Extra-oral forces and appliances

1. 1 Extra Extra- -oral forces oral forces And And Appliances Appliances Prepared by: Prepared by: Dr. Mohammed Alruby Dr. Mohammed Alruby Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

2. 2 Definition Philosophy History and development Classification of extra-oral forces Advantages of extra-oral forces Disadvantages of extra-oral forces Uses of extra-oral forces Headgear Appliance enhanced the action of headgear Protraction appliances Types of reversed headgear Chin cup appliance Orthopedic correction of class III Orthopedic correction of open bite Orthopedic correction of class II Retention after orthopedic correction Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

3. 3 Definition It is a force derived from an extra-oral appliance that uses the forehead, the top of the head or the back of the neck as anchorage to apply forces to the dental or basal arch. It may be orthodontic force or orthopedic force to move the dentition, or restrict or redirect the growth respectively. Philosophy: The philosophy beyond the use of extra-oral force is based upon the old concept that, (the application of appreciable amount of force against the growing bone con modify or alter the direction of bone growth and consequently alter the shape and position of the bone = the well-known best examples are the induced skull deformation in Colombia –India and feet deformation in Chinese girls History and development: Appliances resembling chin cups have been in use since the early 1800's. According to Graber, the early attempts with the chin cup were not successful because of incomplete knowledge of mandibular and facial growth, its use on non-growing patients, and an inadequate understanding of the forces generated by the chin cup. 1802: Cellier and Josef Fox in 1803, utilized chin caps in combination with bite blocks to correct the “underslung chin” 1866: Norman Kingsley introduced extra-oral head cap anchorage or force for maxillary distal movement 1880: Kingsley described an appliance that could influence the position of the dentition in upper jaw with the aid of extra-oral forces 1887: E.H.Angle recommended the use of occipital bandage in treatment of maxillary protrusion 1904: Jackson was first describing the facial mask 1892: headgear appliance was originally designed by Kingsley 1920: Angle and his followers were convinced that class II and class III elastics not only moved teeth but cause a significant skeletal changes: stimulate growth of one and restrain growth for the other so we not need to use any extra-oral force just wait until permanent dentition is completed 1923: Case recommend the use of extra-oral force against maxilla in treatment of class II and class I maxillary protrusion 1947: Kleohn, presented his treatment results with cervical neck strap, subsequent to this report, many other variation of the headgear appliance were presented 1960: Delaire facemask Classification of extra-oral force appliances according to uses The extra-oral pull is generally applied bilaterally, for three main purposes: (1) as a restraining force (2) as a retracting force (3) as a supplementary force. A. Dentofacial orthopedic appliances - Correction of class 3 mal-relation: Facemask - Chin cap - Correction of class 2 mal-relation: Headgear - Cervical gear - Correction of openbite: Chin cap - Correction of deep overbite: Headgear Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

4. 4 B. Orthodontic appliances: - Distalization of maxillary molar: Face bow - mesialization of maxillary molar: Facemask - Retraction of maxillary incisors: Headgear with J-hooks C. Anchorage: Face bow --------------------------------------------------------------------------------------------------------------------- Advantages of extra-oral forces: 1-Minimum anchorage 2-Ability to adjust force level 3-Control tipping and bodily movement 4-Assist correction of transverse defect 5-Allow vertical changes in cases of open bite or deep bite Disadvantages: 1-Need more patient compliance 2-Slower tooth movement 3-Delayed eruption of maxillary 2nd molars Uses of extra-oral forces: Depending on the magnitude of force applied, extra-oral appliance may be used for: 1-Reinforcement of intra-oral anchorage to prevent forward migration of maxillary posterior teeth (100gm/side) 2-Producing dentoalveolar changes, if the magnitude of force increased at least 250gm / side, the force can produce distalization of molars or retraction of incisors 3-If the force is sufficiently increased above 500gm / side, they will act to re-direct the growth of maxilla and midface producing bony changes to correct basal arch relationship and to improve the facial esthetics In summary: the extra-oral force can be used in: a-Anchorage re-enforcement in class I, II, III cases b-Enmass movement of the dental arches: distalization of buccal segment and retraction of incisors particularly in non-extraction cases when the space deficiency not more than 3mm / side c-Inhibition or redirection of maxillary growth d-Inhibition or redirection of mandibular growth N: B: Duterloo, define orthopedic effect in orthodontics as: Change in the position of bones in the skull in relation to each other induced by therapy According to Isaacson, orthopedic appliance provides a new muscular and functional environment for the facial bones that encourages growth changes of either the mandible or maxilla Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

5. 5 Types of Extra-oral appliances 1-Head gears Headgear is an extraoral appliance that uses the head for anchorage and it attached to either the anterior or posterior area of the arch The typical headgear appliance is consisted of: head cap, and face bow = J hooks a-Head cap: The simplest head gear is an elastic neck strap (cervical headgear), they are available commercially and can be adjusted to apply a range of force They utilize the cervical region of the neck to anchor the applied force Head cap utilize other sources of anchorage as: occipital (oblique) or parietal (vertical) bone Head caps constructed in a variety of ways and are available commercially in fibric or plastic tapes. Headgear are classified according to the direction of pull into: 1-Cervical headgear: It was first introduced by Klochn in 1947, it also called cervical or neck strap or straight pull headgear An elastic band used with cervical pad passed around the neck and attached to hooks at the ends of outer bow, it utilizes cervical region of the neck as an anchorage. The main disadvantages of this type are: -When used with removable appliance, the direction of force is move downward so tend to displace the appliance -Because the direction of force is more downward it causes extrusion of molars and thus open the bite, so it should not use in cases of open bite and should be avoided in removable appliances However, it exerts more retracting force and achieve good results 2-Oblique pull headgear: An occipital elastic band with pad passed superior and posterior to the crown of the head and attached to hooks at the level of outer bow, or the head cap hooks attached to the hooks at the ends of outer bow by rubber elastic bands. It utilizes the occipital region as an anchorage 3-Vertical or high pull headgear: Utilize the parietal bone as an anchorage. The headgear is classified according to its use and site of attachment intra-orally into: face bow or J hooks b-Face bow: = Used to anchor the movement or to produce distal movement of maxillary molars and attached to buccal tubes soldered on the molar bands = Composed of outer bow which attached to the elastic band around the patient head or neck and carry the inner bow which attached to the teeth = the outer bow is made of rigid stst wire 1.5mm (0.051 inch) diameter and has two hooks for attachment of elastics, while the inner bow is made of rigid stst wire 1,25mm (0.045inch) diameter = the inner bow fits into the extraoral buccal tube 0.045 diameter soldered to molar bands or on the bridge of Adams Crip in removable appliances = in order to stop the inner bow on the front of molar tubes on of the two adjustment can be made: Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

6. 6 1-U loop: U vertical loops which have the advantage of being able to shorten or lengthen the inner bow, because of the inner bow should not touch the maxillary incisors, if this occurs excessive force will apply upon these teeth so that, the U shape vertical loop are opened as the maxillary molars move distally 2-Bayonet bend: This design has the advantage of stop in addition of correction of rotated molars In some occasions, the clinician may want to produce unilateral force or to increase the force in one side than the other side because of facial a symmetry, in such cases it is necessary to cut the outer bow shorter in this side J – hooks: J hooks headgear used for retraction of incisors, applying backward force against the maxilla and are attached to receptor hooks soldered to the short labial arch in removable appliances and to the base arch between the lateral incisors and canine in fixed appliances. Adjustment of face bow: 1-Adapt and cement molar bands with 0.045 tubes 2-Adjust the inner bow to approximate width of the dental arch, it should be 1-2mm wider 3-Mark the midpoint on the outer and inner bows which should be coincide with the midline 4-The inner bow is placed in the buccal tubes so that: It should pass passively The anterior segment of the bow should be about ¼ inch (7.5mm) away from incisors Mark mesial to the molar tubes on both sides 5-Remove and make the stop which may be: a-Vertical U loop shape which has the advantage to control the length of inner bow, as molar moving distally b-Bayonet bends which has the advantage to correct molar rotation 6-Adjust the arms of the outer bow: a-Length: to control the applied force – if you want to apply more force on one side as in cases of facial a symmetry, you have to cut the arm on this side shorter or to control the applied force by elastics b-Vertical position relative to the occlusal plane (straight up or down) to control the moment of maxilla and the position of 1st molars, this differ according to the requirement of forces direction for each patient 7-Select the design and size (small- medium, large) of the head cap according to the size of patient’ s head and direction of pull (cervical, oblique, vertical) 8-Select the suitable size of elastics which give the desired force 9-Place the face bow and the head cap or vertical, attach the elastics and check for the applied force and correct appliance placement 10-Instruct the patient for: -Appliance insertion and removal -Proper use and care of appliance -Duration of use (12-16 hour /day) usually all the night and few hours in day 11-Follow up: -Every 3 weeks or as required check the following: Molar band, lose or not Adjust the face bow as it easy deformed during sleep Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

7. 7 Check the desired amount of force, if elastics are worn, replace it with new one -Check the patient cooperation: Check the face bow elastics Check the mesio-distal position of molars and compare with original cast, if one molar is moved distally than the other, adjust the force which may be heavier at that side. Check the mobility of the molars If no progress: -The patient may not wear the appliance -Low force magnitude -Presence of interfering factors as unerupted second molar N: B: = Buccally the inner bow is away from the arch from the arch by 3 – 4mm for all points of teeth = The inner bow extended 1mm posterior to the tube to prevent tissue irritation = The inner and outer bow should adjust comfortably between the lips = The outer bow should rest several millimeters from the soft tissue of cheek, this adjustment checked before and after the straps of head attached ** adjustment of neck strap: -Neck strap is attached to the face bow and proper force is obtained from the spring mechanism by moving the hook to adjacent holes on the neck strap -When the force is correct, the plastic connector is cut so that one extra-oral holes is present in the front of corrected hole -Use calibration mark Proffit et al: Headgear wear for 10 -12 hours / day to control growth Wear headgear during night and until morning because increasing the growth hormone Force level: 350 – 400gm / side. = it is difficult to analyze exactly where the center of resistance and center of rotation of maxilla, but generally it is above the teeth and most likely above the premolars teeth. = when the direction of the force passes closer to the center of resistance lead to upward direction of pull Factors affect selection of headgear 1-Headgear anchorage location: Must be chosen to provide preferred component. High pull: superior and distal force of teeth and maxilla Cervical pull: inferior and distal force on teeth and skeletal structure Straight pull: combination of above two. 2-How headgear is attached: a-Face bow to tube on maxillary 1st molars b-Removable splint c-Functional appliance Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

8. 8 3-Types of movement needed: The center of resistance of molars is at mid root region a-If force vector passes through the center of resistance, that causing bodily movement b-Vector below this point cause distal tipping of crown c-Vector above this point cause distal root movement == the same procedure can apply to maxilla: it is preferred to use splint covering all teeth, that allow the force to pass through the center of resistance at premolar region N: B: Short face / deep bite: Some cases have short face with vertical deficiency as in class II with deep bite and reduced face height. This case can treat at growth stage by allowing some extrusion movement of posterior teeth by using headgear cervical pull with outer bow below the center of resistance OR: by using functional appliance (in case of mandibular deficiency that promote eruption of lower posterior teeth to permit treatment of vertical deficiency) = Herbst appliance is not indicated because it n lead to intrusion of molars == Proffit stated 1-that, eruption may occur rapidly in some patient than others depending on: mandibular posture--------- freeway space ------------- amount of appliance wear 2-some patient with short face show extremely rapid mandibular growth when the bite is opened and incisors overlapped is removed N: B: Long face: open bite: Excessive growth in vertical direction in posterior segment lead to more forward and backward rotation of mandible == ways of treatment: 1-high pull headgear to molars: that allow intrusion of maxillary posterior teeth, worn 14 h / day and force is 350gm / side 2-high pull headgear to be directed against all the maxillary teeth not just to molar 3-functional appliance with bite blocks: that inhibit the posterior teeth eruption 4-headgear pull with functional appliance with bite ve with bite block, most aggressive approach for treatment N: B: Orthopedic force: Should be high or greater than 400 – 600gm / side and maximum 800 – 1200gm / side For dental movement: 100 – 200gm Duration: 12 – 14 hour / day – increase the duration will increase the dental effect because the skeletal force must be intermittent It was recommended during night because high growth hormone level N: B: Force of headgear: Stop growth of maxilla: 600gm / side – 12 – 14 hour / day Re-direct growth: 400gm / side 12 – 14 hour / day For dental effect: must below 400gm / side Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

9. 9 Uses of headgears: 1-growth modulation to correct class II malocclusion due to maxillary excess and normal mandible 2-anchorage re-enforcement: in such a case the headgear should wear 10 hours/ day with applied force 300gm / side 3-molar distalization: to correct class II occlusion or to create space to relief crowding 4-molar rotation: by using the inner bow of headgear 5-space maintenance: is an effective means of maintaining arch length by preventing mesial migration of molars 6- limitations of headgear: 1-Most of patient prefer not to wear the headgear appliances 2-Unwanted dental changes are seen with skeletal changes 3-An adequate amount of mandibular growth is required while maxilla is restrained to correct class II relation, this usually augmented by some form of mandibular advancement appliances, usually the functional appliances Face bow Uses Distalize the molars Distal movement of maxilla Rotation of maxilla Opening or closing the bite Site of attachment molars Molar stop Must have a stop mesial to the molar tubes Site of action of force maxillary complex design Have outer and inner bows Appliance enhanced the action of headgear: (Nanda) Vertical holding appliance: Some clinician and investigators use VHA with headgear and it was recommended to use in high angle patient Design: = 0.040-inch wire with helix just distal to each 1st molar = two more helixes are placed at the center of appliance and separated by V bend which mold in acrylic button like dime = acrylic button is at the same line to mesial marginal ridge of 1st molar = acrylic button is away from palate by 2 – 5mm to allow intrusive movement The force generated from VHA is not measured also we can use TPA that is away from the palate by 6mm and the deglutition force applied high pressure intrusive force when appliance engaged on 2nd molar J- hooks Retraction of incisors En-mass movement of maxillary arch Correction of open bite or deep bite The inner bow fit into round extra-oral tubes soldered on maxillary 1st or 2nd J hooks fit into two hooks soldered on the base of the arch, OR, short labial arch mesial to maxillary canine The basal arch wire not have any molar stop The force is directed to the maxillary incisors, then transmitted through the whole arch to give, En mass movement Have two J hooks The force is directed to the maxillary molars, then transmitted to the naso- Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

10. 10 2-protraction appliances History: == Start by protraction of cases with cleft lip and palate by Potpeschingg 1875 in German literature, he attempts to forward movement of 1st molar by tooth regulation == 1943 Johnson made headgear anchored to head to move posterior teeth mesially == 1944 Oppenheim stated that, with treatment of class III need to push the maxilla forward == 1960 John Hickham developed protraction headgear which use chin and top of head for support == 1961 Max pulled the maxillary arch forward by cervico-mental apparatus == 1968, Sheridan described the use of oral orthopedic, starting that, the most effective device for Moving maxilla forward was Hickham chin cap and that treatment of class III could be accomplished before maxillary ossification occurred == 1973 Dellinger used a modified Hickham chin cap in conjunction with expansion appliance. It was Jean Delaire of Nantes, who popularized in 1970 the concept of maxillary protraction with his device called Face Mask == 1980 Nanda introduced a modified protraction headgear face bow that aimed to control the point of force application and direction == 1983 Henry Petit modified Delaire face mask by increasing the amount of force generating by appliance == 1997 Conte et al developed a new appliance called maxillary protractor, which take anchorage from forehead, temporal, and occipital regions, they claimed that, if the force is not applied to mandible any potential TMJ dysfunction is prevented == 2000 Toros Alcan et al developed a maxillary modified protraction headgear MMPH to avoid upward and forward rotation while protracting maxilla Hickham 1991, stated that, the protraction appliances allow four movements: 1-Close spaces by moving posterior teeth forward 2-Protract a deficient maxilla in class III cases 3-Rotate arch segment in cleft palate patients 4-Remove hyper anterior contact in TMJ internal derangement cases Types of protraction appliances: Hickham 1991 1-Protraction headgear 2-Facial mask 3-Sub-orbital protraction appliance 1-Protraction headgear: Developed early 1960, it uses the chin and top of the head for support Because of the difference in the lengths of the vertical arms compared to the horizontal arms, a 600gm force to the teeth produces only 100gm of force to the top of the head. The head strap adjusts so the long arms remain parallel to the lower border of the mandible. Advantages: Appliance does not interfere with sleep More esthetic than other protraction devices. Disadvantage: it must be carefully adjusted to fit comfortably behind the ears. 2-Sub-orbital protraction appliance: A recent development by Grummons, this apparatus has been redesigned to increase the rigidity of the main frame and make the device easier to adjust. The zygomatic anchorage areas Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

11. 11 support the appliance well, and the reciprocal force of the elastics to the teeth is felt at the back of the head. Although they are more sensitive, the two zygomatic areas offer more surface contact than the chin or other points and thus permit the application of similar force magnitudes. There is no force on the TMJ, and the appliance is easy to adjust and to wear during sleep. The disadvantage: is the esthetic objection to mid-facial support. Grummon recently advocated substituting a zygomatic support for the mandibular support. However, zygomatic supports could inhibit the orthopedic effect of the appliance on the middle third of the face, so that only dental movement would be achieved. 3-Facial mask: Introduction of Face mask: The facial mask was first described from more than 100 years ago by: Jackson 1904, and Sutclittte 1914 1960 Delair introduce Delair’s Face mask that used in treatment of class III with maxillary deficiency. It utilizes frontal and chin anchorage, so that, some investigator reported that, face mask used to stimulate the forward growth of maxilla as well as inhibit mandibular growth in the same way Recently Petit has modified the basic concept of Delair by increasing the amount of force generated by the appliance, thus decrease the overall treatment time Types of reversed pull head gears (facial masks): 1-Protraction head gear by Hickham: 1960: = Hickham developed the protraction headgear for forward maxillary traction. This appliance uses the chin and top of head as anchorage and derived its anchorage mainly from chin = The force distribution is as follow: 15% head – 85% chin = It is made up of 2 long and 2 short arms, all of which is originate from the chin cup. = The two short arms in front of the mouth are used to engage maxillary elastics = The two long arms parallel to the lower border of the mandible and rise vertically up from the angle of the mouth and end behind the ears = an elastic strap is attached to the end of long arms to encircle the head Advantages: a-Better esthetics and comfort than other types b-Ability to apply the unilateral force by adding rubber cushion under one arm Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

12. 12 The position of elastics is most often determined by the position of the upper and lower lips as well as the inter-labial gap, to avoid discomfort to the patient. The use of elastics in this appliance system does not allow a change in the point of force application or direction of the force delivery to attain predictable results. if the elastic is attached from the chin cup wire to distal of the upper molars, this system will cause extrusion and mesial uncontrolled tipping of the first molars; both changes are undesirable in the majority of Class III malocclusions. Similarly, if the object of the protraction headgear is to attain orthopedic changes, the elastic will not deliver controlled forces to effect the desired bony changes. The patients who exhibited a narrow skeletal maxillary formation underwent mid-palatal expansion prior to the insertion of the protraction headgear. Immediately after achievement of the desired maxillary width, the protraction headgear was inserted; this averaged 10 to 14 days after the insertion of rapid palatal expansion. The rapid palatal expansion appliance was left on the teeth for periods ranging from 4 to 7 months. A patient with a chin cup and conventional protraction headgear device which uses elastics from the distal aspect of the maxillary molars to the wire extending from the chin cup. Note that for patient comfort, the elastic can come out of the oral cavity from only one place, which limits the point of force application. Appliance activation. The appliance was activated by means of elastics attached from the outer bow to the wires of the chin cup. The elastics delivered a force of 500 to 750 Gm. on each side. In patients who had worn protraction headgear for an average of 20 to 22 hours per day, a force of 500 Gm. was used. At the end of the protraction headgear period cephalometric tracings were made and all patients were given only chin cup devices with an approximate force of 500 Gm. on each side. Patient cooperation: One of the most important force variables of an appliance is the duration of its wear. A major reason often given for dramatic orthopedic changes seen in the primate studies is the continuous force delivery to the facial bones. Based on this information, it was assumed that a 24-hour use versus a 16-hour use may provide better orthopedic results. Thereby, all patients were asked to wear the appliance for 24 hours per day. However, a tabulation of hours by patients indicated an average use of 17 hours The time range of protraction headgear use varied according to patient wear and its noticeable effects. If a patient wore the headgear from 20 to 22 hours, its use was stopped after 4 months. If a patient wore it for 15 to 18 hours, he was allowed to use it for 7 to 8 months. In patients who had rapid palatal expansion, the use of protraction headgear was started on the same day that the active expansion was stopped. the center of resistance of the maxillary dentition was in the vicinity of the apices of the premolars. Results At the end of the active protraction headgear use (4 to 8 months), the forward displacement of the maxilla, as measured by the relation of point A and the anterior nasal spine (ANS) to the cranial base, ranged from 1 to 3 mm. The majority of the patients (70 percent) showed a change of 1.5 mm. Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

13. 13 The mandibular growth as measured at the articulare, after superimposing, ranged from 0 to 1.5 mm. (except in one patient, who grew 3.5 mm.). The most dramatic change was seen in the maxillary dentition. The majority of the patients showed mesial displacement of 2.5 mm. at the maxillary first molars. The range was from 1 to 4 mm N: B: The magnitude of force is controlled by: -Anterior posterior position of elastic attachment bar -Length of outer bow -Size of elastics The direction of force is controlled by the vertical height of attachment bar 2-Delaire face mask: Jean Guy Eugene Raymond Delaire develop the face mask of Delaire 1970 It composed of: = forehead pad and chin cup connected to each other by rigid stst wire, which should be adjusted to the contour of the face, so that the forehead pad and chin cup are fit comfortably = elastic attachment bar which fit on two arms of the connecting wire and its height is adjusted according to the required moment of maxilla. it may place upward above the level of occlusal plane to produce downward moment of maxilla or placed downward to produce upward moment of maxilla = face bow: composed of outer and inner bows, which similar to that of headgear except: Direction of force anteriorly forward U shape bends are made in both ends of inner bow to fit the molar tubes from the distal aspect and the hooks on outer bow arms and reversed = elastic band or ring Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

14. 14 3-Tubinger face mask type: This is a modified type of face mask in which the forehead cap and chin cup was connected with the help of two midline metal rods. Chin cup has two vertical rods that runs in the midline and is shaped to avoid interference with the nose. The upper end of two rods houses forehead cap from which elastics encircle the head An adjustable cross bar extends in front of the mouth to engage the traction elastics. The forehead cap and cross bar can be adjusted by sliding along the rod framework to suit the individual patient 4-Petit face mask: 1983 Henry modified the Delaire face mask by increasing the amount of force generated by the appliance thus decreasing the treatment time Chin cup and forehead is connected by single vertical rod running in the midline made of 0.075 stst which is secured t the main framework by a set screw, thus allowing the position of the cross bar to be adjusted vertically horizontal bar at the level of the mouth is used to engaged elastics Advantage: Forehead cap and chin cup and cross bar can adjust to suit the patient Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

15. 15 Elastic traction: 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 5/16", 14oz elastics bilaterally. Lighter forces may be used during the break-in period, but forces should be increased as the patient adjusts to the appliance. Approximately 12 ounces of force per side is applied for 14 hours per day. Delivery of the Facemask: The current version of the Petit facial mask is available in one size and is fully adjustable to fit the facial contours of any patient. The appliance is held against the face of the patient and the positions of the forehead and chin pads are adjusted by loosening the set screws. The position of the crossbar is similarly adjusted in the vertical dimension to allow the elastics to pass through the inter-labial gap without producing discomfort to the patient. The elastics are connected bilaterally from the hooks in the canine or first deciduous molar regions of the maxillary splint to one of the indentations produced by the contours of the crossbar. The elastics travel in an infero-medial direction anteriorly from the hooks on the splint to the crossbar. Care must be taken that the elastics do not cause irritation to the corners of the mouth. Optimally, the patient is instructed to wear the facial mask on a full-time basis except during meals. Young patients (5 to 9 years old) can usually follow this regimen, particularly if the patient is told that the full-time wear will last only three to five months. In older patients, full-time wear may not be possible, in which case the appliance should be worn at all times except when the patient is in school or participating in contact sports. The patient should be seen every three or four weeks to check the condition of the splint and to evaluate hard and soft tissue changes. The facial mask is usually worn until a positive overjet of 2-4mm is achieved inter-incisally. At this time, part-time or nighttime wear is recommended for an additional three to-six-month retention period. Timing for the orthopedic facemask treatment: The most suitable period of orthopedic treatment is the subject of debate. Some authors claim that treatment should start early so as to normalize the morphology at a young age and thus provide a basis for normal function and development. Other authors are of the opinion that treatment is most effective during the pubertal growth spurt. = McNamara (1975) the optimal time to begin an early Class III treatment regimen is in the early mixed dentition. = Hickham (1991) advised that, the treatment should be initiated before the patient is 8 years old. = (1995) recommended that, the use of protraction facemask during the pre-pubertal stage to provide orthopedic effects on dento-skeletal morphology in class III malocclusion cases. The improvement of facial profile and maxillary apical base is more pronounced in 6-8 years’ age group than in 9-12 years’ age group. = Merwin et al (1997) reported that, there is no significant difference in treatment results between the age group of 4-8 years and that of 8-12 years. = Proffit (2000) recommended that maxillary protraction should be initiated as early as 4 years up to 9 years old to produce more skeletal and less dental changes. Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

16. 16 5-New maxillary protractor by Conte: New generation appliance that takes its anchorage from forehead, temporal, and occipital region According to Proffit: Clinical management of face mask treatment: it is better to defer maxillary protraction until 1st molar have erupted and can be incorporated into the anchorage unit To resist tooth movement as much as possible, the maxillary teeth should be splinted together as single unit either banded or bonded or removable one N: B: “Nanda” Force of face mask: 300 – 600gm / side depending on age Hooks for elastics attachment at canine – primary molar region above the occlusal plane Maxilla can be advanced 2-4mm during 8 -12 months If the line of force parallel to occlusal plane so there is upward and forward translation of maxilla If line of force 20 degree produces pure translator motion of maxilla. N: B: “Hickham” To avoid opening the bite as the maxilla is rotated, the protraction elastics should be attached near the maxillary cuspids. If the elastics are worn to the molar, they should pass through an attachment near the front of the arch New modalities for maxillary protraction therapy: 1. Implant anchorage 2. Intentional ankylosis 3. Distraction osteogensis Implant anchorage: Integrated devices can serve as an absolute anchor for moving teeth and the bones of the craniofacial complex. End-osseous implants require bone availability without the presence of a vital structure at the implant site. Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

17. 17 A study by Smalley et al reported the use of Osseo-integrated titanium implants for maxillofacial protraction in Monkeys. The conclusion of the study was: 1- Titanium implants placed in the facial bones provided stable anchorage for protraction of the maxillofacial complex. 2-Traction applied directly to the maxilla and/or zygomatic bones produced marked movement of the maxillofacial complex anteriorly without significant changes in the dentoalveolar complex. Till date, there are no human studies to validate this phenomenon. But research is going on extensively in this field of endosseous implants and on plants to act as stable anchorage units to effect true skeletal movement. Intentional ankylosis: The prime goal of maxillary protraction is to achieve skeletal movement of maxilla without dentoalveolar movement. So it’s necessary to enhance anchorage of maxillary dentition or to reduce resistance of maxilla to protraction. In 1985, Kokich et al reported a case in which intentionally ankylosed maxillary deciduous canines were used as anchorage for protraction. Distraction osteogensis: Maxillary advancement using distraction osteogensis reportedly has several advantages which includes the ability to treat skeletal dysplasia at a young age without having to wait until skeletal maturity. It also treats only the affected maxilla without having to operate on the normally positioned or even small mandible. Maxillary distraction using Rigid. External Distraction (RED) device allows the clinician to adjust the forces to pass through (straight advancement) or above (downward advancement) the center of mass of the maxilla. In this way the clinician has complete control over the sagittal rotational movements of the maxilla. Judging from published reports on cleft patients The clinical results of maxillary distraction with RED system appear to be superior to those obtained with elastic traction and face mask, as well as those with internal distractors. Figuero and Polley treated successfully 14 CLP patients with RED technique with significant maxillary advancement. 3-chin cup or cap Introduced by Oppenheim in nineteenth century, primarily for prevention of class III that have a relatively normal maxilla Chin cup is restraining appliance that attempts to inhibit the growth of mandible or at least preventing it from projecting forward and downward to obtain better anterior posterior relationship Chin cup appliance is composed of: a-Head cap: occipital or oblique pull is used with chin cup to produce orthopedic force that pass through the condyle to allow retardation of growth of mandible b-Chin cup: available commercially in different sizes, it is made of fabric plastic with soft liner or can be constructed for individual patient from acrylic It has two hooks for attachment c-Elastic band: elastic ring attached between hooks on head cap and chin cup It is adjusted in same manner as the headgear to direct a force through the condyle or below the condyle line Force: 400 – 800gm / side ------ 400gm to redirect the growth -------- 600gm to stop growth Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

18. 18 Types of chin cup: 1-Occipital pull chin cup: This is the most common used type of chin cup, the anchorage from the occipital region of the head Indications: a-Class III skeletal malocclusion with mild to moderate mandibular prognathism b-Patients with slightly protrusive lower incisors as they produce lingual tipping c-Patients who can bring their upper and lower incisors to close edge to edge bite at centric relation == line of force acting through the condyle: impedes the mandibular growth in the same way that extra-oral force against maxilla impedes its growth == line of force acting below the condyle: a-chin is rotated downward and backward b-There is increase in facial height and decrease the prominence in chin c-Less force required 2-Vertical pull chin cup: The chin cup derives anchorage from the parietal bone Indication: a-Patients with steep mandibular plane angle b-Excessive lower anterior facial height Effects: a-Rotate the mandible in anti-clock wise direction b-Decrease mandibular plane angle and gonial angle c-Increase in posterior facial height d-Decrease in anterior facial height Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

19. 19 Orthopedic correction of class III a-Mandibular prognathism: Time of treatment: females: 10.5 – 12.5 years ------- males: 12 – 15 years Objective of treatment: restrain horizontal mandibular growth OR redirect it into more vertical Vector Appliance used: chin cup with occipital anchorage The direction of pull should be along the axis from symphysis to condyle, so the Force pass through condyle (45 degree to mandibular plane) causes alteration Of mandibular growth = in cases of class III open bite, the direction of pull should be vertical as possible, so that, high pull chin cup is used but this would increase the chin prominence = on the other hand, vertical chin cup can reduce class III but increase open bite, so that, oblique chin cup is the appliance of choice = chin cup must be comfortable and lined with an absorbent tissue to prevent irritation = the treatment period depends upon the age of the patient, if chin cup is used in early age take short time of treatment b-Maxillary deficiency: Time of treatment: 6-9 years is the best age for orthopedic correction of maxilla Objective: enhancement of forward growth of maxilla, and restriction of forward growth of mandible appliance used: = Delaire face mask is the treatment of choice of class III maxillary deficiency in growing patients It influences forward growth of maxilla as well as restrain forward mandibular growth in the same way as chin cup = in cases of class III open bite, protraction of maxilla is achieved with clockwise rotation of maxilla to close the bite ------------- this obtained by placing the attachment bar of face mask above the occlusal plane = in class III deep bite, counter clock wise rotation is achieved by placing the attachment bar below the occlusal plane = if protraction should be achieved without any movement of maxilla, the attachment bar should lie at the same level of occlusal plane = the center of resistance of maxilla is located approximately at the zygomatic buttresses = the desired amount of force required to moves maxilla should be at least 450gm / side = there is less resistance to anterior movement than posterior movement Duration: 14 -16 hour / day however some investigation recommended full time wearing Intra-oral appliance: Patient who have maxillary deficiency often deficient in transverse plane, so anterior or posterior cross bite may be present = removable palatal expander should be used if need only to correct the cross bite but also stabilize the effect of face mask = rapid palatal expansion of mid-palatal suture may be recommended in some cases = RME is made with posterior bite plane to free the occlusion which is necessary for correction of the cross bite Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

20. 20 Other methods used to stabilize the maxillary arch: (Nance appliance, TPA) in conjunction with other fixed appliance N: B: True class III malocclusion are difficult to treat because they reflect basal bone discrepancies and there are many limitations to conventional treatment mechanics, as: class III elastics may adversely affect the inclination Orthopedic correction of open bite It was found that, the orthopedic appliance used in correction can produce significant upward and forward rotation of mandible as: correction of class II open bite cases Extra-oral appliance used: 1-Chin cap with parietal anchorage 2-Oblique and high pull headgear: ------ intrusion of maxillary molars and forward and upward rotation of mandible 3-Cervical J hooks on the maxillary anterior segment ------- extrusion Intra-oral appliance used: For correction of malalignment teeth and to stabilize the extra-oral appliance Activator or other functional appliance, blocked posteriorly and opened anterior ------------- to permit over eruption of anterior segment Orthopedic correction of class II Objectives: a-Inhibition or reduction of maxillary growth (in case of maxillary protrusion) b-Enhance the forward growth of mandible (in case of mandibular retrusion) c-Both a, and b Appliance used: A-Extra-oral appliance in severe class II in growing children: -Cervical, oblique, or high pull headgear can be used according to the case -Cervical anchorage is the appliance of choice in severe class II div 1 and div 2 with deep bite -In cases of class II with normal over bite or with open bite, oblique and high pull headgear are recommended B-Activator: Frankel II, Bionator Intra-oral appliance: = Fixed appliance can be used in mixed dentition to stabilize the maxillary arch during headgear therapy = maxillary removable appliance with extra-oral tubes soldered on the Adams crib that used in primary dentition Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby

21. 21 Extraction with Orthopedic force 1st premolars may be extracted in severe cases of gross discrepancy in conjunction with extra-oral force The 2nd molars may be extracted in cases where the 3rd molars are of normal morphology and still not erupted Retention after orthopedic correction The extra-oral appliance may be used as a part time wearing until gradual off Passive monoblock can be used in maintaining the anterior posterior relationship Maxillary and mandibular lingual arch with inter-maxillary elastics Upper and lower Hawley retainer with hooks for class II or III inter-maxillary elastics Extra Extra- -oral force and appliances oral force and appliances Dr. Mohammed Alruby Dr. Mohammed Alruby