Computer-Aided Design ; Humans ; Mandibular Fractures ; diagnostic imaging ; surgery ; Mandibular Neoplasms ; diagnostic imaging ; surgery ; Mandibular Reconstruction ; methods ; Surgery, Computer-Assisted ; methods ; Tomography, X-Ray Computed

OBJECTIVE: To analyze the biomechanical mechanism of mandibular symphyseal fracture combined with bilateral intracapsular condylar fractures using finite element analysis (FEA). METHODS: Maxillofacial CT scans and temporomandibular joint (TMJ) MRI were performed on a young male with normal mandible, no wisdom teeth and no history of TMJ diseases. The three-dimensional finite element model of mandible was established by Mimics and ANSYS based on the CT and MRI data. The stress distributions of mandible with different angles of traumatic loads applied on the symphyseal region were analyzed. Besides, two models with or without disc, two working conditions in occlusal or non-occlusal status were established, respectively, and the differences of stress distribution between them were compared. RESULTS: A three-dimensional finite element model of mandible including TMJ was established successfully with the geometry and mechanical properties to reproduce a normal mandibular structure. Following a blow to the mandibular symphysis with different angles, stress concentration areas were mainly located at condyle, anterior border of ramus and symphyseal region under all conditions. The maximum equivalent stress always appeared on condylar articular surface. As the angle between the external force and the horizontal plane gradually increased from 0° to 60°, the stress on the mandible gradually concentrated to symphysis and bilateral condyle. However, when the angle between the external force and the horizontal plane exceeded 60°, the stress tended to disperse to other parts of the mandible. Compared with the condition without simulating the disc, the stress distribution of articular surface and condylar neck decreased significantly when the disc was present. Compared with non-occlusal status, the stress on the mandible in occlusal status mainly distributed on the occlusal surface, and no stress concentration was found in other parts of the mandible. CONCLUSION When the direction of external force is 60° from the horizontal plane, the stress distribution mainly concentrates on symphyseal region and bilateral condylar surface, which explains the occurrence of symphyseal fracture and intracapsular condylar fracture. The stress distribution of condyle (including articular surface and condylar neck) decreases significantly in the presence of arti-cular disc and in stable occlusal status when mandibular symphysis is under traumatic force.
Finite Element Analysis ; Humans ; Male ; Mandible ; Mandibular Condyle/diagnostic imaging* ; Mandibular Fractures/diagnostic imaging* ; Stress, Mechanical ; Temporomandibular Joint/diagnostic imaging* ; Temporomandibular Joint Disorders

OBJECTIVETo investigate clinical application of endoscopy-assisted internal fixation of ramus and subcondylar fractures.

METHODSIn 11 patients with mandibular ramus and subcondylar fractures, endoscopy-assisted internal fixations with titanium plates were performed using micro-angular drill and screwdriver.

RESULTSAll of the patients showed no visible facial scars. Orthorpantography and three dimensional reconstructions of spiral CT scan demonstrated that all fractures were healed 1 to 15 months after operation. Slight malocclusion existed in 1 case and slight limited mouth openings were found in 2 cases.

CONCLUSIONSEndoscopy-assisted internal fixation of mandibular ramus and subcondylar fracture avoided visible facial scars and the risk of facial nerve damage, it is, therefore, a minimally invasive and effective procedure.

Adult ; Endoscopy ; Female ; Fracture Fixation, Internal ; methods ; Humans ; Male ; Mandibular Fractures ; diagnostic imaging ; surgery ; Radiography

Objective: The mandible is the most common fractured craniofacial bone of all craniofacial fractures in the Philippines, with the mandibular body as the most involved segment of all mandibular fractures. To the best of our knowledge, there are no existing guidelines for the diagnosis and management of mandibular body fractures in particular. General guidelines include the American Academy of Otolaryngology – Head and Neck Surgery Foundation (AAOHNSF) Resident Manual of Trauma to the Face, Head, and Neck chapter on Mandibular Trauma, the American Association of Oral and Maxillofacial Surgeons (AAOMS) Clinical Practice Guidelines for Oral and Maxillofacial Surgery section on the Mandibular Angle, Body, and Ramus, and a 2013 Cochrane Systematic Review on interventions for the management of mandibular fractures. On the other hand, a very specific Clinical Practice Guideline on the Management of Unilateral Condylar Fracture of the Mandible was published by the Ministry of Health Malaysia in 2005. Addressing the prevalence of mandibular body fractures, and dearth of specific guidelines for its diagnosis and management, this clinical practice guideline focuses on the management of isolated mandibular body fractures in adults. Purpose: This guideline is meant for all clinicians (otolaryngologists – head and neck surgeons, as well as primary care and specialist physicians, nurses and nurse practitioners, midwives and community health workers, dentists, and emergency first-responders) who may provide care to adults aged 18 years and above that may present with an acute history and physical and/or laboratory examination findings that may lead to a diagnosis of isolated mandibular body fracture and its subsequent medical and surgical management, including health promotion and disease prevention. It is applicable in any setting (including urban and rural primary-care, community centers, treatment units, hospital emergency rooms, operating rooms) in which adults with isolated mandibular body fractures would be identified, diagnosed, or managed. Outcomes are functional resolution of isolated mandibular body fractures; achieving premorbid form; avoiding use of context-inappropriate diagnostics and therapeutics; minimizing use of ineffective interventions; avoiding co-morbid infections, conditions, complications and adverse events; minimizing cost; maximizing health-related quality of life of individuals with isolated mandibular body fracture; increasing patient satisfaction; and preventing recurrence in patients and occurrence in others. Action Statements The guideline development group made strong recommendationsfor the following key action statements: (6) pain management- clinicians should routinely evaluate pain in patients with isolated mandibular body fractures using a numerical rating scale (NRS) or visual analog scale (VAS); analgesics should be routinely offered to patients with a numerical rating pain scale score or VAS of at least 4/10 (paracetamol and a mild opioid with or without an adjuvant analgesic) until the numerical rating pain scale score or VAS is 3/10 at most; (7) antibiotics- prophylactic antibiotics should be given to adult patients with isolated mandibular body fractures with concomitant mucosal or skin opening with or without direct visualization of bone fragments; penicillin is the drug of choice while clindamycin may be used as an alternative; and (14) prevention- clinicians should advocate for compliance with road traffic safety laws (speed limit, anti-drunk driving, seatbelt and helmet use) for the prevention of motor vehicle, cycling and pedestrian accidents and maxillofacial injuries.The guideline development group made recommendations for the following key action statements: (1) history, clinical presentation, and diagnosis - clinicians should consider a presumptive diagnosis of mandibular fracture in adults presenting with a history of traumatic injury to the jaw plus a positive tongue blade test, and any of the following: malocclusion, trismus, tenderness on jaw closure and broken tooth; (2) panoramic x-ray - clinicians may request for panoramic x-ray as the initial imaging tool in evaluating patients with a presumptive clinical diagnosis; (3) radiographs - where panoramic radiography is not available, clinicians may recommend plain mandibular radiography; (4) computed tomography - if available, non-contrast facial CT Scan may be obtained; (5) immobilization - fractures should be temporarily immobilized/splinted with a figure-of-eight bandage until definitive surgical management can be performed or while initiating transport during emergency situations; (8) anesthesia - nasotracheal intubation is the preferred route of anesthesia; in the presence of contraindications, submental intubation or tracheostomy may be performed; (9) observation - with a soft diet may serve as management for favorable isolated nondisplaced and nonmobile mandibular body fractures with unchanged pre - traumatic occlusion; (10) closed reduction - with immobilization by maxillomandibular fixation for 4-6 weeks may be considered for minimally displaced favorable isolated mandibular body fractures with stable dentition, good nutrition and willingness to comply with post-procedure care that may affect oral hygiene, diet modifications, appearance, oral health and functional concerns (eating, swallowing and speech); (11) open reduction with transosseous wiring - with MMF is an option for isolated displaced unfavorable and unstable mandibular body fracture patients who cannot afford or avail of titanium plates; (12) open reduction with titanium plates - ORIF using titanium plates and screws should be performed in isolated displaced unfavorable and unstable mandibular body fracture; (13) maxillomandibular fixation - intraoperative MMF may not be routinely needed prior to reduction and internal fixation; and (15) promotion - clinicians should play a positive role in the prevention of interpersonal and collective violence as well as the settings in which violence occurs in order to avoid injuries in general and mandibular fractures in particular.
Mandibular Fractures ; Jaw Fractures ; Classification ; History ; Diagnosis ; Diagnostic Imaging ; Therapeutics ; Diet Therapy ; Drug Therapy ; Rehabilitation ; General Surgery

Adult ; Humans ; Imaging, Three-Dimensional ; Jaw Fixation Techniques ; Joint Dislocations ; diagnostic imaging ; etiology ; surgery ; Male ; Mandible ; surgery ; Mandibular Condyle ; diagnostic imaging ; injuries ; surgery ; Mandibular Fractures ; complications ; diagnostic imaging ; surgery ; Tomography, X-Ray Computed

In this paper was analyzed the biomechanical behavior of the mental fractured mandible under the rigid internal fixation (RIF). ANSYS and Pro/E were used to develop a 3-D finite element (3-D FE) model of the mental fractured mandible. By the use of boundary constraints, four biting conditions were simulated. The stress and strain of the mandible and the miniplate-screw were compared under two treatment regimens of one or two miniplate(s) fixation conditions. The strain was larges relatively when fixed with only one miniplate or under the unilateral biting condition, so it would not benefit the healing of bone. Through the biomechanical study, the 3-D FEA of fractured mandible can direct the clinical treatment, and it could serve as a foundation on which to carry out the subsequent biomechanical study for RIF of mandible.
Biomechanical Phenomena ; Computer Simulation ; Finite Element Analysis ; Fracture Fixation, Internal ; methods ; Humans ; Imaging, Three-Dimensional ; Mandibular Fractures ; diagnostic imaging ; surgery ; Tomography, X-Ray Computed

This study was aimed to develop a 3-D finite element (3-D FE) model of the mental fractured mandible and design the boundary constrains. The CT images from a health volunteer were used as the original information and put into ANSYS program to build a 3-D FE model. The model of the miniplate and screw which were used for the internal fixation was established by Pro/E. The boundary constrains of different muscle loadings were used to simulate the 3 functional conditions of the mandible. A 3-D FE model of mental fractured mandible under the miniplate-screw internal fixation system was constructed. And by the boundary constraints, the 3 biting conditions were simulated and the model could serve as a foundation on which to analyze the biomechanical behavior of the fractured mandible.
Adult ; Bone Plates ; Bone Screws ; Computer Simulation ; Finite Element Analysis ; Fracture Fixation, Internal ; instrumentation ; Humans ; Imaging, Three-Dimensional ; Male ; Mandible ; diagnostic imaging ; Mandibular Fractures ; surgery ; Models, Biological ; Prosthesis Design ; Prosthesis Implantation ; instrumentation ; Tomography, X-Ray Computed