Is the Mandible Injury Severity Score a Valid Measure of Mandibular Injury Severity?

Risk Factors for Postoperative Complications Following Mandibular Fracture Repair

Complications following mandibular fracture repair (MFR) may carry significant morbidity to patients. The purpose of our study is to determine the risk factors for postoperative complications following MFR. The authors conducted a retrospective cohort study of trauma patients who underwent MFR in 2018 and 2019. Excluded were patients below 18 years old and those with postoperative follow-up <2 weeks. The primary outcome was the incidence of major and minor postoperative complications following MFR. Of n=275 patients included, mean (SD) age was 35 (14) years and median (IQR) follow up was 49 (26-117) days. Most patients [n=208 (76%)] underwent both maxillomandibular/intermaxillary fixation (MMF/IMF) and open reduction and internal fixation (ORIF). The incidence of major postoperative complications was 19% (n=51) including malunion [n=8 (2.9%)], malocclusion [n=21 (7.6%)], and unplanned reoperation [n=26 (9.5%)]. The incidence of minor postoperative complications was 61% (n=167). Alcohol use at the time of surgery and greater MISS score were associated with greater odds of major complications [adjusted odds ratio (aOR) 95% CI: 3.4 (1.2-9.0), 1.09 (1.02-1.160), respectively]. Smoking at the time of surgery and moderately (>2 mm) and severely displaced fractures (>4 mm) were associated with greater odds of minor complications [aOR (95% CI): 2.1 (1.04-4.2), 2.7 (1.2-6.4), 2.7 (1.1-6.6), respectively]. Alcohol use, smoking, greater MISS score, and displaced fractures >2 mm were significant risk factors for postoperative complications following MFR. Our findings can help guide informed decision making and surgical planning in patients with mandibular fractures.

Do Postoperative Surgeon Phone Calls Improve Outcomes Following Mandibular Fracture Repair?

BACKGROUND

Complications of open reduction and internal fixation (ORIF) of mandibular fractures are influenced by several patient factors. A postoperative surgeon phone call could modify these factors through education and reinforcement of instructions, but its effect has not been studied.

PURPOSE

The purpose of this study was to measure and compare the frequencies of postoperative inflammatory complications (POICs) following ORIF of mandibular fractures in patients who did and did not receive a postoperative surgeon phone call.

STUDY DESIGN, SETTING, SAMPLE

The authors conducted an ambispective cohort study consisting of patients with mandibular fractures treated with ORIF at a large urban trauma hospital with the prospective cohort from January 1, 2021 to March 31, 2022 and a retrospective cohort from April 1, 2020 to December 31, 2020. Prisoners and patients with gunshot wounds were excluded.

PREDICTOR VARIABLE

The primary predictor variable was the surgeon call group. After January 2021, a postoperative call was implemented 1-3 days following fracture repair to review instructions, such as nonchew diet and oral hygiene, and provide education, such as reviewing expectations. Prior to January 2021, patients were not called. This resulted in 3 categories: Not Called, Called and Answered, and No Answer.

MAIN OUTCOME VARIABLES

The primary outcome variable was POICs, defined as the occurrence of exposed or infected hardware, abscess formation, recurrent swelling/pain, nonunion, osteomyelitis, or fistula formation.

COVARIATES

Demographic variables, injury-related variables, and treatment-related variables were also measured.

ANALYSES

Statistical analysis was performed using Fisher's exact and Wilcoxon rank-sum tests, as well as multivariable logistic regression. A P value was considered significant if < .05.

RESULTS

Of the 178 patients in the study, 137 (77%) were male and the average age was 39.9 ± 12.6 years. Sixty-five patients (36.5%) were not called. Of the patients called, 79 (44.4%) answered and 34 (19.1%) did not answer. POICs occurred in 9.2% of the Not Called group and 8.9% of the Called and Answered group (P = .99). In the No Answer group, 29.4% had POICs, which was higher than the other 2 groups (P = .01).

CONCLUSION AND RELEVANCE

A surgeon phone call was not associated with complication rates; however, patients in the No Answer group were significantly more likely to experience a POIC.

Lower Insertional Torque of Fixation Screws for Mandibular Angle Fractures Is Associated With Complications

BACKGROUND

Open reduction and internal fixation (ORIF) is a common treatment for mandibular angle fractures. It is unknown, however, whether the insertional torque of the fixation screws is a risk factor for postoperative complications.

PURPOSE

The purpose of the study was to determine the association between fixation screw insertional torque and postoperative inflammatory complications (POICs).

STUDY DESIGN, SETTING, SAMPLE

The authors conducted a prospective cohort study consisting of all adult patients treated with ORIF of mandibular angle fractures using a single six-hole lateral border plate secured with monocortical screws from January 1, 2020, to October 31, 2022, at a large, urban academic hospital. Patients with gunshot wounds, prolonged maxillomandibular fixation, and bilateral angle fractures were excluded.

PREDICTOR VARIABLE

The predictor variables were the average and lowest insertional torque of the six screws placed for fixation during ORIF.

MAIN OUTCOME VARIABLE

The outcome variable was the presence of POICs, defined as the occurrence of exposed or infected hardware, abscess formation, recurrent swelling/pain, nonunion, osteomyelitis, or fistula formation.

COVARIATES

Demographics, medical history, mechanism, diagnosis, and treatment-related variables were also analyzed.

ANALYSES

Descriptive and bivariate analyses were performed. A P value of ≤ .05 was considered significant.

RESULTS

There were 51 patients included in the study, 37 (72.5%) men, with a mean age of 31.2 ± 10.1 years. POICs occurred in 15.7% of patients. The average insertional screw torque was 46.9 ± 7.8 Ncm, and the mean lowest insertional screw torque per plate was 34.3 ± 10.2 Ncm. The average torque values were not lower in patients who had POICs versus those who did not (45.0 ± 8.6 Ncm vs 48.4 ± 7.6 Ncm, respectively, P = .16). However, the lowest torque value was less in patients who had POICs compared to those who did not (27.5 ± 11.0 Ncm vs 35.6 ± 9.7 Ncm, respectively, P = .04).

CONCLUSION AND RELEVANCE

Among patients with mandibular angle fractures treated with ORIF, decreased insertional torque for the lowest of the six screws placed for fixation was associated with complications. While previous studies have shown certain plating schemes have been associated with complications, the quality of fixation also plays a role.

Correlation between Malocclusion and Mandibular Fractures: An Experimental Study Comparing Dynamic Finite Element Models and Clinical Case Studies

Mandibular fractures are very common in maxillofacial trauma surgery. While previous studies have focused on possible risk factors related to post-operative complications, none have tried to identify pre-existing conditions that may increase the risk of mandibular fractures. We hypothesized, through clinical observation, that anatomical conditions involving poor dental contacts, such as malocclusions, may increase the risk of mandibular fractures. This work was subdivided into two parts. In the first part, Digital Imaging and Communications in Medicine (DICOM) data of four healthy patients characterized by different dentoskeletal occlusions (class I, class II, class III, and anterior open bite) have been used to develop four finite element models (FEMs) that accurately reproduce human bone structure. A vertical and lateral impact have been simulated at increasing speed on each model, analyzing the force distribution within the mandibular bone. Both vertical and lateral impact showed higher level of stress at the impact point and in the condylar area in models characterized by malocclusion. Specifically, the class III and the open bite models, at the same speed of impact, had higher values for a longer period, reaching critical stress levels that are correlated with mandibular fracture, while normal occlusion seems to be a protective condition. In the second part of this study, the engineering results were validated through the comparison with a sample of patients previously treated for mandibular fracture. Data from 223 mandibular fractures, due to low-energy injuries, were retrospectively collected to evaluate a possible correlation between pre-existing malocclusion and fracture patterns, considering grade of displacement, numbers of foci, and associated CFI score. Patients were classified, according to their occlusion, into Class I, Class II, Class III, and anterior open bite or poor occlusal contact (POC). Class I patients showed lower frequencies of fracture than class II, III, and open bite or POC patients. Class I was associated with displaced fractures in 16.1% of cases, class II in 47.1%, class III in 48.8% and open bite/POC in 65.2% of cases (p-value < 0.0001). In class I patients we observed a single non-displaced fracture in 51.6% of cases, compared to 12.9% of Class II, 19.5% of Class III and 22.7% of the open bite/POC group. Our analysis shows that class I appears to better dissipate forces applied on the mandible in low-energy injuries. A higher number of dental contacts showed a lower rate of multifocal and displaced fractures, mitigating the effect of direct forces onto the bone. The correlation between clinical data and virtual simulation on FEM models seems to point out that virtual simulation successfully predicts fracture patterns and risk of association with different type of occlusion. Better knowledge of biomechanics and force dissipation on the human body may lead to the development of more effective safety devices, and help select patients to plan medical, orthodontic/dental, and/or surgical intervention to prevent injuries.

Does a Short Period of Maxillomandibular Fixation Decrease Complications in Open Reduction Internal Fixation of Mandibular Angle Fractures?

PURPOSE

A short duration of postoperative maxillomandibular fixation (MMF) has the potential to reduce complications following open reduction and internal fixation (ORIF) of mandibular angle fractures. The purpose of this study was to determine if a short duration of MMF is associated with a reduced rate of postoperative inflammatory complications (POICs) in patients with mandibular angle fractures undergoing ORIF.

METHODS

The authors conducted a retrospective cohort study consisting of patients treated with ORIF for mandibular angle fractures from August 1, 2015 to May 31, 2020 at an urban, level 1 trauma center. Patients under the age of 18 years, bilateral angle fractures, those with MMF periods of more than 3 weeks, and those patients without documentation of the duration of MMF were excluded from the study. The primary predictor variable was the use of a short duration (less than 2 weeks) of postoperative MMF. The outcome variable of interest was the presence of POICs. Categorical covariates were compared using Fisher's exact tests, while continuous variables were compared using Wilcox rank-sum tests. Multivariable logistic regression adjustment was also performed.

RESULTS

There were 307 patients included in the study, 84.4% of which were men. The average age was 32.5 years. Patients with a short duration of MMF had a POIC rate of 8.3% compared to 18.2% for no MMF (P = .08). In the adjusted analysis, patients with a short duration of MMF time had a significant decrease in POIC risk compared to no MMF (adjusted odds ratio [aOR] = 0.32, 95% confidence interval [CI] = 0.11 to 0.97). Other significant variables in the regression analysis included plating type and noncompliance. Inferior border rigid fixation was associated with decreased POIC risk compared to ladder plates and lateral border plates (aOR 5.8, 95% CI = 1.8 to 18.4 and aOR 5.1, 95% CI = 1.4 to 18.7, respectively).

CONCLUSION

The findings from our study suggest that a short duration of postoperative MMF may reduce POICs following ORIF of mandibular angle fractures.

Comprehensive facial injury (CFI) score as a predictor of surgical time, length of hospital stay, and head injury? Our experience at level I trauma center

Purpose:

The present study aimed to evaluate the statistical significance of comprehensive facial injury (CFI) score concerning total surgical time (ST), length of hospital stay (LHS), and head injury in maxillofacial trauma patients.

Methods:

This retrospective observational study included 288 patients having maxillofacial injuries with or without associated head injury. CFI score was calculated for each of them. One-way ANOVA and Kruskal–Wallis H-test were used to compare ST (minutes), LHS (days), and Glasgow Coma Scale (GCS) score among the CFI score clusters. Head injury among the CFI score clusters was compared using Fisher's exact test. The level of statistical significance was set at P < 0.05.

Results:

Of total 288 cases (males: 83.68%, females: 16.31%, mean age: 30 ± 15.92 years), road traffic accidents accounted for 76.0% of admissions. A definitive approach (open reduction and internal fixation) was used in 26.38% of cases. Statistically significant association of CFI score was obtained with ST and LHS in high-dependency unit (P < 0.001). Posttraumatic head injury was seen in 21.25% of cases. A significant association of CFI score with GCS score (P = 0.032) and with head injury (P = 0.019) was found.

Conclusion:

CFI score is a comprehensive yet simple scale to assess ST and LHS. A strong correlation established between CFI score and these variables further validate its reliability as a perfect tool for communication of the maxillofacial morbidity and in making a treatment protocol, although its predictive ability for associated head injuries needs to be studied further.

Is Distance Between Home and Treatment Site a Risk Factor for Complications After Treating Mandibular Fractures?

PURPOSE

Our level I trauma center provides care over a large geographic area including Alaska, Washington, Idaho, Montana, and Wyoming, with many patients traveling hundreds of miles to receive care. Distance to a treatment site is documented to be an independent risk factor for complications after multisystem trauma, but it is unclear if it is a risk factor for isolated mandibular fractures. The study purpose was to measure the association between distance to treatment site and risk for postoperative complications after treatment of isolated mandibular fractures.

MATERIALS AND METHODS

The investigators designed and implemented a retrospective cohort study and enrolled a sample derived from patients treated for isolated mandibular fractures at Harborview Medical Center by the oral and maxillofacial surgery service between June 2012 and December 2016. The primary predictor variable was distance (miles) between the patient's residence and site of treatment (Harborview Medical Center). The primary outcome variable was postoperative complication (yes or no), subcategorized as major and minor. Secondary outcome variables were time to treatment between injury and operative treatment (days) and length of hospital stay (LOS) (days). Descriptive, bivariate, and multiple logistic regression statistics were computed to measure the association between distance to treatment site and postoperative complications, time to treatment, and LOS. The level of statistical significance was set at P ≤ .05.

RESULTS

The study sample was composed of 403 subjects with a mean age of 32.6 ± 14.3 years and 80% were men. The average distance from the patient's residence to treatment site was 44.8 ± 128.6 miles (range, 0 to 1,440 miles; median, 20.4 miles). Major complications occurred in 11.6% of patients. The average distance between patients with and without postoperative complications was not significantly different (42.3 ± 55.8 miles vs 45.5 ± 141.7 miles; P = .8). Increasing distance was significantly associated with longer LOS (r = 0.16; P < .001) but not time to treatment (r = .04; P = .4).

CONCLUSIONS

In contrast to other studies regarding multisystem trauma, complications after treating isolated mandible fractures were not associated with increasing distance to treatment site. Increasing distance may be associated with longer LOS but not time to treatment.

Neurosensory Recovery Following Mental Nerve Skeletonization in Intraoral Open Reduction and Internal Fixation of Mandible Fractures

PURPOSE

The purpose of this study was to evaluate neurosensory recovery after mental nerve skeletonization in open reduction and internal fixation (ORIF) of mandible fractures.

METHODS

This was a prospective nonrandomized observation study of adult subjects treated at a Level I trauma center between April 1, 2016 and December 31, 2019, with mental nerve skeletonization for ORIF of mandible fractures. Age, sex, and mandibular injury severity score (MISS), and functional sensory recovery (FSR) and subjective neurosensory recovery of skeletonized mental nerve were recorded at preoperative and regularly scheduled follow-up appointments. Uninomial and multinomial logistic regressions were conducted with a significance level of < 0.05.

RESULTS

Twenty-six subjects (all male) completed all the postoperative protocol requirements and were included in this study. All subjects had a loss of FSR (S0) and subjective neurosensation immediately after surgery. Half of the subjects achieved FSR (S3) and subjective neurosensory recovery (VAS < 4) an average of 42 days after surgery. All subjects improved FSR (S4) by 57 days and subjective neurosensory recovery by 90 days after surgery. These were independent of MISS but had decreased recovery time with increased age. No incidences of mental nerve neuropathic pain during the trial period were found.

CONCLUSIONS

FSR and subjective neurosensory recovery from mental nerve skeletonization in intraoral ORIF of mandible fractures was achieved in all subjects by the end of this study. Neurosensory recovery was independent of MISS but decreased with increased age. Initial inverse correlations between objective and subjective neurosensory assessments were insignificant at study completion. No incidences of neuropathic pain were identified during the time of this study. Mental nerve skeletonization in ORIF of mandible fracture may be performed with an anticipated return of functional and subjective neurosensory recovery within 3 months of surgery.

Occlusal Instability Results in Increased Complication Rates After Treatment of Mandibular Fractures

PURPOSE

It is important to understand the factors that can increase the incidence of complications after mandibular fracture (MF) treatment. The objective of the present study was to investigate whether occlusal stability influences the occurrence of postoperative complications in MFs treated with internal rigid fixation.

PATIENTS AND METHODS

We performed a prospective cohort study of patients treated for MF by osteosynthesis with plate and screw fixation. The primary predictor variable was the occlusal stability (yes vs no). Occlusion was scored as stable (group 1) if the patients had all their teeth and no free ends in either dental arch. Occlusion was coded as unstable (group 2) if the patients were partially edentulous with free ends in either dental arch or had edentulism involving more than 6 dental elements. The primary outcome variable was postoperative complication (yes vs no). The secondary outcome variables were the osteosynthesis system used (2.0 or 2.4 mm), local factors, age, and gender. Statistical analysis was performed using the χ² statistical test at 5% significance.

RESULTS

Of 115 patients with 121 MFs, 73 (63.48%) had stable occlusion (group 1) and 42 (36.52%) had unstable occlusion (group 2). The mean age was 34.11 years, and 71.3% were men. The postoperative complication rate was 8.70% (10 patients). Of the 10 patients with complications, 3 (2.6%) were in group 1 and 7 (6.1%) were in group 2 (P = .021 and P < .05, respectively). The 2.0-mm system was used in 107 cases (93%). All the complications were associated with use of the 2.0-mm osteosynthesis plates, occurring in 3 of 69 patients in group 1 (4.34%) and 7 of 38 patients in group 2 (18.42%; P = .032 and P < .05, respectively). The greatest number of complications was associated with unilateral MF (9 of 109). The occurrence of postoperative complications in angle and symphysis/parasymphysis fracture sites was equal.

CONCLUSIONS

The results of the present study suggest that unstable occlusion could increase the rate of postoperative complications in MFs treated with plates and screws. Future studies are required with occlusal stability included as a variable.

Understanding the relevance of comprehensive facial injury (CFI) score: Statistical analysis of overall surgical time and length of stay outcomes

Comprehensive facial injury (CFI) score is a powerful and extremely simple scale used to grade the clinical severity of all facial injuries, and is expressed in terms of the overall surgical time needed for definitive treatment. Its statistical validation was previously reported in 2019. The aim of this study was to investigate further the link with duration of surgery, applying the score to a larger sample of patients, and to evaluate the relationship between CFI score and other extremely relevant dependent variables: length of stay (LOS) in high care units (HCU) and in intensive care units (ICU). 1406 patients with diagnosis of at least one facial bone fracture, and treated by the same team in two highly specialized trauma centers, were studied. For each patient a specific CFI score is assigned and overall surgical time, length of stay, and presence of associated injuries were recorded. Data were divided into six clusters according to CFI score: (1) 0-5, (2) 6-10, (3) 11-15, (4) 16-20, (5) 21-25, and (6) >25. Regressions between CFI clusters and duration of surgery (minutes), LOS in ICU (days), and in HCU (days) were established. In addition, the presence of associated head and/or somatovisceral injuries was analyzed and related to CFI score. Statistical analysis confirmed linear regression existing between each CFI cluster and overall surgical time (p < 0.00001), with improved significance of the results using median values of surgical duration for each cluster (p = 0.0001). It also demonstrated the existence of linear regression between all CFI clusters and LOS in HCU (p = 0.0001) and between CFI clusters 3-6 and median values of LOS in ICU (p = 0.0001). Finally, associated injuries were observed to be more frequent in high CFI score clusters, occurring in around 90% of patients with a CFI score >25 (p < 0.00001). Association of head and facial injuries play a major role in high LOS in ICU values, whereas coexistence of facial, head and somatovisceral involvement increases LOS in ICU to over twice that for single association. Surgical time and length of stay are outcomes traditionally used to assess the statistical significance of many new proposed trauma score. The strong correlation demonstrated between CFI score and each of these variables confirms its value and reliability. CFI score is proven to be an ideal, simple, informative, and reproducible tool for measuring severity of facial injuries and their clinical impact. It allows correlation with associated head and somatovisceral injuries, focusing attention on the interesting field of reciprocal influences in simultaneous, multidistrectual involvement. None of the previously proposed facial injury severity scales have offered such informative and statistically significant features.