Alexandre Meireles Borba

Keratocystic odontogenic tumors and Carnoy’s solution: results and complications assessment

OBJECTIVE Keratocystic odontogenic tumors (KOTs) can be treated with Carnoys solution, although this treatment modality is not free from complications. It is important to verify the incidence of complications after the use of Carnoys solution and compare these with the literature. MATERIALS AND METHODS This study verified the effects of a complementary treatment for KOTs and assessed the incidence of such complications as recurrence, infection, sequestrum formation, mandibular fracture, dehiscence, and neuropathy. RESULTS Twenty-two KOTs treated with Carnoys solution combined with peripheral ostectomy were included, and the follow-up period varied from 12 to 78months with a mean of 42.9months. Complications included recurrence (4.5%), dehiscence (22.7%), infection (4.5%), and paresthesia (18.2%). No difference was found among lesions associated (9.1%) or not (0%) with nevoid basal cell carcinoma syndrome (P>0.05). Dehiscence was influenced by marsupialization (P<0.05), and paresthesia was observed exclusively in cases of mandibular canal fenestration (P<0.01). CONCLUSIONS Complementary treatment with Carnoys solution and peripheral ostectomy appear to provide efficient treatment for KOTs. Complications originating from the use of the solution are less frequent and less serious than complications associated with cryotherapy. Neuropathy seems to be related to direct contact between the solution and the epineurium.

Is there consistency in cephalometric landmark identification amongst oral and maxillofacial surgeons

There may be significant variation amongst oral and maxillofacial surgeons (OMFS) in the identification and placement of cephalometric landmarks for orthognathic surgery, and this could impact upon the surgical plan and final treatment outcome. In an effort to assess this variability, 10 lateral cephalometric radiographs were selected for evaluation by 16 OMFS with different levels of surgical knowledge and experience, and the position of 21 commonly used cephalometric landmarks were identified on radiographs displayed on a computer screen using a computer mouse on a pen tablet. The database consisted of real position measurements (x, y) to determine the consistency of landmark identification between surgeons and within individual surgeons. Inter-examiner analysis demonstrated that most landmark points had excellent reliability (intra-class correlation coefficient >0.90). Regardless of the level of surgeon experience, certain landmarks presented consistently poor reliability, and intra-examiner reliability analysis demonstrated that some locations had a higher average difference for both x and y axes. In particular, porion, condylion, and gonion showed poor agreement and reliability between examiners. The identification of most landmarks showed some inconsistencies within different parameters of evaluation. Such variability among surgeons may be addressed by the consistent use of high-quality images, and also by periodic surgeon education of the definition of the specific landmarks.

Predictors of complication for alveolar cleft bone graft.

We have analysed the predictors of postoperative complications and the need for reoperation after grafting of the alveolar cleft from one specialised cleft centre. The data were obtained from hospital casenotes of patients operated on from December 2004 to April 2010, with a minimum one-year follow-up from the final operation. Independent variables included postoperative complications and the need for reoperation. Conditional variables were sex, age, type of cleft, sides affected, donor area, type of graft material, and the presence of an erupted tooth in contact with the cleft. A total of 71 patients had bone grafted on to the alveolar cleft. The following associations were found to be significant: postoperative complications and need for reoperation (p=0.003); age and complications (p=0.002); affected side and complications (p=0.006); age and reoperation (p=0.000); sex and reoperation (p=0.001); and type of cleft and reoperation (p=0.001). Proper attention should be given to all the variables and risk factors to overcome the many obstacles that might have an adverse influence on a successful outcome of alveolar bone grafting for patients with clefts.

Customized Polymethyl Methacrylate Implants for the Reconstruction of Craniofacial Osseous Defects

Craniofacial defects represent alterations in the anatomy and morphology of the cranial vault and the facial bones that potentially affect an individuals psychological and social well-being. Although a variety of techniques and restorative procedures have been described for the reconstruction of the affected area, polymethyl methacrylate (PMMA), a biocompatible and nondegradable acrylic resin-based implant, is the most widely used alloplastic material for such craniomaxillofacial reconstruction. The aim of this study was to describe a technique for aesthetic and functional preoperative customized reconstruction of craniofacial bone defects from a small series of patients offered by the Brazilian public health system. Three adult male patients attended consultation with chief complaints directly related to their individual craniofacial bone defects. With the aid of multislice computed tomography scans and subsequent fabrication of the three-dimensional craniofacial prototype, custom-made PMMA implants were fabricated preoperatively. Under general anesthesia, with access to the craniofacial defects with a coronal approach, the PMMA implants were adapted and fixated to the facial skeleton with titanium plates and screws. Postoperative evaluation demonstrated uneventful recovery and an excellent aesthetic result. Customized prefabricated PMMA implants manufactured over the rapid prototyping models proved to be effective and feasible.

Physicochemical Properties and Surfaces Morphologies Evaluation of MTA FillApex and AH Plus

The solubility, pH, electrical conductivity, and radiopacity of AH Plus and MTA FillApex were evaluated. In addition, the surfaces morphologies of the sealers were analyzed by using scanning electron microscopy. For pH test, the samples were immersed in distilled water at different periods of time. The same solution was used for electrical conductivity measurement. The solubility and radiopacity were evaluated according to ANSI/ADA. Statistical analyses were carried out at 5% level of significance. MTA FillApex presented higher mean value for solubility and electrical conductivity. No significant difference was observed in the mean values for pH reading. AH Plus presented higher radiopacity mean values. MTA FillApex presented an external surface with porosities and a wide range of sizes. In conclusion, the materials fulfill the ANSI/ADA requirements when considering the radiopacity and solubility. AH Plus revealed a compact and homogeneous surface with more regular aspects and equal particle sizes.

Accuracy of perioperative mandibular positions in orthognathic surgery.

Mandibular position is an important parameter used for the diagnosis of dentofacial deformities, as well as for orthognathic surgery planning and execution. Centric relation (anterior and superior relationship of the mandibular condyles interposed by the thinnest portion of their disks against the articular eminencies), centric occlusion (when lower teeth contact upper teeth at centric relation), and maximal intercuspation (complete interdigitation of lower and upper teeth) are not often addressed as factors that influence the results of orthognathic surgery, although these relationships are critical to ensure accuracy during the surgery. The present study assessed occlusal measurements taken before and after the induction of general anaesthesia from consecutive orthognathic surgery subjects. The variables assessed included the differences between these occlusal measurements, patient age, gender, type of deformity, and type of proposed orthognathic surgical procedure. The results demonstrated statistically significant differences for mandibular retrusion from maximal intercuspation to centric occlusion position, whereas the mandible appeared not to change significantly from centric occlusion after the induction of general anaesthesia. Patient age and the type of deformity appeared to influence the results. While in most instances centric occlusion can be adequately reproduced under general anaesthesia, for some specific orthognathic cases more accurate results might be obtained if the mandible-first sequence is used.

External Reference Nasal Pin for Orthognathic Maxillary Positioning: What Is the Proper Method of Placement?

PURPOSE Intracranial perforation with an external reference nasal pin is a possible complication during maxillary orthognathic surgery. This study attempts to quantify the maximum allowable depth of pin penetration from the soft tissue nasion (STN) and hard tissue nasion (HTN) to the anterior cranial fossa (ACF) and to evaluate the depth and direction of the nasal pin track using postsurgical cone-beam computed tomography (CBCT). MATERIALS AND METHODS Two groups of patients were evaluated. A retrospective cross-sectional chart review evaluated the distance from the STN and HTN to the ACF from random patients on CBCT scans. In addition, a different group of postsurgical orthognathic cases treated between March 2013 and August 2015 were analyzed for the depth and direction of the nasal pin track toward the next anatomic cavity, which included the ACF, frontal sinus, or nasal cavity. RESULTS We identified 103 random patients, aged 14 to 90 years. The mean distance from the STN to the ACF was 21.85 mm (range, 14.06 to 29.12 mm), and the mean distance from the HTN to the ACF was 14.16 mm (range, 7.35 to 20.53 mm). Forty postsurgical CBCT scans showed an overall nasal pin track depth of 12.91 mm (range, 8.53 to 22.60 mm), with the direction of the pin track toward the nasal cavity in most cases. CONCLUSIONS The depth of penetration of an external reference nasal pin should be limited to a maximum of 10 to 12 mm from the STN. Initial skin penetration should begin immediately caudal to the STN, and the pin should be directed in a caudal direction to avoid inadvertent entrance into the ACF, as well as to facilitate a relatively safe penetration into the nasal cavity, if the maximum depth is excessive.

Pleomorphic Multicentric Adenoma in the Submandibular Gland

Neoplasms of salivary glands represent a small group among the diseases involving the head and neck complex. In this group, the pleomorphic adenoma is the most frequent neoplasm, yet involves the submandibular gland in only 12.3% of cases. A patient presenting a swelling in the region of the submandibular gland was submitted to an incisional biopsy, where a fragment of the gland and one juxtaposed node were removed. Histologically they were defined as pleomorphic adenoma. Later, the patient was submitted to submandibulectomy and two other nodes were found close to the gland and removed. All specimens were histologically defined as pleomorphic adenoma. This multicentric finding is of great interest, perhaps explaining the recurrence rate of this neoplasm. The patient is in continuous follow-up and has not presented signs of recurrence.

Prevalence of Malocclusion in Students in a Subpopulation of Mato Grosso, Brazil

Aim: To determine the prevalence of malocclusion in children and students enrolled in public schools and in the Araguaia Family Health Strategy in the municipality of Guarantã do Norte, Mato Grosso, Brazil. Materials and methods: A cross-sectional study was conducted with randomly selected children and adolescents from 6 to 16 years. The students were examined at the selected institutions under natural light by a trained examiner. The sample size was calculated using a 95% confidence interval and data were analyzed by descriptive statistics using absolute and relative frequencies. Results: A total of 400 children and adolescents were selected, 176 (44%) males and 224 females (56%). At facial analysis, the most prevalent facial patterns were mesofacial (43%), dolichofacial (41%), and brachyfacial (16%). In facial profile, 48% were convex, 39% straight, and 13% concave. The occlusal relationship found was 44% class I, 36% class II, and 20% class III; 62% vertical malocclusions, 54% horizontal and 66% harmful habits (bucconasal breathing, finger sucking, and pacifier sucking) were also found. Conclusion: The prevalence of malocclusion was high; over 50% had some type of occlusal changes. Clinical significance: Cross-sectional studies have their importance, as they show the disease situation in different places, subsiding decision-making for prevention and treatment strategies, adapting to the regional financial reality in an attempt to reduce health inequalities among the various social and economic strata of the population.

Physicochemical Properties of MTA and Portland Cement after Addition of Aloe Vera

Introduction: The aim of this in vitro study was to determine the liquid-powder ratio, setting time, solubility, dimensional change, pH, and radiopacity of white structural and non-structural Portland cement, ProRoot MTA and MTA Bio, associated with a 2% glycolic solution containing Aloe Vera, as vehicle. Methods and Materials: Five samples of each material were used for each test, according to the American National Standards Institute/American Dental Association (ANSI/ADA) specification No. 57. Statistical analyses were performed using ANOVA and Tukey’s test at 5% significance. When sample distribution was not normal, non-parametric analysis of variance and the Kruskal-Wallis test were used (α=0.05). Results: No statistical differences were found in liquid-powder ratios among the tested materials. ProRoot MTA showed the longest setting time. Dimensional change values were acceptable in all groups. Also, no significant differences were found in pH values and pH was alkaline in all samples throughout the experiment. Mean radiopacity results obtained for white Portland cements did not meet ANSI/ADA requirements, and were significantly lower than those obtained for MTA-based cements. Finally, Portland cements showed significantly higher mean solubility values compared to the other samples. Conclusion: The physicochemical properties of the tested materials in association with Aloe Vera were compatible with ANSI/ADA requirements, except for the white Portland cements, which failed to meet the radiopacity specification.