Cássio Edvard Sverzut

A retrospective study of mandibular fracture in a 40-month period

This retrospective study evaluated the epidemiology, treatment and complications of mandibular fracture associated, or not associated, with other facial fractures, when the influence of the surgeons skill and preference for any rigid internal fixation (RIF) system devices was minimized. The files of 700 patients with facial trauma were available, and 126 files were chosen for review. Data were collected regarding gender, age, race, date of trauma, date of surgery, addictions, etiology, signs and symptoms, fracture area, complications, treatment performed, date of hospital discharge, and medication. 126 patients suffered mandibular fractures associated, or not, with other maxillofacial fractures, and a total of 201 mandibular fractures were found. The incidence of mandibular fractures was more prevalent in males, in Caucasians and during the third decade of life. The most common site was the condyle, followed by the mandibular body. The therapy applied was effective in handling this type of fracture and the success rates were comparable with other published data.

In vivo bone tissue response to a canasite glass-ceramic.

The aim of this study was to determine the biocompatibility and osteoconductive potential of a high-strength canasite glass ceramic. Glass-ceramic rods were produced using the lost-wax casting technique and implanted in the mid-shafts rabbit femurs. Implants were harvested at 4, 13 and 22 weeks and prepared for light and electron microscopy. Hydroxyapatite was used as a control material. Hydroxyapatite implants were surrounded by new mineralised bone tissue after 4 weeks of implantation. The amount of bone surrounding the implant increased slightly at 13 weeks. In contrast, canasite glass and glass ceramic implants were almost entirely surrounded by soft tissue during all the time periods. Close contact between bone and canasite glass-ceramic implant without the intervening fibrous tissue was observed in only a few regions. The canasite formulation evaluated was not osteoconductive and appeared to degrade in the biological environment. It was therefore concluded that the canasite formulation used was unsuitable for use as implant. Further work is required to improve the biocompatibility of these materials with bone tissue. It is possible that this could be achieved by reducing the solubility of the glass and glass ceramic.

Removal of a maxillary third molar accidentally displaced into the infratemporal fossa via intraoral approach under local anesthesia: report of a case.

The surgical removal of impacted maxillary third molars is a procedure routinely carried out by dentists and oral surgeons, and it is usually associated with low rates of complications and morbidity. 1,2 These complications frequently include fracture of the tuberosity, tooth root fracture, perforation of the maxillary sinus, prolapse of the buccal fat pad, and displacement of the roots or tooth into the maxillary sinus, all of which may be easily managed. 2,3 Although the displacement of an entire tooth into the infratemporal fossa was once considered a rare complication, 3 it has been reported more frequently in the literature in the last 4 decades. 1,2,4-11 This case report describes the location and surgical removal of a left maxillary third molar displaced into the infratemporal fossa during an unsuccessful surgical removal by the patients dental clinician. The diagnostic and treatment problems and the causes of this complication are also discussed.

Accidental Displacement of Impacted Maxillary Third Molar: A Case Report

An unusual case of an impacted right maxillary third molar that was accidentally displaced into the maxillary sinus during exodontia and was surgically retrieved almost 2 years later is described. The tooth was removed under general anesthesia, after maxillary sinus exposure through Caldwell-Luc approach. Postoperative recovery was uneventful. Six months after the retrieval surgery, the maxillary sinus was completely healed and the patient did not present any complaint.

Reconstruction of Mandibular Segmental Defects Using the Guided-Bone Regeneration Technique With Polylactide Membranes and/or Autogenous Bone Graft: A Preliminary Study on the Influence of Membrane Permeability

PURPOSE Bone maintenance after mandibular reconstruction with autogenous iliac crest may be disappointing due to extensive resorption in the long term. The potential of the guided-bone regeneration (GBR) technique to enhance the healing process in segmental defects lacks comprehensive scientific documentation. This study aimed to investigate the influence of polylactide membrane permeability on the fate of iliac bone graft (BG) used to treat mandibular segmental defects. MATERIALS AND METHODS Unilateral 10-mm-wide segmental defects were created through the mandibles of 34 mongrel dogs. All defects were mechanically stabilized, and the animals were divided into 6 treatment groups: control, BG alone, microporous membrane (poly L/DL-lactide 80/20%) (Mi); Mi plus BG; microporous laser-perforated (15 cm(2) ratio) membrane (Mip), and Mip plus BG. Calcein fluorochrome was injected intravenously at 3 months, and animal euthanasia was carried out at 6 months postoperatively. RESULTS Histomorphometry showed that BG protected by Mip was consistently related to larger amounts of bone compared with other groups (P <or= .0001). No difference was found between defects treated with Mip alone and BG alone. Mi alone rendered the least bone area and reduced the amount of grafted bone to control levels. Data from bone labeling indicated that the bone formation process was incipient in the BG group at 3 months postoperatively regardless of whether or not it was covered by membrane. In contrast, GBR with Mip tended to enhance bone formation activity at 3 months. CONCLUSIONS The use of Mip alone could be a useful alternative to BG. The combination of Mip membrane and BG efficiently delivered increased bone amounts in segmental defects compared with other treatment modalities.

Frey's syndrome after condylar fracture: case report

Freys syndrome is the occurrence of hyperesthesia, flushing and warmth or sweating over the distribution of the auriculotemporal nerve and/or greater auricular nerve while eating foods that produce a strong salivary stimulus. Freys syndrome is also known as auriculotemporal syndrome and gustatory sweating. We present a case of Freys syndrome after a condylar fracture and its treatment by internal rigid fixation. A review of the literature is provided along with mention of a simple test (Minors test) that can help in the diagnosis of this syndrome.

A retrospective study of zygomatico-orbital complex and/or zygomatic arch fractures over a 71-month period

BACKGROUND/AIM The aim of this retrospective study was to evaluate the epidemiology, treatment, and complications of zygomatico-orbital complex (ZOC) and/or zygomatic arch (ZA) fractures either associated with other facial fractures or not over a 71-month period. MATERIAL AND METHODS This survey was performed in three hospitals of Ribeirao Preto in Sao Paulo, Brazil, from August 2002 to July 2008. The records of 1575 patients with facial trauma were reviewed. There were 140 cases of ZOC and ZA fractures either associated with other facial fractures or not. Data regarding gender, age, race, addictions, day of trauma, etiology, signs and symptoms, oral hygiene condition, day of initial evaluation, hospital admission, day of surgery, surgery approach, pattern of fractures, treatment performed, post-operative antibiotic therapy, day of hospital discharge, and post-operative complications were collected. The data were subjected to descriptive statistical analyses. RESULTS The most frequent fractures affected Caucasian men and occurred during the fourth decade of life. The most frequent etiology was traffic accident, and symptoms and signs included pain and edema. Type I fractures were the main injury observed, and the treatment of choice was always rigid internal fixation. Post-operative antibiotic therapy was solely employed when there was an indication. Complications were observed in 13.1% of the cases. CONCLUSIONS The treatment protocol yielded suitable post-operative results and also showed success rates comparable to published data around the world.

Bone repair in mandibular body osteotomy after using 2.0 miniplate system – histological and histometric analysis in dogs

The objective of this study was to evaluate the bone repair along a mandibular body osteotomy after using a 2.0 miniplate system. Nine adult mongrel dogs were subjected to unilateral continuous defect through an osteotomy between the mandibular 3rd and 4th premolars. Two four‐hole miniplates were placed in accordance with the Arbeitgeimeinschaft für Osteosynthesefragen Manual. Miniplates adapted to the alveolar processes were fixed monocortically with 6.0‐mm‐length titanium alloy self‐tapping screws, whereas miniplates placed near the mandible bases were fixed bicortically. At 2, 6 and 12 weeks, three dogs were sacrificed per period, and the osteotomy sites were removed, divided into three thirds (Tension Third, TT; Intermediary Third, IT; Compression Third, CT) and prepared for conventional and polarized light microscopy. At 6 weeks, while the CT repaired faster and showed bone union by woven bone formation, the TT and IT exhibited a ligament‐like fibrous connective tissue inserted in, and connecting, newly formed woven bone overlying the parent lamellar bone edges. At 12 weeks, bone repair took place at all thirds. Histometrically, proportions of newly formed bone did not alter at TT, IT and CT, whereas significantly enhanced bone formation was observed for the 12‐week group, irrespective of the third. The results demonstrated that although the method used to stabilize the mandibular osteotomy allowed bone repair to occur, differences in the dynamics of bone healing may take place along the osteotomy site, depending on the action of tension and compression forces generated by masticatory muscles.

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.

Evaluation of in vitro resistance of titanium and resorbable (poly-L-DL-lactic acid) fixation systems on the mandibular angle fracture.

The purpose of this study was to compare, by mechanical in vitro testing, a 2.0-mm system made with poly-L-DL-lactide acid with an analogue titanium-based system. Mandible replicas were used as a substrate and uniformly sectioned on the left mandibular angle. The 4-hole plates were adapted and stabilized passively in the same site in both groups using four screws, 6.0mm long. During the resistance-to-load test, the force was applied perpendicular to the occlusal plane at three different points: first molar at the plated side; first molar at the contralateral side; and between the central incisors. At 1mm of displacement, no statistically significant difference was found. At 2mm displacement, a statistically significant difference was observed when an unfavourable fracture was simulated and the load was applied in the contralateral first molar and when a favourable fracture was simulated and the load was applied between the central incisors. At the failure displacement, a statistically significant difference was observed only when the favourable fracture was simulated and the load was applied on the first molar at the plated side. In conclusion, despite more failure, the poly-L-DL-lactic acid-based system was effective.