Mechanical and photoelastic analysis of conventional screws and cannulated screws for sagittal split osteotomy fixation: a comparative study.

PURPOSE: The aim of the present study was to use mechanical and photoelastic tests to compare the performance of cannulated screws with solid-core screws in sagittal split osteotomy fixation. METHODS: Ten polyurethane mandibles, with a prefabricated sagittal split ramus osteotomy, were fixed with an L inverted technique and allocated to each group as follows: cannulated screw group (CSG), fixed with three 2.3-cannulated screws; and solid-core screw group (SCSG), fixed with three 2.3-solid-core screws. Vertical linear loading tests were performed. The differences between mean values were analyzed through T test for independent samples. The photoelastic test was carried out using a polariscope. RESULTS: The results revealed differences between the two groups only at 1 mm of displacement, in which the cannulated-screw revealed more resistance. Photoelastic test showed higher stress concentration close to mandibular branch in the solid-core group. CONCLUSIONS: Cannulated screws performed better than solid-core ones in a mechanical test at 1-mm displacement and photoelastic tests.

Condylar resorption after orthognathic surgery: a systematic review / Reabsorción condilar después de cirugía ortognática: una revisión sistemática

The aim of this research was to evaluate the risk factors related to condylar resorption (CR) after orthognathic surgery. Was realized a systematic review with a search of the literature performed in the electronic databases PubMed, MedLine, Ovid, Cochrane Library for current evidence in the world literature as conducted, and relevant articles were selected in according to inclusion and exclusion criteria and the findings were compared. Eight papers, (follow-up 12 months to 69 months) were including. A sample of 2567 patient with mandible or bi maxillary surgery with an age range from 14 to 46 year old was observed. In 137 patients (5.3 percent) CR was observed , with a 97.6 percent (122) female. CR was related to 118 cases with mandibular deficiencies with high mandibular plane (advancement surgery). CR were present principally in bi maxillary surgery with a 103 cases (75.2 percent) and only two papers show any analysis to the relation with TMJ dysfunction. Current evidence in CR is poor but supports those female patients with mandibular deficiency and high mandibular plane angle submitted to bi maxillary surgery with change in occlusal plane (counterclockwise) are associated with condylar resorption after orthognathic surgery...

El objetivo de esta investigación fue evaluar los factores de riesgo asociados a reabsorción condilar (RC) posterior a cirugía ortognática. Fue realizada una revisión sistemática con una búsqueda de la literatura realizada en bases de dato electrónicos como PubMed, MedLine, Ovid, Cochrane Library buscando actual evidencia en la literatura mundial; artículos relevantes fueron seleccionados según los criterios de inclusión y exclusión, comparando sus resultados. Ocho artículos (tiempo de seguimiento de 12 a 69 meses) fueron incluidos. Se observó una muestra de 2567 pacientes con cirugía mandibular o bimaxilar con una edad de entre 14 y 46 años. En 137 pacientes (5,3 por ciento) se observó reabsorción condilar, siendo el 97,6 por ciento (122 casos) de sexo femenino. La RC fue observada n 118 casos de deficiencia mandibular con un plano mandibular alto (cirugía de avance mandibular). La RC estuvo presente principalmente en cirugías bimaxilares con 103 casos afectados (75,2 por ciento) y solo dos artículos evidenciaron análisis previo de disfunción de ATM. Actualmente la evidencia en RC es limitada pero fundamenta que mujeres con deficiencia mandibular y alto plano mandibular sometidas a cirugía bimaxilar con alteración del plano oclusal (giro horario) son asociadas a la reabsorción condilar después de la cirugía ortognática...

Influence of wrong determination of occlusal plane in maxillary advancement: a model surgery study

Aim: This study investigated whether an occlusal plane error of acquisition can influence on the treatment planning of maxillary advancement in double-jaw surgeries. Methods: Advancement of 8 and 4 mm were studied in different groups. For each group, 20 maxillary models were mounted by a 13-degree platform with superior articulator arm (control group) and other 20 models mounted with 7 degrees (study group). Intermediate splint was obtained by cast surgery performed in the control group. All the 40 maxillary models were remounted with this intermediate splint. Measurements in vertical and anteroposterior planes were accomplished pre- and postoperatively by digital caliper rule and Erickson’s platform. Results: Statistical analysis showed significant results in two planes. The alteration of occlusal plane from 13 degrees to 7 degrees modified the final result in vertical measurements: right molar from group of 4 mm advancement (p<0.0001) and left molar from two groups of advancement (p<0.0001); in anteroposterior measurements: maxillary incisor from 4 mm of advancement (p<0.005) and 8 mm of advancement (p<0.0001). Conclusions: Notwithstanding the importance of statistical findings, the result probably did not show clinical relevance in orthognathic surgery. Clinical studies addressing these concerns must be supplied in scientific literature.

Oral and maxillofacial surgery - Helmet and maxillofacial trauma: a 10-year retrospective study

Aim: The aim of the present study was to retrospectively evaluate the epidemiologic characteristicsof the prevalence, type and treatment modalities of maxillofacial trauma according to use ofhelmets by motorcyclists in traffic accidents. Methods: Data was collected from patients during a10-year period (1999-2009). Data recorded included demographic, etiology, diagnosis, type offracture, use of helmet, associated facial and general trauma, soft tissue lesions and treatmentmethods. Data analysis included a descriptive analysis, Chi-square test and Kruskal-Wallis test.Results: From 376 motorcycle crash victims, 260 had maxillofacial fractures with a male/femaleratio of 4:1 and a mean age of 26.1. Considering the helmet as a security device, 89 patients werenot wearing a helmet during the crash against 287 patients that were wearing it. One hundred andsixteen patients had soft tissue lesions, 80 of them wore a helmet at the moment of the crash and36 did not (p<0.05). The most frequently fractured facial bone was the zygoma (24%) followedby the mandible. Conclusions: Motorcycle accidents represented almost one third of all maxillofacialinjuries seen at this Oral and Maxillofacial Surgery Division, causing high morbidity. Educationalcampaigns, defensive driving and use of adequate helmets are necessary to decrease thenumber of facial injuries in such accidents.

Condylar Resorption After Orthognathic Surgery: A Systematic Review.

The aim of this research was to evaluate the risk factors related to condylar resorption (CR) after orthognathic surgery. Was realized a systematic review with a search of the literature performed in the electronic databases PubMed, MedLine, Ovid, Cochrane Library for current evidence in the world literature as conducted, and relevant articles were selected in according to inclusion and exclusion criteria and the findings were compared. Eight papers, (follow-up 12 months to 69 months) were including. A sample of 2567 patient with mandible or bi maxillary surgery with an age range from 14 to 46 year old was observed. In 137 patients (5.3%) CR was observed, with a 97.6% (122) female. CR was related to 118 cases with mandibular deficiencies with high mandibular plane (advancement surgery). CR were present principally in bi maxillary surgery with a 103 cases (75.2%) and only two papers show any analysis to the relation with TMJ dysfunction. Current evidence in CR is poor but supports those female patients with mandibular deficiency and high mandibular plane angle submitted to bi maxillary surgery with change in occlusal plane (counterclockwise) are associated with condylar resorption after orthognathic surgery.

Surgical complications of mandibular condylar fractures.

The purpose of this study was to retrospectively evaluate the complications of 58 patients who underwent surgery for mandibular condylar process fractures. Data were collected from patients during a 10-year period (1999-2009). The data recorded included demographic data, etiology, diagnosis, type of condylar fracture, surgical approaches, and postoperative complications. A total of 58 underwent surgery for reduction of the condylar fractures. There were 22 patients with bilateral condyle fractures and 36 patients with unilateral condyle fractures, accounting for 65 surgeries. In 8 fractures, a preauricular approach was performed to access the fractures condyle, whereas the retromandibular approach was performed in 57 fractures. There were 2 temporary facial palsies, 1 permanent facial palsy, and 1 sialocele. There were no cases of hypertrophic scar, Frey syndrome, or salivary fistula. In conclusion, permanent deformities after surgical complications were unusual, and the results are acceptably safe.

A retrospective analysis of submental intubation in maxillofacial trauma patients.

PURPOSE: The aim of this study was to retrospectively evaluate the frequency, indications, and outcomes of airway management by submental intubation in maxillofacial trauma patients. PATIENTS AND METHODS: Data were collected from patients during a 10-year period (1999-2009) from clinical notes and surgical records from each patient using a standardized data collection form that was specifically developed to investigate the epidemiological features of maxillofacial trauma. Data about anesthetic management were assessed. RESULTS: During the study period, 3,149 patients, victims of facial trauma, were evaluated: 2,090 patients presented facial fractures; 674 were submitted to surgery under general anesthesia. There were 449 nasal intubations, 204 oral intubations, 6 tracheotomies, and 15 submental intubations. Submental intubation permitted reduction and fixation of all the fractures without the interference of the tube during surgical procedure in all of the patients. There were no intra- or postoperative complications. CONCLUSIONS: Submental intubation is a simple, safe, with low morbidity technique for operative airway management in maxillofacial trauma patients when there are fractures involving the nasal region and concomitant dental occlusion disturbances.

Surgical approaches and fixation patterns in zygomatic complex fractures.

The aim of this research was to analyze the surgical approaches and methods of rigid fixation used to treat zygomatic complex (ZC) fractures over a 10-year period. One hundred fifty-three patients who underwent surgery to treat ZC fractures between 1999 and 2008 were retrospectively evaluated. Demographic information, signs, and symptoms of the fractures, classification, surgical approaches, and methods of internal fixation were obtained from the medical records. The data were analyzed using statistical descriptive analysis and chi test (P < 0.05). The mean age of the sample was 31 years, and males were predominant (82.3%). In 60.1% of the patients, one surgical approach was used to treat the ZC fractures, whereas 2 surgical approaches were used in 24.8% of the patients. The zygomaticomaxillary buttress was fixed in 86.9% of the patients, followed by infraorbital rim fixation and zygomaticofrontal. There was a statistical significance between fracture displacement and surgical approach for the infraorbital rim (P < 0.0001) and zygomaticofrontal suture (P < 0.0001). Considering that adequate reduction and fixation should be performed and that we try to minimize the amount of scarring, the intraoral zygomaticomaxillary buttress approach is the first choice to treat ZC fractures. In cases of displacement bigger than 5 mm, approaches to 3 of 4 points of the ZC are mandatory to reduce the fractures. The infraorbital rim and zygomaticofrontal suture approaches are indicated to treat displaced fractures.

Oral myiasis caused by Cochliomyia hominivorax treated nonsurgically with nitrofurazone: report of 2 cases.

Accidental oral myiasis are caused by ingestion of fly's eggs or direct oviposition over a compromised area of the host. Here the authors report 2 cases of accidental oral myiasis caused by direct oviposition over an edentulous area in the first patient and in the periodontium in the second patient. Both cases were treated successfully with topical applications of nitrofurazone during a 3-day period. No surgical procedures were required. Flushing the wound with nitrofurazone caused the maggots to endure a liquid-filled anaerobic environment. Healing was uneventful in the 2 cases presented and no adverse reactions were observed during the treatment after 2 months of follow-up. The maggots of both patients were identified as Cochliomyia hominivorax.

Incidence and patterns of mandibular condyle fractures.

PURPOSE: The aim of the present study was to retrospectively evaluate the epidemiologic characteristics of the prevalence, type, and treatment modalities of condylar fractures of the mandible. PATIENTS AND METHODS: Data were collected from patients during an 8-year period (1999 to 2007). The data recorded included demographic data, etiology, diagnosis, type, dislocation, use of protective devices, state of the dentition, associated facial and general trauma, soft tissue lesions, treatment methods, and the interval between trauma and treatment. Data analysis included a descriptive analysis, chi(2) test, Fisher's exact test, t test, and Kruskal-Wallis test. RESULTS: During the 8-year period, 209 unilateral fractures and 54 bilateral fractures were treated, with a male/female ratio of 3.05:1 and a mean age of 28.4 years, for a total of 317 condylar fractures. Male gender was significantly associated with the presence of a condylar fracture (P < .05). The most common cause of condylar fractures was road traffic accidents (57.8%). Of the 317 fractures, 300 were classified as simple fractures, and 249 fractures were not displaced. Protective devices significantly decreased the number of condylar fractures occurring from road traffic accidents (P < .05). Symphysis fractures were significantly associated with both unilateral and bilateral fractures of the mandibular condyle (P < .05). Subcondylar displaced fractures were significantly associated with surgical treatment (P < .05). CONCLUSIONS: Young adults were involved in most of the accidents. Road traffic accidents were the main cause of condylar fractures. The mandatory use of safety helmets and seatbelts and education of those using the road are essential to decrease the number of facial fractures.

Análise subjetiva de pacientes submetidos à cirurgia de enxerto ósseo autógeno de mento / Subjective analysis of patients submited to autogenous chin bone graft surgery

A técnica de realização de enxerto ósseo de mento tem sido muito utilizada em pacientes que não possuem altura ou espessura de rebordo alveolar. Esses pacientes têm as funções fisiológicas e a estética devolvidas através de enxerto, implante e adaptação de uma prótese. A pesquisa objetivou determi nar as sensações dos pacientes nos períodos pré, trans e pós-cirúrgico, e avaliar se os benefícios do enxerto superaram o desconforto durante a cirurgia, e se esses pacientes realizariam, novamente, o mesmo procedimento cirúrgico, caso fosse necessário. Segundo o relato dos pacientes, apesar da ocorrência de parestesia, dor pós-operatória e limitações nas atividades diárias, foi constatado que os pacientes compreenderam a importância dos procedimentos realizados, tiveram credibilidade na técnica e, conseqüentemente, aceitariam realizar novo procedimento cirúrgico, senecessário.