Photoelastic analysis of stress distribution of surgically assisted rapid maxillary expansion with and without separation of the pterygomaxillary suture.

PURPOSE: The aim of this study was to evaluate in vitro the mechanical effect over teeth and bone structures of surgically assisted rapid maxillary expansion (SARME) in photoelastic analogs by observing stress produced during Hyrax-type and Haas-type appliances activation. MATERIALS AND METHODS: Two photoelastic analogs were fabricated by use of birefringent materials to simulate an adult skull that contained teeth, bone, and maxillary sinus. Hyrax-type and Haas-type appliances were applied to the anchor teeth and incrementally activated. SARME was simulated by subsequent cuts of the lateral maxillary wall and midpalatine suture and separation of the pterygomaxillary junction. After each osteotomy, the appliances were activated. Resulting stress patterns were recorded photographically in the field of a plane polariscope. RESULTS: Before any osteotomy, the activation of the appliances distributed stress through the anchoring teeth to the zygomaticomaxillary walls, concentrating at the zygomaticomaxillary and zygomaticofrontal sutures and at the midline of the maxilla. After midpalatal and maxillary wall osteotomies, a marked reduction of the stress at the zygomaticomaxillary walls was observed. With successive activations, the stresses increased in intensity at the molars, maxillary tuberosity, and pterygoid plates. After pterygomaxillary separation, the stress intensity at the molar area, maxillary tuberosity, and pterygoid plates decreased considerably. With successive activations, stress increased in intensity around the molars and maxillary tuberosity. There were no differences between stresses produced by the 2 appliances. CONCLUSIONS: In this biomechanical model, sectioning of all maxillary articulations, including separation of the pterygomaxillary junction, caused a decrease in stress over anchorage teeth. These data cannot be completely extrapolated to the clinical situation but indicate that electing to perform the SARME technique should be based on periodontal health and amount of expansion necessary for each case.

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.

Variables related to surgical and nonsurgical treatment of zygomatic complex fracture.

The aim of this retrospective research was to establish the association between variables for the surgical treatment of zygomatic complex (ZC) fractures. In a 10-year period, 532 patients were examined for ZC fractures. The medical records of patients were analyzed to obtain information related to sociodemographic characteristics, trauma etiology, sign and symptoms of patients, and surgical or nonsurgical treatment. Statistical analysis was performed using χ test with statistical significance of P < 0.05. Most fractures were sustained by subjects between 21 and 40 years of age (55.8%), being principally men (80.1%), and 153 patients underwent surgery (28.8%). Surgical treatment of ZC fractures was statistically associated to the presence of other facial fractures (P = 0.004), alteration of occlusion (P = 0.0001; probably due to jaw fractures), presence of the comminuted fractures (P = 0.0002), and infraorbital nerve sensory disturbances (P = 0.003). A mixture of complex variables can be associated to surgical treatment; however, variables as comminuted fracture and alteration of occlusion were associated to surgical treatment indications.

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.

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.

Surgically assisted palatine expansion in adult patients: evaluation of a conservative technique.

PURPOSE: This study was conducted to assess a conservative technique for surgically assisted palatine expansion (SAPE) done under local anesthesia and conscious sedation in adults. Dental inclination, uniformity of expansion, and satisfaction of orthodontist were evaluated. PATIENTS AND METHODS: Twenty-seven consecutive patients, ranging in age from 25 to 42 years, underwent SAPE under local anesthesia. The surgical procedure involved osteotomy of the lateral wall of the maxilla, from the maxillary tuberosity to the nasal cavity, with the nasal septum and the ptyerigoid plates left intact. Cast models were obtained before surgery and 1 year after surgery. Cuspid inclinations were assessed, with intercanine distance in 2 points, the incisal and cervical borders, measured before and after surgery. Molar inclination was obtained by measuring intermolar distance at the cervical margin and occlusal table. The results were statistically analyzed by analysis of variance. A questionnaire with 4 questions was addressed to the orthodontists to evaluate the level of satisfaction with the procedure. RESULTS: Cuspid and molar inclination occurred, but there was no statistically significant difference (P < .05) in dental inclination before and after surgery. The expansion was greater at the molar level than at the canine level, but this difference also was not statistically significant (P > .05). According to the questionnaire, 100% of the procedures allowed the expansion, 100% of the orthodontists were satisfied, and 68.75% observed dental inclination, but this inclination was not excessive in 100% of the cases. CONCLUSIONS: The proposed technique is a safe, predictable, and reliable method for SAPE in adult patients. Although ptyerigoid plate and nasal septum fractures were not performed, the maxillary bone exhibited uniform expansion. Dental inclination was not significant, either clinically or during cast model analysis. Orthodontists could achieve treatment objectives with this surgical procedure.

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.