Do Hybrid Arch Bar Screws Pose a Risk to the Dentition?
Location
Medical Education Building, LSUHSC-NO
Presentation Date
10-10-2019 10:00 AM
End Date
10-10-2019 12:00 PM
Description
Introduction: Hybrid arch bars have become popular alternatives to traditional Erich arch bars for use in craniomaxillofacial surgery. They offer the benefit of decreased time for application, reduced risk of sharps exposure to healthcare personal, and decreased risk of compromised periodontal health. However, it has not been established if they pose a significant risk to the dentition. Damage to the teeth, such as violation of the pulpal canal or root fracture can lead to clinically significant sequela. The purpose of the study was to examine if the screws contact or violate the tooth structure during placement. Method: A retrospective radiographic review was conducted of 50 patients treated with Stryker SMARTLock Hybrid Maxillomandibular fixation system at University Medical Center Hospital in New Orleans from January 2018 to August 2018. Post-operative axial slices of computed tomography (CT) scans were examined for screw position relative to the adjacent tooth roots. Patients were excluded if they were fully edentulous, incarcerated, and if they did not have arch bars applied to both arches. Variables examined were screw violation of the periodontal ligament, gross disruption of tooth root dentin, pulpal violation, and root fracture. The location of the tooth injured in regards to maxilla versus mandible and anterior, premolar, or molar dentition was also examined. Statistical analysis was performed with unpaired t-test and one-way ANOVA with Tukey post hoc test. Results: 50 patients were analyzed, for a total of 507 screws in 100 arches with 1340 teeth present. Overall, 31.49% of teeth had contact or injury with the screws, with screw violation of the periodontal ligament 7.39%, dentin 19.78%, pulp 3.81%, and root fracture 0.45%. There was a significantly higher incidence of root fracture in the mandible (Total:5) versus maxilla (Total:1) (p<0.05). Maxillary teeth (mean 4.74 ±1.64) (p<0.05) were significantly more likely to experience contact or injury with screws compared to the mandibular teeth (mean 3.68 ± 1.63). The occurrence of screw contact or injury to the root according to location was anterior dentition 13.66%, premolars 7.99%, and molars 9.78%. The anterior teeth were significantly more likely to be in contact or sustain injury from a screw when compared to the premolar and molar teeth (p<0.05). Conclusions: Hybrid arch bars offer many benefits to the surgeon, but there does exist a risk of the screw contacting or violating the tooth structure. There is an increased risk to the anterior dentition and the maxillary dentition. Mandibular teeth are also more likely to experience root fracture compared to the maxilla. The hybrid arch bars should be applied with consideration to patient anatomy and tooth position to prevent injury to the tooth roots.
Recommended Citation
Kim, Chris DMD, MSE, "Do Hybrid Arch Bar Screws Pose a Risk to the Dentition?" (2019). Medical Student Research Poster Symposium. 24.
https://digitalscholar.lsuhsc.edu/sommrd/2019/posters/24
Do Hybrid Arch Bar Screws Pose a Risk to the Dentition?
Medical Education Building, LSUHSC-NO
Introduction: Hybrid arch bars have become popular alternatives to traditional Erich arch bars for use in craniomaxillofacial surgery. They offer the benefit of decreased time for application, reduced risk of sharps exposure to healthcare personal, and decreased risk of compromised periodontal health. However, it has not been established if they pose a significant risk to the dentition. Damage to the teeth, such as violation of the pulpal canal or root fracture can lead to clinically significant sequela. The purpose of the study was to examine if the screws contact or violate the tooth structure during placement. Method: A retrospective radiographic review was conducted of 50 patients treated with Stryker SMARTLock Hybrid Maxillomandibular fixation system at University Medical Center Hospital in New Orleans from January 2018 to August 2018. Post-operative axial slices of computed tomography (CT) scans were examined for screw position relative to the adjacent tooth roots. Patients were excluded if they were fully edentulous, incarcerated, and if they did not have arch bars applied to both arches. Variables examined were screw violation of the periodontal ligament, gross disruption of tooth root dentin, pulpal violation, and root fracture. The location of the tooth injured in regards to maxilla versus mandible and anterior, premolar, or molar dentition was also examined. Statistical analysis was performed with unpaired t-test and one-way ANOVA with Tukey post hoc test. Results: 50 patients were analyzed, for a total of 507 screws in 100 arches with 1340 teeth present. Overall, 31.49% of teeth had contact or injury with the screws, with screw violation of the periodontal ligament 7.39%, dentin 19.78%, pulp 3.81%, and root fracture 0.45%. There was a significantly higher incidence of root fracture in the mandible (Total:5) versus maxilla (Total:1) (p<0.05). Maxillary teeth (mean 4.74 ±1.64) (p<0.05) were significantly more likely to experience contact or injury with screws compared to the mandibular teeth (mean 3.68 ± 1.63). The occurrence of screw contact or injury to the root according to location was anterior dentition 13.66%, premolars 7.99%, and molars 9.78%. The anterior teeth were significantly more likely to be in contact or sustain injury from a screw when compared to the premolar and molar teeth (p<0.05). Conclusions: Hybrid arch bars offer many benefits to the surgeon, but there does exist a risk of the screw contacting or violating the tooth structure. There is an increased risk to the anterior dentition and the maxillary dentition. Mandibular teeth are also more likely to experience root fracture compared to the maxilla. The hybrid arch bars should be applied with consideration to patient anatomy and tooth position to prevent injury to the tooth roots.
Comments
Mentor: Dane St. John, DMD, MD (Oral and Maxillofacial Surgery)