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The use of orthodontic chain elastic for temporary intermaxillary fixation
I 1993 l’hc British Arwciatmn
ofOrdl and Yaxillofacial
I
Surgeons
TECHNICAL NOTE The useof orthodontic chain elastic for temporary intermaxillary fixation A. T. Smith St Lawrence Hospitul Plustic und Reconstructive Surgery Centre, Chepstow
SUMMARY. A method of application of firm and resilient temporary intermaxillary fixation using readily available orthodontic elastomeric chain is described. Advantages lie in the time efficiency of its use, relative safety compared to tie-wiring techniques, flexibility of direction of pull, and the ease and rapidity with which it can be removed. Consideration is given to other potential uses of the material in the retention of various appliances used in orthognathic procedures.
Numerous methods have been described for the achievement of intermaxillary fixation (IMF) in the treatment of fractures of the facial skeleton and many oral and maxillofacial surgeons apply temporary IMF at the intermediate stage of bimaxillary orthognathic procedures. The placement of one mobilised component in a locating device such as an acrylic preformed occlusal wafer requires firm, even attachment, and an ability to resist displacing forces whilst the new position of the alveolus is established and fixed with either skeletal fixation or definitive IMF. Traditional wiring is a potential source of ‘needlestick’ type injury in the contaminated environment of the oral cavity and represents a health risk to surgeons and assistants. Conventional elastic or rubber rings may be difficult to place, and large numbers often need to be applied to prevent displacement of the fragments from the wafer. Elastomeric orthodontic chain elastic (Fig. 1) is readily available from orthodontic suppliers and has
become popular in orthodontic practice for the application of force to teeth (Sonis et al., 1986) or segments since its introduction in the late 1960s and early 1970s by orthodontic equipment manufacturers in the USA. Such elastic exerts a pull of approximately 250-500 g per ‘turn’ depending on its specification (De Genova et al., 1985), and multiple ‘turns’ around anchorage points increase the firmness of retention (Fig. 2). It is resilient, and even if displaced by stretching, tends to return the segments to their correct location in the splint or wafer, whereas wire ties once stretched, or if inadequately tightened become passive and allow free movement. The chain is relatively expensive, but ease of use and the rapidity and flexibility with which it can be applied and retrieved save valuable operating time. It can be cold sterilised if desired and is designed to retain its physical properties within the oral environment. On removal, unlike wires and elastic rings which easily break or tear and may be difficult to retrieve from the mouth or wound, it can be recovered in one strip and, as an additional check, the holes can be
Fig. 1 - Continuous orthodontic chain.
Fig. 2 - Chain added ‘surgical
INTRODUCTION
and spaced
link versions
of elastomeric 250
elastic applied hooks’.
to orthodontic
fixed appliance
with
Use of orthodontic
elastic
for intermaxillary
fixation
251
ate wafer. Glove puncture, an ever present threat which is not always noticed (Burke & Wilson, 1990) can be avoided in this way. Orthodontic chain is a versatile material and it may be possible to extend its use to longer-term IMF in trauma cases and in the prevention of anterior open bite after mandibular orthognathic surgery. It may also be used for the retention of individual appliances or splints, which can be held to archwires or archbars by a short length of chain processed into the acrylic.
counted and documented. It can be released more readily in the event of any airway crisis using nurse’s scissors or an artery clip, thus removing the requirement for wire cutters. This represents an improvement in the security of an adequate airway which can be compromised by intermaxillary fixation (Williams & Cawood, 1990). The force exerted by elastic modules is known to decrease over time (Wong, 1976) and the force decays by 17-70% (Hershey & Reynolds, 1975; Brooks & Hershey, 1976) over the first 24 h, depending on the precise material and format of the chain, and whether it has been pre-stretched (Young & Sandrik, 1979; Brantley ef al., 1979). More recent polymers are less prone to these problems, but as the requirement in this particular application is only for interim or temporary fixation of the fragments, this is not important.
Thanks are due to Mr A. W. Sugar, Consultant Oral & Maxihofaciaf surgeon, for permission to publish clinical photographs, and to Mr Alan Boccd, Senior Chief Maxillofacial Technician for technical work and innovation relating to the acrylic wafers.
METHOD
References
Elastomeric chain can readily be applied to any form of archbar with ball cleat or hook attachments, on fixed orthodontic appliances with surgical hooks, or where points of attachment can be added to or are intrinsic to the arch fixation. Eyelet loops can be bent to form hooks, or the type of German silver hook described by Ramsey Baggs can be employed (Ramsey Baggs, 1990). Leonard type buttons or bonded orthodontic brackets are equally useful. Starting at one quadrant, preferably leaving a short ‘tail’ of rings for easy identification of the end point, the chain is tightly wound around hooks, cleats, brackets or archwires in the traditional ‘zig-zag’ fashion. The direction of pull of any particular ‘turn’ can be varied to provide guidance of the occlusal components into the wafer or occlusion. The chain can be guided into position using an artery clip or boathook. After every few turns, by applying the ring over a hook rather than behind or around it, the tendency for the chain to ‘unravel’ should it be cut or torn is eliminated. One length of chain of approximately 10-l 5 cm should sufice for firm fixation of both stages of a bimaxillary procedure. The chain can be used to give adequate fixation even in extreme circumstances where the degree of control afforded by wire loops may be limited or unstable. Once in situ a series of 10 x 1 cm ‘turns’ of the elastic should resist a displacing force of between 30.-40 Newtons approximately (Data on file, 1992). Any tendency to displacement of the occlusion can be remedied by quick removal and replacement of the chain, if necessary with a different angle of pull. This can be troublesome and time consuming with wire ties or individual ring elastics, particularly as wires tend to work-harden and break. After the initial mobilised fragment has been adequately positioned and appropriate skeletal fixation applied, the chain can be removed easily, atraumatically and completely by holding one end in an artery clip and ‘unwinding’ it to release the intermedi-
Acknowledgements
Brdntfey, W. A., Salander S., Myers C. L. &Winders, R. V. (1979). Effects of prestretching on force degradation characteristics of plastic modules. Angle Orfhodontisr, 49, 37. Brooks, D. G. & Hershey, H. G. (1976). Effect of heat and time on stretched plastic orthodontic modules. (Abstract). Journal of Dental Research, 55B, no. 363, Bl52. Burke, F. J. T. & Wilson, N. H. F. (1990). The incidence of undiagnosed punctures in non-sterile gloves. British Dental Journul,
De Genova, (1985). product
168,61.
D. C.. Mclnnes-Lcdoux, P., Weinberg, R. & Shaye, Force degradation of orthodontic elastic chains-A comparison study. Americun Journal of Orthodontics,
R.
87,377.
Hershey, H. G. & Reynolds, W. G. (1975). The plastic module as a tooth moving mechanism. American Journal of Orthodontics, 67,554. Laboratory data on file (1992). Department of Basic Sciences, Dental Hospital, Heath Park, Cardilf. Ramsey Baggs. P. (1990). The eyelet fights back. Brifish Journal of Oral
Sonis,
and Maxillofacial
Orthodontics,
28,350.
89, 73.
Williams, J. G. & Cawood, tixation on pulmonary and Maxilldfuciat
Wone.
Surgery,
A. L., Van der Plas, E. & Gianelly, A. (1986). A comparison of elastomeric auxiliaries versus elastic thread on premolar extraction site closure: An in vivo study. American Juurnal of J. I. (1990). Effect of intermaxillary function. Inrernurionol Journal of Oral
Surgery,
19, 76.
A. K. (1976).
Orthodontic elastic materials. Anele .. &rhodotksr, 46, 196. Young, J. & Sandrik, J. L. (1979). The influence of preloading stress relaxation of orthodontic elastic polymers. Angle Orlhodontist, 49, 104.
on
The Author A. T. Smith MBBCh, FDS, FRCS Registrar Department of Oral & Maxillofacial St Lawrence Hospital Regional Centre for Burns, Plastic Chepstow Gwent NP6 5YX
Surgery & Maxillofacial
Surgery
Correspondence and requests for offprints to Mr A. T. Smith, Department of Oral & Maxillofacial Surgery, Medicine and Pathology, University of Wales Dental Hospital & School, Heath Park, CarditT, S. Glamorgan, CF4 4XY Paper received 22 September 1992 Accepted 22 December 1992
ofOrdl and Yaxillofacial
I
Surgeons
TECHNICAL NOTE The useof orthodontic chain elastic for temporary intermaxillary fixation A. T. Smith St Lawrence Hospitul Plustic und Reconstructive Surgery Centre, Chepstow
SUMMARY. A method of application of firm and resilient temporary intermaxillary fixation using readily available orthodontic elastomeric chain is described. Advantages lie in the time efficiency of its use, relative safety compared to tie-wiring techniques, flexibility of direction of pull, and the ease and rapidity with which it can be removed. Consideration is given to other potential uses of the material in the retention of various appliances used in orthognathic procedures.
Numerous methods have been described for the achievement of intermaxillary fixation (IMF) in the treatment of fractures of the facial skeleton and many oral and maxillofacial surgeons apply temporary IMF at the intermediate stage of bimaxillary orthognathic procedures. The placement of one mobilised component in a locating device such as an acrylic preformed occlusal wafer requires firm, even attachment, and an ability to resist displacing forces whilst the new position of the alveolus is established and fixed with either skeletal fixation or definitive IMF. Traditional wiring is a potential source of ‘needlestick’ type injury in the contaminated environment of the oral cavity and represents a health risk to surgeons and assistants. Conventional elastic or rubber rings may be difficult to place, and large numbers often need to be applied to prevent displacement of the fragments from the wafer. Elastomeric orthodontic chain elastic (Fig. 1) is readily available from orthodontic suppliers and has
become popular in orthodontic practice for the application of force to teeth (Sonis et al., 1986) or segments since its introduction in the late 1960s and early 1970s by orthodontic equipment manufacturers in the USA. Such elastic exerts a pull of approximately 250-500 g per ‘turn’ depending on its specification (De Genova et al., 1985), and multiple ‘turns’ around anchorage points increase the firmness of retention (Fig. 2). It is resilient, and even if displaced by stretching, tends to return the segments to their correct location in the splint or wafer, whereas wire ties once stretched, or if inadequately tightened become passive and allow free movement. The chain is relatively expensive, but ease of use and the rapidity and flexibility with which it can be applied and retrieved save valuable operating time. It can be cold sterilised if desired and is designed to retain its physical properties within the oral environment. On removal, unlike wires and elastic rings which easily break or tear and may be difficult to retrieve from the mouth or wound, it can be recovered in one strip and, as an additional check, the holes can be
Fig. 1 - Continuous orthodontic chain.
Fig. 2 - Chain added ‘surgical
INTRODUCTION
and spaced
link versions
of elastomeric 250
elastic applied hooks’.
to orthodontic
fixed appliance
with
Use of orthodontic
elastic
for intermaxillary
fixation
251
ate wafer. Glove puncture, an ever present threat which is not always noticed (Burke & Wilson, 1990) can be avoided in this way. Orthodontic chain is a versatile material and it may be possible to extend its use to longer-term IMF in trauma cases and in the prevention of anterior open bite after mandibular orthognathic surgery. It may also be used for the retention of individual appliances or splints, which can be held to archwires or archbars by a short length of chain processed into the acrylic.
counted and documented. It can be released more readily in the event of any airway crisis using nurse’s scissors or an artery clip, thus removing the requirement for wire cutters. This represents an improvement in the security of an adequate airway which can be compromised by intermaxillary fixation (Williams & Cawood, 1990). The force exerted by elastic modules is known to decrease over time (Wong, 1976) and the force decays by 17-70% (Hershey & Reynolds, 1975; Brooks & Hershey, 1976) over the first 24 h, depending on the precise material and format of the chain, and whether it has been pre-stretched (Young & Sandrik, 1979; Brantley ef al., 1979). More recent polymers are less prone to these problems, but as the requirement in this particular application is only for interim or temporary fixation of the fragments, this is not important.
Thanks are due to Mr A. W. Sugar, Consultant Oral & Maxihofaciaf surgeon, for permission to publish clinical photographs, and to Mr Alan Boccd, Senior Chief Maxillofacial Technician for technical work and innovation relating to the acrylic wafers.
METHOD
References
Elastomeric chain can readily be applied to any form of archbar with ball cleat or hook attachments, on fixed orthodontic appliances with surgical hooks, or where points of attachment can be added to or are intrinsic to the arch fixation. Eyelet loops can be bent to form hooks, or the type of German silver hook described by Ramsey Baggs can be employed (Ramsey Baggs, 1990). Leonard type buttons or bonded orthodontic brackets are equally useful. Starting at one quadrant, preferably leaving a short ‘tail’ of rings for easy identification of the end point, the chain is tightly wound around hooks, cleats, brackets or archwires in the traditional ‘zig-zag’ fashion. The direction of pull of any particular ‘turn’ can be varied to provide guidance of the occlusal components into the wafer or occlusion. The chain can be guided into position using an artery clip or boathook. After every few turns, by applying the ring over a hook rather than behind or around it, the tendency for the chain to ‘unravel’ should it be cut or torn is eliminated. One length of chain of approximately 10-l 5 cm should sufice for firm fixation of both stages of a bimaxillary procedure. The chain can be used to give adequate fixation even in extreme circumstances where the degree of control afforded by wire loops may be limited or unstable. Once in situ a series of 10 x 1 cm ‘turns’ of the elastic should resist a displacing force of between 30.-40 Newtons approximately (Data on file, 1992). Any tendency to displacement of the occlusion can be remedied by quick removal and replacement of the chain, if necessary with a different angle of pull. This can be troublesome and time consuming with wire ties or individual ring elastics, particularly as wires tend to work-harden and break. After the initial mobilised fragment has been adequately positioned and appropriate skeletal fixation applied, the chain can be removed easily, atraumatically and completely by holding one end in an artery clip and ‘unwinding’ it to release the intermedi-
Acknowledgements
Brdntfey, W. A., Salander S., Myers C. L. &Winders, R. V. (1979). Effects of prestretching on force degradation characteristics of plastic modules. Angle Orfhodontisr, 49, 37. Brooks, D. G. & Hershey, H. G. (1976). Effect of heat and time on stretched plastic orthodontic modules. (Abstract). Journal of Dental Research, 55B, no. 363, Bl52. Burke, F. J. T. & Wilson, N. H. F. (1990). The incidence of undiagnosed punctures in non-sterile gloves. British Dental Journul,
De Genova, (1985). product
168,61.
D. C.. Mclnnes-Lcdoux, P., Weinberg, R. & Shaye, Force degradation of orthodontic elastic chains-A comparison study. Americun Journal of Orthodontics,
R.
87,377.
Hershey, H. G. & Reynolds, W. G. (1975). The plastic module as a tooth moving mechanism. American Journal of Orthodontics, 67,554. Laboratory data on file (1992). Department of Basic Sciences, Dental Hospital, Heath Park, Cardilf. Ramsey Baggs. P. (1990). The eyelet fights back. Brifish Journal of Oral
Sonis,
and Maxillofacial
Orthodontics,
28,350.
89, 73.
Williams, J. G. & Cawood, tixation on pulmonary and Maxilldfuciat
Wone.
Surgery,
A. L., Van der Plas, E. & Gianelly, A. (1986). A comparison of elastomeric auxiliaries versus elastic thread on premolar extraction site closure: An in vivo study. American Juurnal of J. I. (1990). Effect of intermaxillary function. Inrernurionol Journal of Oral
Surgery,
19, 76.
A. K. (1976).
Orthodontic elastic materials. Anele .. &rhodotksr, 46, 196. Young, J. & Sandrik, J. L. (1979). The influence of preloading stress relaxation of orthodontic elastic polymers. Angle Orlhodontist, 49, 104.
on
The Author A. T. Smith MBBCh, FDS, FRCS Registrar Department of Oral & Maxillofacial St Lawrence Hospital Regional Centre for Burns, Plastic Chepstow Gwent NP6 5YX
Surgery & Maxillofacial
Surgery
Correspondence and requests for offprints to Mr A. T. Smith, Department of Oral & Maxillofacial Surgery, Medicine and Pathology, University of Wales Dental Hospital & School, Heath Park, CarditT, S. Glamorgan, CF4 4XY Paper received 22 September 1992 Accepted 22 December 1992