Mandibular cortical bone evaluation on cone beam computed tomography images of patients with bisphosphonate related osteonecrosis of the jaws

Objectives The objective of this study was to develop a technique for detecting cortical bone dimensional changes in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ). Study Design Subjects with BRONJ who had cone-beam computed tomography imaging were selected, with age- and gender-matched controls. Mandibular cortical bone measurements to detect bisphosphonate-related cortical bone changes were made inferior to mental foramen, in 3 different ways: within a fixed sized rectangle, in a rectangle varying with the cortical height, and a ratio between area and height. Results Twelve BRONJ cases and 66 controls were evaluated. The cortical bone measurements were significantly higher in cases than controls for all 3 techniques. The bone measurements were strongly associated with BRONJ case status (odds ratio 3.36-7.84). The inter-rater reliability coefficients were high for all techniques (0.71-0.90). Conclusions Mandibular cortical bone measurement is a potentially useful tool in the detection of bone dimensional changes caused by bisphosphonates. Long-term administration of bisphosphonates (BPs) affects bone quality and metabolism following accumulation in bone.1 Since the first cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) were published in 2003,2 there has been a search for factors that can predict the onset of the condition. Oral and intravenous BPs reduce bone resorption, increase mineral content of bone, and alter bony architecture.3, 4, 5 and 6 Previous studies have demonstrated these changes both radiographically and following histologic analysis.1, 3, 7, 8, 9 and 10 The BP-related jaw changes may present radiological features, such as thickening of lamina dura and cortical borders, diffuse sclerosis, and narrowing of the mandibular canal3 and 11; however, oral radiographs of patients taking BPs do not consistently show radiographic changes to the jaws.11 and 12 The challenge is to find imaging tools that could improve the detection of changes in the bone associated with BP use. Various skeletal radiographic features associated with BRONJ in conventional periapical and panoramic radiographs, computed tomography, magnetic resonance imaging, and nuclear bone scanning have been described.3, 8, 9, 10 and 11 There has also been a search for BP-related quantitative methods for the evaluation of radiographic images, to avoid observer subjectivity in interpretation. Factors thought to be important include trabecular and cortical structure, and bone mineralization.4 Consequently, measurable bone data have been reported in subjects taking BPs through many techniques, including bone density, architecture, and cortical bone thickness.1, 4, 7 and 13 Trabecular microarchitecture of postmenopausal women has been evaluated with noninvasive techniques, such as high-resolution magnetic resonance images showing less deterioration of the bone 1 year after initiation of oral BP therapy.4 A decrease in bone turnover and a trend for an increase in the bone wall thickness has been detected by histomorphometry in subjects taking BPs.1 Alterations in the cortical structure of the second metacarpal have been detected in digital x-ray radiogrammetry of postmenopausal women treated with BPs.7 Mandibular cortical width may be measured on dental panoramic radiographs, and it has been suggested as a screening tool for referring patients for bone densitometry for osteoporosis investigation.14 and 15 Inhibition of the intracortical bone remodeling in the mandible of mice taking BPs has been reported.16 Thus, imaging evaluation of the mandibular cortical bone could be a biologically plausible way to detect BP bone alterations. Computed tomography can assess both cortical and trabecular bone characteristics. Cone-beam computed tomography (CBCT) can provide 3-dimensional information, while using lower doses and costing less than conventional CT. The CBCT images have been studied as a tool for the measurement of trabecular bone in patients with BRONJ.13 Therefore, cortical bone measurements on CBCT of the jaws might also help to understand bone changes in patients with BRONJ. There is no standard in quantifying dimensional changes of mandibular cortical bone. We explored several different approaches to take into consideration possible changes in length, area, and volume. These led to the 3 techniques developed in this study. This article reports a matched case-control study in which mandibular cortical bone was measured on CBCT images of subjects with BRONJ and controls. The aim of the study was to explore the usefulness of 3 techniques for detecting mandibular cortical bone dimensional changes caused by BP.

Prevalência de oclusopatias e comparação entre a Classificação de Angle e o Índice de estética dentária em escolares do interior do estado de São Paulo-Brasil

INTRODUÇÃO: as oclusopatias estão entre os principais problemas de saúde bucal em todo o mundo, juntamente com a cárie dentária e a doença periodontal, e vários índices têm sido utilizados para registrá-las. OBJETIVOS: verificar a prevalência de oclusopatias utilizando a Classificação de Angle e o Índice de Estética Dentária (DAI), sua severidade e a necessidade de tratamento ortodôntico registradas pelo DAI, e comparar os resultados de ambos os índices, visando correlacionar o padrão dos dados coletados e a viabilidade de utilizá-los de forma conjunta. MÉTODOS: a amostra consistiu de 734 escolares com idade de 12 anos, de ambos os sexos, da rede pública do município de Lins/SP. Foram realizados exames nos pátios das escolas com utilização de sondas IPC a olho nu. RESULTADOS: pela Classificação de Angle, encontrou-se 33,24% das crianças com oclusão normal e 66,76% com má oclusão. Pelo DAI, observou-se que 65,26% das crianças apresentavam-se sem anormalidades ou com más oclusões leves. A má oclusão definida esteve presente em 12,81%, a má oclusão severa foi observada em 10,90% e a muito severa ou incapacitante em 11,03%. A maioria das crianças (70,57%) apresentou relação molar normal, e o overjet maxilar anterior foi a alteração mais frequentemente observada. No cruzamento dos índices houve semelhanças e divergências. CONCLUSÃO: o DAI não foi sensível a alguns problemas de oclusão detectados pela Classificação de Angle, e a recíproca foi verdadeira, demonstrando que ambos os índices possuem pontos distintos na detecção das oclusopatias, podendo ser utilizados de forma reciprocamente complementar.

Analysis of association between posterior crossbite, median line deviation and facial asymmetry

Facial asymmetry is a common human characteristic and can occur on many levels, originate of genetic factors, and can be caused by traumas or due to cross bite and/or muscular disability. The aim of this study was to evaluate the relation between posterior crossbite, median line deviation and facial asymmetry. For this study 70 children aged between 3 and 10 years-old were examined and photographed. Using Microsoft Office Power Point 2007, horizontal lines and one vertical line on median line were drawn, to subjectively analyze facial discrepancies. In relation to overjet, the majority of children (78.6%) showed normal relation, followed by high overjet (17.1%), anterior crossbite (4.3%). In relation to overbite, the majority of children (60%) showed normal relation, 27.1% anterior opened bite (negative overbite), and 12.9% showed high overbite. Posterior crossbite was present in 27.1% of children. Among them, 68.4% showed unilateral crossbite on right side, 21.1% bilateral crossbite and 10.5% unilateral crossbite on left side. The relation between posterior crossbite and facial asymmetry, according to Fisher´s Exact Test (p=0.0970), there was no statistically significant association. In relation to median line, the association was statistically significant with posterior crossbite (p=0.0109) and with facial asymmetry (p=0.0310). There was association between posterior crossbite and median line deviation. There was no association between posterior crossbite and facial asymmetry.

Avaliação histométrica das áreas de tração e compressão do periodonto dos primeiros molares de ratos submetidos à movimentação dentária induzida

Metidos a movimentação dentária induzida. Métodos: utilizou-se 30 ratos Wistar, divididos em três grupos (GI, GII e GIII), compostos por 10 animais cada e sacrificados, respectivamente, 7, 14 e 21 dias após o início do experimento. Os valores médios individuais dos grupos experimentais foram comparados com seu respectivo controle por meio do teste Mann-Whitney. Comparou-se, também, os valores entre regiões em um mesmo período de tempo e, ainda, entre períodos de tempo diferentes em uma mesma região através da Análise de Variância (ANOVA), Kruskal-Wallis e subsequente teste de Tukey. Resultados: os grupos GI e GII exibiram a dimensão do LPD diminuída nas regiões apical da raiz mesiovestibular e cervical da raiz distovestibular, e aumentada nas regiões cervical da raiz mesiovestibular, apical da raiz distovestibular e média de ambas as raízes. Conclusão: a diminuição e o aumento da dimensão do LPD evidenciada em uma mesma raiz — mesiovestibular ou distovestibular —, caracterizou o movimento dentário no sentido de inclinação. As três regiões, apical, média e cervical, comparadas entre si em cada período de tempo, bem como os três períodos de tempo, 7, 14 e 21 dias, comparados entre si em cada região, confirmaram o movimento de inclinação em GI e GII, e a diminuição gradual da intensidade dos fenômenos de GI para GII, até o restabelecimento da normalidade dimensional em GIII.

Avaliação da movimentação dentária induzida após trauma de subluxação: estudo experimental em ratos

Objetivo: avaliar as alterações histológicas ocorridas na área periodontal de molares de ratos submetidos à movimentação dentária induzida (MDI), logo após um trauma intencional (subluxação). Métodos: quarenta ratos Wistar machos adultos (Rattus norvegicus albinus) foram selecionados. Os animais foram divididos em oito grupos (n = 5), de acordo com a combinação das variáveis: Grupo 1 – controle (sem trauma e sem MDI); Grupo 2 – MDI; Grupos 3, 4, 5 e 6 – grupos de trauma dentoalveolar correspondendo, respectivamente, para 1, 3, 8 e 10 dias após o trauma; Grupos 7 e 8 – os molares murinos foram submetidos a um impacto de 900cN e, de um e três dias após o evento trauma, o movimento do dente foi induzido. Os primeiros molares superiores dos animais foram movidos mesialmente durante sete dias, com uma mola fechada (50cN). Após período experimental de cada grupo, os animais foram sacrificados por overdose anestésica e as maxilas direitas foram removidas e processadas para análise histológica qualitativa. Resultados: nos animais dos grupos 3, 4, 5 e 6, as alterações histológicas não foram muito significativas. Consequentemente, o efeito do movimento dentário induzido logo após um evento de subluxação (grupos 7 e 8) foi muito semelhante ao descrito para o grupo 2. Conclusão: não houve diferença na qualidade do reparo periodontal quando a MDI foi aplicada aos dentes que sofreram um trauma de subluxação.

Dentoalveolar comparative study between removable and fixed cribs, associated to chincup, in anterior open bite treatment

Objective: The aim of this prospective study was to compare the dentoalveolar effects produced by two types of palatal crib, removable (Rpc+C) and fixed (Fpc+C), combined with chincup in growing patients with anterior open bite. Material and Methods: Each group comprised 30 patients, in the mixed dentition phase, with similar cephalometric characteristics and skeletal ages. Group 1 (Rpc+ C) presented initial mean age of 8.3 years and mean anterior open bite of 4.0 mm. Group 2 (Fpc+C) presented initial mean age of 8.54 years and mean anterior open bite of 4.3 mm. The evaluation period comprised 12 months between initial (T1) and second lateral radiograph (T2). The T2-T1 changes were compared cephalometrically in the 2 groups using the non-paired t-test. Results: Vertical changes in the posterior dentoalveolar region were similar between the groups (about 1 mm) and no significant differences were found in molar mesialization. The Fpc+C group had in average 1.6 mm more improvement of the overbite as a result of greater maxillary incisor extrusion (1.3 mm). Patients in this group also presented less lingual tipping of maxillary incisors and more mandibular incisors uprighting. Conclusions: The Fpc+C combination was more efficient in the correction of the negative overbite mainly due to greater extrusion of the maxillary incisors. However, the Rpc+C appliance promoted better upper and lower incisor inclination, resulting in a more adequate overjet.

In adults: 47.2% have periodontitis! How about in orthodontic patients?

The occurrence of chronic inflammatory periodontal disease due to dental plaque in adults over 30 years of age was noticed in 47.2% of the 3,742 subjects studied, representing a 64.7 million people population in the 50 states of the U.S. and the District of Columbia. The methods used by the authors were uniquely precise and the results brought us to great insight on the correlation between orthodontic treatment and periodontal health, which is described below.

Vertical growth control during maxillary expansion using a bonded Hyrax appliance

INTRODUCTION: Rapid maxillary expansion (RME) for the treatment of maxillary deficiency and posterior crossbite may induce changes in the vertical dimension. Expanders with occlusal splints have been developed to minimize unwanted vertical effects. OBJECTIVE: This preliminary study used cephalometri radiographs to evaluate the vertical effects of RME using a Hyrax appliance in children with maxillary deficiency. METHOD: Twenty-six patients (11 boys; mean age = 8 years and 5 months) with maxillary deficiency and posterior crossbite were treated using a Hyrax appliance with an acrylic occlusal splint. Radiographs and cephalometric studies were performed before the beginning of the treatment (T1) and after RME active time (T2), at a mean interval of 7 months. Results were compared with normative values. RESULTS AND CONCLUSIONS: At the end of treatment, there were no statistically significant changes, and measurements were similar to the normative values. Data showed that there were no significant effects on vertical growth, which suggests that appliances with occlusal splints may be used to correct transverse deficiencies regardless of the patient's growth pattern.

Dahlberg formula: a novel approach for its evaluation

INTRODUCTION: The accurate evaluation of error of measurement (EM) is extremely important as in growth studies as in clinical research, since there are usually quantitatively small changes. In any study it is important to evaluate the EM to validate the results and, consequently, the conclusions. Because of its extreme simplicity, the Dahlberg formula is largely used worldwide, mainly in cephalometric studies. OBJECTIVES: (I) To elucidate the formula proposed by Dahlberg in 1940, evaluating it by comparison with linear regression analysis; (II) To propose a simple methodology to analyze the results, which provides statistical elements to assist researchers in obtaining a consistent evaluation of the EM. METHODS: We applied linear regression analysis, hypothesis tests on its parameters and a formula involving the standard deviation of error of measurement and the measured values. RESULTS AND CONCLUSION: we introduced an error coefficient, which is a proportion related to the scale of observed values. This provides new parameters to facilitate the evaluation of the impact of random errors in the research final results.

Induced tooth movement: standardization of terms to describe the effects of forces on the periodontal ligament: compression/Traction instead of Pressure/Tension

There is no reason for Dentistry to use different terms for phenomena defined in Physics, the specific field in which concepts associated with forces are established and adapted. In place of pressure/tension, the compression/traction pair should be used. This study defines each one of these terms and justifies their use. Our contemporary world demands standardized criteria, methods, measures, concepts and terms to ensure that study protocols, results and applications are used in the same way in any country or area of human action.

Influence of anatomical barriers on maxillary incisor root resorption after orthodontic treatment with premolar extractions

INTRODUCTION: Apical root resorption is a frequent and occasionally critical problem in orthodontic patients undergoing induced tooth movement. One of the factors that might influence prognosis, especially in maxillary incisors, which most frequently present resorptions, are the so-called the anatomical barriers; that is, proximity of the buccal and palatal cortical bones to the maxillary incisor roots. OBJECTIVE: The purpose of this research was to investigate whether patients with excessive vertical growth really present a small distance between the alveolar cortical bones and the maxillary incisor roots, and whether there is a correlation between this distance and the root resorption index in comparison with patients presenting horizontal growth. METHODS: The sample comprised orthodontic records of 18 patients with extraction planning of first maxillary premolars and treatment by the standard and/or preadjusted edgewise brackets. Their initial and final periapical radiographs were evaluated to determine the amount of root resorption that occurred. RESULTS: On the palatal side, patients with excessive vertical growth (Group 2 - SN-GoGn > 43º) showed a narrower alveolar bone than the horizontal growth patients (Group 1 - SN-GoGn < 29º). However, the distance between the buccal cortical bone and the central incisor root apex showed no significant difference between Groups 1 and 2; CONCLUSIONS: It was concluded that there are no correlations between the proximity of buccal cortical bone, maxillary incisor roots and the root resorption index.

Temporomandibular disorders and parafunctional oral habits: an anamnestic study

OBJECTIVE: To assess the frequency and severity of the signs and symptoms of temporomandibular disorders (TMD), the frequency of parafunctional oral habits and the correlation between the variables by means of the patients' perception regarding their problem. METHODS: One hundred patients diagnosed with TMD, through a clinical examination of their masticatory system, answered the questions of a previously published protocol concerning the signs and symptoms most frequently reported in the literature. RESULTS: According to the results from the non parametric statistical analysis, the frequency for the following signs and symptoms was significant: Fatigue and muscle pain, joint sounds, tinnitus, ear fullness, headache, chewing impairment and difficulty to yawn (p<0.01) and otalgia (p<0.05). As to the parafunctional oral habits, there was a significant presence of teeth clenching during the day and night (p<0.01) and teeth grinding at night (p<0.05). The variable correlation analysis showed that there was a positive correlation between symptom frequency and severity; age was correlated with the presence of otalgia, cervical pain and teeth sensitivity, besides being correlated with muscle and joint pain severity. Habit frequency was negatively correlated with age. TMD duration was also positively correlated with the symptoms of tinnitus, ear fullness, muscle and joint pain. CONCLUSION: The study results showed that the anamnestic assessment using ProDTMMulti can predict the severity of the TMD case.

Treatment of snoring and sleep apnea syndrome with a removable mandibular advancement device in patients without TMD

INTRODUCTION: Among the sleep disorders reported by the American Academy of Sleep, the most common is obstructive sleep apnea-hypopnea syndrome (OSAHS), which is caused by difficulties in air passage and complete interruption of air flow in the airway. This syndrome is associated with increased morbidity and mortality in apneic individuals. OBJECTIVE: It was the objective of this paper to evaluate a removable mandibular advancement device as it provides a noninvasive, straightforward treatment readily accepted by patients. METHODS: In this study, 15 patients without temporomandibular disorders (TMD) and with excessive daytime sleepiness or snoring were evaluated. Data were collected by means of: Polysomnography before and after placement of an intraoral appliance, analysis of TMD signs and symptoms using a patient history questionnaire, muscle and TMJ palpation. RESULTS: After treatment, the statistical analysis (t-test, and the "before and after" test) showed a mean reduction of 77.6% (p=0.001) in the apnea-hypopnea index, an increase in lowest oxyhemoglobin saturation (p=0.05), decrease in desaturation (p=0.05), decrease in micro-awakenings or EEG arousals (p=0.05) and highly significant improvement in daytime sleepiness (p=0.005), measured by the Epworth Sleepiness Scale. No TMD appeared during the monitoring period. CONCLUSION: The oral device developed in this study was considered effective for mild to moderate OSAHS.

Comparative study of classic friction among different archwire ligation systems

OBJECTIVE: To describe and compare three alternative methods for controlling classical friction: Self-ligating brackets (SLB), special brackets (SB) and special elastomeric ligatures (SEB). METHODS: The study compared Damon MX, Smart Clip, In-Ovation and Easy Clip self-ligating bracket systems, the special Synergy brackets and Morelli's twin bracket with special 8-shaped elastomeric ligatures. New and used Morelli brackets with new and used elastomeric ligatures were used as control. All brackets had 0.022 x 0.028-in slots. 0.014-in nickel-titanium and stainless steel 0.019 x 0.025-in wires were tied to first premolar steel brackets using each archwire ligation method and pulled by an Instron machine at a speed of 0.5 mm/minute. Prior to the mechanical tests the absence of binding in the device was ruled out. Statistical analysis consisted of the Kruskal-Wallis test and multiple non-parametric analyses at a 1% significance level. RESULTS: When a 0.014-in archwire was employed, all ligation methods exhibited classical friction forces close to zero, except Morelli brackets with new and old elastomeric ligatures, which displayed 64 and 44 centiNewtons, respectively. When a 0.019 x 0.025-in archwire was employed, all ligation methods exhibited values close to zero, except the In-Ovation brackets, which yielded 45 cN, and the Morelli brackets with new and old elastomeric ligatures, which displayed 82 and 49 centiNewtons, respectively. CONCLUSIONS: Damon MX, Easy Clip, Smart Clip, Synergy bracket systems and 8-shaped ligatures proved to be equally effective alternatives for controlling classical friction using 0.014-in nickel-titanium archwires and 0.019 x 0.025-in steel archwires, while the In-Ovation was efficient with 0.014-in archwires but with 0.019 x 0.025-in archwires it exhibited friction that was similar to conventional brackets with used elastomeric ligatures.

Maxillary incisors mesiodistal angulation changes in patients with orthodontically treated anterior superior diastemas

OBJECTIVE: The aims of this study were to describe the patterns of maxillary incisor angulation in patients with upper interincisive diastemas, to evaluate angulation changes with treatment and posttreatment period, and to assess whether there are association between incisor angulation and interincisive diastema relapse. METHODS: The sample comprised 30 Class I or Class II patients with at least one pretreatment anterior diastema of 0.77 mm or greater after eruption of maxillary permanent canines. Data were obtained from panoramic radiographs at pretreatment, posttreatment and at least 2 years post-retention. RESULTS: Incisors presented a mesial tipping tendency after treatment, but only lateral incisors showed significant changes between pre and posttreatment stages. CONCLUSION: Regarding post-retention period, no changes were found. Finally, no relation was found between diastema relapse and maxillary incisor axial angulation.