Cone beam computed tomography study of apical root resorption induced by Herbst appliance

Objective This study evaluated the frequency of root resorption during the orthodontic treatment with Herbst appliance by Cone Beam Computed Tomography (CBCT).Material and Methods The sample comprised 23 patients (11 men, 12 women; mean ages 15.76±1.75 years) with Class II division 1 malocclusion, treated with Herbst appliance. CBCT was obtained before treatment (T0) and after Herbst treatment (T1). All the dental roots, except third molars, were evaluated, and apical root resorption was determined using the axial guided navigation method. Paired t-tests and Wilcoxon T Test were used to compare the dependent samples in parametric and nonparametric cases, respectively. Chi-Square Test with Yates’ correction was used to evaluate the relationship between apical root resorption and gender. Results were considered at a significance level of 5%.Results Apical resorption was detected by CBCT in 57.96% of 980 roots that underwent Herbst appliance treatment. All patients had minimal resorption and there was no statistical significance between the genders.Conclusion CBCT three-dimensional evaluation showed association between Herbst appliance and minimal apical root resorption, mostly in the anchoring teeth, without clinical significance

Untersuchung und Bewertung von Hitzeeinwirkungen auf Bergleute im Steinkohlenbergbau. Report 2/2000 Materialband zum Abschlussbericht

38 miners were examined over a period of 125 manshifts in exposed working sites in coal mines (local temperature average 16 C#<=#BET#<=#32 C). The following parameters wre measured: Heart rate, rectal temperature, loss of weight, and at the onset of the study also the energy consumption for typical activities, body positions, and static and dynamic work components. Load protocols were drawn up parallel to the working cycles with climate, noise, underground working depth and inclination as main parameters. Anthropogenic parameters were body size, body mass, age, and years of working underground. The physical fitness was established by ergometric measurements, and the maximum oxygen uptake Vo_2_m_a_x as calculated on this basisDa bisher keine umfangreichen Studien zur Beanspruchung von Bergleuten an klimatisch belasteten Arbeitsplaetzen im Steinkohlenbergbau vorlagen, wurden 38 Bergleute ueber insgesamt 125 Schichten an Arbeitsplaetzen im Abwetterbereich von Streben untersucht (mittlere Klimabelastung am Arbeitsplatz (lokal): 16 C#<=#BET#<=#32 C). Es wurden folgende Beanspruchungsgroessen erhoben: Herzschlagfrequenz, Rektaltemperatur, Gewichtsverlust, zu Beginn der Studie auch der Energieumsatz bei typischen Taetigkeiten, Koerperstellungen und -haltungen sowie statische und dynamische Arbeitsanteile. Auf seiten der Belastungsgroessen wurden Arbeitsablaufprotokolle - orientiert an Arbeitszyklen - erstellt, sowie als wesentliche Parameter der Arbeitsumgebung Klima, Laerm, Fahrhoehe und Einfallen erfasst. An anthropometrischen Groessen wurden Koerpergroesse, Koerpermasse, Alter und Untertagejahre erfasst. Die koerperliche Leistungsfaehigkeit wurde ergometrisch bestimmt und daraus die maximale Sauerstoffaufnahme Vo_2_m_a_x ermittelt. (orig.)Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLELandesoberbergamt Nordrhein-Westfalen, Dortmund (Germany)DEGerman

Estudo cefalométrico do tratamento precoce da má oclusão de Classe II, 1ª divisão, com o aparelho Herbst: alterações esqueléticas sagitais Cephalometric study of the early treatment of Class II division 1 malocclusion with the Herbst appliance: sagittal skeletal alterations

OBJETIVO: o presente estudo teve o objetivo de avaliar as alterações esqueléticas sagitais produzidas pelo aparelho de Herbst. METODOLOGIA: foram avaliados 22 indivíduos com má oclusão de Classe II, 1ª divisão, sendo 11 do gênero masculino e 11 do gênero feminino, com média de idade de 9,01 anos (±6 meses), apresentando padrão facial Classe II, deficiência mandibular e padrão esquelético de Classe II (ANB>5º e Co-Gn-Co-Sn<20mm), tratados consecutivamente com o aparelho Herbst por um período de 12 meses. Todos os indivíduos encontravam-se no período intertransitório da dentadura mista e no estágio pré-puberal. Para tal avaliação utilizaram-se telerradiografias de perfil obtidas em três tempos distintos: T1) inicial, T2) logo após a remoção do aparelho, T3) 2 anos após o final do tratamento. O grupo controle foi constituído de 105 indivíduos com má oclusão de Classe II esquelética, não tratados ortodonticamente, pareados quanto às idades óssea e cronológica ao grupo experimental. O tratamento estatístico foi realizado por meio da Análise de Variância (ANOVA), complementada pelo teste de Comparações Múltiplas de Tukey e Teste t de Student, com nível de significância de 5%. RESULTADOS E CONCLUSÕES: os resultados evidenciaram um efeito clinicamente insignificante de restrição do crescimento maxilar, um estímulo do crescimento mandibular e um posicionamento mais anterior da mandíbula, contribuindo para uma melhora significativa na relação entre as bases apicais. Após 12 meses de tratamento, estas alterações esqueléticas sagitais contribuíram em cerca de 41% para correção da relação molar de Classe II e em 65% para correção do trespasse horizontal. No final do período de 2 anos pós-remoção do aparelho, houve uma tendência de redução da magnitude das alterações induzidas, no entanto uma melhora significativa na relação entre as bases apicais, no trespasse horizontal e na relação molar foram evidentes.<br>AIM: the present study aimed at evaluating the sagittal skeletal alterations after Herbst appliance treatment. METHODS: the sample was comprised by in 22 subjects with Class II division 1 malocclusion, being 11 males and 11 females, with a mean age of 9.01 years (±06 months), who presented Class II facial pattern, mandibular deficiency and Class II skeletal pattern (ANB>5º and Co-Gn - Co-Sn <20mm) and were consecutively treated with the Herbst appliance for a mean period of 12 months. All subjects were on the intermediate period of the mixed dentition and on the pre-pubertal stage. Evaluation was performed on lateral cephalograms taken in three different moments: T1) initial, T2) soon after removal of the appliance, T3) 2 years after treatment completion. The control group was composed by 105 subjects with skeletal Class II malocclusion not submitted to orthodontic treatment, matched as to the bone and chronological ages of the study group. Statistical analysis was performed by means of Analysis of Variance (ANOVA), complemented by the Tukey test for multiple comparisons and the Student's t test, at a significance level of 5%. RESULTS AND CONCLUSION: the results revealed an not significant effect of restriction of the maxillary growth, stimulation of the mandibular growth and forward positioning of the mandible, which contributed to a significant improvement in the jaw relationship. These sagittal skeletal alterations accounted for about 41% of the correction of the Class II molar relationship and 65% of the overjet correction. At 2 years after removal of the appliance there was a tendency towards a reduction in the magnitude of the alterations achieved; however, significant improvements in the jaw relationship, overjet and molar relationship were noticeable