Prospective study of postoperative sensory disturbances after surgical treatment of mandibular fractures

Introduction: This present study's purpose is to evaluate the degree of paresthesia and recovery of inferior alveolar nerve in patients with mandible fractures who underwent surgical treatment. Material and methods: Nineteen patients were evaluated (27 hemimandibles) at six different times: preoperative (T1), postoperative 1 week (T2), postoperative 1 month (T3), postoperative 3 months (T4), postoperative 6 months (T5), and postoperative 1 year (T6). Subjective and objective methods were used for this evaluation. Results: The results were analyzed using likelihood ratio chi-square test for the hypothesis of no association between indicators of sensitivity and responses to the questionnaire, and the Cochran-Mantel-Haenszel test for equality hypothesis. All objective tests showed a statistically significant worsening in sensitivity at T2 (p < 0. 0001) and a significant improvement after T4 (α < 0. 05). The subjective tests showed an association with the objectives tests, and improvement in sensitivity after T4 (p < 0. 0001) was noted. Discussion: The first postoperative week is the period in which there are major changes with respect to sensitivity, and after 3 months postoperatively, the recovery reaches its apex with little difference observed after this period. In this research 100 % of the patients analyzed recovered all sensibility until T6. © 2012 Springer-Verlag.

Implant-supported rehabilitation after treatment of atrophic mandibular fractures: report of two cases

Objective The objective of this article is to present options of rehabilitation with dental implants in two cases of severely atrophic mandibles (<10 mm) after rigid internal fixation of fractures. Patients and method Two patients who sustained fractures in severely atrophic mandibles with less than 10 mm of bone height were treated by open reduction and internal fixation through a transcervical access. Internal fixation was obtained with 2.4-mm locking reconstruction plates. The first patient presented satisfactory bone height at the area between the mental foramens and after 2 years, received flapless guided implants in the anterior mandible and an immediate protocol prosthesis. The second patient received a tent pole iliac crest autogenous graft after 2 years of fracture treatment and immediate implants. After 5 months, a protocol prosthesis was installed in the second patient. Results In both cases, the internal fixation followed AO principles for load-bearing osteosynthesis. Both prosthetic devices were Branemark protocol prosthesis. The mandibular reconstruction plates were not removed. Both patients are rehabilitated without complications and satisfied with esthetic and functional results. Conclusion With the current techniques of internal fixation, grafting, and guided implants, the treatment of atrophic mandible fractures can achieve very good results, which were previously not possible.

Incidence, aetiology and pattern of mandibular fractures in central Switzerland

The two major causative factors for mandibular fractures, as stated in the literature, are either interpersonal violence or motor vehicle accidents. The purpose of this study was to describe epidemiological trends of mandibular fractures in Switzerland. A special emphasis was directed towards the potential impact of socio-economic standards on the mechanism and pattern of mandible fractures.

Effect of the number of screws on the stability of locking mandibular reconstruction plates

Atrophic mandible fractures are frequently a challenge to stabilize. This study evaluated, through mechanical testing in vitro, the number of locking screws that is sufficient to withstand loading when applied with a locking reconstruction plate in the fixation of atrophic mandible fractures. Polyurethane mandibles with a simulated linear fracture at the midline were used as substratum. Results show that resistance of the fixation is poor when one and two screws are used on each side of the fracture. Three screws on each side of the fracture significantly increases the resistance to displacement. However, no additional strength is added to the construct when more than three screws per side are used. © 2013 International Association of Oral and Maxillofacial Surgeons.

Bite force, electromyography, and mandible mobility during the 6-month period after surgical treatment for isolated fractures of the zygomatico-orbital complex

Objective. The aim of this study was to identify the behavior of masticatory muscles after fractures of the zygomatico-orbital complex (ZOC) and subsequent surgical treatment, by using analyses of bite force, electromyography (EMG), and mandible mobility during a 6-month period after surgery. Study design. Five patients with fractured ZOCs treated surgically by using an intraoral approach and fixation exclusively in the region of the zygomaticomaxillary buttress were evaluated. The control group included 12 other patients. During postoperative follow-up, bite force, mandible mobility, and EMG analysis of the masticatory muscles were evaluated. Results. There was an increase in bite force with time, but a decline in EMG activity during the same period. In the mandible mobility analysis, only maximum mouth-opening values increased significantly after the surgical treatment. Conclusions. The masticatory musculature, according to bite force and EMG, returned to its normal condition by the second month after surgery, and maximum mouth opening was observed after the first month. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:e1-e7)

Finite-element Analysis Of 3 Situations Of Trauma In The Human Edentulous Mandible.

Maxillofacial trauma resulting from falls in elderly patients is a major social and health care concern. Most of these traumatic events involve mandibular fractures. The aim of this study was to analyze stress distributions from traumatic loads applied on the symphyseal, parasymphyseal, and mandibular body regions in the elderly edentulous mandible using finite-element analysis (FEA). Computerized tomographic analysis of an edentulous macerated human mandible of a patient approximately 65 years old was performed. The bone structure was converted into a 3-dimensional stereolithographic model, which was used to construct the computer-aided design (CAD) geometry for FEA. The mechanical properties of cortical and cancellous bone were characterized as isotropic and elastic structures, respectively, in the CAD model. The condyles were constrained to prevent free movement in the x-, y-, and z-axes during simulation. This enabled the simulation to include the presence of masticatory muscles during trauma. Three different simulations were performed. Loads of 700 N were applied perpendicular to the surface of the cortical bone in the symphyseal, parasymphyseal, and mandibular body regions. The simulation results were evaluated according to equivalent von Mises stress distributions. Traumatic load at the symphyseal region generated low stress levels in the mental region and high stress levels in the mandibular neck. Traumatic load at the parasymphyseal region concentrated the resulting stress close to the mental foramen. Traumatic load in the mandibular body generated extensive stress in the mandibular body, angle, and ramus. FEA enabled precise mapping of the stress distribution in a human elderly edentulous mandible (neck and mandibular angle) in response to 3 different traumatic load conditions. This knowledge can help guide emergency responders as they evaluate patients after a traumatic event.

Mechanical And Photoelastic Analysis Of Four Different Fixation Methods For Mandibular Body Fractures.

The aim of the present study was to compare four methods of fixation in mandibular body fractures. Mechanical and photoelastic tests were performed using polyurethane and photoelastic resin mandibles, respectively. The study groups contained the following: (I), two miniplates of 2.0 mm; (II) one 2.0 mm plate and an Erich arch bar; (III) one 2.4 mm plate and an Erich arch bar, and (IV) one 2.0 mm plate and one 2.4 mm plate. The differences between the mean values were analyzed using Tukey's test, the Mann-Whitney test and the Bonferroni correction. Group II recorded the lowest resistance, followed by groups I, IV and III. The photoelastic test confirmed the increase of tension in group II. The 2.4 mm system board in linear mandibular body fractures provided more resistance and the use of only one 2.0 mm plate in the central area of the mandible created higher tension.

Development Plates For Stable Internal Fixation: Study Of Mechanical Resistance In Simulated Fractures Of The Mandibular Condyle.

To develop Y-shaped plates with different thicknesses to be used in simulated fractures of the mandibular condyle. Ten plates were developed in Y shape, containing eight holes, and 30 synthetic polyurethane mandible replicas were developed for the study. The load test was performed on an Instron Model 4411 universal testing machine, applying load in the mediolateral and anterior-posterior positions on the head of the condyle. Two-way ANOVA with Tukey testing with a 5% significance level was used. It was observed that when the load was applied in the medial-lateral plate of greater thickness (1.5 mm), it gave the highest strength, while in the anteroposterior direction, the plate with the highest resistance was of the lesser thickness (0.6 mm). A plate with a thickness of 1.5 mm was the one with the highest average value for all displacements. In the anteroposterior direction, the highest values of resistance were seen in the displacement of 15 mm. After comparing the values of the biomechanical testing found in the scientific literature, it is suggested that the use of Y plates are suitable for use in subcondylar fractures within the limitations of the study.

Intraoral open reduction and internal fixation of displaced mandibular angle fractures using a specific ad hoc reduction-compression forceps: a preliminary study

OBJECTIVES: To preliminarily evaluate prospectively the accuracy and reliability of a specific ad hoc reduction-compression forceps in intraoral open reduction of transverse and displaced mandibular angle fractures. STUDY DESIGN: We analyzed the clinical and radiologic data of 7 patients with 7 single transverse and displaced angle fractures. An intraoral approach was performed in all of the patients without using perioperative intermaxillary fixation. A single Arbeitsgemeinschaft Osteosynthese (AO) unilock reconstruction plate was fixed to each stable fragment with 3 locking screws (2.0 mm in 5 patients and 2.4 mm in 2 patients) at the basilar border of the mandible, according to AO/American Society of Internal Fixation (ASIF) principles. Follow-up was at 1, 3, 6, and 12 months, and we noted the status of healing and complications, if any. RESULTS: All of the patients had satisfactory fracture reduction as well as a successful treatment outcome without complications. CONCLUSION: This preliminary study demonstrated that the intraoral reduction of transverse and displaced angle fractures using a specific ad hoc reduction-forceps results in a high rate of success.

Are open mandibular fractures still an emergency?

INTRODUCTION: Early surgical management is often advocated for fractures of the tooth-bearing portion of the mandible. A 6-hour delay has been mentioned for the fixation of these fractures. Our aim was to bring this paradigm into question. METHODS: All patients referred to our department from September 2012 to May 2014 for fractures of the tooth-bearing portion of the mandible were retrospectively included. For each patient, age, gender, aetiology of the fracture, and characteristics of the fractures were recorded. Tobacco and/or alcohol addictions, diabetes and mandibular dental condition were taken into account. We also noticed the preoperative delay and the occurrence of complications such as: haematoma, infection, wound dehiscence, osteosynthesis failure and pseudarthrosis. RESULTS: Among the 47 patients referred, 36 were treated with a delay of more than 6hours (76.6%). In 88.8% of the cases, the reason for this delay was unavoidable. The mean delay time from trauma to surgery was 52hours (range: 7-312). Forty-nine percent of the patients had comorbidities. Complications occurred in 6 patients leading to an overall complication rate of 16.67%. A statistically significant higher complication rate was observed among smokers (P=0.006). No statistical relationship was found between the delay and the occurrence of complications (P=0.994). This study suggests that fractures of the tooth-bearing portion of the mandible should no longer be considered as an emergency that must be treated within a 6-hour delay.

Epidemiologic Evaluation of Mandibular Fractures in the Rio de Janeiro High-Complexity Hospital

The aim of this study was to gather data on trauma etiology and mandibular fracture localization in patients who presented at the General Hospital of Nova Iguacu, Rio de Janeiro, Brazil. From March 2007 to December 2008, 95 patients with mandibular fracture were registered in a medical form, at the Bucomax-illofacial Surgery Department of the General Hospital of Nova Iguacu, Rio de Janeiro, Brazil. Concerning mandibular fracture etiology, 21.05% were caused by motorcycle accidents, followed by interpersonal violence without use of weapons (punches, kicks, bumps with the head, blows with the elbow, etc) (16.84%) and interpersonal violence with firearm (14.73%). It was found that 52.63% of the patients had a single fracture line. The most affected fracture area was the parasymphysis (26.02%), followed by the condyle (22.60%) and mandibular angle (18.49%). Concerning the injury area, 24.21% were directed to the mandibular symphysis, 22.17% of the patients did not remember the injury area, and 18.94% had multiple injuries. When the injury was directed to the symphysis, the result was more condyle fractures (11.64%), and injuries at the mandibular angle resulted in fractures at the angle itself (8.90%). The most common fracture cause was traffic accidents, mainly motorcycle accidents, and the most affected areas were the parasymphysis and the condyle. The mandible isolated fractures occurred in half of the cases. Motorcycle accidents resulted in more fractures in the parasymphysis area, and when the symphysis area is affected by injuries, the result is a higher percentage in condyle fractures.

Rigid internal fixation with titanium versus bioresorbable miniplates in the repair of mandibular fractures in rabbits

The purpose of this study was to compare by qualitative histology the efficacy of rigid internal fixation with titanium system and the Lacto Sorb® system in mandibular fractures in rabbits. Thirty male adult rabbits Oryctolagus cuniculus were used. Unilateral mandibular osteotomies were performed between the canine and first premolar. The animals were divided into two groups: for Group I - rigid internal fixation was performed with titanium system 1.5 mm (Synthes, Oberdorf, Switzerland), with two screws of 6 mm (bicortical) on each side of the osteotomy. For Group II-rigid internal fixation was performed with PLLA/PGA system 1.5 mm (Lacto Sorb®, WLorenz, Jacksonville, FL, USA). The histological analysis evaluated the presence of inflammatory reaction, degree of bone healing and degree of resorption of the Lacto Sorb® screws. The results of both fixation systems were similar, only with a small difference after 15 and 30 days. In Group I a faster bony healing was noted. But after 60 days, bony healing was similar in both groups. It is concluded that both PLLA/PGA and titanium plates and screws provide sufficient strength to permit mandibular bone healing. The resorption process of PLLA/PGA osteosynthesis material did not cause acute or chronic inflammatory reaction or foreign body reaction during the studied period. © 2004 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Biomechanical Study in Polyurethane Mandibles of Different Metal Plates and Internal Fixation Techniques, Employed in Mandibular Angle Fractures

The aim of this study was to perform a physicochemical and morphological characterization and compare the mechanical behavior of an experimental Ti-Mo alloy to the analogous metallic Ti-based fixation system, for mandibular angle fractures. Twenty-eight polyurethane mandibles were uniformly sectioned on the left angle. These were divided into 4 groups: group Eng 1P, one 2.0-mm plate and 4 screws 6 mm long; group Eng 2P, two 2.0-mm plates, the first fixed with 4 screws 6 mm long and the second with 4 screws 12 mm long. The same groups were created for the Ti-15Mo alloy. Each group was subjected to linear vertical loading at the first molar on the plated side in a mechanical testing unit. Means and standard deviations were compared with respect to statistical significance using ANOVA. The chemical composition of the Ti-15Mo alloy was close to the nominal value. The mapping of Mo and Ti showed a homogeneous distribution. SEM of the screw revealed machining debris. For the plates, only the cpTi plate undergoes a surface treatment. The metallographic analysis reveals granular microstructure, from the thermomechanical trials. A statistically significant difference was found (P < 0.05) when the comparison between both internal fixation techniques was performed. The 2P technique showed better mechanical behavior than 1P.

A six-year retrospective study of maxillofacial fractures from radiographic findings in Brazil

Objective: this study aimed to present the causes and prevalence of maxillofacial fractures that occurred in the region of Araraquara-SP – Brazil, during a 6-year period. Methods: information regarding age, gender, etiology, and maxillofacial fracture site, as well as type of radiographic examination were evaluated. Data were gathered from the radiographic examination and radiographic report of the Division of Dentomaxillofacial Radiology, and from charts of the Division of Oral and Maxillofacial Surgery of patients attending for maxillofacial fractures from 2004 to 2009. A descriptive statistical analysis was developed using Epi-Info 3.5.1. Results: from a total of 11,728 patients assisted, 407 patients presented maxillofacial fractures. The prevalent age ranged from 21 to 30 years old. From the total patients, 322 were men and 85 were women (ratio of men to women was 3.8:1). Panoramic radiography (n = 306) was most frequently used to observe maxillofacial fractures. Mandibular fractures were frequent in the body of the mandible (n = 127), followed by symphysis (n = 102), and the prevalent cause was traffic accidents (n = 161). Conclusion: more than half of affected individuals were younger than 40 years of age. The body of the mandible was the most common fracture location visualized by panoramic radiography for traffic accidents and fights.

Treatment of Atrophic Mandibular Fractures with the Pencilboneplate: Report of 2 Cases

The incidence of fractures of the atrophic edentulous mandible is still low, even with the increasing life expectancy. The reduced blood supply of the sclerotic bone, the diminished contact area between bone fragments and the patient’s systemic condition makes the treatment of those fractures a challenge for any professional. Treatment of atrophic mandibular fractures by means of miniplate osteosynthesis has not been the preferred method of fixa- tion by many authors. Yet, many surgeons have applied this type of fixation for the atrophied jaw sections. This paper reports 2 cases of fractured atrophic mandibles treated with the pencilboneplate, a monocortical 2.0 mm titanium, 8 or 10-hole hardware with reinforcement on its middle portion, highlighting important considerations of its use. The pencilboneplate appears to be a valuable option for the treatment of atrophic mandibular fractures, espe- cially by an intra-oral approach, and warrants further bio- mechanical and clinical studies.