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.

Analysis of 185 maxillofacial fractures in the state of Santa Catarina, Brazil

A retrospective study was performed to assess maxillofacial fractures in patients treated at a public hospital from 2002 to 2006. The data collected included age, gender, etiology, type of injury, treatment modalities and period of treatment. Causes were grouped into seven categories: road traffic collisions, sports accidents, occupational accidents, gunshot fractures, falls, violence and other causes. The analyses involved descriptive statistics, the Chi-squared Test and the Fisher Exact Test. Records from 132 patients sustaining 185 maxillofacial fractures were evaluated. The mandible (54.6 percent) was the most commonly fractured bone in the facial skeleton, followed by the zygoma (27.6 percent). The mean age of the patients was 37.7 years, and the male:female ratio was 4.3:1. Most fractures occurred in adults with ages ranging from 18 to 39 years. A significant statistical relation was found between the age and the etiology of the trauma (p < 0.05), and between the number of fractured sites and the age of the patient (p < 0.05). Considering the age groups, accidents were the most frequent cause of maxillofacial fractures in the age group between 18 to 39 years, and interpersonal violence was the most frequent cause of maxillofacial fractures in the age group between 40 to 59 years. Treatment was performed on the same day as the diagnosis in 44.7 percent of the patients. Open surgery with internal stable fixation was indicated for most of the patients. Facial fractures occurred primarily among men under 30 years of age, and the most common sites of fractures in the face were the mandible and the zygomatic complex. Traffic road collisions were the main etiologic factor associated with maxillofacial trauma.