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Objective:To analyze the differents in the upper airway morphology and hyoid position between skeletal class III malocclusion of high-angle and normal occlusion by cone beam CT(CBCT), and to study the influence of skeletal class III malocclusion of high-angle in the upper airway and hyoid position of the adults preliminarily.Methods:A total of 42 adults in Department of Orthodontics, Dalian Stomatology Hospital were chosen, including 21 adults with skeletal class III malocclusion of high-angle and 21 adults with normal occlusion. MIMICS 20.0 software was used to measure the line spacing, cross-sectional area and volume of each upper airway segment and line distance of hyoid of the patients on CBCT; SPSS 20.0 software was used for statistical analysis.Results:Compared with normal occlusion group, the maximum lateral distance (LAT1) of the nasopharynx, the maximum anterior-posterior distance (AP2) of the velopharyngeal, and the volume of the velopharyngeal (VOL2) of the patients in skeletal class III malocclusion of high-angle group were increased (P0.05)Conclusion:Cross-sectional area and volume of velopharyngeal have the tendency of increase, but cross-sectional area and volume of laryngopharynx have the tendency of decrease in the patients with skeletal class ? malocclusion of high-angle. The hyoid bone has a tendency to shift forward and upward in the patients with skeletal class ? malocclusion of high-angle.
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OBJECTIVE@#We aim to examine teenagers with varying vertical facial skeletal types with near-normal occlusion. We further aim to identify and study mandibular morphology and dentition characteristics to establish normal ranges and variations for future clinical reference.@*METHODS@#According to the results of the case studies, 42 adolescents with near-normal occlusion were divided into three groups, namely, low- (7 cases), average- (23 cases) and high-angle (12 cases) groups. We used Invivo 5 software for Digital Imaging and Communications in Medicine (DICOM) data to calculate the cant of occlusal plane, axis corner of L6, ∠L1/MP, ∠L6/MP, Balkwill angle and Bonwill triangle of each group.@*RESULTS@#Markedly, the finding shows that the cant of occlusal plane and axis corner of L6 in the low-angle group were smaller than those of the other two groups. In the average-angle group, ∠L1/MP was larger than that of the high-angle group. Lastly, in the high-angle group, ∠L6/MP was smaller than those of the two other groups. On the one hand, these differences were considered statistically significant (P0.05).@*CONCLUSIONS@#In the low-angle group, the parallelisation of the occlusal plane tends to be more obvious compared with the two other groups. In the coronal section of the low-angle group, the axis of the mandibular first molar is up-right, whereas it is distally tilted in the sagittal section of the high-angle group. Furthermore, a number of differences are noted in the adult groups. Factors, such as aging and development in the craniofacial region, lead to changes in functional occlusion.
Subject(s)
Adolescent , Humans , Cephalometry , Dental Occlusion , Dentition , Mandible , ToothABSTRACT
Objective:To explore the influence of gender and age on the measurement of cone beam CT (CBCT) in normal and occluded craniofacial hard tissues for Han nationality in Changsha area.Methods:A total of 80 CBCT data of normal and occluded craniofacial hard tissues for Han nationality in Changsha area were collected,including 40 adults [16 males and 24 females,aged (17.57±1.83) years] and 40 children[16 males and 24 females,age (11.50±1.26) years].Threedimensional cephalometric measurements were carried out by Dolphion Imaging software,and the influence of gender and age was compared.Results:The symmetry of craniofacial hard tissues in male and female in the adults was good (the maximum asymmetric rate R was 6.39％ and the minimum asymmetric rate R was 0.08％).There was no significant differencein the anterior palatal width,palatal width,the upper incisor protrusion distance,the lower incisor protrusion distance,hyoid-mandibular plane,basal epiglottis width,and palatal plane airway width between the males and females (all P＞0.05);while the remaining indicators were significantly higher in males than those in females (all P＜0.05).There was no significant gender difference in angle indicators (all P＞0.05).There were significant differences in the posterior height,the maxillary length,the lower incisor protrusion,and the mandibular plane angle between the adults and the children(all P＜0.05);but the rest of indicators were not significant difference (all P＞0.05).Conclusion:The symmetry of craniofacial hard tissues for Han nationality in Changsha area is good.The gender and age affect the line space measurements but not affect the most of the angle measurements.
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ABSTRACT Objective: The purposes of this investigation were to determine the horizontal distances between the mandibular posterior teeth and the WALA ridge in a sample of Peruvians with normal occlusion and to compare them by tooth type, sex, arch side, and age groups. Methods: 65 dental casts of subjects with normal occlusion were collected. Posterior teeth, except for third molars, were evaluated. The horizontal distances between the occluso-gingival midpoints of the buccal surfaces (FA points) of each tooth and the WALA ridge were measured using a modified digital caliper. The values between each different tooth type within the sample were compared using the ANOVA and Scheffe tests, while comparisons by sex, arch side and age groups, using the Student's t-test. Results: The mean distances in the sample was 0.96 mm for first premolars, 1.45 mm for second premolars, 2.12 mm for first molars and 2.55 mm for second molars. Statistically significant differences between each of the four tooth types were found. There were no significant differences found between sex, arch side and age groups. Conclusion: The horizontal distances between the mandibular posterior teeth and the WALA ridge increased progressively from the first premolars to the second molars in Peruvians with normal occlusion. The WALA ridge was a good landmark to evaluate the positions of posterior teeth in Peruvians with normal occlusion.
RESUMO Objetivos: o objetivo dessa investigação foi determinar a distância horizontal entre os dentes posteroinferiores e a borda WALA, em uma amostra de peruanos com oclusão normal, e compará-la por tipo de dente, sexo, lado da arcada dentária e grupo etário. Métodos: foram selecionados 65 modelos dentários de indivíduos com oclusão normal, nos quais foram avaliados os dentes posteriores, com exceção dos terceiros molares. As distâncias horizontais entre o ponto oclusogengival médio da face vestibular (pontos EV) de cada dente e a borda WALA foram medidas utilizando-se um compasso digital modificado. Os testes de Scheffe e ANOVA foram usados para comparações entre os valores de cada tipo de dente estudado, enquanto o teste t de Student foi usado para as comparações entre sexos, lados da arcada e faixa etárias. Resultados: as distâncias médias nessa amostra foram de 0,96 mm para os primeiros pré-molares; 1,45 mm para os segundos pré-molares; 2,12 mm para os primeiros molares, e 2,55 mm para os segundos molares. Foram encontradas diferenças estatisticamente significativas entre cada um dos quatro tipos dentários. Não houve diferenças significativas entre os sexos, lados da arcada e grupos etários. Conclusão: nos peruanos com oclusão normal dessa amostra, as distâncias horizontais entre os dentes posteroinferiores e a borda WALA aumentaram progressivamente dos primeiros pré-molares para os segundos molares. Nesses pacientes, a borda WALA funcionou como um bom ponto de referência para se avaliar a posição dos dentes posteroinferiores.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Young Adult , Bicuspid/anatomy & histology , Dental Arch/anatomy & histology , Mandible/anatomy & histology , Molar/anatomy & histology , Odontometry , Peru , Sex Factors , Age Factors , Models, Dental , Dental OcclusionABSTRACT
Objective:To analyze the correlation between arch width and different vertical facial skeletal types of the adults with individual normal occlusion.Methods:52 adults with individual normal occlusions(females 31,males 21) were included.According to the values of mandibular plane angle MP-FH,SN-MP measured on CBCT image the subjects were divided into 3 groups(13 cases with highangle,19 with average-angle and 20 with low-angle groups).12 parameters were measured for each sample,including maxillary and mandible arch width and alveolar arch width between canines,between first premolars and between first molars,the difference between the maxillary arch width and mandibular arch width were calculated.The data were statistically analyzed by one-way ANOVA and Pearson~ rank correlation test.Results:In the group of high-angle,average-angle and low-angle the alveolar arch width(mm) between maxillary canines was 38.03 ± 1.90,39.65 ± 1.80 and 39.78 ± 2.20 respectively(P ＜ 0.05).The arch width between maxillary first premolars of high-angle group(37.01 ± 1.60) was smaller than that of low-angle group(38.65 ± 1.30).The arch width difference in canine area between maxillary and mandibular alveolar in high-angle,average-angle and low-angle groups was 7.39 ± 1.82,9.04 ± 1.43 and 9.26 ± 1.67 respectively(P ＜0.05);in maxillary first premolars area in high-angle(6.8 ± 1.59) was smaller than that in averageangle(7.79 ± 1.09),maxillary and mandibular arch width showed no statistical difference.Pearson correlation test showed that among 3 groups,upper and lower alveolar arch width difference in canine and first premolars area was negatively correlated with the mandibular plane angle.while upper and lower arch width difference showed no statistical correlation with the mandibular plane angle.Conclusion:The maxillary middle arch width of the subjects with individual normal occlusion was correlated with vertical facial type.
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@#BACKGROUND Recent studies show malocclusion rate among Mongolian population is increasing year by year. Malocclusion has a strong relationship with dental caries and its complications. Cephalometric measurement norms are one of the important tools that are used for diagnosis and treatment of malocclusions. Nowadays there are no cephalometric linear measurement norms among Mongolian population according to age and sex. Background of this study was to determine cephalometric linear measurement norms among Mongolian children. METHODS Total 161 children of 6 years old were participated in this study and 79 (36 male and 43 female) children with normal occlusion were selected to determine cephalometric linear measurement norms. Winceph 11.0 program is was used for measurements. RESULTS From all participants’ children with normal occlusion occupied 49% (79 children). Result of measurement results shows no significant statistical differences between males and females. CONCLUSION These cephalometric linear measurements norms will be standard norms for Mongolian children and it is very important tool for orthodontic practice.
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Objective The aim of our work is to characterize individual normal occlusions to establish appropriate treatment standards for different vertical facial types. Methods A total of 30 patients with near-normal occlusion were grouped into high-angle group (eight cases), medium-angle group (12 cases), and low-angle group (10 cases) according to vertical facial skeletal type. Invivo5 software was used and digital imaging and communications in medicine data were rebuilt to measure the ∠L1/MP, ∠L6/MP, axis corner of L6, cant of occlusion plane, Balkwill angle, and Bonwill triangle of each group. Results Among the groups, the low-angle group had the smallest ∠L6/MP (P<0.05) and largest cant of occlusion. No significant difference was observed among the three groups with regard to the other parameters (P>0.05). Conclusion Patients with low-angle vertical facial skeletal type requires a modified treatment standard. In this group, the treatment standard must ensure that the cant of occlusion plane is more parallel to the Frankfurt horizontal plane compared with those of the other groups, and the axis of L6 is tilted distally relative to the mandibular plane.
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Objetivo: as modificações regionais inerentes ao processo de crescimento mandibular, como a reabsorção da borda anterior do ramo, determinam o aumento do espaço na região retromolar e mostram a necessidade ou não de exodontia dos terceiros molares. O objetivo deste trabalho foi avaliar, quantitativamente, o crescimento anteroposterior da região retromolar mandibular e verificar a ocorrência de dimorfismo sexual dessa variável. Material e métodos: foram utilizadas telerradiografias obtidas em norma lateral de 45 jovens, de ambos os sexos, leucodermas, entre nove e 11 anos de idade, mesofaciais, com perfis faciais harmônicos e oclusão normal. Foi aferido o espaço retromolar ao longo do plano oclusal funcional, entre a borda anterior do ramo da mandíbula e a face distal do primeiro molar inferior. Os dados obtidos submeteram-se, primeiramente, ao teste t de Student, para verificar o erro sistemático, e ao teste de correlação para o erro casual, ambos intraexaminador, indicando ausência de erro do método. Empregou-se o teste de Tukey, para comparar as medidas obtidas nas diferentes idades, e a análise de variância, para verificar a ocorrência de dimorfismo sexual. Resultados e conclusão: verificou-se um crescimento da região retromolar de 3,29 mm, entre os nove e os 11 anos. Nas idades de dez aos 11 anos ocorreu um aumento de 2,55 mm, sendo estatisticamente maior do que o constatado dos nove aos dez anos, de 0,74 mm. A análise de variância indicou ausência de dimorfismo sexual.
Objective: regional mandibular growth changes as the resorption of the anterior ramus border that increases the retromolar space determining if lower third molars need to be removed or not. The aim of this study was to evaluate, quantitatively, the mandibular alveolar sagital growth and also if sexual dimorphism was present. Material and methods: lateral cephalograms of 45 Brazilian Caucasian children of both genders, aging from 9 to 11 years, with balanced faces and good occlusion were used. The retromolar mandibular space was measured at the functional occlusal plane, from the anterior border of the ramus to the distal aspect of the lower first molar. The data was firstly examined about systematic and random intra-examiner errors through Student's "t" test and correlation test, respectively. In order to compare the data among different ages and occurrence of sexual dimorphism Anova and Tukey's test were performed. Results and conclusions: it was found an increase of 3.29 mm in the mandibular retromolar space from 9 to 11 years of age. Between 10 and 11 years there was an increase of 2.55 mm, statistically greater than those verified from 9 to 10 years of age, which was 0.74 mm. Anova demonstrated no sexual dimorphism.
Subject(s)
Dental Occlusion , Molar, Third/growth & development , Sex Characteristics , Alveolar Process , TeleradiologyABSTRACT
Introdução: Diferenças da atratividade encontradas entre os protocolos de tratamento Classe II em longo prazo e no pós-tratamento incitou estes estudos. O Elemento II demonstrou que os rostos bem equilibrados tem incisivos superiores posicionados em um relacionamento anteroposterior individualmente calculado com a testa. Deste modo, o Elemento II foi utilizado para investigar as características iniciais dos pacientes. Além disso, para avaliar as mudanças que os protocolos de extrações resultam nos tecidos moles, uma revisão sistemática foi realizada com busca nas bases de dados PubMed, Web of Science, Embase, Scopus e Cochrane. Resultados: O grupo CII teve posição AP dos incisivos superiores mais anteriores quando comparado ao grupo NO. Além disso, as posições AP dos incisivos nos subgrupos de extração foram à frente, quando comparado com o subgrupo NE. Alterações dos tecidos moles estatisticamente significantes foram ângulo nasolabial (NLA) que aumentou de 2,4º a 5,40º no protocolo de extração de 2 pré-molares e de 1º a 6,84º no protocolo de extração de 4 pré-molares. Retrusão dos lábios superior e inferior também foram verificadas, com menor retração do lábio inferior nos grupos de extração de dois pré-molares. Conclusões: Indivíduos com Classe II apresentaram os incisivos superiores significativamente mais protruídos que os indivíduos com oclusão normal. Na Classe II divisão 1, o subgrupo tratado com extrações apresentaram os incisivos significativamente mais protruídos em comparação com o subgrupo sem extrações. Quando Classe II divisão 1 é tratada com extrações de pré-molares, há aumento do NLA e os lábios são retraídos. No entanto, há menor retração do lábio inferior no protocolo de extração de 2 prémolares superiores.(AU)
Introduction: Differences in long-term and posttreatment attractiveness between Class II treatment protocols motivated these studies. Element II demonstrated that well-balanced faces have maxillary incisors positioned in an individually calculated anteroposterior relationship with the forehead. Thus, it was used to investigate the initial characteristics of the patients. Moreover, to evaluate the soft-tissue changes with extraction protocols, a systematic review was performed searching PubMed, Web of Science, Embase, Scopus and Cochrane electronic databases. Results: The CII group had forward incisors AP position when compared to the NO group. Also, the incisors AP positions in the extraction subgroups were forward when compared to the NE subgroup. Statistically significant soft-tissue changes reported included nasolabial angle (NLA) increasing from 2.4 to 5.40 degrees in the 2-premolar extraction protocol and from 1 to 6.84 degrees in the 4-premolar extraction protocol. Retrusion of the upper and lower lips were also verified, with less retraction of the lower lip in the 2-premolar extraction group. Conclusions: Class II subjects presented the maxillary incisors significantly more protruded than normal occlusion subjects. Class II division 1 extraction subgroups demonstrated significantly more protruded incisors as compared to the non-extraction subgroup. When Class II division 1 malocclusion is treated with premolar extractions, the NLA increases and the lips are retracted. However, there is less retraction of the lower lip in the 2- maxillary premolar extraction protocol.(AU)
Subject(s)
Humans , Male , Female , Adolescent , Forehead/anatomy & histology , Incisor/anatomy & histology , Malocclusion, Angle Class II/pathology , Malocclusion, Angle Class II/surgery , Maxilla/anatomy & histology , Case-Control Studies , Esthetics , Tooth Extraction , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>We measured and analyzed the angle between the longitudinal axis of incisor crown and tooth to provide a reference for orthodontists for selecting orthodontic methods and evaluating treatment results.</p><p><b>METHODS</b>A total of 120 participants were included according to the criteria of Andrews' six keys, and cephalometric radiograph under the instructions of modified natural head position acquirement method was performed. The angles of maxillary incisor crown longitudinal axis, tooth longitudinal axis, occlusion plane (OP), and true vertical (TV) plane were measured, as well as mandibular incisors.</p><p><b>RESULTS</b>As for maxillary incisors, the angle between crown longitudinal axis and TV plane, OP, and tooth longitudinal axis were 11.72°±4.71°, 73.29°±5.69°, and 20.04°±3.71°, respectively. For mandibular incisors, the angle between crown longitudinal axis and TV plane, OP, and tooth longitudinal axis were 16.03°±5.40°, 81.76°±4.81°, and 14.82°±4.01°, respectively. For the maxillary incisor, the angles between crown longitudinal axis and tooth longitudinal axis were mainly within 15° to 25°, whereas those for mandibular incisors were within 10° to 20°.</p><p><b>CONCLUSIONS</b>The longitudinal axis inclinations of the maxillary and mandibular incisor crown and of the incisor tooth need to be considered when cephalometric radiographs are used for treatment planning or for evaluating the treatment result.</p>
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Humans , Cephalometry , Dental Occlusion , Incisor , Mandible , Maxilla , Tooth CrownABSTRACT
Objective:To study the morphologic standard values of craniofacial hard-tissue of the youths in Xi'an.Methods:CBCT scanned cephalometric data of 100 selected volunteers (50 males and 50 females)with individual normal occlusion were collected.31 landmarks and 31 measurements were compared between sexes and between 3D and 2D data with software InvivoDental 5.2,WinCeph 8.0.and SPSS 19.0.Results:1.In the 3D measurements,vertical growth of mandible in the females was more than that in the males. The values of torque of lower incisor,basis length,height of rumi mandibulae and length of corpora mandibulae in the males were bigger than those in the females.2.Compared with 2D measurements,there existed statistically significant differences in most parameters except U1-NA(mm).Conclusion:3D analysis with CBCT may provide more accurite morphologic data for craniofacial hard tissues.
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Objective: The aim was to find the prevalence of dental caries, periodontitis, and oral hygiene index‑simplified (OHI‑S) among 12‑year schoolchildren having normal occlusion and malocclusion in Mathura city. Materials and Methods: The present study was a cross‑sectional study done among the 100 subjects who have been selected from 5 schools in four different geographical locations. The data regarding their socio‑demographic characteristics, dental caries status, periodontitis status and oral hygiene status was collected using structured proforma. Means, standard deviations and test of significant were used as statistics to describe the data. Results: The results showed that there was no significant difference between dental caries status, periodontitis status among subjects having normal occlusion and malocclusion (P = 0.06, 0.093) but significant relationship was found OHI‑S and children who were having malocclusion (and P = 0.022). Significant difference was also found between periodontitis and oral hygiene status (P = 0.00). Conclusion: It was observed from the present study that normal occlusion and malocclusion had no or weak significant effect on overall caries and periodontitis prevalence whereas oral hygiene status had a strong effect on overall periodontitis prevalence but not in relation to prevalence of dental caries in 12‑year‑old school children in Mathura city.
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Child , Dental Caries/epidemiology , Dental Occlusion/adverse effects , Female , Humans , India/epidemiology , Malocclusion/epidemiology , Male , Oral Hygiene , Periodontitis/epidemiology , PrevalenceABSTRACT
OBJECTIVE: The purposes of this study were 1) to classify lingual dental arch form types based on the lingual bracket points and 2) to provide a new lingual arch form template based on this classification for clinical application through the analysis of three-dimensional virtual models of normal occlusion sample. METHODS: Maxillary and mandibular casts of 115 young adults with normal occlusion were scanned in their occluded positions and lingual bracket points were digitized on the virtual models by using Rapidform 2006 software. Sixty-eight cases (dataset 1) were used in K-means cluster analysis to classify arch forms with intercanine, interpremolar and intermolar widths and width/depth ratios as determinants. The best-fit curves of the mean arch forms were generated. The remaining cases (dataset 2) were mapped into the obtained clusters and a multivariate test was performed to assess the differences between the clusters. RESULTS: Four-cluster classification demonstrated maximum intercluster distance. Wide, narrow, tapering, and ovoid types were described according to the intercanine and intermolar widths and their best-fit curves were depicted. No significant differences in arch depths existed among the clusters. Strong to moderate correlations were found between maxillary and mandibular arch widths. CONCLUSIONS: Lingual arch forms have been classified into 4 types based on their anterior and posterior dimensions. A template of the 4 arch forms has been depicted. Three-dimensional analysis of the lingual bracket points provides more accurate identification of arch form and, consequently, archwire selection.
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Humans , Young Adult , Classification , Cluster Analysis , Dental ArchABSTRACT
OBJECTIVE: The purposes of this study were 1) to classify lingual dental arch form types based on the lingual bracket points and 2) to provide a new lingual arch form template based on this classification for clinical application through the analysis of three-dimensional virtual models of normal occlusion sample. METHODS: Maxillary and mandibular casts of 115 young adults with normal occlusion were scanned in their occluded positions and lingual bracket points were digitized on the virtual models by using Rapidform 2006 software. Sixty-eight cases (dataset 1) were used in K-means cluster analysis to classify arch forms with intercanine, interpremolar and intermolar widths and width/depth ratios as determinants. The best-fit curves of the mean arch forms were generated. The remaining cases (dataset 2) were mapped into the obtained clusters and a multivariate test was performed to assess the differences between the clusters. RESULTS: Four-cluster classification demonstrated maximum intercluster distance. Wide, narrow, tapering, and ovoid types were described according to the intercanine and intermolar widths and their best-fit curves were depicted. No significant differences in arch depths existed among the clusters. Strong to moderate correlations were found between maxillary and mandibular arch widths. CONCLUSIONS: Lingual arch forms have been classified into 4 types based on their anterior and posterior dimensions. A template of the 4 arch forms has been depicted. Three-dimensional analysis of the lingual bracket points provides more accurate identification of arch form and, consequently, archwire selection.
Subject(s)
Humans , Young Adult , Classification , Cluster Analysis , Dental ArchABSTRACT
BACKGROUND:Posterior arch length deficiency is closely related to the formation and development of malocclusion. OBJECTIVE:To measure the posterior arch length in individual normal occlusions of adults in Lanzhou. METHODS:A total of 102 current col ege students with individual normal occlusions, with a mean age of (19.33±2.67) years (range 18-24 years), including 47 males and 55 females from Gansu Province, were chosen to take lateral cephalograms. Al research objects were divided into three groups according to mandibular plane angle:high angle group (Frankfort mandibular-plane angle>32°), low angle group (Frankfort mandibular-plane angleRESULTS AND CONCLUSION:Posterior arch length of maxil ary arch was slightly longer in male group than that in female group, and the difference was not significant (P>0.05). The posterior arch length of mandibular arch was slightly longer in male group than that in female group, but the difference was no significant (P>0.05). Comparison between groups revealed that the posterior arch length of low angle mandibular arch was significantly longer than that of high angle mandibular arch in male group, and the difference was significant (P<0.05). The results indicate that the gender wil not influence the development of posterior arch length. Different vertical facial types and different genders have different posterior arch length in individual normal occlusions of adults
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OBJECTIVE: The purpose of this study was to investigate the relationship between the mandibular dental and basal arch forms in subjects with normal occlusion and compare them with those of Class III malocclusion using cone-beam computed tomography (CBCT). METHODS: CBCT images of 32 normal occlusion (19 males, 13 females; 24.3 years) and 33 Class III malocclusion subjects (20 males, 13 females, 22.2 years) were selected. Facial axis and root center points were identified from the left to right mandibular first molars. Distances between the facial axis and root center points for each tooth were calculated, and 4 linear and 2 ratio variables were measured and calculated for each arch form. The variables were compared between groups by independent t-test. Pearson correlation coefficient was applied to assess the relationships between dental and basal variables within each group. RESULTS: The mandibular dental and basal intercanine widths were significantly greater in the Class III group than in normal occlusion subjects (p < 0.05). The dental and basal intercanine widths as well as the dental and basal intermolar widths were strongly correlated in normal occlusion and moderately correlated in Class III malocclusion. CONCLUSIONS: The dental arch form demon strated a strong positive correlation with the basal arch form in the normal occlusion group and moderate correlation in the Class III malocclusion group. These results might be helpful for clinicians to have a better understanding of the importance of basal arch form in the alveolar bone.
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Female , Humans , Male , Axis, Cervical Vertebra , Cone-Beam Computed Tomography , Dental Arch , Malocclusion , Molar , ToothABSTRACT
O objetivo deste estudo transversal foi verificar a presença de hábitos bucais em crianças na faixa etária de três a cinco anos, de ambos os gêneros, no estágio de dentadura decídua, matriculados em pré-escolas municipais e associá-los com oclusão normal e má-oclusão por meio do teste estatístico do qui-quadrado. Para tanto,foi utilizado um questionário sobre hábitos bucais para ser respondido pelos pais e realizado exame clínico nestas crianças, a fim de avaliara presença de mordida aberta anterior, mordida cruzada posterior e sobressaliência acentuada. Os resultados obtidos mostraram que o hábito de sucção de chupeta e a mordida aberta anterior se destacaram neste estudo, assim como, a influência da amamentação natural como meio de prevenção para o desenvolvimento de más-oclusões.
The aim of this transversal study will be to determine the presence of oral habits in children from 3 to 5years-old, both gender,at mixed dentition stage, enrolled at municipal preschools. Also, oral habits was associated with normal ar malocclusion through chi-square statistical testo Therefore, a questionnaire on oral habits was responded by the children's parents and these children was submitted to oral examination for assessing the presence of anterior open bite, posterior crossbite, and marked overjet. The results showed that pacifier: sucking and anterior open bite were highlight in this study, as soon as, the natural breast-feeding as help preventive to development malocclusion.
Subject(s)
Humans , Male , Female , Child, Preschool , Chi-Square Distribution , Dental Occlusion , Habits , Malocclusion , Tooth, Deciduous , Open Bite , Pacifiers , Surveys and QuestionnairesABSTRACT
OBJECTIVE: The present study aimed to determine from a sample of Amazonian youngsters, with normal occlusion, the mean values for soft profile characteristics using cephalometric radiographs obtained in lateral norm. METHODS: The cephalometric radiographs of the 30 youngsters, being 15 males and 15 females, with mean age of 21.6 years old, were assessed. For statistical analysis, central tendencies and dispersion measurements (mean and standard deviation) were used and, for both the comparison of the mean values of males and females and the correlations between the measurements of the soft profile and bony profile, the unpaired Student's t-test was applied. RESULTS AND CONCLUSION: After obtaining statistical data, parameters were set based on the cephalometric norms regarding the specialized literature, revealing that all variables presented a normal distribution pattern. There was sexual dimorphism for the following measurements: ANB, NAP, ANS-Me, N-ANS, Sn'-Me', and N'-SN'. Norms were determined for all the assessed measurements. Statistical differences were observed between the norm found in the present study and those found in the specialized literature.
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Background: There has always been a constant search for the definition of idealistic and realistic orthodontic treatment goals for different ethnic groups around the world. This study was hence devised to study the mesio-distal angulations and labio-lingual inclinations of the clinical crowns in Dravidian population with pleasing profiles and non-orthodontic normal occlusion. Materials and Methods: Forty dental casts from a Dravidian sample (21.5 years) with Class I canine and molar relation; normal maxillo-mandibular relationship; well-aligned arches; with no dental anomaly, restorations or attrition; no history of previous orthodontic treatment, and exhibiting normal growth were studied. A custom-made tip-torque device was used to measure the crown angulations and inclinations. The arithmetic mean and standard deviations for each tooth type were compared with those of Andrew's Caucasian norms using Student's 't' test. Results: The study group exhibited statistically significant decrease in crown angulation (mesial tip) and increased labial crown torque in both upper and lower anteriors. The lower anteriors exhibited distal crown tip while the posteriors were significantly tipped more mesially. All the posteriors demonstrated increased lingual crown torque. Conclusion: Tip and torque modifications are suggested for the fine finishing and easy retention of occlusion in Dravidians while using straight wire appliance.
ABSTRACT
OBJETIVO: comparar, eletromiograficamente, os potenciais de ação do músculo orbicular da boca, segmentos superior e inferior, bilateralmente, em jovens com Classe II, 1ª divisão, e em jovens com oclusão normal, verificando a ocorrência ou não de diferenças na atividade eletromiográfica entre os grupos. MÉTODOS: a amostra consistiu-se de 50 jovens do sexo feminino, com idades entre 8 e 10 anos, com ausência de tratamento ortodôntico prévio, distribuídas em dois grupos: 25 com Classe II, 1ª divisão; e 25 com oclusão normal. Para a captação dos sinais eletromiográficos, utilizaram-se eletrodos de superfície passivos de Ag/AgCl. Registrou-se a atividade muscular na situação de repouso, na contração isométrica e na contração isotônica, determinando-se o valor da RMS de cada movimento. Submeteu-se os dados coletados à análise estatística de variância e ao teste de Tukey (α=0,05). RESULTADOS: os resultados revelaram que ocorreram diferenças nas atividades eletromiográficas entre as jovens com Classe II, 1ª divisão, e as com oclusão normal. As atividades musculares mostraram-se maiores nas jovens com Classe II, 1ª divisão. CONCLUSÃO: observou-se uma menor competência do músculo orbicular da boca nas jovens do sexo feminino com Classe II, 1ª divisão.
AIM: The purpose of this study was to make an electromyographic comparison of the action potentials of the upper and lower segments of the orbicularis oris muscle, bilaterally, in youngsters with Class II, Division 1 malocclusion and youngsters with normal occlusion in order to verify whether or not there is a difference between the two groups with regard to the electromyographic activity that occurs.METHODS: The sample consisted of 50 girls, in the age-range from 8 to 10 years, with no previous orthodontic treatment, divided into two groups: 25 with Class II, Division 1 malocclusion and 25 with normal occlusion. Electromyographic signals of the orbicularis oris muscle were acquired using Ag/AgCl surface electrodes. Muscle activity was recorded in the resting position, in the isometric contraction and in the isotonic contraction and the Root Mean Square (RMS) values of each movement were determined. The data collected were submitted to statistical analyses of variance and Tukey test (α=0.05).RESULTS: The results showed that there was a difference in electromyographic activity between the young girls with Class II, Division 1 malocclusion and those with normal occlusion. Muscle activity was higher in the girls with malocclusion than in those with normal occlusion.CONCLUSION: This suggests lower competence of the orbicularis oris muscle in the girls with Class II, Division 1 malocclusion.