Guilherme de Araújo Almeida

TMJ response to mandibular advancement surgery: an overview of risk factors

Objective In order to understand the conflicting information on temporomandibular joint (TMJ) pathophysiologic responses after mandibular advancement surgery, an overview of the literature was proposed with a focus on certain risk factors. Methods A literature search was carried out in the Cochrane, PubMed, Scopus and Web of Science databases in the period from January 1980 through March 2013. Various combinations of keywords related to TMJ changes [disc displacement, arthralgia, condylar resorption (CR)] and aspects of surgical intervention (fixation technique, amount of advancement) were used. A hand search of these papers was also carried out to identify additional articles. Results A total of 148 articles were considered for this overview and, although methodological troubles were common, this review identified relevant findings which the practitioner can take into consideration during treatment planning: 1- Surgery was unable to influence TMJ with preexisting displaced disc and crepitus; 2- Clicking and arthralgia were not predictable after surgery, although there was greater likelihood of improvement rather than deterioration; 3- The amount of mandibular advancement and counterclockwise rotation, and the rigidity of the fixation technique seemed to influence TMJ position and health; 4- The risk of CR increased, especially in identified high-risk cases. Conclusions Young adult females with mandibular retrognathism and increased mandibular plane angle are susceptible to painful TMJ, and are subject to less improvement after surgery and prone to CR. Furthermore, thorough evidenced-based studies are required to understand the response of the TMJ after mandibular advancement surgery.

Cone-beam tomography assessment of the condylar position in asymptomatic and symptomatic young individuals

STATEMENT OF PROBLEM Studies of the condyle-mandibular fossa relationship are common, although the role of this relationship in the development of a temporomandibular disorder remains controversial. PURPOSE The purpose of this study was to quantitatively evaluate the condyle-mandibular fossa relationship in young individuals with intact dentitions and compare it to that between individuals with and without symptoms of temporomandibular disorder. MATERIAL AND METHODS Volunteers were classified as asymptomatic (n=20) or symptomatic (n=20) according to research diagnostic criteria for temporomandibular disorders. Each participant underwent 2 cone beam-computed tomography scans of the middle and lower third of the face: 1 scan of the maximum intercuspation position and 1 of the centric relationship position. The distance between the condyle and mandibular fossa was measured on frontal and lateral images of the temporomandibular joint. The condylar position was compared across groups (asymptomatic, symptomatic) by using the Mann-Whitney U test (α=.05). Within each group, the condylar position was compared across maximum intercuspation and centric relationship positions by using the Mann-Whitney U test (α=.05). RESULTS No statistically significant differences were found in condylar positions between centric relationships and maximum intercuspation in either asymptomatic or symptomatic young adults, and no significant differences were found between asymptomatic and symptomatic young adults. CONCLUSIONS The condyle-mandibular fossa relationships of these young adults were similar in the centric relationships and maximum intercuspation positions when evaluated by computed tomography. The presence or absence of temporomandibular disorder was not correlated with the condyle position in the temporomandibular joint.

Comparative analysis between mandibular positions in centric relation and maximum intercuspation by cone beam computed tomography (CONE-BEAM)

ABSTRACT This research consisted of a quantitative assessment, and aimed to measure the possible discrepancies between the maxillomandibular positions for centric relation (CR) and maximum intercuspation (MI), using computed tomography volumetric cone beam (cone beam method). The sample of the study consisted of 10 asymptomatic young adult patients divided into two types of standard occlusion: normal occlusion and Angle Class I occlusion. In order to obtain the centric relation, a JIG device and mandible manipulation were used to deprogram the habitual conditions of the jaw. The evaluations were conducted in both frontal and lateral tomographic images, showing the condyle/articular fossa relation. The images were processed in the software included in the NewTom 3G device (QR NNT software version 2.00), and 8 tomographic images were obtained per patient, four laterally and four frontally exhibiting the TMA’s (in CR and MI, on both sides, right and left). By means of tools included in another software, linear and angular measurements were performed and statistically analyzed by student t test. According to the methodology and the analysis performed in asymptomatic patients, it was not possible to detect statistically significant differences between the positions of centric relation and maximum intercuspation. However, the resources of cone beam tomography are of extreme relevance to the completion of further studies that use heterogeneous groups of samples in order to compare the results.

Assessment of the mandibular symphysis of Caucasian Brazilian adults with well-balanced faces and normal occlusion: the influence of gender and facial type

OBJECTIVE: This study aimed to establish cephalometric reference values for mandibular symphysis in adults. Dentoalveolar, skeletal and soft tissue variables were measured considering the influence of gender and facial type. METHODS: The sample consisted of sixty cephalometric radiographs of white Brazilian adult patients, with a mean age of 27 years and 6 months, who had not undergone orthodontic treatment and who presented well-balanced faces and normal occlusion. The sample was standardized according to gender (30 males and 30 females) and facial type (20 were dolichofacial, 20 mesofacial and 20 brachyfacial). RESULTS: The results showed that male and female symphyses are similar, except for symphyseal height, which was greater in males. In terms of facial type, the dolichofacial group presented narrower symphysis in dentoalveolar and basal areas, with a more accentuated lingual dentoalveolar inclination. CONCLUSION: The brachyfacial group showed broader symphysis in the dentoalveolar and basal areas and a greater buccal dentoalveolar inclination. The projection of the chin was 6.67 mm below the subnasal vertical line and there was no significant difference between the genders or facial types.

Temporomandibular disorder and anxiety, quality of sleep, and quality of life in nursing professionals

To evaluate the association between temporomandibular disorder (TMD) and anxiety, quality of sleep, and quality of life in nursing professionals at the Hospital de Clínicas de Uberlândia of the Universidade Federal de Uberlandia--HCU-UFU (Medical University Hospital of the Federal University of Uberlândia), four questionnaires were given to nursing professionals. The questionnaires were completed by 160 of these professionals. The Fonsecas questionnaire was used to evaluate the presence and severity of TMD, the IDATE was used to evaluate anxiety, the SAQ was used to evaluate quality of sleep, and the SF-36 was used to evaluate quality of life. Forty-one nurses (25.6%) reported having no TMD (Fonsecas questionnaire score ≤ 15), 66 (41.3%) had mild TMD (Fonsecas questionnaire score 20-40), 39 (24.4%) had moderate TMD (Fonsecas questionnaire score 45-65), and 14 (8.8%) had severe TMD (Fonsecas questionnaire score ≥ 70). According to Fonsecas questionnaire, the presence of TMD was associated with trait anxiety, but the TMD severity was associated with state anxiety classification (mild, moderate, severe). The SAQ score differed significantly from Fonseca classification. The Fonsecas questionnaire score correlated negatively with the score of each dimension of the SF-36 (r = -0.419 to -0.183). We conclude that TMD is common among nursing professionals; its presence was associated with trait anxiety, and its severity was associated with state anxiety. Hence, the presence of TMD may reduce quality of sleep and quality of life.

Class III malocclusion with maxillary deficiency, mandibular prognathism and facial asymmetry

ABSTRACT This article reports the clinical case of a female patient with history of unsuccessful orthodontic treatment. She presented with Class III malocclusion, mandibular and maxillary constriction, anterior crossbite and facial asymmetry resulting from laterognathism triggered by hyperactivity of the condyle revealed by vertical elongation of the right mandibular ramus. Patients treatment consisted of orthodontic mechanics and two orthognathic surgical interventions with satisfactory and stable outcomes. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO), as part of the requirements for obtaining the BBO Diplomate title.

Efficiency of compensatory orthodontic treatment of mild Class III malocclusion with two different bracket systems

ABSTRACT Objective: The purpose of this study was to assess the efficiency of compensatory orthodontic treatment of patients with mild Class III malocclusion with two preadjusted bracket systems. Method: Fifty-six matched patients consecutively treated for mild Class III malocclusion through compensatory dentoalveolar movements were retrospectively evaluated after analysis of orthodontic records. The sample was divided into two groups according to the brackets used: Group 1 = non-Class III compensated preadjusted brackets, Roth prescription (n = 28); Group 2 = compensated Class III preadjusted brackets, Capelozza III prescription (n = 28). Cephalometric analysis, number of appointments and missed appointments, months using Class III elastics, and bond/band failures were considered. Treatment time, Peer Assessment Rating (PAR) index at the beginning (PAR T1) and end of treatment (PAR T2) were used to calculate treatment efficiency. Comparison was performed using a MANOVA at p< 0.05. Results: Missed appointments, bond or band failures, number of months using the Class III intermaxillary elastics, and cephalometric measurements showed no statistically significant difference (p> 0.05) between groups. Patients treated with Roth brackets had a treatment time 7 months longer (p= 0.01). Significant improvement in the patient’s occlusion (PAR T2-T1) was observed for both groups without difference (p= 0.22). Conclusions: Orthodontic brackets designed for compensation of mild Class III malocclusions appear to be more efficient than non-compensated straight-wire prescription brackets. Treatment time for Class III patients treated with brackets designed for compensation was shorter than with Roth prescription and no difference in the quality of the occlusal outcome was observed. A prospective randomized study is suggested to provide a deeper look into this subject.