Incisor root length in individuals with and without anterior open bite: a comparative CBCT study

ABSTRACT Objective: This study aimed to compare the root length of maxillary and mandibular incisors between individuals with open bite versus matched individuals with adequate overbite. Methods: This comparative, matched and retrospective study included 48 cone beam computed tomographies (CBCTs) obtained at a university radiological center. Scans belonged to 24 individuals with open bite (overbite ≤ 0 mm) and 24 individuals with adequate overbite (controls). Both groups were matched by age, sex, malocclusion classification and skeletal characteristics (ANB and FMA angles). Root length of each maxillary and mandibular incisor was measured in millimeters (mm) in a sagittal section from a perpendicular line to the enamel cement junction until the root apex (384 length measurements were made). The means of root length in both groups were compared using t-tests. In addition, correlations between variables were evaluated with the Pearson correlation coefficient (α = 0.05). Results: In both groups, the root length of the upper central incisors was approximately 12 mm and the root length of the maxillary lateral incisors was approximately 13 mm (p˃ 0.05). Likewise, the root length of lower central incisors in both groups measured approximately 12 mm (p˃ 0.05). However, the mandibular lateral incisor roots of open bite patients were significantly longer than in the normal overbite patients (approximately 1 mm, p= 0.012 right side, p= 0.001 left side). Conclusions: Root length of maxillary incisors and central mandibular incisor is similar in individuals with or without open bite, but the mandibular lateral incisor roots in open bite patients were significantly longer than in the normal overbite patients.

RESUMO Objetivo: O presente estudo teve como objetivo comparar o comprimento radicular de incisivos superiores e inferiores em indivíduos com mordida aberta versus indivíduos com sobremordida normal. Método: Esse estudo comparativo e retrospectivo incluiu 48 tomografias computadorizadas de feixe cônico (TCFC) obtidas em um centro radiológico universitário. As tomografias foram realizadas em 24 indivíduos com mordida aberta (sobremordida ≤ 0 mm) e 24 indivíduos com sobremordida normal (controle). Ambos os grupos foram compatibilizados de acordo com a idade, sexo, má oclusão e padrão esquelético (ângulos ANB e FMA). O comprimento radicular de todos os incisivos superiores e inferiores foi medido em milímetros (mm) em um corte sagital, de uma linha perpendicular à junção cemento-esmalte até o ápice radicular (384 medidas de comprimento foram realizadas). A média de comprimento radicular em ambos os grupos foi comparada utilizando-se o teste t. Adicionalmente, correlações entre as variáveis foram avaliadas usando o coeficiente de correlação de Pearson (α = 0,05). Resultados: Em ambos os grupos, o comprimento radicular dos incisivos centrais superiores foi de, aproximadamente, 12 mm, e o comprimento radicular dos incisivos laterais superiores foi de, aproximadamente, 13 mm (p˃ 0,05). Da mesma forma, o comprimento radicular dos incisivos centrais inferiores, em ambos os grupos, obteve a medida de aproximadamente 12 mm (p>0,05). No entanto, o comprimento radicular dos incisivos laterais inferiores em indivíduos com mordida aberta foi significativamente maior em comparação aos pacientes com sobremordida normal (aproximadamente 1 mm, p=0,012 do lado direito, p=0,001 do lado esquerdo). Conclusões: O comprimento radicular de incisivos superiores e incisivos centrais inferiores foi similar em indivíduos com ou sem mordida aberta, mas o comprimento radicular de incisivos laterais inferiores em indivíduos com mordida aberta foi significativamente maior em comparação a pacientes com sobremordida normal.

Cone-beam computed tomography for evaluating root length of maxillary and mandibular anterior teeth in open bite patients / 中南大学学报(医学版)

OBJECTIVES@#To compare the root length of maxillary and mandibular anterior teeth between open bite patients and normal overbite patients via cone-beam computed tomography (CBCT) as well as the root length of anterior teeth in different degree of open bite patients, and to analyze the correlation between the degree of open bite and root length.@*METHODS@#A total of 106 untreated patients were enrolled retrospectively (53 anterior open bite patients and 53 normal overbite patients).Three-dimensional position of the CBCT image for the patient's teeth was performed using Dolphin software. The median sagittal plane of the tooth was used as the measurement plane, and the line connecting the apical point and the midpoint between the labial and lingual cementoenamel junctions was defined as the root length. Independent @*RESULTS@#Significant differences were found in the root length of maxillary and mandibular anterior teeth between the open bite group and the normal overbite group (@*CONCLUSIONS@#The root length of maxillary and mandibular anterior teeth in the open bite patients is shorter than that in the normal overbite patients, and the severer the degree of open bite, the shorter the root length of the mandibular central incisor tends to be. There is a certain relationship between maxillary anterior teeth and the root length of anterior teeth.

Identification and characterization of CircRNAs involved in the regulation of wheat root length

BACKGROUND: Recent studies indicate that circular RNAs (circRNAs) may play important roles in the regulation of plant growth and development. Plant roots are the main organs of nutrient and water uptake. However, whether circRNAs involved in the regulation of plant root growth remains to be elucidated. METHODS: LH9, XN979 and YN29 are three Chinese wheat varieties with contrasting root lengths. Here, the root circRNA expression profiles of LH9, XN979 and YN29 were examined by using high-throughput sequencing technology. RESULTS: Thirty-three and twenty-two differentially expressed circRNAs (DECs) were identified in the YN29-LH9 comparison and YN29-XN979 comparison, respectively. Among them, ten DECs coexisted in both comparisons. As the roots of both LH9 and XN979 were significantly larger and deeper than YN29, the ten DECs coexisting in the two comparisons were highly likely to be involved in the regulation of wheat root length. Moreover, three of the ten DECs have potential miRNA binding sites. Real-time PCR analysis showed that the expression levels of the potential binding miRNAs exhibited significant differences between the long root plants and the short root plants. CONCLUSIONS: The expression levels of some circRNAs exhibited significant differences in wheat varieties with contrasting root phenotypes. Ten DECs involved in the regulation of wheat root length were successfully identified in which three of them have potential miRNAs binding sites. The expression levels of putative circRNA-binding miRNAs were correlated with their corresponding circRNAs. Our results provide new clues for studying the potential roles of circRNAs in the regulation of wheat root length.

Root growth and carbohydrate partitioning in cotton subjected to shading in the initial phase / Crescimento radicular e partição de carboidratos em algodoeiro submetido ao sombreamento na fase inicial

ABSTRACT: Cotton cultivation in Brazil tends to occur mostly in the rainy season, and at the time of developing the crop there are often prolonged periods of low solar radiation. The objective of this work was to evaluate the root development of cotton cultivars subjected to shading in the initial phase. The experiment was carried out in a greenhouse, using rhizotrons. The experimental design was a 2x2 factorial in randomized blocks with five replications. The treatments were composed of cotton cultivars TMG 1WS (early) and TMG 8WS (late) and luminosity conditions: non-shaded and shaded (50% reduction of luminosity). There were no interactions between the factors "shading" and "cultivars" for any parameter evaluated. Shading reduced total and lateral root growth from the 21 days after emergence (DAE) and the main root at 24DAE. Shading caused reductions in length (60%), surface (65%), mean diameter (15%), root volume (69%), root dry matter mass (83%) and shoot (64%), as well as decreasing the content (36%) and the accumulation of carbohydrates in the shoot (73%). Shading at early cotton development reduces the shoot carbohydrates production, affecting dry matter accumulation and root growth, and this response is independent of the cultivar.

RESUMO: O cultivo do algodoeiro no Brasil está concentrado no período chuvoso, e no momento do estabelecimento da lavoura frequentemente há períodos prolongados de baixa radiação solar. O objetivo deste trabalho foi avaliar o desenvolvimento radicular de cultivares de algodoeiro submetidos ao sombreamento na fase inicial da cultura. O experimento foi realizado em ambiente controlado, em rizotrons. O delineamento experimental foi um fatorial 2x2 em blocos ao acaso com cinco repetições. Os tratamentos foram as cultivares de algodão TMG 11WS (precoce) e TMG 81WS (tardia) e as condições de sombra: sem sombra e com sombra (50% de redução da luminosidade). Não houve interação entre os fatores "sombra" e "cultivares estudadas" para nenhum parâmetro avaliado. A sombra reduziu o crescimento radicular total e das raízes laterais a partir dos 21 dias de emergência (DAE) e da raiz principal aos 24DAE. O sombreamento reduziu o comprimento (60%), a superfície (65%), o diâmetro médio (15%), o comprimento por volume (60%), o volume radicular (69%), a massa de matéria de seca da raiz (83%) e da parte aérea (64%), o teor (36%) e o acúmulo de carboidratos na parte aérea (73%). Em conclusão, o sombreamento na fase inicial de desenvolvimento do algodoeiro reduz a produção de carboidratos da parte aérea, afetando o acúmulo de matéria seca e o crescimento radicular, sendo que essa resposta independe da cultivar.

Root canal system in permanent anterior teeth studied by cone beam computed tomography / 实用口腔医学杂志

Objective:To study the root canal system in permanent anterior teeth by cone-beam computer tomography(CBCT).Methods:12 85g anterior teeth in 1 103 patients were divided into group A(≤40 years) and group B(＞40 years).The CBCT images of 6 404 maxillary anterior teeth and 6 454 mandibular anterior teeth were collected.The number of roots and root canals,crown-root length,the types of root canal configurations,symmetry,age-related changes and gender differences were analyzed statistically.The correlation of double root canals system in mandibular anterior teeth were compared.Results:All of the maxillary anterior teeth and mandibular incisors had only one root while 1.66％ double roots were found in canines.The prevalence of double root canals in maxillary and mandibular anterior teeth were 0.03％ and 11.25％ respectively,that of the lateral incisors was the highest(17.40％).Type Ⅰ was the most frequent type (88.75％) in permanent anterior teeth followed by Type Ⅲ (7.07％).There was symmetrical distribution of the bilateral root canals of anterior teeth.There was no statistical significance of crown-root length among different age groups in permanent teeth (P ＞ 0.05).The variation of the root canal rate increased gradually at the age of 18-50 years,decreased gradually after the age of 50.The incidence of double root canals was higher in males (13.12％)than in females (9.93 ％) in mandibular anterior teeth.The incidence of double root canals of mandibular central incisors was positively correlated with lateral incisors and canines respectively (P ＜0.05).Conclusion:The root canal morphology of mandibular anterior teeth is complicated.The prevalence of double root canals is symmetic,age-related and gender difference.

Changes in root morphology and dry matter production in Pfaffia glomerata (Spreng. ) Pedersen accessions in response to excessive zinc / Alterações na morfologia radicular e produção de matéria seca em acessos de Pfaffia glomerata (Spreng. ) Pedersen em resposta ao excesso de zinco

ABSTRACT Zinc (Zn) participates of numerous metabolic processes in plants. However, it can become toxic to plants in excessive concentrations in the soil. Pfaffia glomerata is a Brazilian medicinal species that has stood out because of its numerous chemical and functional properties, mainly by the triterpene saponins and ecdysteroids accumulated in its roots. This study aimed to evaluate the effects of zinc excess on many root morphological parameters of Pfaffia glomerata. A 4 x 3 factorial design was employed in a completely randomized scheme with 3 replicates. The treatments consisted of four concentrations of Zn (2, 100, 200, and 300 µM) and three accessions of P. glomerata (BRA, GD, and JB) grown in a hydroponic system for 7 and 14 days. Differences in root morphology and dry mass production were observed among the three accessions in response to excessive Zn. Some growth parameters of GD accession increased with the addition of Zn, ranging from 36 to 79 µM. However, the GD and JB accessions presented reduction in dry mass production, root area, length, and volume with increasing Zn levels. The BRA accession, which had the lowest growth among accessions, presented chlorotic leaves. The shoot/root dry mass ratio and root diameter increased linearly for BRA and GD accessions at 7 days. Based on the evaluated parameters, we observed the following order of Zn excess tolerance in P. glomerata accessions: GD> JB> BRA.

RESUMO O zinco (Zn) participa de numerosos processos metabólicos nas plantas. No entanto, em concentrações excessivas no solo pode tornar-se tóxico para os vegetais. Pfaffia glomerata é uma espécie medicinal brasileira que tem se destacado devido as suas inúmeras propriedades químicas e funcionais, devido principalmente às saponinas triterpênicas e ecdisteróides acumuladas em suas raízes. O objetivo do presente trabalho foi avaliar os efeitos do excesso de Zn sobre vários parâmetros morfológicos radiculares de Pfaffia glomerata. O delineamento experimental utilizado foi o inteiramente casualizado com três repetições, dispostos em um arranjo fatorial (4 x 3). Os tratamentos consistiram em quatro níveis de Zn (2, 100, 200 e 300µM) e três acessos (BRA, GD e JB) de P. glomerata cultivados em sistema hidropônico em casa de vegetação por 7 e 14 dias. Diferenças na morfologia radicular e na produção de material seca foram observadas entre os três acessos em resposta ao excesso de Zn. Alguns parâmetros de crescimento do acesso GD aumentaram sob a adição de Zn variando entre 36 e 79 µM. No entanto, os acessos GD e JB apresentaram redução na matéria seca, bem como na área de superfície, comprimento e volume radicular com o aumento dos níveis de Zn. O acesso BRA, que teve o menor crescimento entre os acessos, apresentou folhas cloróticas. A razão entre matéria seca da parte aérea e raízes e o diâmetro radicular aumentou linearmente para os acessos BRA e GD aos 7 dias de cultivo. Baseando-se nos parâmetros avaliados foi observada a seguinte ordem de tolerância ao excesso de Zn: GD> JB> BRA.

Mixed and monospecific stands of eucalyptus and black-wattle: I - fine root length density / Plantios monoespecíficos e mistos de eucalipto e acácia-negra: I - densidade do comprimento de raízes finas

Fine root length density (FRLD) was evaluated in mixed and monospecific stands of Eucalyptus grandis x E. urophylla and Acacia mearnsii in Southern Brazil. FRLD (≤2,0mm) at 8 and 18 months after planting in the treatments: 100E (100% of eucalyptus); 100A (100% of Acacia mearnsii); 50E:50A (50% of eucalyptus + 50% of Acacia mearnsii). The findings demonstrated that the FRLD at 8 months of age have the same distribution, in the two different species, in the distribution of the different soil layers, reaching the maximum projection of 125cm from the tree trunk. For the age of 18 months after planting, it was verified that the FRLD in the monospecific stand of Acacia mearnsii was higher than in the monoculture and mixed stand of Eucalyptus grandis x E. urophylla. Therefore, no interaction, neither positive nor negative, between the root systems of Eucalyptus grandis x E. urophylla and Acacia mearnsii during the 18 months after planting was found. The higher FRLD is found at the soil layers surface, next to the tree trunk and in the planting line, followed by the diagonal and planting rows. The initial growth in length of the root system of Acacia mearnsii is more dynamic with higher density than the eucalyptus, but without interfering directly in the global growth of fine roots in mixed stands.

Avaliou-se a densidade do comprimento de raízes finas (DCRF) de plantios monoespecíficos e misto de Eucalyptus grandis x E. urophylla e de Acacia mearnsii na região sul do Brasil. A DCRF (≤2,0mm) foi determinada aos 8 e 18 meses após o plantio nos tratamentos: 100E (100% de eucalipto); 100A (100% de Acacia mearnsii); 50E:50A (50% de eucalipto + 50% de Acacia mearnsii). A DCRF aos oito meses de idade possui o mesmo comportamento para a ocupação das diferentes camadas do solo, atingindo uma projeção máxima de 125cm de distância em relação ao tronco da árvore. Já, aos 18 meses após o plantio, verificou-se que, no cultivo monoespecífico de Acacia mearnsii, a DCRF foi superior em relação ao monocultivo e plantio misto de Eucalyptus grandis x E. urophylla. Não ocorreram interações positivas ou negativas entre os sistemas radiculares do eucalipto e da acácia-negra durante os primeiros 18 meses após o plantio. A maior DCRF encontra-se nas camadas superficiais do solo, nas proximidades do tronco da árvore e na linha de plantio, seguida pela diagonal e entrelinha de plantio. O crescimento inicial em comprimento do sistema radicular da Acacia mearnsii é mais dinâmico e maior do que a do eucalipto, mas sem interferir diretamente no crescimento global das raízes finas no cultivo misto.

Root-crown ratios of permanent teeth in Malay patients attending HUSM Dental Clinic

The objectives of this study were to determine the normal mean value of the root-crown (R/C ratios) in Malay patients and their variations by gender and dental arch from orthopantomogram radiographs (OPGs). Two thousand nine hundred and twenty teeth with fully developed roots were measured from 112 OPGs. Subjects with history of maxillofacial trauma or orthodontic therapy were excluded. The mean age of the subjects was 19.1 (SD 2.08) years old for males while females 18.9 (SD 2.19) years old in the range from 15 to 22 years old. The intra-examiner reproducibility of the assessment method was good (Intraclass correlation coefficient 0.81). Results of this study showed that there was no significant difference between R/C ratios of males and females groups. However, the ratios of the antagonist teeth for both males and females were significantly greater in the mandible than in the maxilla (p<0.05 for right and left lateral incisors and right first premolars in male; p<0.001 for all other teeth). In both gender, the highest R/C ratio was mandibular second premolars and the lowest R/C ratio were maxillary central incisors. The rootcrown ratio could be used as a baseline data and reference to help in orthodontic diagnosis, treatment planning and prognosis as well as evaluation developmental root deficiency.

Accuracy Of A New Apex Locator Apex NRG Blue-- An Invitro Study.

The purpose of this study was to test in an in-vitro model the accuracy of a new multi frequency third generation apex locator Apex NRG blue both in dry and various wet environments. 60 extracted teeth were taken. The teeth were divided into 6 groups of 10 each. The actual length of the root canal of each tooth was determined and then the teeth were embedded in an alginate model. The radiographic working length was determined and later the electronic working length was taken using different irrigating solutions, (3%H2O2, 3%Naocl, 0.2% chlorhexidine, normal saline and 17%EDTA). The results were compared and sent for statistical analysis. This study showed that the new multi frequency electronic apex locator NRG blue is quiet reliable in determining the root canal length both in dry as well as in wet environment.

The changes of root length and form in immature teeth after orthodontic treatment / 대한치과교정학회지

Previous studies have focused on the causes of root resorption after orthodontic treatment and treatment methods to reduce this phenomenon, and have been mainly associated with developed, mature roots. As parents become increasingly interested in their children's' dentition, orthodontists are performing fixed orthodontic treatment on patients of less than 10 years and before the completion of the immature root. Thus, the author evaluated the changes of root length and root form of maxillary immature incisors after orthodontic treatment, com-pared with those of mature teeth, and investigated the correlation according to gender, treatment duration, and displacement of incisors. The sample consisted of an immature root group of twenty-eight persons (between 8 and 10 years old) and a mature root group of thirty-one persons (between 11 and 15 years old). The crown and root length of the maxillary four incisors were measured with a periapical radiograph, changes in root length and crown-root ratio were calculated, and root form was classified according to a scoring system. The results were as follows. 1. The development of immature roots was not affected by orthodontic treatment and mostly showed normal root length and apical form. 2. Root length of immature teeth was sustained or became shorter, partially in long treatment duration or with open bite patients. Even though the teeth reached their normal root length, they demonstrated a blunt form. 3. Most of the mature roots showed mild resorption, and the form of mature roots was more blunt than the developed form of the immature roots (p<0.05). 4. The developed form of the immature roots was statistically related to treatment duration, while the form of the mature roots was significantly related to the displacement of incisors (p<0.05). 5. In contrast, other variables such as gender, classification of malocclusion, changes in overbite, and changes of U1 to SN showed no correlation with the root resorption of both groups.

A study about the change of locations of the center of resistance according to the decrease of alveolar bone heights and root lengths during anterior teeth retraction using the laser reflection technique / 대한치과교정학회지

Treatment mechanics should be individualized to be suitable for each patient`s personal teeth and anatomic environment to get a best treatment result with the least harmful effects to teeth and surrounding tissues. Especially, the change of biomechanical reaction associated with that of the centers of resistance of teeth should be considered when crown-to-root ratio changed due to problematic root resorption and/or periodontal disease during adult orthodontic treatment. At the present study in order to investigate patterns of initial displacements of anterior teeth under certain orthodontic force when crown-to-root ratio changed in not only normal periodontal condition but also abnormal periodontal and/or teeth condition, the changes of the centers of resistance for maxillary and mandibular 6 anterior teeth as a segment were studied using the laser reflection technique, the lever&pulley force applicator and the photodetector with these quantified variables reducing alveolar bone 2mm by 2mm for each of maxillary 6 anterior teeth until the total amount of 8mm and root 2mm for each of mandibular 6 anterior ones until the total amount of 6mm. The results were as follows: 1. Under unreduced condition, the center of resistance during initial displacement of maxillary 6 anterior teeth was located at the point of about 42.4% apically from cemento-enamel junction(CEJ) of the averaged tooth of them and kept shifting to about 76.7% with alveolar bone reduction. 2. The distance from the averaged alveolar crest level of maxillary 6 anterior teeth to the center of resistance for the averaged tooth of them kept decreasing with alveolar bone reduction, but the ratio to length of the averaged root embedded in the alveolar bone was stable at around 33% regardless of that. 3. Under unreduced condition, the center of resistance during initial displacement of mandibular 6 anterior teeth was located at the point of about 43% apically from CEJ of the averaged tooth of them and this ratio kept increasing tc about 54% with root reduction. Bur the distance from CEJ to the center of resistance decreased from around 5.3mm to around 3.3mm, that is to say, the center of resistance kept shifting toward CEJ with the shortening of root length. 4. A unit reduction of alveolar bone had greater effects on the change of the centers of resistance than that of root did during initial phase of each reduction. But both of them had similar effects at the middle region of whole length of the averaged root.