Outcomes research: Mandibular fractures in the diabetic population

FOXO 1 deletion in chondrocytes rescues diabetes-impaired fracture healing by restoring angiogenesis and reducing apoptosis

Introduction

Diabetes mellitus is associated with higher risks of long bone and jaw fractures. It is also associated with a higher incidence of delayed union or non-union. Our previous investigations concluded that a dominant mechanism was the premature loss of cartilage during endochondral bone formation associated with increased osteoclastic activities. We tested the hypothesis that FOXO1 plays a key role in diabetes-impaired angiogenesis and chondrocyte apoptosis.

Methods

Closed fractures of the femur were induced in mice with lineage-specific FOXO1 deletion in chondrocytes. The control group consisted of mice with the FOXO1 gene present. Mice in the diabetic group were rendered diabetic by multiple streptozotocin injections, while mice in the normoglycemic group received vehicle. Specimens were collected 16 days post fracture. The samples were fixed, decalcified, and embedded in paraffin blocks for immunostaining utilizing anti cleaved caspase-3 or CD31 specific antibodies compared with matched control IgG antibody, and apoptosis by the TUNEL assay. Additionally, ATDC5 chondrocytes were examined in vitro by RT-PCR, luciferase reporter and chromatin immunoprecipitation assays.

Results

Diabetic mice had ~ 50% fewer blood vessels compared to normoglycemic mice FOXO1 deletion in diabetic mice partially rescued the low number of blood vessels (p < 0.05). Additionally, diabetes increased caspase-3 positive and apoptotic chondrocytes by 50%. FOXO1 deletion in diabetic animals blocked the increase in both to levels comparable to normoglycemic animals (p < 0.05). High glucose (HG) and high advanced glycation end products (AGE) levels stimulated FOXO1 association with the caspase-3 promoter in vitro, and overexpression of FOXO1 increased caspase-3 promoter activity in luciferase reporter assays. Furthermore, we review previous mechanistic studies demonstrating that tumor necrosis factor (TNF) inhibition reverses impaired angiogenesis and reverses high levels of chondrocyte apoptosis that occur in fracture healing.

Discussion

New results presented here, in combination with recent studies, provide a comprehensive overview of how diabetes, through high glucose levels, AGEs, and increased inflammation, impair the healing process by interfering with angiogenesis and stimulating chondrocyte apoptosis. FOXO1 in diabetic fractures plays a negative role by reducing new blood vessel formation and increasing chondrocyte cell death which is distinct from its role in normal fracture healing.

Comprehensive analysis of patients with failure of mandibular hardware

OBJECTIVE

The purpose of the study was to characterize patients who had failure of mandibular hardware (FMH).

STUDY DESIGN

This retrospective cohort study consisted of patients with mandible fractures (MFs) that required surgical intervention from 2012 to 2020. Patients were included when mandibular hardware failed. Descriptive variables were collected.

RESULTS

During the study period, 57 patients (47 male, average age 38.7 years) met the inclusion criteria. Incidence of FMH was 7.4%. Most patients were African American (n = 45, 78.9%) with American Society of Anesthesiologists classification II (n = 40, 70.2%). Tobacco use (n = 31, 54.4%) and/or alcohol (n = 33, 57.9%). The most common etiology was assault (n = 28, 49.1%). The most common location was the angle of the mandible. Most mandibles had fracture at 1 location (n = 31, 54.4%) and a tooth was involved in the fracture line (n = 44, 77.2%). More than half of patients were treated with transoral surgical approach (n = 35, 61.4%). The majority of patients received preoperative antibiotics (n = 51, 89.4%). Patients had varying levels of compliance with postoperative care, and most were not compliant. Infection (n = 45) was the most common presentation of FMH.

CONCLUSION

High American Society of Anesthesiologists score, smoking, excessive alcohol use, parafunctional habits, and compliance with postoperative instructions may affect surgical outcome.

Algorithmic Approach to Antibiotic Prophylaxis for Traumatic Craniomaxillofacial Injuries

ABSTRACT

Prophylactic antibiotics are commonly used in the management of traumatic injuries to the maxillofacial complex, yet there are no set guidelines for when and when not to prescribe. The purpose of this review is to present the evidence for antibiotic prophylaxis in different clinical scenarios and to propose algorithms to facilitate the decision making process with the ultimate goal of improving antibiotic prescribing practices. A number of databases were searched using a wide range of keywords to ensure the topic was fully encapsulated. The review is divided into 3 sections: soft tissue trauma, maxillofacial fractures, and ballistic injuries. The algorithms were constructed using the current evidence as well as pathophysiologic principles, especially when there were insufficient studies. This review found the literature on antibiotic prophylaxis to be highly varied and not standardized. Creating an algorithm for providers to follow will help to set a standard of care and decrease the misuse of antibiotics.

Bone quality analysis of jaw bones in individuals with type 2 diabetes mellitus-post mortem anatomical and microstructural evaluation

OBJECTIVES

With the higher risk of dental implant failure with type 2 diabetes mellitus (T2DM), there is a need to characterize the jaw bones in those individuals. The aim of this post mortem study was to compare jaw bone quality of individuals with T2DM to healthy controls.

MATERIAL AND METHODS

Bone cores from the edentulous lower first molar region and the region of mandibular angle were collected from male individuals with T2DM (n = 10, 70.6 ± 4.5 years) and healthy controls (n = 11, 71.5 ± 3.8 years) during autopsy. Within the T2DM, a subgroup treated with oral antidiabetics (OAD) and one on insulin were identified. Bone quality assessment encompassed evaluation of bone microstructure, matrix composition, and cellular activity, using microcomputed tomography (micro-CT), quantitative backscattered electron imaging (qBEI), Raman spectroscopy, and bone histomorphometry.

RESULTS

In the mandibular angle, T2DM showed 51% lower porosity of the lingual cortex (p = 0.004) and 21% higher trabecular thickness (p = 0.008) compared to control. More highly mineralized bone packets were found in the buccal cortex of the mandibular angle in insulin-treated compared to OAD-treated T2DM group (p = 0.034). In the molar region, we found higher heterogeneity of trabecular calcium content in T2DM insulin compared to controls (p = 0.015) and T2DM OAD (p = 0.019). T2DM was associated with lower osteocyte lacunar size in the trabecular bone of the molar region (vs. control p = 0.03).

CONCLUSIONS

Alterations in microstructure, mineralization, and osteocyte morphology were determined in jaw bone of individuals with T2DM compared to controls.

CLINICAL RELEVANCE

Future studies will have to verify if the mild changes determined in this study will translate to potential contraindications for dental implant placements.

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.