Márcio Lima Grossi

Occlusal Risk Factors for Temporomandibular Disorders

OBJECTIVE To determine the role of occlusal variables (overbite; overjet; number of anterior and posterior teeth; bilateral canine guidance on lateral and protrusive movements; anterior centric slide; Angle Classes I, II, and III malocclusion) as risk indicators for the development of temporomandibular disorders (TMDs). MATERIALS AND METHODS Seventy-two TMD patients with myofascial pain, with or without limited opening and arthralgia, as well as 30 age- and gender-matched pain-free concurrent controls were included. The association (critical odds ratio [OR] = 2.0) between the significant occlusal variables and TMD was calculated. Confounders were controlled in the inclusion-exclusion criteria as well as in the analysis stage (unconditional logistic regression) by variation in the OR (15%). RESULTS Angle Class II malocclusion (crude OR = 8.0, confidence interval [CI] = 2.2 to 29.3) and the absence of bilateral canine guidance on lateral excursion (crude OR = 3.9, CI = 1.6 to 9.7) were statistically more common in patients than in controls. Spontaneous pain as well as pain on palpation (Class II or higher) were also statistically worse in TMD patients. Significant confounders (ie, employment, age, cigarette and alcohol consumption) acted as effect modifiers not changing the critical OR (adjusted OR Angle Class II and bilateral canine guidance = 8.3 to 12.4 and 2.2 to 4.1, respectively). CONCLUSIONS Absence of bilateral canine guidance on lateral excursion and particularly Angle Class II malocclusion were considered important risk indicators for the development of TMD in this investigation, even when some sociodemographic factors were considered as effect modifiers.

Validation of the Bitestrip versus polysomnography in the diagnosis of patients with a clinical history of sleep bruxism

OBJECTIVE This validation study compared an electromyography (EMG) device, Bitestrip, versus polysomnography in the diagnosis of sleep bruxism (SB). STUDY DESIGN Forty-nine consecutive patients (32 women and 17 men, 41.2 ± 12.9 years old) with a clinical history of SB were included in the study from the Orofacial Pain Clinic, Faculty of Dentistry, Pontifical Catholic University of Rio Grande do Sul in Brazil. RESULTS Initially, we compared an SB positive/negative test result for both systems (agreement 87.8%, sensitivity 84.2%, positive predictive value 100%, and crude kappa 0.71). We then compared a 4-scale test (no, light, moderate, or severe bruxism) between the 2 methods (agreement 80.27%, weighted kappa 0.51, and Kendall W coefficient 0.575). CONCLUSIONS The Bitestrip can be considered as a moderate screening method for the diagnosis of SB, because it is more precise in detecting the presence or absence of SB but less precise in detecting its intensity.

Maximum occlusal force and medial mandibular flexure in relation to vertical facial pattern: a cross-sectional study.

BackgroundVertical facial pattern may be related to the direction of pull of the masticatory muscles, yet its effect on occlusal force and elastic deformation of the mandible still is unclear. This study tested whether the variation in vertical facial pattern is related to the variation in maximum occlusal force (MOF) and medial mandibular flexure (MMF) in 51 fully-dentate adults.MethodsData from cephalometric analysis according to the method of Ricketts were used to divide the subjects into three groups: Dolichofacial (n = 6), Mesofacial (n = 10) and Brachyfacial (n = 35). Bilateral MOF was measured using a cross-arch force transducer placed in the first molar region. For MMF, impressions of the mandibular occlusal surface were made in rest (R) and in maximum opening (O) positions. The impressions were scanned, and reference points were selected on the occlusal surface of the contralateral first molars. MMF was calculated by subtracting the intermolar distance in O from the intermolar distance in R. Data were analysed by ANCOVA (fixed factors: facial pattern, sex; covariate: body mass index (BMI); alpha = 0.05).ResultsNo significant difference of MOF or MMF was found among the three facial patterns (P = 0.62 and P = 0.72, respectively). BMI was not a significant covariate for MOF or MMF (P > 0.05). Sex was a significant factor only for MOF (P = 0.007); males had higher MOF values than females.ConclusionThese results suggest that MOF and MMF did not vary as a function of vertical facial pattern in this Brazilian sample.

Analysis of the effects of a mandibular advancement device on sleep bruxism using polysomnography, the BiteStrip, the sleep assessment questionnaire, and occlusal force.

PURPOSE This before and after study evaluated the effects of a mandibular advancement device (MAD) on sleep bruxism (SB) activity and its associated signs and symptoms. MATERIALS AND METHODS Nineteen young adults (39.9 ± 12.9 years, 58% women) with a clinical history of SB without sleep or neurologic disorders and no spontaneous temporomandibular disorder pain were selected. SB activity was assessed after a habituation period of 2 weeks. The results of a 3-month treatment with a thermoplastic monoblock MAD were compared to baseline using electromyogram polysomnography and the BiteStrip, a portable EMG device. Sleep disorders were assessed and validated against the polysomnography sleep assessment questionnaire (SAQ). Additionally, common signs and symptoms of SB were evaluated with the research diagnostic criteria for temporomandibular disorders. Occlusal force was compared to baseline using a cross-arch force transducer. RESULTS There was a significant improvement in both SB activity and sleep scores (including SB episodes per hour) according to the BiteStrip and the SAQ, respectively. There was also a significant reduction in the signs and symptoms of SB, including grinding and/or clenching, temporomandibular joint (TMJ) sounds, muscle pain, and occlusal force. None of the SB subjects experienced MAD breakage, but in 24% of patients, the MAD treatment had to be interrupted due to TMJ/muscle pain and/or discomfort. CONCLUSION The MAD treatment resulted in the reduction of SB activity, SB signs and symptoms, sleep disorders, and occlusal force.

Prevalence of Temporomandibular Disorders in an Adult Brazilian Community Population Using the Research Diagnostic Criteria (Axes I and II) for Temporomandibular Disorders (The Maringá Study)

PURPOSE The primary objective of this study was to assess the prevalence of temporomandibular disorders (TMDs) and comorbid factors (sleep bruxism and headaches). This study was a cross-sectional population survey in the city of Maringá, state of Paraná, Brazil. MATERIALS AND METHODS Axes I and II of the Research Diagnostic Criteria for TMD (RDC/TMD) were used for assessment of TMD signs and symptoms. The population was users of the Brazilian public health system (SUS), of both sexes, between the ages of 20 and 65 years, and not seeking treatment for TMD. RESULTS The selected population (N = 1,643) was composed mostly of (a) women (65.9%), (b) married or single individuals (90.6%), (c) Caucasians (70.1%), (d) individuals aged 32.7 ± 10.3 years, (e) individuals earning a medium income (75.1%), and (f) those who had completed a high school education or higher (79.9%). According to the chronic pain grade classification (CPG) in the RDC/TMD Axis II, 36.2% of the population had some degree of TMD pain (CPG I to IV); however, only 5.1% had severe limitation due to pain (CPG III or IV). In the RDC/TMD Axis I diagnoses, 29.5% presented with muscle disorders (group I), 7.9% with disk displacements (group II), and 39.1% with other joint disorders (group III). Headaches were present in 67.9% and awake and sleep bruxism in 30% and 33.4% of the population, respectively. CONCLUSION The prevalence of signs and symptoms of TMD was high in this population, but with low disability; however, the proportion of patients in need of treatment was much lower.

Cell Culture–Based Tissue Engineering as an Alternative to Bone Grafts in Implant Dentistry: A Literature Review

Several biomaterials and techniques for bone grafting have been described in the literature for atresic bone tissue replacement caused by edentulism, surgical resectioning, and traumas. A new technique involves tissue engineering, a promising option to replace bone tissue and solve problems associated with morbidity of autogenous grafting. This literature review aims to describe tissue-engineering techniques using ex vivo cell culture as an alternative to repair bone maxillary atresias and discuss the concepts and potentials of bone regeneration through cell culture techniques as an option for restorative maxillofacial surgery.

Avaliação da depressão e de testes neuropsicológicos em pacientes com desordens temporomandibulares

A cross-sectional retrospective study was undertaken, with the primary objective of discovering if there were any neuropsychological differences among and within groups. The California Verbal Learning Test (CVLT) and the Brown-Peterson Consonant Trigram Auditory Memory Test (CCC) were used. Depression was assessed by the Beck Depression Inventory (BDI - Portuguese Version).The neuropsychological tests used did not present any statistically significant differences among the three groups studied, which might be due to the low proportion of patients with post high school education (20%). However, the experimental group (Groups I plus II) showed higher scores on depression (p<0.05) than Group III. In addition, Group II showed higher levels of depression (p<0.01) than Group I, and no statistical differences were found between Group I and III. Taken together, these results suggest that memory tests are highly dependent on the education levels of the participants and cannot be widely used. Additionally, depression plays a role not only in the etiology, but also in the perpetuation of TMD.

In vitro evaluation of cytotoxicity of hyaluronic acid as an extracellular matrix on OFCOL II cells by the MTT assay

OBJECTIVE To evaluate the cytotoxicity of hyaluronic acid (HA) on a tissue-engineered compound for bone grafting containing osteoblastic cells (OFCOL II), platelet-rich plasma (PRP) with or without thrombin (Thr), and hydroxyapatite (HP) by the MTT assay. STUDY DESIGN Studied groups were formed as follows: (A) Cells + HA + PRP with Thr + hydroxyapatite (HP); (B) Cells + HA + PRP + HP; (C) Cells + HA + HP; (D) Cells + HP; (E) Cells + HA; (F) Cells + PRP with Thr; (G) Cells + PRP; and (H) Pure Dulbeccos modified Eagles medium (DMEM) with 15% fetal bovine serum. A 2-way ANOVA and Tukeys test were applied for statistical analysis (P < .05). RESULTS Results of cell viability for each group were as follows: A: 79%, B: 67%, C: 68%, D: 99%, E: 74%, G: 89%, F: 90%, and Group H: 100%. CONCLUSIONS Results suggested a decrease in cell viability in the presence of HA.

Marginal Bone Loss in Implants Placed in the Maxillary Sinus Grafted With Anorganic Bovine Bone: A Prospective Clinical and Radiographic Study.

BACKGROUND Sinus elevation is a reliable and often-used technique. Success of implants placed in such situations, even with bone substitutes alone, prompted the authors of this study to strive for bone loss close to zero and research variables that cause higher or lower rates of resorption. The objective of this study is to evaluate survival rates and marginal bone loss (MBL) around implants placed in sites treated with maxillary sinus augmentation using anorganic bovine bone (ABB), and identify surgical and prosthetic prognostic variables. METHODS Fifty-five implants were placed in 30 grafted maxillary sinuses in 24 patients. Periapical radiographs were evaluated immediately after implant placement (baseline), 6 months, and at the most recent follow-up. MBL was calculated from the difference between initial and final measurements, taking into account a distortion rate for each radiograph compared with original implant measurements. RESULTS Survival rate was 98.2%, with only one implant lost (100% survival rate after loading) over a mean follow-up time of 2.0 ± 0.9 years. MBL ranged from 0 to 2.85 mm: 75.9% of mesial sites and 83.4% of distal sites showed <1 mm of MBL, whereas 35.2% of mesial sites and 37% of distal sites exhibited no bone loss. MBL was significantly (P <0.05) greater in open-flap compared with flapless surgery. CONCLUSIONS Within the limitations of the present study, it was concluded that maxillary sinus elevation with 100% ABB gives predictable results, and that flapless surgery results in less MBL compared with traditional open-flap surgery.

Effects of the bite splint 15-day treatment termination in patients with temporomandibular disorder with a clinical history of sleep bruxism: a longitudinal single-cohort study

OBJECTIVE The aim of this study was to assess the effects of bite splint (BS) treatment termination in patients treated for temporomandibular disorder (TMD) and sleep bruxism (SB). STUDY DESIGN This longitudinal single-cohort study assessed 30 patients (29.5 ± 7.8 years old, 86.7% women) who were successfully treated with BS for SB and TMD for 30 days to 6 months prior to termination of the use of BS. The Research Diagnostic Criteria for TMD Axes I and II, Sleep Assessment Questionnaire, Beck Depression Inventory, and BiteStrip were used to assess TMD signs and symptoms, sleep disorders, depression, and SB at baseline and after 15 days of BS disuse. RESULTS TMD symptoms, including the disability points, characteristic pain intensity, and present pain at rest, increased significantly (P < 0.05). After 15 days of BS termination, there were no significant differences in SB and depression levels, sleep quality, and TMD signs. CONCLUSIONS In patients with TMD and SB, BS treatment cessation is not recommended.