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The biomechanical basis for prophylactic internal fixation of the radial osteocutaneous donor site
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Abstracts / British Journal of Oral and Maxillofacial Surgery 45 (2007) e1–e29
P 74 A novel technique of ‘horseshoe’ Le Fort I ostoetomy Kathleen Fan∗ , D. Coombes, J. Mckenzie, J. Collyer, K. Sneddon Queen Victoria Hospital, East Grinstead, United Kingdom Introduction: Le Fort I osteotomy is the most commonly used technique to correct mid face deformities. Downfracture allows for 3 dimensional repositioning of maxilla either as a single unit or in segments. Long face syndromes necessitate impaction of the maxilla and significant impactions, especially posteriorly are amongst the most challenging. Such impactions require corresponding reduction of the nasal septum to prevent distortion of the nose. Moreover impingement of the palate on the inferior turbinates may lead to functional complications. We describe a modification to the standard Le Fort I osteotomy which reduces some of the technical difficulties and may mitigate some of the functional concerns. A horse shoe osteotomy of the palate is carried out from above. The tooth bearing segment of the maxilla is separated from the vault of the palate enabling independent impaction of the dento-alveolar segment. The potential benefits are easier impaction of the maxilla, lesser reduction of the nasal septum, reduced impingement on the inferior turbinates, and reduce changes in the cross-sectional area of the nose with potentially improved function. doi:10.1016/j.bjoms.2007.07.177 P 75 The camera never lies? Standardising orthognathic photographic records Prakash Promod∗ , K. Salisbury, T. Hill, J. Collyer, K.J. Sneddon Queen Victoria Hospital, East Grinstead, United Kingdom Orthognathic surgery is routinely documented with clinical photography. Lateral cephalometry is a standardised and easily reproducible investigation – coupled with clinical photographs this combined data set is used in patient assessment, treatment planning and follow up using a variety of methods. To make valid comparisons of this data it is essential that the photographic record is similarly standardised. We present examples of a number of simple photographic errors and their effect on the facial proportions of the resulting images. We suggest a standardised method for image capture to avoid these errors and produce consistent data. doi:10.1016/j.bjoms.2007.07.178
P 76 The biomechanical basis for prophylactic internal fixation of the radial osteocutaneous donor site Christopher Avery∗ , A. Best, P. Patterson, J. Rolton, A. Ponter University Hospitals of Leicester, United Kingdom Introduction: Fracture of the radial osteocutaneous donor site is not unusual, 15% (Thoma 1999), mean of 25% (Bowers 2000), and 18% (Clark 2004). Fracture following prophylactic internal fixation (PIF) with a bone plate is uncommon, 9.6% (Werle 2000), 1.9% (Kim 2005) and zero (Nunez 1999, Villaret 2005, Militsakh 2005). The plate may be placed anteriorly (over section defect) or posteriorly (on opposite intact cortex). We investigated the effect of different types of plate and position. Methods: Fifty matched pairs of adult sheep tibiae were tested in torsion and bending. Intact and osteotomised bones were compared to assess the weakening effect of an osteotomy. Pairs of osteotomised bones were compared with and without reinforcement with a steel or titanium plate, placed either anteriorly or posteriorly. Results: In torsion the mean strength of the intact bone was 45% greater than after osteotomy (p = 0.02). The reinforced bone was on average 61% stronger than the unreinforced bone (p < 0.001). The tibia withstood greater bending forces. In bending the mean strength of the intact bone was 188% greater than after osteotomy (p = 0.02). The reinforced bone was on average 184% stronger than the unreinforced bone (p < 0.001). A 3.5 mm dynamic compression plate was the strongest reinforcement. Torsional strength was equally increased in either position but the posterior plate resisted greater bending forces (p = 0.03). Conclusions: A plate in either position has a significant strengthening effect in both torsion and bending. A posterior plate has a greater effect on bending strength. The routine use of PIF is recommended. doi:10.1016/j.bjoms.2007.07.179 P 77 Evaluation of airborne contamination with Staphylococcus aureus and MRSA at the Eastman Dental Hospital Mohammed El Maaytah∗ , M. Drydaki, W. Jerjes, T. Upile, C. Hopper, D. Ready, S. Nair Eastman Dental Institute, London, United Kingdom Introduction: Methicillin resistant Staphylococcus aureus (MRSA) has become a major problem for hospitals worldwide. There is also an increasing incidence of MRSA strains circulating at the community. The dental clinic is considered to be an environment in which cross contamination may occur and there are reports of Staphylococcus aureus and MRSA transmission during dental treatments.
Abstracts / British Journal of Oral and Maxillofacial Surgery 45 (2007) e1–e29
P 74 A novel technique of ‘horseshoe’ Le Fort I ostoetomy Kathleen Fan∗ , D. Coombes, J. Mckenzie, J. Collyer, K. Sneddon Queen Victoria Hospital, East Grinstead, United Kingdom Introduction: Le Fort I osteotomy is the most commonly used technique to correct mid face deformities. Downfracture allows for 3 dimensional repositioning of maxilla either as a single unit or in segments. Long face syndromes necessitate impaction of the maxilla and significant impactions, especially posteriorly are amongst the most challenging. Such impactions require corresponding reduction of the nasal septum to prevent distortion of the nose. Moreover impingement of the palate on the inferior turbinates may lead to functional complications. We describe a modification to the standard Le Fort I osteotomy which reduces some of the technical difficulties and may mitigate some of the functional concerns. A horse shoe osteotomy of the palate is carried out from above. The tooth bearing segment of the maxilla is separated from the vault of the palate enabling independent impaction of the dento-alveolar segment. The potential benefits are easier impaction of the maxilla, lesser reduction of the nasal septum, reduced impingement on the inferior turbinates, and reduce changes in the cross-sectional area of the nose with potentially improved function. doi:10.1016/j.bjoms.2007.07.177 P 75 The camera never lies? Standardising orthognathic photographic records Prakash Promod∗ , K. Salisbury, T. Hill, J. Collyer, K.J. Sneddon Queen Victoria Hospital, East Grinstead, United Kingdom Orthognathic surgery is routinely documented with clinical photography. Lateral cephalometry is a standardised and easily reproducible investigation – coupled with clinical photographs this combined data set is used in patient assessment, treatment planning and follow up using a variety of methods. To make valid comparisons of this data it is essential that the photographic record is similarly standardised. We present examples of a number of simple photographic errors and their effect on the facial proportions of the resulting images. We suggest a standardised method for image capture to avoid these errors and produce consistent data. doi:10.1016/j.bjoms.2007.07.178
P 76 The biomechanical basis for prophylactic internal fixation of the radial osteocutaneous donor site Christopher Avery∗ , A. Best, P. Patterson, J. Rolton, A. Ponter University Hospitals of Leicester, United Kingdom Introduction: Fracture of the radial osteocutaneous donor site is not unusual, 15% (Thoma 1999), mean of 25% (Bowers 2000), and 18% (Clark 2004). Fracture following prophylactic internal fixation (PIF) with a bone plate is uncommon, 9.6% (Werle 2000), 1.9% (Kim 2005) and zero (Nunez 1999, Villaret 2005, Militsakh 2005). The plate may be placed anteriorly (over section defect) or posteriorly (on opposite intact cortex). We investigated the effect of different types of plate and position. Methods: Fifty matched pairs of adult sheep tibiae were tested in torsion and bending. Intact and osteotomised bones were compared to assess the weakening effect of an osteotomy. Pairs of osteotomised bones were compared with and without reinforcement with a steel or titanium plate, placed either anteriorly or posteriorly. Results: In torsion the mean strength of the intact bone was 45% greater than after osteotomy (p = 0.02). The reinforced bone was on average 61% stronger than the unreinforced bone (p < 0.001). The tibia withstood greater bending forces. In bending the mean strength of the intact bone was 188% greater than after osteotomy (p = 0.02). The reinforced bone was on average 184% stronger than the unreinforced bone (p < 0.001). A 3.5 mm dynamic compression plate was the strongest reinforcement. Torsional strength was equally increased in either position but the posterior plate resisted greater bending forces (p = 0.03). Conclusions: A plate in either position has a significant strengthening effect in both torsion and bending. A posterior plate has a greater effect on bending strength. The routine use of PIF is recommended. doi:10.1016/j.bjoms.2007.07.179 P 77 Evaluation of airborne contamination with Staphylococcus aureus and MRSA at the Eastman Dental Hospital Mohammed El Maaytah∗ , M. Drydaki, W. Jerjes, T. Upile, C. Hopper, D. Ready, S. Nair Eastman Dental Institute, London, United Kingdom Introduction: Methicillin resistant Staphylococcus aureus (MRSA) has become a major problem for hospitals worldwide. There is also an increasing incidence of MRSA strains circulating at the community. The dental clinic is considered to be an environment in which cross contamination may occur and there are reports of Staphylococcus aureus and MRSA transmission during dental treatments.