Bakgrund: Ortodontisk behandling utförs vanligtvis på ungdomar och kan innebära en risk för den orala hälsan. Studier har visat att patienter med fast apparatur löper större risk att utveckla svullen gingiva och karies. Syfte: Syftet med studien är att undersöka tandvårdspersonalens rutiner kring munhygien hos patienter med fast apparatur på ortodontikliniker. Metod: Studien är en kvantitativ tvärsnittsstudie i form av en enkät med 11 frågor. Enkäten skickades till fyra ortodontikliniker i fyra olika län i södra Sverige. Enkäten innehöll frågor gällande munhygien-rutiner och tandhygienistprofessionen. Sammanlagt 59 personer tillfrågades delta i studien. Resultat: Enkäten besvarades av 38 personer. Resultatet visade att majoriteten av deltagarna in-struerade munhygieninstruktion vid insättning av fast apparatur och vid uppvisad dålig munhy-gien. Samtliga deltagare instruerade munhygien på patienten och större delen gav även samtal och uppföljning. Gällande tandhygienistprofessionen har majoriteten av klinikerna inte någon tandhygienist anställd. Av samtliga deltagare ansåg 29% (n=11) att det skulle vara bra att ha en tandhygienist anställd på ortodontikliniker och 45% (n=17) såg behov av kontakt. Slutsats: Det fanns inte några större skillnader mellan professionerna och klinikerna gällande munhygienru-tiner och hur de utförs. Nästan hälften av deltagarna såg behov av kontakt med tandhygienist vid insättning av fast apparatur och vid munhygieninstruktion. / Background: Orthodontic treatment is usually performed on adolescents and increase risks for the oral health. Studies have shown that patients with fixed appliances more likely develop gingival enlargement and caries. Aim: The aim of this study was to investigate the dental pro-fessional’s routines including oral hygiene in patients with fixed appliances on orthodontic clin-ics. Method: The study was a quantitative cross-sectional study with questionnaire regarding 11 questions. The questionnaire was sent to four orthodontic clinics in four counties in southern Sweden and contained questions regarding oral hygiene routines and dental hygienists. Alto-gether 59 individuals were asked to participate. Results: The questionnaire was answered by 38 individuals. The result showed that the majority gave oral hygiene instructions at insertion of fixed appliances and when oral hygiene was poor. All participants practice oral hygiene in-structions on patients and almost everyone had conversations and follow-up visits. The majority of clinics didn´t have dental hygienists employed. Of all participants 29% (n=11) thought it would be good to have dental hygienists employed and 45% (n=17) saw need of contact. Conclusion: No major differences between professions and clinics were shown regarding oral hy-giene routines and performance. Almost half of the participants saw need of contact with dental hygienists.

A radiografia panorâmica é o exame complementar de imagem mais solicitado pelos cirurgiões-dentistas e parte essencial da documentação utilizada pelos ortodontistas no planejamento do tratamento ortodôntico. Durante a transição da dentadura mista para a permanente, o processo biológico é complexo, podendo ocorrer falhas ou irregularidades odontogênicas, que resultam em anomalias dentárias. Entretanto, outras alterações podem ser vistas nas imagens radiográficas panorâmicas, que modificam densidade óssea e alteram o trabeculado ósseo no período entre o início e o término do tratamento ortodôntico. Algumas destas alterações podem interferir ou modificar o diagnóstico durante o tratamento ortodôntico. O número de imagens radiográficas obtidas durante o tratamento ortodôntico depende do protocolo estabelecido caso a caso. Neste estudo interpretamos 500 imagens panorâmicas, sendo 250 pré-tratamento ortodôntico e 250 pós-tratamento ortodôntico, de pacientes com idade de 11 a 18 anos, pertencentes ao Departamento de Ortodontia da Faculdade de Odontologia de Bauru FOB USP. A interpretação radiográfica foi realizada por um único examinador. Nosso objetivo foi avaliar imagens que foram obtidas no início e no final do tratamento ortodôntico e os resultados nos permitiram concluir que no grupo referente à transição da dentadura mista para a dentição permanente, as imagens panorâmicas possuíram o maior número de achados incidentais; a remodelação apical ortodôntica dos incisivos foi encontrada em 180 casos pós-tratamento ortodôntico; houve diferença estatisticamente significante (Teste de Wilcoxon; p<0,05) nos resultados da ossificação do complexo estilo-hióideo bilateral e realização de tratamento endodôntico pré e pós-tratamento ortodôntico; e, muitos dos achados necessitam de intervenção durante o tratamento. / Panoramic radiograph is the most requested imaging exam by dentists and it plays essential role in documentation for orthodontic treatment planning. During the transition from mixed dentition to permanent dentition, the biological process is complex and may experience odontogenic failures or irregularities that result in dental abnormalities. However, other changes can be seen in the panoramic radiography that modify bone density and trabecular bone when it is compared before and after orthodontic treatment. Some of these changes may affect and modify the diagnosis during orthodontic treatment. The number of radiographic images obtained in orthodontic treatment depends on the protocol established for each case. In this study we interpret 500 panoramic radiograph, of patients with age of 11 to 18, belonging to the Department of Orthodontics, Bauru Dental School. The radiographic interpretation was performed by a single examiner. Our objective was to evaluate images that were taken at the beginning and end of orthodontic treatment and the results allowed us to conclude that the most incidental findings were observed in panoramic images in the group concerning the transition from mixed dentition to permanent dentition; apical root resorption of the incisors was found in 180 orthodontic post-treatment cases; there was a statistically significant difference (Wilcoxon Test; p<0.05) between the results of ossification of complex bilateral stylohyoid and endodontic treatment before and after orthodontic treatment; and many of the findings require intervention during treatment.

Com a grande procura da sociedade moderna pela estética perfeita a cirurgia ortognática para conseguir melhores resultados e mais precisos, começou a planejar e diagnosticar os casos clínicos utilizando medidas obtidas de grandezas do perfil tegumentar dos pacientes com o auxílio de imagens digitais empregadas em softwares de planejamento, Neste estudo foi proposto aferir as medidas de brasileiros leucodermas de descendência européia e compará-las com as medidas já padronizadas por ARNETT, com o intuito de criar novas medidas para serem seguidas por brasileiros utilizando-se o software Dolphin Imaging 9.0 de predicção cirúrgica. Foi utilizado na metodologia radiografias cefalométricas de 60 pacientes com oclusão classe I de Angle e harmonia facial. Todas as radiografias foram digitalizadas e inseridas no software Dolphin 9.0 e um total de 16 pontos de tecido mole e 22 pontos do esqueleto facial foram marcados, seguindo exatamente as marcações da análise de Arnett & McLaughlin presentes no programa. Os resultados obtidos foram avaliados estatisticamente e mostram que o perfil do brasileiro é quase totalmente diferente do perfil norte-americano, exceção feita a apenas quatro pontos para os homens e outros quatro, para as mulheres. Os brasileiros apresentam uma face menos protruída, um perfil mais convexo e menor proeminência do queixo do que o grupo controle. Os dados obtidos mostram a necessidade de realizar algumas mudanças nas grandezas numéricas para que um perfeito diagnóstico e planejamento possa ser realizado em brasileiros, criando assim o padrão do perfil facial do brasileiro leucoderma de descendência européia. / Considering that modern orthognatic surgery is mainly concerned in planning and diagnosing clinical cases by the use of patients\' soft tissue measurements obtained from digital images employed in planning software, the aim of this study is to establish Caucasian Brazilians measures and to compare them to the standard North American measures. For this, a total of 60 Angle\'s class I patients not previously submitted to orthodontic treatment and presenting harmonious facial features were invited to participate in the study as volunteers. The patients were initially photographed in frontal and lateral views and, afterwards, cephalograms were obtained. The images were digitized, adjusted and indexed in Dolphin\'s image software. In order to procede cephalometric analysis, a total of 16 soft tissue profile points and 22 hard tissue profile points were demarcated, accordingly to North American original measurements used in Dolphin\'s digital image program. After, all cephalograms were again evaluated to determine intra-examiner error according to paired Student\'s t test. Mean and standard error measures were obtained and compared to American measures by unpaired Student\'s t test with 95% confidence level. The results obtained have shown that all measurements, except for four points in male and four points in female, are significantly different (p < 0.05) between Brazilian and American samples. Datas show that Brazilians\' soft tissue profile is almost completely different from North Americans\', with a less protrusive face, shorter chin projection and a more convex profile. This suggests the necessity of performing some changes in numerical values to obtain an ideal diagnosis and planning of orthognatic surgery in Caucasian Brazilians.

Ziel dieser Studie war es, die Behandlungsqualität und Behandlungsdauer der Kiefer- orthopädischen Abteilung einer Universitätsklinik zu bestimmen. Dazu wurden die Behandlungsmodelle vor und nach der Behandlung mit Hilfe des PAR (Peer Assess- ment Rating)-Indexes beurteilt. Weiterhin wurden mögliche Einflußgrößen auf die Behandlungsqualität und Behandlungsdauer untersucht. Die Behandlungsunterlagen von 100 fortlaufend abgeschlossenen Patienten (62 weiblich, 38 männlich) wurden retrospektiv ausgewertet. Das durchschnittliche Alter bei Behandlungsbeginn lag bei 14,9 Jahren (7,4 - 42,2 Jahre). Am häufigsten wurde die Behandlung im Alter von 9 oder 10 Jahren begonnen, 24 Patienten waren er- wachsen. Die Angle-Klasse II (71%) war am zahlreichsten vertreten, gefolgt von der Angle-Klasse I (21%) und der Klasse III (8%). 77 Patienten versäumten vereinbarte Termine, 38 Patienten mußten wegen ungenügender Mitarbeit ermahnt werden. Es kam ein breites Spektrum kieferorthopädischer Behandlungsgeräte zum Einsatz. Bei 95 Patienten wurde eine festsitzende Apparatur verwendet. Bei 52 Patienten er- folgte die Behandlung ausnahmslos mit dieser Apparatur, 33 Patienten wurden auf- einanderfolgend mit herausnehmbaren und festsitzenden Geräten behandelt und 10 Patienten kombiniert kieferorthopädisch und kieferchirurgisch. Nur 5 Patienten wur- den ausschließlich mit herausnehmbaren funktionskieferorthopädischen Geräten the- rapiert. Bei 31 Patienten wurden während der kieferorthopädischen Behandlung Zähne extrahiert. Der PAR Wert vor Behandlungsbeginn lag für die Gesamtgruppe bei durchschnittlich 23,9 Punkten. Der PAR Wert nach Behandlungsende lag bei 5,2. Die prozentuale Verbesserung betrug 75,6%. 65 Patienten hatten nach Behandlungsende einen PAR Wert ? 5 und 89 Patienten einen PAR Wert ? 10. Nur 4 Patienten erreichten einen PAR Wert von null. Die Verteilung der Patienten auf die einzelnen Verbesserungs- Kategorien lautete: greatly improved" 33 Patienten, improved" 65 Patienten, worse - no different" 2 Patienten. Auf die Behandlungsqualität hatte keiner der untersuchten Faktoren (Behandlungsmittel, Extraktion/Nichtanlage, Angle-Klasse, Mitarbeit und Geschlecht) einen signifikanten Einfluß. Die mittlere Behandlungsdauer aller Patienten betrug 39,1 Monate (8 - 85 Monate). Auf die Behandlungsdauer hatten von den untersuchten Faktoren (PAR Anfangswert, Behandlungsmittel, Extraktion/Nichtanlage, Angle-Klasse, Mitarbeit, Geschlecht und Alter bei Behandlungsbeginn) der PAR Anfangswert bei festsitzender Behandlung, die Behandlungsmittel, die Mitarbeit und das Alter bei Behandlungsbeginn einen signifikanten Einfluß. Die Behandlung mit herausnehmbaren und anschließend fest- sitzenden Apparaturen dauerte mit durchschnittlich 56,2 Monaten erwartungsgemäß am längsten. Die alleinige Behandlung mit festsitzenden Apparaturen benötigte im Schnitt 30,3 Monate, eine kieferorthopädisch-kieferchirurgische Kombinationsthera- pie beanspruchte 27,1 Monate. Extraktionen und/oder Nichtanlagen zeigten Tenden- zen zu längeren Behandlungszeiten. Jüngere Patienten benötigten eine signifikant längere Behandlungszeit. / The aim of this study was to assess the treatment standards and treatment time in a university clinic. Pre-treatment and post-treatment study casts were assessed by the PAR (Peer Assessment Rating) Index. The influence of various factors upon treat- ment quality and treatment duration was analysed. The treatment records of 100 consecutively finished patients (62 females and 38 males) were evaluated retrospectively. The mean age was 14.9 years (7.4 42.2 years) at the pre-treatment stage. Most of the patients were between the ages of 9 and 10 years old, 24 patients were over the age of 18. At the start of treatment, 71 patients had an Angle Class II, 21 an Angle Class I and 8 patients an Angle Class III. There were 77 patients who failed at least once to show up for their appointments and 38 patients had negative chart entries regarding appliance wear. There was a wide range of appliance types used in this sample. The treatment involved fixed appliances for 95 patients. 52 patients were treated only with this type of appliance, 33 were treated with removable and fixed appliances successively and 5 patients were treated solely with removable functional appliances. 10 patients received combined orthodontic treatment and orthognatic surgery. 31 patients had extractions of permanent teeth as part of their treatment. The average pre- and post-treatment PAR scores were 23.9 and 5.2, repectively. The mean percentage reduction in PAR score was 75.6%. Post-treatment, 65 patients fell in the 0-5 PAR score group and 89 patients had a PAR score of 10 or less. However, only 4 patients scored 0 at the end of treatment. 33 patients have been "greatly im- proved", 65 patients "improved" and 2 ranked "worse or no different". Of all the fac- tors examined (type of therapy, extractions/agenesis, Angle Classes, compliance and gender) none showed a significant influence on post-treatment PAR scores. The mean treatment duration was 39.1 months (8 - 85 months). When treatment time was analysed, with all the factors examined (pre-treatment PAR score, type of treat- ment, extractions/agenesis, Angle Classes, compliance, gender and age at treatment start) only pre-treatment PAR score in the fixed appliance group, type of treatment, compliance and age at treatment start, were significantly related. As expected, the sequence of removable and fixed appliances required the longest treatment time (56.2 months). Fixed appliance therapy alone took 30.3 months, a combination of orthodontics and orthognatic surgery lasted for 27.1 months on average. Extractions and/or congenitally missing permanent teeth showed a tendency to higher treatment times. Inadequate compliance did significantly prolong treatment duration. Younger patients required longer treatment times.

Este trabalho teve como objetivo avaliar cefalometricamente a estabilidade das medidas SNA, SNB, ANB, 1.NA, 1-NA, 1 .NB, 1 -NB, 1.ENP-ENA, IMPA e 1.1 a longo prazo, de pacientes tratados ortodonticamente com extrações dos quatro primeiros pré-molares e verificar, paralelamente a isto, se foram realizadas as compensações dentárias na mecânica ortodôntica e se estas foram preservadas cinco anos após o término do tratamento. Vinte e sete pacientes foram analisados no início (T1), no final (T2) e cinco anos após a finalização terapêutica (T3). No início do tratamento, a idade média era de 13 anos e 5 meses e todos os componentes apresentavam o ângulo ANB maior que 4º. Quatorze componentes apresentavam más oclusões Classe II, 1ª divisão de Angle, 12 componentes apresentavam más oclusões Classe I e 1, má oclusão Classe II, 2ª divisão. Os casos foram tratados com a técnica Edgewise. Nas três fases de estudo os cefalogramas laterais foram realizados manualmente, obtendo-se as oito grandezas angulares e as duas lineares. A análise estatística indutiva envolveu a análise de variância a um critério para identificar as alterações interfases no valor de cada variável estudada, e o teste de Tukey para indicar, especificamente, entre quais fases de estudo estaria ocorrendo diferenças estatisticamente significantes. Utilizou-se o coeficiente de correlação de Pearson, no afã de relacionar a medida cefal ométrica 1.1 com as demais medidas nas três fases de estudo. De acordo com os resultados obtidos, todas as medidas estudadas entre as fases inicial e final se alteraram significantemente refletindo a influência da mecânica ortodôntica sobre os movimentos dentários e entre as fases final e cinco anos após, todas as medidaspermaneceram estáveis. Obtiveram-se as compensações dentárias necessárias no final do tratamento ortodôntico e estas foram preservadas a longo prazo / The main objective of this study was to evaluate the long-term stability of the following cephalometric measurements: SNA, SNB, ANB, 1.NA, 1-NA, 1 .NB, 1 -NB, 1.ENP-ENA, IMPA, 1.1 . This analysis was carried out in orthodontically treated patients which had the four first pre-molars extracted. Alternatively, this study also determined the influence of the proposed treatment at the dento-basal arrangements by orthodontic mechanics and its preservation after five years of treatment completion. The sample of this study was comprised of twenty-seven patients that were assessed at the beginning (T1), at the end (T2) and five years later (T3). At the beginning of treatment the patients age averaged thirteen years and five months and all the subjects displayed an ANB angle over than 4 degrees. Among the studied sample, 14 subjects were classified as Angle Class II, Division 2 malocclusion, 12 subjects displayed Angle Class I, and 1 Angle Classe II, Division 2. All the subjects were orthodontically treated by means of edgewise appliances. During all the three phases of the study the radiological data were obtained through lateral cephalograms, which were performed manually, depicted eight angular and two linear measurements. The statistical analysis in which the data were processed included one way analysis of variance in order to identify the changes between the phases related to each studied measurement. As an adjunctive method, the Tukey test was conducted to indicate in which phases of the proposed study the statistically significant changes were occurring. The Pearson Product Moment Correlation was recorded to relate the 1.1 cephalometric measurements with all the remaining measurements obtained throughout the three phases of the study. According to the obtained results, all the studied measurements, between phases T1 and T2, significantly changed reflecting the influence of orthodontic mechanics on the dental movement. Between the T2 and T3 phases, all the measurements remained stable. By the end of the orthodontic treatment all the necessaries dental arrangements were performed and preserved in a long-term fashion.

Este trabalho teve como objetivo avaliar cefalometricamente a estabilidade das medidas SNA, SNB, ANB, 1.NA, 1-NA, 1 .NB, 1 -NB, 1.ENP-ENA, IMPA e 1.1 a longo prazo, de pacientes tratados ortodonticamente com extrações dos quatro primeiros pré-molares e verificar, paralelamente a isto, se foram realizadas as compensações dentárias na mecânica ortodôntica e se estas foram preservadas cinco anos após o término do tratamento. Vinte e sete pacientes foram analisados no início (T1), no final (T2) e cinco anos após a finalização terapêutica (T3). No início do tratamento, a idade média era de 13 anos e 5 meses e todos os componentes apresentavam o ângulo ANB maior que 4º. Quatorze componentes apresentavam más oclusões Classe II, 1ª divisão de Angle, 12 componentes apresentavam más oclusões Classe I e 1, má oclusão Classe II, 2ª divisão. Os casos foram tratados com a técnica Edgewise. Nas três fases de estudo os cefalogramas laterais foram realizados manualmente, obtendo-se as oito grandezas angulares e as duas lineares. A análise estatística indutiva envolveu a análise de variância a um critério para identificar as alterações interfases no valor de cada variável estudada, e o teste de Tukey para indicar, especificamente, entre quais fases de estudo estaria ocorrendo diferenças estatisticamente significantes. Utilizou-se o coeficiente de correlação de Pearson, no afã de relacionar a medida cefal ométrica 1.1 com as demais medidas nas três fases de estudo. De acordo com os resultados obtidos, todas as medidas estudadas entre as fases inicial e final se alteraram significantemente refletindo a influência da mecânica ortodôntica sobre os movimentos dentários e entre as fases final e cinco anos após, todas as medidaspermaneceram estáveis. Obtiveram-se as compensações dentárias necessárias no final do tratamento ortodôntico e estas foram preservadas a longo prazo / The main objective of this study was to evaluate the long-term stability of the following cephalometric measurements: SNA, SNB, ANB, 1.NA, 1-NA, 1 .NB, 1 -NB, 1.ENP-ENA, IMPA, 1.1 . This analysis was carried out in orthodontically treated patients which had the four first pre-molars extracted. Alternatively, this study also determined the influence of the proposed treatment at the dento-basal arrangements by orthodontic mechanics and its preservation after five years of treatment completion. The sample of this study was comprised of twenty-seven patients that were assessed at the beginning (T1), at the end (T2) and five years later (T3). At the beginning of treatment the patients age averaged thirteen years and five months and all the subjects displayed an ANB angle over than 4 degrees. Among the studied sample, 14 subjects were classified as Angle Class II, Division 2 malocclusion, 12 subjects displayed Angle Class I, and 1 Angle Classe II, Division 2. All the subjects were orthodontically treated by means of edgewise appliances. During all the three phases of the study the radiological data were obtained through lateral cephalograms, which were performed manually, depicted eight angular and two linear measurements. The statistical analysis in which the data were processed included one way analysis of variance in order to identify the changes between the phases related to each studied measurement. As an adjunctive method, the Tukey test was conducted to indicate in which phases of the proposed study the statistically significant changes were occurring. The Pearson Product Moment Correlation was recorded to relate the 1.1 cephalometric measurements with all the remaining measurements obtained throughout the three phases of the study. According to the obtained results, all the studied measurements, between phases T1 and T2, significantly changed reflecting the influence of orthodontic mechanics on the dental movement. Between the T2 and T3 phases, all the measurements remained stable. By the end of the orthodontic treatment all the necessaries dental arrangements were performed and preserved in a long-term fashion.

Objectives: Dental Monitoring® (“DM,” Dental Monitoring, Paris, France), is a cloud-based software that allows orthodontists to track patients’ treatment remotely. The purpose of this study was to investigate the accuracy of the software in making linear measurements. Methods: Patients took intraoral photographs using the DM application, immediately followed by impressions for plaster models. Intercanine and intermolar width and arch depth measurements were made by DM and compared to measurements made on the plaster models. Data was analyzed using two one-sided t-tests for equivalence with equivalence bounds of +/-0.5mm. Significance level was set at 0.05. Results: Thirty sets of measurements were compared. The intercanine and intermolar measurement differences were on average 0.17mm and -0.02mm, respectively, and were deemed equivalent. The arch depth measurements had an average difference of -0.54mm and were deemed not equivalent. Conclusion: The monitoring software seems to provide an accurate assessment of linear tooth movements.

Introduction: This study aimed to compare the third molars angulation and eruption status in Class I and II malocclusions in orthodontic treatment with and without first premolar extractions. Methods: The sample was comprised by 96 patients divided into four groups: Group 1 Class I malocclusion treated with first premolars extraction; Class I malocclusion treated without extractions; Group 3 Class II malocclusion treated with first premolars extraction; Group 4 Class II malocclusion treated without extractions. Panoramic radiographs were used to evaluate third molars mesiodistal angulations at T1, T2 and at T3. Third molar eruption status was assessed in dental casts. Intergroup angulations and eruption status comparisons were performed using ANCOVA followed by Tukey tests and Kruskal-wallis test, respectively. Results: Significantly greater mesial angulation and percentage of erupted right maxillary third molars were found in Class I extraction group. Significantly greater distal angulation and percentage of erupted right mandibular third molars were found in Class II extraction group. Conclusion: Class I and II extraction treatment exhibited more favorable angulations and greater number of erupted third molars than nonextraction treatment. Regardless the treatment performed third molars showed a more uprighted position in each malocclusion type. / Introdução: Este estudo comparou as angulações mesiodistais e o grau de irrompimento dos terceiros molares nas más oclusões de Classe I e II no tratamento ortodôntico com e sem extrações dos primeiros pré-molares. Métodos: Foram avaliados 96 pacientes divididos em quatro grupos. Grupo 1, indivíduos com má oclusão de Classe I tratada com extrações dos primeiros pré-molares. Grupo 2, má oclusão de Classe I tratada sem extrações. Grupo 3 indivíduos com má oclusão de Classe II tratada com extração dos primeiros pré-molares. Grupo 4 má oclusão de Classe II tratada sem extrações. As angulações mesiodistais dos terceiros molares foram avaliadas em radiografias panorâmicas e o grau de irrompimento em modelos de estudo. Para comparar as angulações e o grau de irrompimento entre os grupos, utilizou-se o teste ANCOVA seguido do teste Tukey e o teste de Kruskal-wallis, respectivamente. Resultados: O grupo 1 apresentou significativamente maior angulação mesial do terceiro molar superior direito assim como uma porcentagem maior de molares irrompidos. O grupo 2 apresentou significativamente maior angulação distal do terceiro molar inferior direito e uma porcentagem maior de molares irrompidos. Conclusão: Os tratamentos de Classe I e II com extrações apresentaram angulações mais favoráveis e uma porcentagem maior de terceiros molares irrompidos do que os tratamentos sem extrações. Independentemente do tratamento realizado, os terceiros molares apresentaram uma posição mais vertical.

Nickel stands out as the main cause of contact allergy in both children and adults, which has given rise to concern and the introduction of regulations by official bodies. Today´s youths are frequently exposed to body piercing and orthodontic treatment. Changes in youth lifestyle practices are also likely to influence nickel exposure and thus, the occurrence of nickel allergy. However, against patient and parental concern regarding nickel exposure to orthodontic appliances, often evoked by allergies following piercing, stand results from studies indicating that early orthodontic appliance treatment may reduce, rather than increase, prevalence of nickel allergy; a finding that has been suggested to result from tolerance induction by early exposure to nickel via the oral route. The objective of the present thesis was to investigate the association between nickel allergy and exposure to different orthodontic appliances and lifestyle, in particular piercing, as well as to study nickel release from orthodontic appliances into the oral cavity. Furthermore, one objective was to establish baseline prevalence data of nickel allergy in a Swedish adolescent population. Data was generated from a cross-sectional survey, in which about 6000 youths completed a questionnaire and almost 4500 of these were patch-tested for contact allergy. Information on exposure to orthodontic appliances was verified by dental records, whilst nickel content in saliva and dental biofilm was measured in a clinical study. Questionnaire data demonstrated a reduced risk of nickel allergy when orthodontic treatment preceded piercing (OR 0.5; 95 % CI 0.3-0.8) and similar results were found for data verified from dental records, however statistical significance was lost when adjusting for background factors (OR 0.6, 95 % CI 0.4-1.0). Exposure to full fixed appliances with NiTi-containing alloys, as well as a pooled ‘high nickel-releasing’ appliance group prior to piercing correlated with a significantly reduced risk of nickel allergy and a trend towards a reduced risk with exposure duration. Nickel could also be found in significantly higher concentrations from dental plaque samples, but not saliva samples, in orthodontic patients who were well into treatment compared to patients who had not been exposed to orthodontic appliances. The effect was not found to be due to differences in estimated dietary nickel intake between the two groups. Significantly more girls than boys (13.3 % versus 2.5 %) were found to be patch-test positive to nickel. Positive nickel tests were also most prevalent in occupational programmes and least prevalent in natural science programmes, indicating differences in lifestyle and exposure to nickel. Dropout from testing was handled using a missing-value analysis. This internal validation showed that our results overestimated the occurrence of nickel allergy to a minor degree. More girls than boys reported piercing, vegetarian/vegan diet, and smoking practices, whereas an interesting shift in tattooing prevalence was observed with a larger proportion of girls reporting this practice compared to boys. Sex, number of piercings, smoking and orthodontic appliance treatment prior to piercing were found to influence weighted risk estimates of nickel allergy. To conclude, although orthodontic patients are exposed to nickel intraorally, we found no increased risk of sensitising adolescents to nickel by the use of oral orthodontic appliances. On the contrary, early orthodontic treatment preceding piercing reduced the risk of nickel allergy by a factor of 1.5-2.0. This reduced risk appears to be associated with estimated nickel release of the appliance and duration of treatment, in all supporting a hypothesised induction of immunological tolerance via oral administration of nickel. Our study also showed a strong association between lifestyle and nickel allergy. Although there have been changes in lifestyle over time, as indicated by the strong shift in tattooing practices, no large change in nickel allergy prevalence was found compared with previous Swedish data. Our data will serve as a baseline for future studies of the effect of nickel exposure regulations, such as the Nickel Directive, and for studies of lifestyle changes and their effects on nickel allergy.

During the last three decades there has been an increased influx of refugees and immigrants into Scandinavia. The overall aim of this thesis was primarily to improve our knowledge of malocclusion and orthodontic treatment need, both normative and self-perceived, in adolescents of varying geographic origin. A further aim was to determine whether any differences with respect to perception of general appearance and psychosocial well-being were related to geographic origin. Papers I and II concerned self perceived and normative orthodontic treatment need. About 500 12-13 year-old subjects, stratified into different groups: A-Sweden, B-Eastern/Southeastern Europe, C-Asia and D-other countries, answered a questionnaire and underwent clinical examination by the author. In paper III the association between the two variables in papers I and II was investigated. Paper IV was a follow up study, at 18-19 years of age, of the relationship between geographic origin and prevalence of malocclusion, self-perceived treatment need, temporomandibular symptoms and psychosocial wellbeing. In Paper V a qualitative study of 19-20 year old subjects was conducted, to identify the strategies they had adopted to handle the issue of persisting poor dental aesthetics. The main findings were that at 12-13 years of age, immigrant subjects had a lower perceived orthodontic treatment need than subjects of Swedish background. Girls of Swedish background had the highest self perceived treatment need, whilst girls of non-Swedish background were most concerned that fixed appliance therapy would be painful. In a few of the clinical variables measured at 12-13 years of age, the Swedish group exhibited the greatest space deficiency and irregularity in both the maxillary and mandibular anterior segments and greater overjet, compared to the Eastern/Southeastern European and Asian groups. The clinical implications were negligible. The orthodontic treatment need according to “Index of Orthodontic Treatment Need - Dental HealthComponent” (IOTN-DHC) grades 4 and 5, ranged from 30 to 40 percent, without any inter-group differences. There were strong associations between subjects perceiving a need for orthodontic treatment and 6IOTN-DHC grades 4 and 5, anterior crossbite and avoiding smiling because they were self-conscious about their teeth. At the age of 18-19 years, the frequency of malocclusion was similar in all groups. Subjects of Asian origin had a higher self-perceived orthodontic treatment need than their Swedish counterparts and a higher frequency of headache than those of Eastern/Southeastern European origin. Psychological wellbeing was reduced in nearly one quarter of the sample, more frequently in girls than boys. No association was found between self-perceived orthodontic treatment need and psychological wellbeing. The theory “Being under the pressure of social norms” was generated in Paper V, and it can be applied to improve our understanding of young adults who have adjusted to living with poor dental aesthetics and also aid to identify those who are not as well-adjusted and would probably benefit from treatment. Undisclosed dental fear is an important barrier to acceptance of orthodontic treatment in early adolescence. Despite demographic changes due to immigration, no major change in the prevalence of malocclusion and normative orthodontic treatment need has been disclosed. This does not apply to adolescents and adults who immigrated at an older age.