Igor Batista Camargo

Comparative Finite Element Analysis of the Biomechanical Stability of 2.0 Fixation Plates in Atrophic Mandibular Fractures

PURPOSE The objective of the present study was to conduct a computational, laboratory-based comparison of the biomechanical stability of 2.0 fixation locking plates with different profiles in Class III atrophic mandibular fractures using 3-dimensional finite element analysis. MATERIALS AND METHODS Three-dimensional finite element models simulating Class III atrophic mandibular fractures were constructed. The models were divided into 4 groups according to plate thickness (1.0, 1.5, 2.0, and 2.5 mm). Fractures were simulated in left mandibular bodies, and 3 locking screws were used on each side of each fracture for fixation. Bite forces of approximately 63 N were simulated in the incisor and molar regions of the mandibles in finite element models. RESULTS The level of compressive strain on the bone around the screw was within the physiological limit. No significant difference was observed in the displacement of bone segments in the fracture region. Von Mises stress was higher during simulated bites in the molar region for plates with thicknesses of 1.0 mm. Plate tension values were below the level required for permanent deformation or fracture in all models. The 2.5-mm-thick plate presented better biomechanical performance than all other plates. The 2.0-mm-thick plate also showed satisfactory results and adequate safety limits. CONCLUSION Large-profile (2.0-mm-thick) locking plates showed better biomechanical performance than did 1.0- and 1.5-mm-thick plates and can be considered an alternative reconstruction plate for the treatment of Class III atrophic mandibular fractures.

Surgical Complications After Implant Placement

Placement of dental implants in the maxillofacial region is routine and considered safe. However, as with any surgical procedure, complications occur. Many issues that arise at surgery can be traced to the preoperative evaluation of the patient and assessment of the underlying anatomy. In this article, the authors review some common and uncommon complications that can occur during and shortly after implant placement. The emphasis of each section is on the management and prevention of complications that may occur during implant placement.

Simultaneous Removal of Third Molars During a Sagittal Split Does Not Increase the Incidence of Bad Splits in Patients Aged 30 Years or Older.

PURPOSE An increasing number of patients who are 30 years old or older have been presenting for orthognathic surgery, some of whom have impacted third molars. The purpose of our report was to review the incidence of bad splits in this age group, both with and without third molars (3Ms). MATERIALS AND METHODS A retrospective cohort analysis of all patients who had undergone sagittal split osteotomy (SSO) who were 30 years old or older was performed. The inclusion criteria were age 30 years or older and performance of an SSO. Those with incomplete data or who were younger than 30 years old were excluded. A history and radiographic review was performed to find cases with a bad split that had occurred during the surgical procedures. The fractures were correlated with the presence or absence of the lower 3Ms, the degree of impaction of the 3Ms, and patient age and gender. For this aged sample, the variables of 3M presence and gender were analyzed using the Fisher exact test. For patient age, analysis of variance was applied, and for the degree of impaction, the Pearson test was used. All the tests used the level significance of 0.05%. RESULTS Of the 220 patients who underwent SSO during the study period, 52 were older than 30 years (24%). Of these, 8 patients (15%) had had at least 1 3M present at surgery. Most of the patients had undergone sagittal splits without complications. A total of 3 patients had had bad splits in this sample, 1 of whom had a 3M present at surgery and 2 of whom did not. No association was found between the occurrence of a bad split and the variables studied, including the presence of a 3M (P = .089), degree of impaction (P = .074), age (P = .963), and gender (P = .266). CONCLUSIONS From the results in this small subset of patients, 3Ms can be removed in patients older than 30 years concomitant with bilateral SSO.

Treatment of condylar fractures with an intraoral approach using an angulated screwdriver: Results of a multicentre study

BACKGROUND This multicentre study aimed to investigate long-term radiographic and functional results following the treatment of condylar fractures using an angulated screwdriver system and open rigid internal fixation with an intraoral surgical approach. METHODS Twenty-nine patients with a total of 32 condylar fractures were evaluated. The patients were investigated prospectively based on the following variables: age, sex, aetiology, side, location and classification of the fracture, degree of displacement, associated fractures, surgical approach, oral health status, type of osteosynthesis plate, duration of surgery, mouth-opening, complications, and duration of follow-up. RESULTS The fractures were classified as subcondylar (n = 25) or condylar neck (n = 7). Mean patient age was 36.38 ± 16.60 years. The median duration of postoperative follow-up was 24.39 ± 13.94 months. No joint noise, weakness of the facial nerve, joint pain, or muscle pain was observed. An additional retromandibular approach was necessary to enable the treatment of one subcondylar fracture with medial displacement. CONCLUSION Subcondylar or condylar neck fractures with medial or lateral displacement can be treated using an intraoral approach with satisfactory results with the advantages of the absence of visible scarring, the avoidance of facial nerve injury, and the ability to obtain rapid access to the fracture.

Sublingual hematoma after usual warfarin dose.

prognathia has a risk for negative pressure pulmonary edema because it makes a patient’s upper airway space narrower by moving the lower jaw backward. Bleeding and swelling in the oral cavity also make the airway space narrower. In addition, oozing from the wound sometimes irritates the patient’s larynx and might initiate a laryngospasm. To maintain an open airway in the recovery room or ward, monitoring with a pulse oxymeter and capnography might be necessary. Intermaxillary fixation produces a significant degree of airway obstruction; thereafter, impairment of pulmonary function should be assessed before operation in patients who are at high risk. Wire cutters are a necessary safety precaution and a standard part of practice. Nurses and patients should know the proper technique for clearing the mouth and airway of a patient in IMF. Hemorrhage evaluation and secretion control also require skilled observation and assistance by the nurse. The mean time taken to release the jaws was a mean of 35.3 seconds by experienced oral surgeons and a mean of 2 minutes 9 seconds by hospital staff involved in caring for these patients. Therefore, the practice of releasing IMF is required for nurses and house staff. In the fatality case (case 1), the time intervals from the first notice to the initiation of AMBU bagging and the completion of tracheostomy were 5 minutes and 50 minutes, respectively. In the survival case (case 2), however, the time intervals from the first notice to the initiation of AMBU bagging and the completion of tracheostomy were 3 minutes and 10 minutes, respectively. We suggest that a pulse oxymeter should be applied at least 48 hours after operation. Fully equipped and readily available suction, epinephrine spray, intubation, and tracheostomy sets should be prepared at the bedside. In cases of cyanosis or tachycardia, the IMF should be removed and intubation must be performed. If the intubation fails or bradycardia appears, a tracheostomy should be performed immediately.

Correlational study of impacted and non-functional lower third molar position with occurrence of pathologies

BackgroundLower third molar (M3) eruption is unpredictable. The purpose of this study was to correlate radiographic position of M3 on a preexistent film with the current clinical, histopathological, and radiographic findings.MethodsA retrospective cohort study was performed. The sample was collected from a database of patients covered by Medical Fund of Brazilian Army. Radiographs were obtained a minimum of 5 years prior to the presurgical visit and after their clinical exam. The primary outcome variables were the teeth positions using Pell and Gregory/Winter classifications on panoramic X-rays. Those variables were analyzed at both the beginning (T0) and end of the study (T1). Clinical assessments and histopathological study of the thirds that were extracted were performed only at T1. Correlation between the teeth positions were related to the clinical, histopathological, and radiographic parameters using statistical analysis tests with significance set at p < 0.05.ResultsTwenty-six patients with 49 M3 were assessed over 10 months. Mean age was 14.92 years at T0 and 21.87 years at T1. The average time between T0 and T1 was 6.77 years. A significant relationship (p = 0.024) was found between the presences of root resorption on the second molar if M3 presented in an IB horizontal position at T1. There was also a significant correlation (p = 0.039) between dental crowding of the anterior lower teeth with IIIB position at T0 and if the patient finished orthodontic treatment without lingual retainers.ConclusionsLower M3 in position IIIB seen in a teenager and IB seen in an adult is more likely to have negative consequences and should be followed closely.

Root contact with maxillomandibular fixation screws in orthognathic surgery: incidence and consequences.

The use of maxillomandibular fixation (MMF) screws in orthognathic surgery has become common in recent years. The risk of injury to adjacent roots with their placement in this population has not been studied extensively. The aim of this study was to review the incidence and consequences of root contact/injury in patients undergoing orthognathic surgery. A retrospective analysis of the treatment and radiographic records of patients who underwent orthognathic surgery between January 2013 and September 2014 at a university in Kentucky, USA was performed. The mean number of screws used was correlated to the mean number of roots affected using Spearmans test, set to a level of significance of 5%. Of 125 patients who underwent orthognathic surgery, 15 (12%) had evidence of root contact. Subsequent radiographs showed resolution of the bone defects. There was no clinical evidence of pulpal necrosis or pain during follow-up. The average number of screws used was 3.14±0.35 per patient, with an average of 0.17±0.52 root contacts per patient. There was no correlation between the number of screws used and the number of roots injured (P=0.279). Based on these results, MMF screws can safely be used to establish interim fixation during orthognathic surgery. Caution should be taken during placement to avoid direct injury to the roots of teeth.

Decision making in third molar surgery: a survey of Brazilian oral and maxillofacial surgeons.

This study was designed to evaluate the variations in decision making among Brazilian oral and maxillofacial surgeons (OMFS) and trainees in relation to third molar surgery. A survey on 18 diverse clinical situations related to the assessment and treatment of the third molar surgeries was conducted during the 20th Brazilian National OMFS meeting. Participants were divided into three groups according to their level of training. Another variable studied was length of experience. Correlation between the question answers and the variables was analysed using the chi-square test and the f test. The mean age of participants was 32.68 years, and their mean length of experience was 5.24 years. There were no statistical differences between the level of training and number of years of experience and the responses to 15 of the 18 questions on clinical situations. However, differences were found in responses to prophylactic extraction of asymptomatic third molars, use of non-steriodal anti-inflammatory drugs (NSAIDs) during the preoperative surgical period and the use of additional imaging to plan extractions. The group with shorter time of experience (3.8 ± 3.94 years) tended to recommend extractions of asymptomatic third molars more frequently compared with the more experienced surgeons (P = 0.041). More experienced surgeons used NSAIDs in the preoperative surgical period, whereas the majority of the youngest surgeons (4.1 ± 5.96 years of experience) did not (P = 0.0042). The certificated trained and in practice group tended to treat deep lower third molar impactions based on the findings of a panoramic radiograph, without obtaining additional imaging [cone beam computed tomography (CBCT)] before treatment (P = 0.0132). Decision making regarding third molar treatment differs according to the level of training and is influenced by the number of years of experience. Therefore, further continuous education programmes in this area are warranted to make recommendations regarding third molars consistent with the current literature.

The nasal lift technique for augmentation of the maxillary ridge: technical note

Placement of dental implants in a severely resorbed anterior maxillary alveolar ridge is limited by the fact that implants may penetrate the nasal cavity. However, when the maxilla shows unusual anatomical changes, reconstruction with implants can be a challenge. Options to increase the bone in this region to permit placement of implants include: maxillary onlay bone graft, Le Fort I interpositional bone graft, and augmentation of the nasal floor, which is a procedure where only the piriform rim and the anterior nasal spine are exposed through an intraoral approach. In our case we modified this to what we call the nasal lift technique, which is a combination of turbinectomy followed by lifting of the anteroposterior nasal floor through a lateral window using autogenous bone or bone substitutes to augment the space.