Management of Fractures of the Mandibular Body and Symphysis

What Is the Relationship Between Maxillofacial Injury Location and Associated Injuries?

BACKGROUND

Patients sustaining maxillofacial fractures are at risk for associated injuries (AIs) to other body regions. The incidence of AIs is reported to be from 20 to 35%. AIs may be life-threatening and play a key role in considering first-line management at the emergency department, as well as planning the definitive treatment of maxillofacial fractures.

PURPOSE

The study aimed to determine the frequency and risk factors for AIs in patients with maxillofacial fractures.

STUDY DESIGN, SETTING, SAMPLE

The investigators designed and implemented a retrospective cohort study of patients with facial fractures treated at Central Hospital (Lahti, Finland) from January 1, 2009 through December 31, 2019. All adult patients with verified maxillofacial fractures were included. Patients under 18 years of age were excluded from the study.

PREDICTOR VARIABLE

The predictor variable was the location of the maxillofacial fractures grouped into three categories: mandible alone, midface alone, and both midface and mandible.

MAIN OUTCOME VARIABLE(S)

The primary outcome variable was associated body region injuries coded as present or absent. The secondary outcome variable was the location of the AI categorized as skull, neck, thorax, pelvis, or extremity injuries.

COVARIATES

Other study variables included demographic data (age, sex, alcohol use), Glasgow Coma Scale, and etiology (fall, traffic- and bicycle accident, assault, pedestrian hit by motor vehicle, work-related, or sports/free-time injuries).

ANALYSES

Continuous variables were analyzed for normal distribution using the Shapiro-Wilks test and compared with categorical variables using the Mann-Whitney test. The univariate analyses of categorical variables were analyzed by the χ2 test (P ≤ .05 was considered statistically significant).

RESULTS

During the study period, 443 adult (≥18) patients had maxillofacial fractures. AIs were present in 88 subjects (20%). The mean age was 47.6 years (range 18-91); 52 years with AIs (range 19-91), and 47 years (range 18-92) without AIs (P = .03). Subjects with midface and mandible + midface fractures had greater risk to AIs compared to mandibular fractures (relative risk 2.0, P = .002, relative risk 2.8, P = .009).

CONCLUSION AND RELEVANCE

Every fifth maxillofacial trauma patient had an associated injury. Trauma patients should be evaluated in institutions with trauma protocols and imaging modalities before determining and executing the treatment plan for maxillofacial fractures.

Challenges and Future Perspectives for Additively Manufactured Polylactic Acid Using Fused Filament Fabrication in Dentistry

Additive manufacturing (AM), which is also called rapid prototyping/3D printing/layered manufacturing, can be considered as a rapid conversion between digital and physical models. One of the most used materials in AM is polylactic acid (PLA), which has advantageous material properties such as biocompatibility, biodegradability, and nontoxicity. For many medical applications, it is considered as a leading biomaterial. In dentistry, in addition to its uses in dental models (education, teaching, simulation needs), it can be used for therapeutic objectives and tissue engineering. The fused filament fabrication (FFF) technique, also called fused deposition modeling (FDM), is widely used as an AM technique to perform complex and functional geometries directly from CAD files. In this review, the objective was to present the different challenges and future perspectives of this additively manufactured material by using FFF in dentistry areas. Some suggestions for future directions to extend to more dental applications (support structures, lattice structures, etc.) and to consider more criteria (sustainability, uncertainty etc.) will be discussed. Advanced studies such as machine learning (ML) techniques will be suggested to reduce the failure cases when using the additively manufactured PLA by FFF in dentistry.

Development of the Customized Asymmetric Fixation Plate to Resist Postoperative Relapse of Hemifacial Microsomia Following BSSO: Topology Optimization and Biomechanical Testing

Hemifacial microsomia (HFM), one of the most common congenital facial anomalies, was usually treated with the bilateral sagittal split osteotomy (BSSO) procedure to correct the asymmetric appearance and malocclusion of the mandible. However, the frequent post-operative relapse incidents would lead to the restoration of the mandibular segment to its preoperative position and failure of the BSSO procedure. In this study, a customized asymmetric fixed plate (CAF plate) was developed to resist relapse due to hemifacial microsomia occlusal forces and the different muscular traction forces on both sides of the mandible. For the actual HFM case in this study, the reconstructed mandibular segmental bone model was fixed using BSSO with a rectangular plate (the original CAF plate appearance) in the topology optimization analysis. With the topology optimization technique, the CAF plate was designed with a lightweight profile and excellent structural strength in consideration of the HFM asymmetrical muscle traction and occlusal force. Using biomechanical simulations, the von-Mises stress and CAF plate mandibular segment displacement and the miniplate were compared to evaluate which had superior relapse resistance. In the in-vitro biomechanical test, a fatigue force of 250,000 cycles and a constant muscle traction force were applied to the HFM mandibular model, which was fixed with the CAF plate fabricated using metal 3D printing (selective laser melting, SLM) to obtain the mandibular segment displacement as a relapse assessment. The topology optimization analysis showed that the CAF plate has the best characteristics, light weight and structural strength with 30% volume retention. The biomechanical analysis showed that the maximum von Mises stress of the mini-plate was 2.71 times higher than that of the CAF plate. The relapse displacement of the mandibular segment fixed with the mini-plate was 1.62 times higher than that fixed with the CAF plate. The CAF plate ability to resist relapse was confirmed by the biomechanical testing results so that only 0.29 mm of recurrence displacement was observed in the mandibular segment. The results indicated that the CAF plate structural strength and resistance to relapse was significantly better than that of the mini-plate. This study developed a customized asymmetric fixation plate for hemifacial microsomia, integrating topology optimization, metal 3D printing, and in vitro biomechanical testing to resist occlusal forces and differential muscle traction on both sides of the mandible to reduce relapse and improve fixation stability.

Retrospective Evaluation of Maxillofacial Fractures With Cone-Beam Computed Tomography

ÖZ Amaç: Bu çalışmanın amacı maksillofasiyal bölgede meydana gelen fraktürlerin yaş ve cinsiyete göre dağılımlarını, lokalizasyonlarını, sayısını, deplasman varlığını, radyolojik özelliklerini Konik Işınlı Bilgisayarlı Tomografi (KIBT) ile retrospektif olarak değerlendirmektir. Gereç ve Yöntemler: Zonguldak Bülent Ecevit Üniversitesi Diş Hekimliği Fakültesi, Ağız Diş ve Çene Radyolojisi Anabilim Dalı’na 2019 ve 2021 yılları arasında travma nedeniyle başvuran 84 hastadan alınan KIBT görüntüleri retrospektif olarak incelenmiştir. Yaş, cinsiyet, fraktür lokalizasyonu, fraktürlerde deplasman varlığı kayıt altına alındı. İstatistiksel analiz için tüm hasta grubuna tanımlayıcı ve frekans analizleri uygulanırken, hastaların yaş ve cinsiyetlerini; fraktür hattı ve fraktür bölgesi ile karşılaştırırken ki-kare testi uygulandı. Bulgular: 60 erkek 24 kadın hasta (E/K, 2,5/1) olmak üzere toplam 84 hastanın maksillofasiyal travma nedeniyle KIBT görüntüsü incelendi. Çalışmada incelenen hasta grubunun yaşları 6 ve 72 arasında değişmekte olup yaş ortalaması 33.17±1.48 olarak belirlendi. Farklı etiyolojik nedenlerden kaynaklı çeşitli lokalizasyonlarda meydana gelen 116 fraktür hattı sayısı radyolojik olarak tespit edildi. İncelenen tüm fraktürlerin 73’ünde deplasman izlenirken kalan 43 fraktür hattında deplasman görülmedi. Meydana gelen fraktürler en sık angulus mandibulada (%22,61:n=19) tespit edildi. En az fraktür mandibula ramus (%3,57; n=3) ve koronoid proseste (%3,57; n=3) görüldü. Sonuçlar: Fraktür hatlarının varlığının, lokalizasyonlarının ve kırık parçalarının yer değişiminin doğru radyografik teknikler aracılığıyla tespit edilmesi, gerekli tedavi prosedürlerinin uygulanması açısından önem taşımaktadır. İki boyutlu radyografilerin kullanımının yetersiz kaldığı durumlarda KIBT gibi üç boyutlu görüntüleme yöntemleri tercih edilmelidir. Anahtar Kelimeler: Konik Işınlı Bilgisayarlı Tomografi, Fraktür, Mandibula, Teşhis

Simple dentate area fractures of the mandible - can we prevent postoperative infections?

OBJECTIVE

To evaluate the occurrence of surgical site infections and predisposing factors for these in simple mandibular fractures.

MATERIAL AND METHODS

A retrospective study of patients with fractures of the dentate part of the mandible included patients with intraorally treated simple fractures of the mandibular body, symphysis, and parasymphysis. The primary outcome variable was postoperative surgical site infection. Use of antibiotics, injury mechanism, fracture and surgery-related explanatory variables, patient-related variables and level of oral hygiene according to the modified Total Dental Index were evaluated.

RESULTS

Of 254 patients with mandibular fractures, 107 were included in the final analysis. The infection group consisted of 18 patients (16.8%). Despite the high infection occurrence, significant differences were not found between antibiotic use or other studied variables and infection occurrence. Infections occurred mainly in patients without any specific explanatory factor for infection.

CONCLUSION

The notably high occurrence of surgical site infections despite antibiotic use after simple mandibular fracture surgery highlights the importance of perioperative tissue handling and local oral circumstances. It is also necessary to consider whether we generally accept the high risk of infection associated with the intraorally treated simple mandibular fractures.

Analysis of factors that influence quality of life of individuals undergoing treatment for mandibular fractures: A systematic review and meta-analysis

OBJECTIVE

To address the factors that affect the quality of life (QoL) of individuals undergoing treatment for mandibular fractures.

STUDY DESIGN

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the search strategy was constructed according to the Populations, Interventions, Comparison, Outcomes, and Study Design principle in the following databases: PubMed, Web of Science, Scopus, and EMBASE. Risk of bias assessment was performed with Risk Of Bias In Non-randomized Studies of Interventions and Cochrane Risk of Bias tool for randomized trials 2.

RESULTS

Nineteen studies were included: 15 observational and 4 clinical trials. Mean age ranged from 28 to 39 years, with a higher proportion of males. The condyle was the main fracture location and traffic accident was the fracture cause. Treatment approaches were mostly open reduction (89.4%) and maxillomandibular fixation (63%). QoL measurements varied considerably with the General Oral Health Assessment Index (31.5%) and Oral Health Impact Profile-14 (21%) as the main instruments. Meta-analysis showed that open reduction and maxillomandibular fixation did not present significant differences to QoL (P = .39), but significant differences were observed with time (P < .00001). Other factors affected QoL, such as mental health, pain, socializing, appearance, and eating difficulties.

CONCLUSIONS

Several factors, apart from the treatment approach, mentioned in this review seemed to affect the QoL of patients with mandibular trauma. Treatment choice should be based on well-stablished clinical criteria and on all other factors mentioned here.

Radiological investigation of acute mandibular injury

This article focuses on the different imaging modalities used to evaluate acute mandibular fractures and explores important concepts relating to their diagnosis, investigation, and treatment. Significant focus will be given to exploring general management principles, considerations regarding first-line imaging, and recent technological advancement. Computed tomography (CT) is the preferred method when attempting to identify acute mandibular fractures, particularly in trauma patients, and has very high specificity and sensitivity. Multidetector CT now represents the standard of care, enabling fast scan times, reduced artifact, accurate reconstructed views, and three-dimensional (3D) reconstructions. Cone-beam CT is a newer advanced imaging modality that is increasingly being used worldwide, particularly in the ambulatory and intraoperative setting. It produces high-resolution images with submillimeter isotropic voxels, 3D and multiplanar reconstruction, and low radiation dose, however is less widely available and more expensive. Ultrasound is a valuable method in identifying a fracture in unstable patients, but is limited in its ability to detect nondisplaced fractures. Magnetic resonance imaging is useful in determining the presence of soft-tissue injury. CT angiography is invaluable in the assessment of potential vascular injury in condylar fracture dislocations.

The Influence of the Mandibular Chin Angle on the Occurrence of Mandibular Condylar Fracture: A Retrospective Study

Background

Condylar fractures are commonly associated with symphysis/parasymphysis fractures. Condylar fractures have been attributed to direct and indirect traumatic forces, the direction and magnitude of the forces, and the condylar anatomy. The chief aim of this study was to determine the association between the newly defined mandibular chin angle and the occurrence of condylar fractures.

Materials and Methods

A retrospective study was conducted to analyze two-dimensional computed tomography (2D CT) scans of patients with a history of chin trauma. The outcome was a symphysis/parasymphysis fracture with or without fracture of the mandibular condyle. The Mediff InstaRISPACS web-based platform was used to measure the chin angle. The cerebral aqueduct of Sylvius in the corresponding 2D CT midsagittal image was the standard reference plane to measure the chin angle. The SPSS Version 20 (IBM Corp, Armonk, NY) was used for data analysis.

Results

The sample size included 120 2D CT scans of patients with symphysis/parasymphysis fractures (60 associated with condylar fractures and 60 without condylar fractures). The mean chin angle in the group without condylar fracture was 133.35 ± 3.87°, which was approximately 15° lesser than in the condylar fracture group (mean, 148.56 ± 5.49°), and these findings were statistically significant (P < 0.05).

Conclusion

Individuals with a high chin angle are potentially at a higher risk of sustaining associated condylar fractures.

Mandibular Body Fractures

Fractures of the mandibular body most commonly occur after interpersonal violence or motorized vehicle accident but can occur in athletes. Mandibular body fractures are often associated with additional mandibular fractures. The treatment goal is to achieve preinjury occlusion and facial appearance, and this can be done via a closed reduction and maxillomandibular fixation or open reduction and fixation with or without maxillomandibular fixation. The authors present 3 cases in this article.

Postoperative Computed Tomography for Facial Fractures

In order for a radiologist to create reports that are meaningful to facial reconstructive surgeons, an understanding of the principles that guide surgical management and the hardware employed is imperative. This article is intended to promote efficient and salient reporting by illustrating surgical approaches and rationale. Hardware selection can be inferred and a defined set of potential complications anticipated when assessing the adequacy of surgical reconstruction on postoperative computed tomography for midface, internal orbital, and mandible fractures.

Is Open Reduction Internal Fixation Using Titanium Plates in the Mandible as Successful as We Think?

ABSTRACT

Titanium plats are the gold-standard for fracture fixation. Titanium is considered biocompatible, corrosion resistant with an elasticity-modulus closest to bone. Nonetheless, titanium plates are not always as inherent as hoped. The authors investigated morbidity associated with titanium plates in mandibular fractures. A retrospective study of mandibular fractures treated between 2000 and 2018 using internal-fixation was conducted. Data included age, gender, complications, and location. Predictor-variable was location. Outcome-variable was plate removal. A total of 571 patients were included, 107 resulted in plate removal (18.7%). Body was the most prevalent location of fracture (29.3%). Symphysis/para-symphysis showed the highest removal rate (24.1%), followed by body and angle (21.3/19.8%). A total of 23.4% of double-plating cases resulted in plate removal, upper-border in 15% and lower-border in 8.8%, all reconstruction-plates. Exposure was the most frequent complication leading to removal. Although titanium plates are the gold standard, almost every fifth patient returns for plate removal. Age-distribution emphasizing 41 to 50 with decrease towards extremities may imply better healing in the young and soft-tissue elasticity and less complaints in the elderly. Significantly more complications in double-plating compared to lower border suggests proximity to the oral-cavity as a risk-factor for removal. Complication rates and patterns are not negligible and perhaps should encourage clinicians to consider using biodegradable-systems for upper-border plates.

A rare case of large left internal maxillary artery pseudoaneurysm secondary to mandibular fracture: A case report and review of the literature

INTRODUCTION AND IMPORTANCE

Pseudoaneurysms secondary to traumatic vessel wall disruption are a rare but potentially fatal complication after traumatic injury. The majority of the cases are found incidentally.

CASE PRESENTATION

An 80-year-old woman was brought into our Level 1 Trauma Center after sustaining a ground-level fall with significant facial swelling. Her imaging revealed an acute traumatic comminuted fracture of the right mandibular condyle and left mandibular ramus. The patient underwent closed maxillomandibular fixation (MMF) to stabilize fractures, and allow the swelling to decrease for definitive fixation. During the definitive procedure, profuse bleeding was encountered. CT angiography evaluation was immediately performed and determined the presence of a left internal maxillary artery pseudoaneurysm which was successfully treated by coil and glue embolization.

CLINICAL DISCUSSION

This case highlights an unusual presentation of a vascular injury following major traumatic mandibular fracture and its management. Mandibular fractures have been reported in a series of cases to be a risk factor for vascular injuries. When a vascular injury is suspected, or the evaluation is unclear, surgeons should carefully determine the necessity to perform additional studies like CT angiogram. Vascular injuries secondary to mandibular fractures can be fatal if left unrecognized and untreated. Hence adequate recognition and treatment are warranted to avoid prolonged length of stay with bad outcomes.

CONCLUSION

Optimal management of pseudoaneurysms is achieved by endovascular approach with prior resuscitation and adequate hemodynamic stabilization. Open surgical management is deferred only for those cases where endovascular treatment is not available, or disruption is found intraoperatively.

Association between shape of the mandibular condylar head and the occurrence of unilateral condylar fracture - A retrospective computed tomographic study

This retrospective study aims to evaluate the correlation between the shape of the mandibular condylar head and the incidence of unilateral condylar fracture using computed tomography. Medical records of patients diagnosed with unilateral condylar fractures from the year 2012-2019 were reviewed. The shape of the condylar head on the non - fractured side was analysed using a Radiant Dicom Viewer. The analysis was done using both visual and analytical methods. In the analytical method, a horizontal line was drawn at the base of the curvature of the condylar head. The highest peak point of the head was marked, and a perpendicular line was drawn connecting the highest point to the horizontal line. The shape was categorized into four types as convex, flat, angled, and round based on these lines. 201 CT scans were examined, of which 69 were excluded as they did not meet the inclusion criteria. The remaining 132 were included in our study. On examining the shape, flat-shaped condyle was seen in 57 scans (43.2%), followed by convex in 31 scans (23.4%), angled in 30 (22.7%) and round in 14 scans (10.6%). The relationship between the shape of the mandibular condylar head and the incidence of unilateral condylar fracture was analysed using a chi-square test, which showed high statistical significance (p value 0.0001). The flat-shaped condylar head was more prone to fracture, and the round-shaped condylar head was least prone to fracture. In conclusion, the shape of the mandibular condylar head had a statistically significant association with the incidence of unilateral condylar fracture. The assessment of the shape of the condylar head can be taken as a guide to suspect condylar fractures and other associated mandibular fractures.

Treatment of Mandible Fractures Using a Miniplate System: A Retrospective Analysis

Three-dimensional (3D) mini plate systems are used in the treatment of mandibular fractures. The system is advantageous in comparison to conventional plates due to the stabilization of tension and compression areas, improved initial stability, and biomechanical behavior. The aim of this retrospective study was to evaluate the use of a 3D miniplate system for the treatment of patients with mandibular fractures. Patients with mandibular fractures treated with a 3D plate system at the Department of Oral and Maxillofacial Surgery, University Hospital Münster, during a period of 5 years, were included in this study. Mandibular fracture conditions and minor and major post-operative complications were reported. In total, 336 patients and 391 mandibular fractures were assessed. The most common fracture site was anterior mandible, and 155 cases involved a tooth-bearing area. Minor complications were seen in 8.03% of cases, whereas only 1.49% of patients suffered from major complications. The treatment of mandible fractures using 3D miniplates resulted in fracture reduction with a low complication rate.

Open Reduction, Internal Fixation, or Maxillo-Mandibular Fixation for Isolated, Unilateral, Tooth-Bearing, Mandibular Body Fractures in Children

BACKGROUND

Mandibular body fractures can cause severe and long-term morbidity in the pediatric population. Nonetheless, there is insufficient data on the treatment and management of this specific fracture type in children. This study aimed to investigate the etiology, treatment, and outcomes of pediatric mandibular body fractures by analyzing our institution's experience managing these uncommon injuries.

METHODS

This was a 30-year retrospective, longitudinal cohort study of pediatric patients presenting to a single institution with isolated, unilateral, mandibular body fractures. Patient data was extracted from electronic medical records, while subgroup analysis was completed by dentition stage.

RESULTS

A total of 14 patients met inclusion criteria, of whom 8 (57.1%) had deciduous, 3 (21.4%) had mixed, and 3 (21.4%) had permanent dentition. Deciduous dentition patients with displaced, mobile or comminuted fractures underwent open reduction and internal fixation (ORIF), while those with nondisplaced and/or nonmobile fractures received soft diet or closed treatment with maxillomandibular fixation. For the mixed dentition cohort, all patients (100%) received closed treatment with maxillomandibular fixation. Among permanent dentition patients, most patients (66.6%) underwent ORIF regardless of fracture severity. The post-ORIF complication rate was 20% (dental maleruption).

CONCLUSIONS

Isolated, unilateral mandible body fractures are relatively uncommon in the pediatric population, and management differs by dentition stage and injury pattern. While isolated body fractures had considerable associated morbidity, this fracture pattern did not result in major growth restrictions or malformations.

Facial fractures: classification and highlights for a useful report

In patients with facial trauma, multidetector computed tomography is the first-choice imaging test because it can detect and characterize even small fractures and their associated complications quickly and accurately. It has helped clinical management and surgical planning, so radiologists must communicate their findings to surgeons effectively. In Le Fort fractures, there is a breach between the pterygoid plates and the posterior maxilla. These fractures are classified in three basic patterns that can be combined and associated with various complications. Conceptualized when low-speed trauma was predominant, the Le Fort classification system has become less relevant giving more importance on maxillary occlusion-bearing segments. The classification of naso-orbito-ethmoid depends on the extent of injury to the attachment of the medial canthal tendon, with possible complications like nasofrontal duct disruption. Displaced fractures of the zygomaticomaxillary complex often widen the angle of the lateral orbital wall, resulting in increased orbital volume and sometimes in enophthalmos. Severe comminution or angulation can lead to wide surgical exposure. In orbital fractures, entrapment of the inferior rectus muscles can lead to diplopia, so it is important to assess its positioning and morphology. Orbital fractures can also result in injuries to the globe or infraorbital nerve. Frontal sinus fractures that extend through the posterior sinus wall can create a communication with the anterior cranial fossa resulting in leakage of cerebrospinal fluid, intracranial bleeding. It is essential to categorize fracture patterns and highlight features that may affect fracture management in radiology reports of facial trauma.

Postoperative CT of the Mandible Following Trauma: Review of Normal Appearances and Common Complications

RATIONALE AND OBJECTIVES

Surgeons aim to restore occlusion and jaw function to baseline status for patients with mandibular fractures using either closed treatment or reduction and fixation.

MATERIALS AND METHODS

Occlusion is defined as the relationship between the maxillary and mandibular teeth as they approach each other.

RESULTS

Radiologists should be familiar with the goals of repair to help identify which treatment is adequate as well as to diagnose potential complications. Some of the more common complications encountered are infection, nonunion or malunion, and malocclusion.

CONCLUSION

We provide a comprehensive review of both the desired and untoward CT findings after surgical repair of traumatic mandibular injuries.

Comparison of two incisions for open reduction and internal fixation of mandibular body fractures: A randomised controlled clinical trial evaluating the surgical outcome

PURPOSE

The purpose of the study is to compare the surgical access and post-operative outcome of two intra-oral incisions used for approaching a mandibular body fracture.

METHODS

This clinical trial involved 60 patients with mandibular body fractures who were randomly allocated to control and study groups. The fractures were approached using the routine vestibular incision in the control group and crevicular incision with vertical release in the study group. The effects of incision design on the post-surgical outcome variables like swelling, trismus, paresthesia, wound healing and gingival recession were statistically analysed with non-parametric tests by using SPSS 22.0 software. Comparison of continuous variables between the groups and time points was done using Mann Whitney test and Friedman test respectively. Chi-square test was used to compare proportions between groups. Dunn's test with Bonferroni correction was used for pair wise comparisons.

RESULTS

The study group demonstrated favourable surgical outcome in the immediate postoperative phase as compared to the control group. The difference in mouth opening, swelling and neurosensory impairment between the two groups was found to be statistically significant (p < 0.05).

CONCLUSION

Crevicular incision was found to be an ideal alternative to vestibular incision in achieving surgical access and fixation of mandibular body fractures with reduction in postoperative patient discomfort and better surgical outcome.

Multidetector CT of Mandibular Fractures, Reductions, and Complications: A Clinically Relevant Primer for the Radiologist

After the nasal bones, the mandible is the second most common site of facial fractures, and mandibular fractures frequently require open reduction. In the trauma injury setting, multidetector computed tomography (CT) has become the cornerstone imaging modality for determining the most appropriate treatment management, fixation method, and surgical approach. Multidetector CT is also used to assess the adequacy of the reduction and evaluate potential complications in the postoperative period. For successful restoration of the mandible's form and function, as well as management of posttraumatic and postoperative complications, reconstructive surgeons are required to have a detailed understanding of mandibular biomechanics, occlusion, and anatomy. To provide added value in the diagnosis, treatment planning, and follow-up of mandibular fractures, radiologists should be aware of these concepts. Knowledge of the techniques commonly used to achieve occlusal and anatomic reduction and of the rationale behind the range of available treatment options for different injury patterns-from isolated and nondisplaced fractures to multisite and comminuted fractures-also is essential. This article focuses on the use of multidetector CT for pre- and postoperative evaluation of mandibular fractures and outlines fundamental concepts of diagnosis and management-beginning with an explanation of common fracture patterns and their biomechanical underpinnings, and followed by a review of the common postoperative appearances of these fractures after semirigid and rigid fixation procedures. Specific considerations regarding fractures in different regions of the tooth-bearing and non-tooth-bearing mandible and the unique issues pertaining to the edentulous atrophic mandible are reviewed, and key features that distinguish major from minor complications are described. (©)RSNA, 2016.

Finite Element Evaluation of Stable Fixation in Combined Mandibular Fractures

PURPOSE

The fixation of combined mandibular fractures, especially symphyseal-condylar fractures, although occurring commonly and having a higher complication rate in the clinic, is rarely investigated regarding predictable therapeutic approaches. Thus this study's aim was to assess different forms of condylar fixation when combined with symphyseal fracture fixation.

MATERIALS AND METHODS

Using finite element models, we analyzed the stress distribution that occurs when a condylar fracture is fixed with 1 miniplate, 2 miniplates, or a trapezoidal condylar miniplate and when a symphyseal fracture is fixed with 2 parallel plates, 2 perpendicular plates, or 2 lag screws. The null hypothesis was that there would be no differences among the different fixation techniques.

RESULTS

The results showed a stress concentration in the anterior region of the condyle, close to the sigmoid notch. Moreover, adequate fixation in the symphysis could result in less tension at the condylar region. Therefore, when the symphysis was fixed with a lag-screw technique, condylar fixation was less required, showing a more adequate stress distribution when the condyle was fixed with 1 or 2 plates. Conversely, when the symphyseal fixation was less effective, by use of perpendicular plates, there was a change in the stress distribution at the condylar region, altering fixation behavior and resulting in more tension and displacement in the condyle, especially when a trapezoidal plate was used.

CONCLUSIONS

A lag screw and parallel double plates appear to be suitable for symphyseal fixation, whereas 2 straightly positioned plates and a trapezoidal plate are suitable for condylar fixation. However, the combination of perpendicular plates in symphyseal fixation and a trapezoidal plate in condylar fixation showed an altered stress distribution.

Systemic Preoperative Antibiotics with Mandible Fractures: Are They Indicated at the Time of Injury?

Mandible fractures are the most common result of facial trauma. The proximity of oral flora to the site of both the injury and resulting surgical instrumentation makes managing infection a unique challenge. The benefit of antibiotic prophylaxis at the time of surgical treatment of mandible fractures is well established. However, the routine use of antibiotics between the time of injury and surgery is of unclear benefit. We aim to define the role of antibiotics in the preoperative period: from the time of injury to surgical intervention. Demographic and clinical data were collected retrospectively on all patients who were treated for mandible fracture by the Division of Plastic and Reconstructive Surgery at our institution between 2003 and 2013. The use of both preoperative (between injury and surgery) and perioperative (at the time of surgery) systemic antibiotics was recorded along with the incidence of postoperative infections and other complications. Complete data were available for 269 patients. Of the 216 patients who received preoperative antibiotics, 22 (10%) developed an infection postoperatively. Of the 53 patients who did not receive preoperative antibiotics, 2 (4%) developed infection ( p  = 0.184). Likewise, preoperative antibiotics were not significantly associated with hardware complication rates. In our retrospective review, the use of antibiotics between injury and surgical repair had no impact on postoperative infection rates. These data suggest that preoperative antibiotic use may actually be associated with an increased incidence of postoperative infection. Our results do not support the routine use of antibiotics between injury and surgical repair in patients with mandible fractures.

Managing a grossly comminuted and infected mandibular fracture using a maxillary extra-oral distractor as stabilizing agent: A clinical case report

Facial fracture management dates as early as Hippocratic era. Comminuted mandibular fractures are one of the challenging clinical condition requiring high surgical expertise to achieve a good functional and esthetic outcome. In presence of infection and other facial fractures managing comminuted mandibular fracture becomes more challenging.

Here we present a case of grossly comminuted and infected mandibular fracture with delayed presentation managed by using maxillary distractor as stabilizing agent. Using a maxillary distractor for managing a fractured mandible has been seldom reported in literature. Current case report gives idea to practicing clinician about the possibility of treatment beyond the established principles.

The Effect of Local Rosuvastatin on Mandibular Fracture Healing

Mandibular fracture is the most common injury seen in facial fractures and plays an important role for oral and maxillofacial surgery department. The purpose of this study is to investigate the potential of the local administration of rosuvastatin (RSV) on mandibular fracture healing in rats. Thirty-two rats were divided into 4 groups: group C-14 (control), group R-14, group C-28 (control), and group R-28. A unilateral standard vertical osteotomy was performed right side of the mandibula extending from the tooth to the mandibular basis for each animal. In groups C-14 and C-28 sterile saline treated absorbable collogen sponge was applied to the fracture area, in groups R-14 and R-28 absorbable collogen sponge with saline solution containing 1 mg RSV was applied to the fracture area. Animals in groups C-14 and R-14 were euthanized on the 14th day, groups C-28 and R-28 were euthanized on the 28th day after operation. Stereologic analyses were performed. New bone area and connective tissue volumes were measured. Stereologic analysis showed that group R-14 had significantly more new bone at 2 weeks compared with group C-14. Connective tissue volumes were also significantly higher in R-14. New bone and connective tissue volume differences were not statistically significant between groups C-28 and R-28. Locally administered RSV enhances early bone regeneration on mandibular fracture in rats.

Mechanics in the Production of Mandibular Fractures: A Clinical, Retrospective Case-Control Study

As the mandible is susceptible to fracture, the aim of this study was to use multivariate logistic regression analysis to identify and distinguish various internal factors that may influence the location of mandibular fractures. The study included 1131 patients with maxillofacial fractures during the period from January 2000 to December 2009 to evaluate the association of mandibular fracture location (unilateral symphysis, body, angle, condylar, or bilateral condylar fractures) with various internal factors. Among the 1131 patients, 869 had mandibular fractures. Data on age, sex, soft tissue injuries, dental trauma, and maxillofacial fracture type were collected and analyzed using multivariate logistic regression. In total, 387, 210, 139, 319, and 172 patients were diagnosed with unilateral symphysis, body, angle, unilateral, or bilateral condylar fractures, respectively. The dental trauma in patients with bilateral condylar fractures differed from that in patients with unilateral condylar fractures. Patients with mandibular fracture (unilateral symphysis, body, unilateral or bilateral condylar) possessed an approximately equal risk of soft tissue injuries in the mandible. Patients with either unilateral or bilateral condylar fractures were associated with a low risk of mandibular angle fracture (OR < 1). Similarly, patients with mandibular angle fracture were associated with a low risk of unilateral or bilateral condylar fractures (OR < 1). Moreover, patients with symphysis fracture were associated with a low risk of bilateral condylar fractures (90 of 387 [23.3%], OR 0.899). By contrast, patients with bilateral condylar fractures were associated with a high risk of symphysis fracture (90 of 172 [52.3%], OR 17.38). Patients with condylar fractures, particularly those with bilateral condylar fractures, were infrequently associated with secondary mandibular fractures. Mandibular fractures tended to have less of an association with midfacial fractures. The occurrence of mandibular fractures is strongly correlated with age, sex, soft tissue injuries, dental trauma, and the pattern and position of the maxillofacial fractures in patients.