|Year : 2019 | Volume
| Issue : 1 | Page : 87-89
A simplified method for fabricating customized arch form
Chandra Sekhar Gandikota1, Nemani Shivaram2, Syed Amaan Husain3
1 Prof. and Head, Department of Orthodontics and Dentofacial Orthopedics, Panineeya Institute of Dental Sciences and Research Centre, Hyderabad, Telangana, India
2 Senior Lecturer, Department of Orthodontics and Dentofacial Orthopedics, Panineeya Institute of Dental Sciences and Research Centre, Hyderabad, Telangana, India
3 PG Student, Department of Orthodontics and Dentofacial Orthopedics, Panineeya Institute of Dental Sciences and Research Centre, Hyderabad, Telangana, India
|Date of Submission||04-Dec-2017|
|Date of Acceptance||25-Jun-2018|
|Date of Web Publication||04-Feb-2019|
Dr. Nemani Shivaram
17-127/15/1, Sri Raghavendra Nagar Colony, Survey of India, Uppal, Hyderabad - 500 039, Telangana
Source of Support: None, Conflict of Interest: None
Customized and prefabricated arch forms are the two basic types of arch forms which determine the outcome of orthodontic treatment. With the introduction of preadjusted edgewise appliance, customized arch forms were rapidly replaced by prefabricated archwires. Although the former was more suitable for a particular patient, they were time-consuming in making and required a lot of chair-side time. The present paper describes a single jig which makes the fabrication of one such arch form (Bonwill Hawley) for any number of patients with different arch dimensions easy and less cumbersome.
Keywords: Bonwill–Hawley arch forms, Customized arch forms, Individualized Treatment Plan
|How to cite this article:|
Gandikota CS, Shivaram N, Husain SA. A simplified method for fabricating customized arch form. J Indian Orthod Soc 2019;53:87-9
|How to cite this URL:|
Gandikota CS, Shivaram N, Husain SA. A simplified method for fabricating customized arch form. J Indian Orthod Soc [serial online] 2019 [cited 2019 Feb 21];53:87-9. Available from: http://www.jios.in/text.asp?2019/53/1/87/251551
| Introduction|| |
The dental arch form represents a morphologic pattern of each which is controlled by the underlying basal bone and balance between circumoral and intraoral muscles., As the pre-adjusted edgewise appliances were introduced, many orthodontists turned a blind eye toward individualized arch forms which lead to the popularity of pre-fabricated archwires. These archwires were accounted for the tipping combined with extrusion, undesirable expansion of the teeth beyond their centered position over basal bone which may lead to relapse and have periodontal implications in the long run. Hence, individualized arch forms although uncommon, still hold a superior stand over preformed archwires. There have been various types of individualized arch forms till date; however, due to the arduous procedure, they were disregarded expeditiously. One such arch form is the Bonwill–Hawley arch form. The objective of this paper is to introduce a simplified method of constructing Bonwill–Hawley arch form using a customized jig.
| Design and Fabrication|| |
The Bonwill–Hawley arch form in the incisor region follows the contour of a circle with the radius equal to the sum of mesiodistal widths of the anterior teeth and from cuspid to molar, it follows a straight line. The sum of mesiodistal widths of incisors, canine with an additional 3 mm form the radius of the smaller circle which is the initial step in making an arch form.
The minimum and the maximum ranges of the widths of maxillary anterior teeth are taken [Table 1]. The Bonwill–Hawley arch forms for the various dimensions of the teeth were drawn in a single template. A line is drawn from the center of the arch (Point A) to the points where the curved part of each arch contacts the posterior straight line on both sides. Lines from the Point A, posterior straight segments of the innermost arch and a line at the base of arch forms, a quadrilateral which constitutes the shape of the Jig used in this study. The jig is made with the dimensions of arch form with the mesiodistal widths of anterior teeth as 15 mm.
|Table 1: Amount of separation between the distractor arms for each arch form|
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Two straight wires are attached to jig on Lines a, b to which a distractor is attached. As the two arms of the distractor move, the framework moves along the axis of line a, b. The device was then calibrated; the amount of separation between the distractor arms and the corresponding arch forms was noted [Table 1].
The posterior segments of each arch form are drawn from the jig. The anterior curved arch is drawn by the scribing an arc from both initial points of the posterior segments using the radius of the smaller circle [Table 1]. The two arcs meet in the center from which a semicircle is drawn to join both posterior segments; thus, forming the complete arch form. A Bonwill–Hawley arch for the anterior teeth mesiodistal width of 17 mm using the jig is drawn in this study [Figure 1].
|Figure 1: (a) The separation between the two arms is 5 mm indicating the (M-D) of the teeth being 17 mm. (b and c) The posterior segments constructed with the jig. (d-f) The anterior arc and the arcs being scribed with a radius of 20 mm. (g and h) Anterior arc being formed with radius of 20 mm|
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| Observation|| |
Different arch forms of mesiodistal width 15 mm and 21 mm were made using the Jig and compared with the manually made Bonwill–Hawley arch forms of the same dimensions by superimposition [Figure 2]. The two arches formed manually and from the jig were equal and showed complete overlapping.
|Figure 2: (a) Bonwill–Hawley arch drawn using the traditional method for the mesiodistal width of 15 mm. (b) Bonwill–Hawley arch drawn using the jig for mesiodistal width of 15 mm. (c) Superimposition of the two arch forms. (d) Bonwill–Hawley arch drawn using the traditional method for mesiodistal width of 21 mm. (e) Bonwill–Hawley arch drawn using the jig for mesiodistal width of 21 mm. (f) Superimposition of the two arch forms|
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| Advantages|| |
- Archwires of different dimensions for different patients with the same jig can be fabricated with ease. There is no need to fabricate Bonwill–Hawley arch diagram for every patient
- Requires less time and effort
- No special operative skills are required.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
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Weaver KE, Tremont TJ, Ngan P, Fields H Dischinger T, Martin C, et al
. Changes in dental and basal arch forms with preformedand customized archwires during orthodontic treatment. Orthod Waves 2012;71:45-50.
Santoro M, Ayoub ME, Pardi VA, Cangialosi TJ. Mesiodistal crown dimensions and tooth size discrepancy of the permanent dentition of Dominican Americans. Angle Orthod 2000;70:303-7.
[Figure 1], [Figure 2]