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Comparative assessment of two methods used for interdental immobilization
Journal of Cranio-Maxillofacial Surgery (2003) 31, 159–161 r 2003 European Association for Cranio-Maxillofacial Surgery. doi:10.1016/S1010-5182(03)00022-2, available online at http://www.sciencedirect.com
Comparative assessment of two methods used for interdental immobilization Ashraf F. Ayoub1, John Rowson2 1
University of Glasgow Dental School & Canniesburn Hospital, Glasgow, UK; 2 Queens Medical Centre, University Hospital, Nottingham, UK
SUMMARY. Aim: This investigation was carried out to compare Dimac wires with arch bars for interdental
immobilization. Material and methods: The assessment was conducted on 50 patients who had mandibular fractures and in whom intermaxillary fixation was required as a part of the treatment. The time required for applying each method of fixation, the needle-stick injuries that occurred during their application, and the periodontal damage that followed interdental immobilization was investigated. Results: The mean time required for the application of Dimac wires was significantly less than that required for arch bars. The needle-stick injuries were significantly less with Dimac wires. Patients reported difficulty with oral hygiene with arch bars in place. This was associated with periodontal damage following removal of fixation. Conclusion: Dimac wires is safer to use and less traumatic to the periodontium r 2003 European Association for Cranio-Maxillofacial Surgery.
threaded at one end and fitted with a threaded nylon nut that has a concave upper surface (Fig. 1). There are 167 precision-cut threads per inch on the wire, and each full turn of the threaded nylon nut represents 0.152 mm of movement along the wire. The wire is applied by being passed between adjoining teeth from buccal to lingual and back to the buccal surface through the next interdental space, encircling the tooth. After the nylon nut is snugged against the teeth, it is unwound 10 turns, and the distal end of the wire is brought medially and clockwise around the proximal end. It is turned sharply on itself to create a tight hook, and any excess wire is snipped off. The nut is then tightened down, and any excess wire protruding through the centre of the nut is trimmed off in the concavity so that it does not irritate the mucosa (Fig. 2).
INTRODUCTION Different methods have been used for intermaxillary fixation including custom-made arch bars, eyelet wires, and Schuchardt arch-shaped splints made of metal and acrylic (Schuchardt and Metz, 1966). However, these are time-consuming methods, with a constant danger of trauma to the surgeon’s fingers by the sharp wire ends. Twisting a wire around a tooth conveys little feel as to its tightness and there is a danger of avulsion if force is too great. Wires tightened during the application of arch bars around the teeth may cause ischaemic necrosis of the mucosa and the periodontal membrane and if damage is extensive, tooth loss may result (Wilson and Hohmann, 1976). On the other hand if the wires are not sufficiently tight around the teeth at the time of operation, they may further loosen and require retightening. Besides being unpleasant for the patients, retightening carries the risk of wire breakage and possibly a need for further anaesthesia to replace the wire. Recently, self-tapping alveolar screws have been advocated for intermaxillary fixation (Jones, 1999). Despite the fact that the method is easy to apply it carries the risk of damage of the roots of the teeth. It has been shown that the surgical treatment of the mandibular fractures is associated with a high incidence of glove perforation when a wiring technique is used (Avery and Johnson, 1992). These ‘‘needlestick’’ injuries carry the risk of transmitting infection between patients and surgeons (Scully and Porter, 1991). The Dimac wire (US Food and Drug Administration No. K910090; Dimac Medical Inc., Blaine, Wash) was developed as a simple and precise method for jaw immobilization that promised greater safety to both the patients and surgeons. Each wire is made of 22-gauge malleable stainless steel that is
MATERIAL AND METHODS In order to compare Dimac wires with ready-made arch bars, this study was carried out on 50 patients who had minimally displaced mandibular fractures and in whom intermaxillary fixation was required as a part of the treatment. Only cases with almost full dentition were considered in the study. Cases were randomly allocated to have either Dimac wires or Erick arch bars for intermaxillary immobilization. The investigation was carried out in two centres, Canniesburn Hospital, the West of Scotland Regional Maxillofacial Unit, UK, and Norfolk & Norwich Hospital, UK. Two surgeons, one from each centre, applied Dimac wires and arch bars, with an equal number of patients treated at each centre. All the cases in the arch bar group had the treatment carried out under general anaesthesia, whereas, 20% of the cases in Dimac wire groups had their treatment under local anaesthesia. The 159
160 Journal of Cranio-Maxillofacial Surgery
Fig. 2 – Interdental immobilization using Dimac wires. Fig. 1 – Dimac wires. Each wire is made of 22-gauge malleable stainless-steel threaded at one end and fitted with a threaded nylon nut that has a concave upper surface.
following parameters assessment:
were
considered
in
the
1. The time in minutes required for application of arch bars or Dimac wires. 2. The percentage of cases with needle-stick injuries during application. 3. Subjective assessment of gingival and periodontal damage following the use of arch bars or Dimac wires. RESULTS Of the 50 cases, 29 patients were allocated to the Dimac wires group and 21 to the arch bar group. The average time required for the application of full upper and lower arch bars was 34.6 min (sd 7.2) in comparison with 19.9 min (sd 4.9) for the Dimac wires (Fig. 3). The difference between the two groups was statistically significant (Student’s t-test at po0:05). There was a significant reduction in the incidence of skin-penetrating injuries when Dimac wires were used for fixation (po0:05) (Fig. 4). There were no statistically significant differences between the two centres in the application time required or the percentage of needle-stick injuries associated with the methods of fixation. The mean time of intermaxillary fixation was 21 days in Dimac wire group and 19 days in arch bar group. Patients reported considerable difficulty in maintaining oral hygiene measures with arch bar fixation, leading to associated periodontal problems. Patients did not report any difficulty in cleaning around Dimac wires. In five cases in the arch bar groups, soft wax was applied on the edges of the arch bars to protect the oral mucosa of the cheeks and lips. After removal of interdental devices, more marginal periodontitis was noticed in the patients who had arch bar fixations in comparison to cases in the other group.
Fig. 3 – (a, b) Mean time required to apply arch bars and Dimac wires.
Minimal adjustment was required in 21 (58%) of the cases that had Dimac wire for intermaxillary fixation. Dimac wire did not break in any case and none of the patients required further application of a new wire to strengthen the fixation. In the arch bar group, breakage of a wire was observed in eight (38%) cases and a new wire was applied. DISCUSSION The surgical treatment of mandibular fracture is associated with a relatively high incidence of glove
Comparative assessment for interdental immobilization 161
for the application of the upper and lower arch bars. This reduces the operating time required for intermaxillary fixation by 43%. When the remaining teeth are not sufficient for interdental wiring, arch bars should be used. In these cases circum-mandibular or piriform aperture wires can be also applied. Dimac wires are less traumatic to apply and remove, easier to keep clean and any further adjustment can be implemented. When arch bars are used for intermaxillary fixation, the end of the wires should be secured with an artery forceps whilst passing wire interproximally. This would minimize the needle-stick injuries associated with application of arch bars. Fig. 4 – Incidence of skin-penetrating injuries when Dimac wires and arch bars were used for intermaxillary immobilization.
perforation. The overall incidence of perforation is especially high when a wiring technique is used (Avery and Johnson, 1992). The majority of reported wire-stick injuries occurred whilst passing wire interproximally, by snagging a glove upon an exposed wire in the forceps or upon an inadequately positioned interproximal wire. This problem does not exist when using Dimac wires because these are threaded at one end and fitted with a threaded nylon nut to fit interproximally between the teeth. This study demonstrates that Dimac wires are safer to use with less needle-stick injuries in comparison with arch bars. Needle-stick injuries carry the potential risk of transmitting HIV infection between patients and dental staff (Scully and Porter, 1991). However, this risk is very low (Klein et al., 1988) due to the fact that the amount of blood carried out by wire-stick is smaller than that carried in a hollow needle. The risk of the transmission of hepatitis B infection under similar circumstances is much greater (Royal College of Surgeons of England, 1992). The main flaw of this study is the lack of a precise method for periodontological assessment. The damage of the periodontium surrounding the teeth was recorded subjectively, by visual inspection, at the time of removing the wires and arch bars. Dimac wires are not suitable in deep overbite cases, because this will bring the nylon nuts into a close proximity to each other and the correct intermaxillary wiring would not be achieved. Despite the fact that Dimac wires are more expensive than arch bars, they are still cost-effective. The average time taken for the application of Dimac wires was 20 min in comparison to 35 min required
CONCLUSION Dimac wires are safer to use and less harmful to the surrounding periodontium in comparison to the arch bars the wires were compared with.
References Avery CME, Johnson PA: Surgical glove perforation and maxillofacial trauma: to plate or wire? Br J Oral Maxillofac Surg 30: 31–35, 1992 Jones DC: The intermaxillary screw: a dedicated bicortical bone screw for temporary intermaxillary fixation. Br J Oral Maxillofac Surg 37: 115–116, 1999 Klein RS, Phelan JA, Freeman K, Schable C, Friedland GH, Trieger N, Steigbigel NH: Low occupational risk of human immunodeficiency virus infection among dental professionals. N Engl J Med 318: 86–90, 1988 Royal College of Surgeons of England: A statement by the college on A.I.D.S. and H.I.V. infection, 1990&1992 Schuchardt K, Metz HJ: Injuries of the facial skeleton. Modern Trends Plast Surg 2: 62–107, 1966 Scully C, Porter S: The level of risk of transmission of human immunodeficiency virus between patients and dental staff. Br Dent J 170: 94–100, 1991 Wilson KS, Hohmann A: Dental anatomy and occlusion. Otolaryngol Clin North Am 9: 425–438, 1976 Dr. Ashraf F Ayoub, MDS, PhD, FDSRCS (Ed) FDSRCPS(Glasg) Glasgow Dental Hospital and School Oral and Maxillofacial Surgery 378 Sauchiehall Street Glasgow G2 3JZ UK Tel: +44-141-211-9650 Fax: +44-141-211-9601 E-mail: [email protected] Paper received 29 May 2002 Accepted 13 March 2003
Comparative assessment of two methods used for interdental immobilization Ashraf F. Ayoub1, John Rowson2 1
University of Glasgow Dental School & Canniesburn Hospital, Glasgow, UK; 2 Queens Medical Centre, University Hospital, Nottingham, UK
SUMMARY. Aim: This investigation was carried out to compare Dimac wires with arch bars for interdental
immobilization. Material and methods: The assessment was conducted on 50 patients who had mandibular fractures and in whom intermaxillary fixation was required as a part of the treatment. The time required for applying each method of fixation, the needle-stick injuries that occurred during their application, and the periodontal damage that followed interdental immobilization was investigated. Results: The mean time required for the application of Dimac wires was significantly less than that required for arch bars. The needle-stick injuries were significantly less with Dimac wires. Patients reported difficulty with oral hygiene with arch bars in place. This was associated with periodontal damage following removal of fixation. Conclusion: Dimac wires is safer to use and less traumatic to the periodontium r 2003 European Association for Cranio-Maxillofacial Surgery.
threaded at one end and fitted with a threaded nylon nut that has a concave upper surface (Fig. 1). There are 167 precision-cut threads per inch on the wire, and each full turn of the threaded nylon nut represents 0.152 mm of movement along the wire. The wire is applied by being passed between adjoining teeth from buccal to lingual and back to the buccal surface through the next interdental space, encircling the tooth. After the nylon nut is snugged against the teeth, it is unwound 10 turns, and the distal end of the wire is brought medially and clockwise around the proximal end. It is turned sharply on itself to create a tight hook, and any excess wire is snipped off. The nut is then tightened down, and any excess wire protruding through the centre of the nut is trimmed off in the concavity so that it does not irritate the mucosa (Fig. 2).
INTRODUCTION Different methods have been used for intermaxillary fixation including custom-made arch bars, eyelet wires, and Schuchardt arch-shaped splints made of metal and acrylic (Schuchardt and Metz, 1966). However, these are time-consuming methods, with a constant danger of trauma to the surgeon’s fingers by the sharp wire ends. Twisting a wire around a tooth conveys little feel as to its tightness and there is a danger of avulsion if force is too great. Wires tightened during the application of arch bars around the teeth may cause ischaemic necrosis of the mucosa and the periodontal membrane and if damage is extensive, tooth loss may result (Wilson and Hohmann, 1976). On the other hand if the wires are not sufficiently tight around the teeth at the time of operation, they may further loosen and require retightening. Besides being unpleasant for the patients, retightening carries the risk of wire breakage and possibly a need for further anaesthesia to replace the wire. Recently, self-tapping alveolar screws have been advocated for intermaxillary fixation (Jones, 1999). Despite the fact that the method is easy to apply it carries the risk of damage of the roots of the teeth. It has been shown that the surgical treatment of the mandibular fractures is associated with a high incidence of glove perforation when a wiring technique is used (Avery and Johnson, 1992). These ‘‘needlestick’’ injuries carry the risk of transmitting infection between patients and surgeons (Scully and Porter, 1991). The Dimac wire (US Food and Drug Administration No. K910090; Dimac Medical Inc., Blaine, Wash) was developed as a simple and precise method for jaw immobilization that promised greater safety to both the patients and surgeons. Each wire is made of 22-gauge malleable stainless steel that is
MATERIAL AND METHODS In order to compare Dimac wires with ready-made arch bars, this study was carried out on 50 patients who had minimally displaced mandibular fractures and in whom intermaxillary fixation was required as a part of the treatment. Only cases with almost full dentition were considered in the study. Cases were randomly allocated to have either Dimac wires or Erick arch bars for intermaxillary immobilization. The investigation was carried out in two centres, Canniesburn Hospital, the West of Scotland Regional Maxillofacial Unit, UK, and Norfolk & Norwich Hospital, UK. Two surgeons, one from each centre, applied Dimac wires and arch bars, with an equal number of patients treated at each centre. All the cases in the arch bar group had the treatment carried out under general anaesthesia, whereas, 20% of the cases in Dimac wire groups had their treatment under local anaesthesia. The 159
160 Journal of Cranio-Maxillofacial Surgery
Fig. 2 – Interdental immobilization using Dimac wires. Fig. 1 – Dimac wires. Each wire is made of 22-gauge malleable stainless-steel threaded at one end and fitted with a threaded nylon nut that has a concave upper surface.
following parameters assessment:
were
considered
in
the
1. The time in minutes required for application of arch bars or Dimac wires. 2. The percentage of cases with needle-stick injuries during application. 3. Subjective assessment of gingival and periodontal damage following the use of arch bars or Dimac wires. RESULTS Of the 50 cases, 29 patients were allocated to the Dimac wires group and 21 to the arch bar group. The average time required for the application of full upper and lower arch bars was 34.6 min (sd 7.2) in comparison with 19.9 min (sd 4.9) for the Dimac wires (Fig. 3). The difference between the two groups was statistically significant (Student’s t-test at po0:05). There was a significant reduction in the incidence of skin-penetrating injuries when Dimac wires were used for fixation (po0:05) (Fig. 4). There were no statistically significant differences between the two centres in the application time required or the percentage of needle-stick injuries associated with the methods of fixation. The mean time of intermaxillary fixation was 21 days in Dimac wire group and 19 days in arch bar group. Patients reported considerable difficulty in maintaining oral hygiene measures with arch bar fixation, leading to associated periodontal problems. Patients did not report any difficulty in cleaning around Dimac wires. In five cases in the arch bar groups, soft wax was applied on the edges of the arch bars to protect the oral mucosa of the cheeks and lips. After removal of interdental devices, more marginal periodontitis was noticed in the patients who had arch bar fixations in comparison to cases in the other group.
Fig. 3 – (a, b) Mean time required to apply arch bars and Dimac wires.
Minimal adjustment was required in 21 (58%) of the cases that had Dimac wire for intermaxillary fixation. Dimac wire did not break in any case and none of the patients required further application of a new wire to strengthen the fixation. In the arch bar group, breakage of a wire was observed in eight (38%) cases and a new wire was applied. DISCUSSION The surgical treatment of mandibular fracture is associated with a relatively high incidence of glove
Comparative assessment for interdental immobilization 161
for the application of the upper and lower arch bars. This reduces the operating time required for intermaxillary fixation by 43%. When the remaining teeth are not sufficient for interdental wiring, arch bars should be used. In these cases circum-mandibular or piriform aperture wires can be also applied. Dimac wires are less traumatic to apply and remove, easier to keep clean and any further adjustment can be implemented. When arch bars are used for intermaxillary fixation, the end of the wires should be secured with an artery forceps whilst passing wire interproximally. This would minimize the needle-stick injuries associated with application of arch bars. Fig. 4 – Incidence of skin-penetrating injuries when Dimac wires and arch bars were used for intermaxillary immobilization.
perforation. The overall incidence of perforation is especially high when a wiring technique is used (Avery and Johnson, 1992). The majority of reported wire-stick injuries occurred whilst passing wire interproximally, by snagging a glove upon an exposed wire in the forceps or upon an inadequately positioned interproximal wire. This problem does not exist when using Dimac wires because these are threaded at one end and fitted with a threaded nylon nut to fit interproximally between the teeth. This study demonstrates that Dimac wires are safer to use with less needle-stick injuries in comparison with arch bars. Needle-stick injuries carry the potential risk of transmitting HIV infection between patients and dental staff (Scully and Porter, 1991). However, this risk is very low (Klein et al., 1988) due to the fact that the amount of blood carried out by wire-stick is smaller than that carried in a hollow needle. The risk of the transmission of hepatitis B infection under similar circumstances is much greater (Royal College of Surgeons of England, 1992). The main flaw of this study is the lack of a precise method for periodontological assessment. The damage of the periodontium surrounding the teeth was recorded subjectively, by visual inspection, at the time of removing the wires and arch bars. Dimac wires are not suitable in deep overbite cases, because this will bring the nylon nuts into a close proximity to each other and the correct intermaxillary wiring would not be achieved. Despite the fact that Dimac wires are more expensive than arch bars, they are still cost-effective. The average time taken for the application of Dimac wires was 20 min in comparison to 35 min required
CONCLUSION Dimac wires are safer to use and less harmful to the surrounding periodontium in comparison to the arch bars the wires were compared with.
References Avery CME, Johnson PA: Surgical glove perforation and maxillofacial trauma: to plate or wire? Br J Oral Maxillofac Surg 30: 31–35, 1992 Jones DC: The intermaxillary screw: a dedicated bicortical bone screw for temporary intermaxillary fixation. Br J Oral Maxillofac Surg 37: 115–116, 1999 Klein RS, Phelan JA, Freeman K, Schable C, Friedland GH, Trieger N, Steigbigel NH: Low occupational risk of human immunodeficiency virus infection among dental professionals. N Engl J Med 318: 86–90, 1988 Royal College of Surgeons of England: A statement by the college on A.I.D.S. and H.I.V. infection, 1990&1992 Schuchardt K, Metz HJ: Injuries of the facial skeleton. Modern Trends Plast Surg 2: 62–107, 1966 Scully C, Porter S: The level of risk of transmission of human immunodeficiency virus between patients and dental staff. Br Dent J 170: 94–100, 1991 Wilson KS, Hohmann A: Dental anatomy and occlusion. Otolaryngol Clin North Am 9: 425–438, 1976 Dr. Ashraf F Ayoub, MDS, PhD, FDSRCS (Ed) FDSRCPS(Glasg) Glasgow Dental Hospital and School Oral and Maxillofacial Surgery 378 Sauchiehall Street Glasgow G2 3JZ UK Tel: +44-141-211-9650 Fax: +44-141-211-9601 E-mail: [email protected] Paper received 29 May 2002 Accepted 13 March 2003