MBT Bracket System PDF

MBT Bracket System Dr. Shaho Ziyad Al-Talabani Assistant prof. – P.O.P Dept. College of Dentistry /HMU B.D.S-M.Sc.- Ph.D. – Specialist Orthodontist December 2023  What is Occlusion Occlusion, in a dental context, means simply the contact between teeth. More technically, it is the...

MBT Bracket System Dr. Shaho Ziyad Al-Talabani Assistant prof. – P.O.P Dept. College of Dentistry /HMU B.D.S-M.Sc.- Ph.D. – Specialist Orthodontist December 2023  What is Occlusion Occlusion, in a dental context, means simply the contact between teeth. More technically, it is the relationship between the maxillary (upper) and mandibular (lower) teeth when they approach each other, as occurs during chewing or at rest.  What is Orthodontics ? Orthodontics is the speciality of dentistry concerned with the management and treatment of malocclusion. In the majority of cases, a malocclusion does not in itself represent a disease state, but rather a variation from what is considered ideal. It is therefore important for the orthodontist to have a clear definition of what is meant by an ideal occlusion, as this will form a basis for diagnosis and treatment planning.  Ideal Occlusion The ideal relationship of the teeth can be defined in terms of static (or morphological) and functional occlusion Lawrence Andrews redefined the concept of an ideal static occlusion by describing it in terms of six individual keys, including an updated ideal relationship for the first molars ( Andrews, 1972) Molar relation Crown angulation Crown Inclination No Rotation Lawrence Andrew –Six key of occlusion -1972 No Spacing Flat occlusal plane Andrews' paper was based on the measurement of 120 nonorthodontic normal cases. He then used the data as a basis to design a bracket system. A first generation of  Roth 2nd generation Roth was anxious to avoid the inventory difficulties of a multiple bracket system. his arch form was wider than Andrews' in order to avoid damage to canine lips during treatment and to assist in obtaining good protrusive function. THE WORK OF MCLAUGHLIN AND BENNETT BETWEEN 1975 AND 1993 THE WORK OF MCLAUGHLIN. BENNETT, AND TREVISI BETWEEN 1993 AND 1997 THE WORK OF MCLAUGHLIN, BENNETT, AND TREVISI BETWEEN 1997 AND 2001 OVERVIEW OF THE MBT™ TREATMENT PHILOSOPHY Bracket specification Versatility of the bracket system Accuracy of bracket positioning Light continuous forces The.022 versus the.018 slot Anchorage control early in treatment The use of three arch forms One size of rectangular steel wire Archwire hooks space closure Persistence in finishing DESIGN FEATURES OF A MODERN BRACKET SYSTEM  Aesthetic brackets The newer ceramic brackets are stronger, and notching has not proved to be a problem, especially in the anterior region where minimal sliding occurs  IN-OUT SPECIFICATION It has been observed by the authors that the in-out measurements (including molar rotation) for the original StraightWire Appliance™ have, for the most part, proven to be quite satisfactory The MBT™ Versatile+ Appliance System offers a bicuspid bracket with an increased 0.5 mm in/out value. This is useful for cases where upper second bicuspids are smaller than upper first bicuspids. TIP SPECIFICATION TIP SPECIFICATION  Torque specification A rectangular.019 ×.025 stainless steel wire in an.022 slot can yield approximately 10° of torque loss. The actual amount depends on variability in both wire and slot, but the true torque achieved is less than the value built into the slot. In contrast, torque is not efficiently expressed, owing to two mechanical reasons: To counteract the natural tendency of incisor proclination during orthodontic tooth movement, Upper Canine torque Lower Canine torque THE VERSATILITY OF THE BRACKET SYSTEM  Aspects of versatility Seven main areas of versatility are listed below, and they will be reviewed in turn: 1. Options for palatally displaced upper lateral incisors (-10°). 2. Three torque options for the upper canines (-7°, 0 ° , and +7°). 3. Three torque options for lower canines (-6°, 0", and +6"). 4. Interchangeable lower incisor brackets - the same tip and torque. 5. Interchangeable upper premolar brackets - the same tip and torque. 6. Use of upper second molar tubes on first molars in non-HG cases. 7. Use of lower second molar tubes for the upper first and second molars of the opposite side, when finishing cases to a Class II molar relationship Inverted upper lateral incisor brackets  Canine bracket selection Three torque options for the upper Three torque options for the lower canines (-7°, 0°, +7°) canines (-6°, 0°, +6°) Arch form If the patient has well- developed arches, and if substantial tooth movements are not required, then -7° upper and -6° lower canine brackets are normally chosen. Ectopic upper canines (palatal) Ectopic upper canines (buccal)  Canine brackets after premolar extractions the 0° brackets tend to maintain the canine roots in cancellous bone, thereby making tip control of the canine roots easier. The 0° canine bracket carries a hook, as it is often considered for cases which require canine retraction or Class II mechanics  Canine control after RME After rapid maxillary expansion (RME) it is helpful to use –ve torque brackets for good root control. There is a tendency for the crowns to tip towards the buccal during expansion (whether by RME or quadhelix) and use of -7° torque brackets encourages correction without the need for wire bending. Lower canine tip in Class Ill cases Lower incisor brackets are interchangeable Inverted lower incisor brackets (+6° torque) Interchangeable upper premolar brackets Use of upper second molar tubes on first molars in non-HG cases Use of lower second molar tubes for the upper first and second molars of the opposite side, when finishing cases in a Class II molar relationship  The.022 versus the.018 slot The preadjusted appliance seems to perform best in the.022 form. The larger slot allows more freedom of movement for the starting wires, and hence helps to keep forces light. Later in treatment, the steel rectangular working wires of.019/.025 have been found to perform well.  The.022 versus the.018 slot With the.018 slot, the main working wire is normally.016/.022 or.017/.025. These wires are more flexible and hence show greater deflection and binding during space closure 14 with sliding mechanics  One size of rectangular steel wire Only one size of steel rectangular wire is used in normal treatment, and this is.019/.025  Accuracy of bracket positioning Mesiodistal position of brackets Vertical position of brackets Axial or long axis position of the brackets The long axis of the clinical crown (LACC) is used as a refer􀁍 nce for bracket and tube positioning. The bracket wings should strad dle 1t.  McLaughlin or MBT vertical bracket positioning chart 1) Measure the clinical crown height of fully erupted teeth on the upper and lower study cast by dividers and millimeter rulers. 2) To obtain middle of clinical crown divide the measured height of each crown into half and round the obtained value to the nearest 0.5mm.For example if crown height is 10.75mm.Half the crown height would be 5.4 mm. Make this measurement to 5.5 mm.  McLaughlin or MBT vertical bracket positioning chart 3) Create separate rows of measurements for maxillary and mandibular teeth. Now compare your values of maxillary and mandibular teeth with that of proposed charts. If your chart measurement don't exactly tally with that of proposed MBT charts then find a row on the chart which m a t c h e s m o s t o f y o u r r e c o r d e d measurements. 4) After a specific row is selected, each for maxillary and mandibular teeth, position the bracket following the standard bonding procedure  McLaughlin or MBT vertical bracket positioning chart 5)Place the bracket on tooth in the mesiodistal and vertical middle of clinical crown by visualizing it. After placing the bracket on the tooth use the bracket positioning gauge to adjust the height of the bracket. By firmly positioning the bracket, cement flash will be squeezed from underneath the bracket. 6) Light cure cements are preferred for brackets bonding because they give longer working time. 12 11 11 10 10 8 6 5.5 5.5 5 5 4  Measure the height of clinical crown / 2 Central Lateral Canine 1st Pre 2nd Pre Maxillary Mandibul ar  Points to be considered during bracket placement In MBT system it has been proposed In MBT system teeth which that teeth which are in open bite are in deep bite are bonded should be bonded 0.5 mm more 0.5mm more incisal gingival than their prescribed position. Incisal or occlusal crown fractures or tooth wear Crowns with long, tapered buccal cusps. Flat facial contour Arch wire sequences Archwires and arch form Archwires and arch form  There are two important principles: The mandibular bone is the main factor determining the form of the human dental arch, and there is variation in the shape of this. In many cases, if arch form is changed, it tends to return to its original shape. Therefore, the pre-treatment arch shape is normally the best guide for arch form.  When can arch form be changed? In patients with a relatively narrow maxilla, and a mandibular arch that is tending to collapse lingually, with an associated deep curve of Wilson. In deep bite cases where lower canines arc inclined lingually, and influenced by the upper teeth. Digit sucking or lip sucking cases, where the arch form is affected by an influence such as the thumb and that influence will be removed during treatment Managing arch form - Part one  Managing arch form - Part two The bracket indentation are used to shape a. 0191. 025 softened base plate dental wax is pressed down on the rectangular steel wire, as a basis for an individualized lower arch, so that the brackets leave indentations arch form  Managing arch form - Part two The lower individual arch form wire shape is photocopied, and used for all lower rectangular steel wires. An upper arch form is made, coordinated to the lower, and is 3 mm wider all around. MODIFICATIONS TO ARCH FORM AND ARCHWIRE COORDINATION Upper arch expansion with archwires  Anchorage control Control of anchorage lies at the heart of good orthodontic care. There is often a main focus on antero-posterior (AlP) control, but vertical and lateral control are also important,  Anchorage control - Why?? Anchorage control is needed to prevent the malocclusion from becoming worse It is used to ensure that the incisors and the rest of the dentition are properly positioned in the facial complex at the end of treatment Antero-posterior (AlP) anchorage during levelling and aligning  Principles of anchorage control There are two main aspects to anchorage control: 1. Reduction of anchorage needs during leveling and aligning. There is a need to minimize the factors which threaten anchorage and which produce unwanted tooth movements. This reduces the demands on anchorage. 2. Anchorage support during tooth leveling and aligning. Where necessary, there is a need to use anchorage support, such as palatal or lingual bars, to help to control certain teeth, or groups of teeth  REDUCED ANCHORAGE NEEDS DURING TOOTH LEVELING AND ALIGNING Bracket design A total of 10° less distal root tip in the upper anterior segment and 12° less distal root tip in the lower anterior segment is needed, compared with the original S W A. This reduces the anchorage needs, lessens the tendency to bite deepening in the early stages, and puts less demand on patient cooperation. Archwire forces Avoidance of elastic chain  ANTERO-POSTERIOR ANCHORAGE SUPPORT DURING TOOTH LEVELING AND ALIGNING ANTERO-POSTERIOR ANCHORAGE SUPPORT DURING TOOTH LEVELING AND ALIGNING The initial purpose of lacebacks (0.010) was to prevent canines from tipping forward Bend backs for A/P incisor control A/P anchorage control of lower molars - the lingual arch A/P anchorage support and control for upper molars - the palatal bar A/P anchorage support and control for upper molars - the use of headgear VERTICAL ANCHORAGE CONTROL DURING TOOTH LEVELING AND ALIGNING Vertical control of the incisors  ANCHORAGE CONTROL IN THE LATERAL (CORONAL) PLANE Inter-canine width Molar crossbites Molar crossbites Temporary Anchorage devices Arch levelling and overbite control  THE TOOTH MOVEMENTS OF BITE OPENING Eruption/extrusion of posterior teeth Distal tipping of posterior teeth Proclination of incisors Intrusion of incisors A combination of two or more of the above tooth movements. Eruption/extrusion of posterior teeth. Distal tipping of posterior teeth.  Intrusion of anterior teeth Proclination of incisors NON-EXTRACTION TREATMENT This is particularly helpful in low-angle deepbite cases, Blue colored direct bonding material  The importance of second molars provides an excellent lever arm for eruption or extrusion of the premolars and first molars, and assists in incisor intrusion  Torque issues Rectangular steel wires are normally placed flat. After they have been in place for at least 6 weeks, upper palatal root torque and lower labial root torque can be introduced into the wires, as shown above. Bite-opening curves  EXTRACTION TREATMENT Most of the mechanical treatment procedures described for deep-bite non-extraction cases also apply to deep-bile extraction cases. However, there are two other important factors in extraction deep-bite cases: With extraction cases, lower incisors are normally maintained in their position or brought to a more retroclined position. This makes the bite opening more difficult. If space closure is attempted before proper arch levelling and overbite control, it will lead to bite deepening L&A after premolar extraction- no crowding L&A after premolar extraction- mild crowding 2 stage levelling and alignment in moderate crowding Tiebacks  Settling the case It is helpful to consider the finishing stages of an orthodontic treatment in three steps: The correction of errors made before finishing Overcorrection Case settling The correction of errors made before finishing  Overcorrection Overcorrection is an accepted principle in good orthodontics. As a rule it is wise to overcorrect whatever is known to have a risk of relapse, in particular overjet and horizontal discrepancies, and tooth rotations  Case settling Frequent lower arch options Frequent upper arch options The.016 HANT settling wire The.014 stainless steel 2 x 2 sectional wire The.014 stainless steel wire The.014 upper steel 3 x 3 sectional wire The full.014 steel upper wire