|Year : 2017 | Volume
| Issue : 1 | Page : 51-53
Wing-bib multi helix maxillary expander
Mugdha P Mankar
Asst Prof., Department of Orthodontics and Dentofacial Orthopedics, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital, Nagpur, Maharashtra, India
|Date of Submission||05-May-2016|
|Date of Acceptance||05-Jun-2016|
|Date of Web Publication||31-Jan-2017|
Mugdha P Mankar
52, Netaji Society, Near Friends Colony, Katol Road, Nagpur - 440 013, Maharashtra
Source of Support: None, Conflict of Interest: None
An orthodontic appliance for maxillary expansion is presented, which consists of a wire assembly fabricated from 0.032” round straight length beta-titanium wire. Posterior active portion of the appliance consists of a trihelix omega loop parallel to palatal surface, providing transverse expansion and distalizing forces on the first molars. Anterior active portion consisting of an acrylic apron (bib) over a (wing-like) wire framework, provides transverse expansion at the anterolateral slopes of the palate including the depths; lying directly over the envisioned canine- first premolar root area of the palatal vault surface.
Keywords: Beta-titanium, expansion, palatal vault
|How to cite this article:|
Mankar MP. Wing-bib multi helix maxillary expander. J Indian Orthod Soc 2017;51:51-3
| Introduction|| |
The presented invention is a slow maxillary expander made from beta-titanium wire and is a tooth and tissue anchored device. It is a screw-less (nonimplant and nonexpansion screw) appliance, provides light continuous forces, and provides flexibility of adjustments. Amidst the distinctly extreme properties of available expansion appliances,,, the intermediate and uniquely balanced properties of the beta-titanium  provide a competent and mechanically proficient expander.
The principal objective is to increase the width of the palate at its anterolateral slopes including depths, by bone remodeling, which could possibly create room for uprighting the canine and premolar roots in combination with simultaneous arch wire expansion.
Another objective is to provide a light continuous distal force to the expanding dentition for correction of the presented anterior malocclusion.
| Method of Fabrication|| |
[Figure 1]a shows the wire framework; prepared from 0.032” titanium-molybdenum alloy wire.
- Posterior part consists of a tri-helix omega loop (10 mm × 10 mm) at the center of the palate and anteroposteriorly at the level of mesial end of the lingual sheath (0.032”) on first permanent molars. Ends of the loop are continued, over and two mm above, the palatal surface to be inserted into the sheaths as posterior hooks, which extend 2 mm posteriorly from the distal ends of the sheaths [Figure 1]a and [Figure 1]b
- The intermediate part consists of helices (one mm away from the palatal surface) which are the source of activation for the appliance and also a break between the forces from the anterior and posterior active parts providing option of independent functioning of the two. The number of vertically overlapping helices could be varied from three to five depending on the ability of the lowest helix to reach level of approximate junction of middle and the apical third of the canine- first premolar root areas [Figure 1]b and [Figure 1]c
- The area of force application should be designated before the fabrication of the wire framework for the anterior wing-bibs. Shape is such that the extremities of the framework should confirm the area between the long axes of canine and first premolar roots at their predicted position after expansion [Figure 1]b and [Figure 1]c. An acrylic apron of 2 mm thickness covers the wire framework, so that the shape confirms the complete root area [Figure 1]c. A layer of soft liner is added on the palatal surface of the wing-bibs [Figure 1]d, which cushions the palatal tissues off direct forces as well as provides for differential remodeling (thickness anterior 2 mm, posterior 1 mm, apical 2 mm, occlusal 1 mm).
|Figure 1: (a) Wire framework, (b) outline delineating the area of force application and wire framework prepared on it, (c) anterior part with acrylic wing-bibs, (d) appliance placed upside down showing only posterior activation, resultant anterior separation should be noticed, palatal layer of soft liner should be noticed|
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The activated appliance [Figure 1]d works in conjugation with a rigid expanded buccal archwire for simultaneous dental correction [Figure 2]a and [Figure 2]b.
|Figure 2: (a) Pretreatment clinical occlusal photographs (b) insertion and ligation of the appliance along with a buccal expanded archwire, (c) results after 6 months of appliance insertion|
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[Figure 2]c is showing results of the appliance 6 months from insertion in a 22-year-old girl. Intercanine width increased by 5 mm, interpremolar width increased by 3 mm, and intermolar width increased by 3 mm; when measured from definite respective, tooth crown landmarks on the study casts. Premolar basal arch width increased 1.5 mm. At the depth of palate, over the apical third root area of canine and premolar teeth, the widths increased by 2.5 mm and 2.25 mm, respectively. Mandibular intercanine width increased by 1 mm, interpremolar width increased by 2 mm, and intermolar width increased by 2 mm.
Activation is done by opening the helices. To judge the required transverse activation the appliance could be placed upside down over the occlusal surfaces of the teeth on the working model at the anteroposterior position of the actual insertion site in to the lingual sheaths [Figure 1]d. Information of practical importance has to be revealed that the posterior activation itself provides the desired separation between the anterior wing-bibs [Figure 1]d; also, posterior correction gradually increases the anterior force. Hence, any independent anterior activation is not required during the initial stages of appliance wear. On completion of the prescribed posterior correction, the contouring over the anterolateral slopes of the palate should be assessed to consider independent anterior activation, if required. Another significant reason for development of this strategy has been described hence.
Exaggerated independent anterior activations of more than 20° over the original angulations of the wing-bibs caused pain over the entire maxillary region, migrating toward ears. This may be attributed to a skeletal expansive force delivered by the appliance. But exaggerated forces also resulted into penetration of the anterior wing-bibs, to some extent, into the palatal soft tissues. A layer of long term soft liner has been expectedly added over the palatal surfaces of the wing-bibs to protect the palatal soft tissues. The appliance in its current form is a slow expander and does not recommend exaggerated (more than 20°) independent anterior activations. Our aim during the introduction of the appliance was bone remodeling at the canine- first premolar root area and not rapid skeletal expansion; however, the tissue reactions observed at such an activation force were definitely an indication for rapid expansion. Study on the appliance is in process to evaluate force distribution over the maxillary tissues and skeletal effects; at different activations, which shall elucidate its use as a rapid maxillary expander.
Method of insertion and removal
During insertion, the anterior wing-bibs are held between the thumb and index finger and oriented. They are then slightly compressed and taken in to the oral cavity and over the palate, while allowing the hook on one side to slide through the sheath, followed by other side. Hooks are secured in place with figure of eight ligature ties on the sheaths.
During removal, ligature wire is first removed, the wing-bib on one side is held with a plier or forceps slightly away from the palate. Using another plier, hook is slide out of the lingual sheath from its mesial end. The other side hook readily slides out after.
The appliance in its active state perfectly adapts to the inner surface of the palate with force, so that the anterior and posterior parts concomitantly provide anchorage to one another and hence its dislodgment between appointments is least expected.
Presented results have been analyzed on study casts. Further study using advanced diagnostic procedures is in process to provide precise quantifiable evidence to the hypothesis that the palatal vault surface at the canine-premolar root area could be expanded and remodeled with use of the discussed expander.
- Expansion and remodeling at the anterolateral slopes of the palatal vault surface for accommodation and uprighting of the canine and premolar roots
- Slow maxillary expansion.
- Provides expansion at anterior palatal region
- Practically economic with balanced and efficient properties
- Provides for easy insertion and removal
- Dislodgment between the appointments is least expected
- Very frequent activations are not obligatory owing to the uniquely balanced properties of beta-titanium.
The authors are thankful to the parents, teachers, and the faculty and patients at Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital, Nagpur, for their endless support.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
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[Figure 1], [Figure 2]