the maxilla is observed.

26. Forward movement of the maxillary dentition. Lingual tipping of the lower incisors. This tipping often occurs as a pre-existing anterior crossbite is being corrected. Redirection of mandibular growth in a more vertical direction.

27. The ideal stage of dental development in which to begin facial mask therapy is at the time of eruption of the upper permanent central incisor. Usually ,the lower incisors have already erupted into the occlusion.

28. The achievement of a positive horizontal and vertical overlap of the incisors during treatment is essential in providing an environment that will help maintain the achieved anteroposterior correction of the original class III malocclusion. Optimally, the patient is instructed to wear the facial mask on a full-time basis except during meals.

29. Young patients (5-9yr old) usually can follow this regimen. In older pts, full-time wear may not be possible. Particularly if the patient is told the full-time wear will last only 4-6 months.

30. The facial mask should be discontinued immediately if the pt complains of any symptoms of temporomandibular disorders. Immediate discontinuance of the appliance usually results in a reversal of the symptomatology.

31. Demet Kaya, Ilken Kocadereli, Bahadir Kan, and Ferda Tasar studied the effects of facemask treatment anchored with miniplates after alternate rapid maxillary expansions in July 2011 (Angle Orthod.)

32. It is a relatively old orthopedic appliance. Introduced by Oppenheim.

33. This is not analogous to the use of extraoral force against the maxilla because there are no mandibular sutures to influence. Mandibular condyle - growth site Condylar growth is largely a response to translation as surrounding tissues grow,

34. There are two major ways to direct force against the mandible. Heavy force aimed directly at the condylar area, or lighter force aimed below the condyle to produce downward rotation of the mandible.

35. Diagrammatic representation of a typical response to chin cup therapy, showing the downward and backward rotation of the mandible accompanied by an increase in facial height.

36. W h e n e x t r a o r a l f o r c e i s a pp li e d a g a i n s t t h e c h i n , i t is difficult to avoid tipping the lower incisors lingually. I f t h e m a n d i b u l a r d e n t i t i o n w a s p r o t r u s i v e i n i t i a ll y , uprighting of the incisors is desirable

37. Chin cups are divided into 2 types: Occipital-pull chin cup (used in mandibular prognathism)

38. a b

39. a b

40. 2) Vertical-pull chin cup (used in cases of steep mandibular plane angle and excessive anterior facial height)

41. According to Samir E. Bishara  : Effect on Mandibular Growth . The orthopedic effects of a chin cup on the mandibular include (1) redirection of mandibular growth vertically , (2) backward repositioning (rotation) of the mandible , and (3) remodeling of the mandible with closure of gonial angle. To date, there is no agreement in the literature as to whether chin cup therapy may or may not inhibit the growth of the mandible . however , chin cup theryapy has been shown to produce a change in the mandible associated with a downward and backward rotation and a decrease in the angle of the mandible . In addition, there is less incremental increase in mandibular length together with posterior movement of B point and pogonion . Because of the backward mandibular rotation, control of the vertical growth during chin cup treatment is difficult to manage.

42. Effects of Maxillary Growth . Some studies have indicated that a chin cup appliance has no effect on the anteroposterior growth of the maxilla . However , Uner , Yuksel , and Uncuncu showed that early correction of an anteriro crossbite with a chin cup appliance prevents retardation of anteroposterior maxillary growth . Sugawara et al compared the growth changes of patients after chin cup treatment with control subjects and reported that , at age 17, the midface is more deficient in patients of the control groups than in those of the treatment groups

43. At the time of appliance delivery, the force level of 150- 300 grams per side is used initially. Over the next 2 months, the force level is increased to 450-700 grams per side (if the force is directed through the condyles and slightly less if force is directed below the condyle)

44. Patient is instructed to wear the chin cup 14hours per day with an acceptable range of wear being 10-16 hours per day. After correction of a preexisting anterior crossbite has been accomplished, the patient wears the appliance during the night only as a retention appliance.

45. Both the occipital and vertical pull chin cups create pressure on the temporo-mandibular joint region. If any signs and symptoms of TM disorders are noted, the use of the chin cup should be discontinued immediately.

46. Heavy intermittent force is less likely to produce damage to roots of teeth, probably because the stimulus for undermining resorption is diluted during the times that the heavy force is removed.

47. Force is a potent weapon in the hands of an orthodontist. How he makes use of that weapon determines the relative success or failure of the orthodontist.