Dental arch characteristics among South Indian twins - A morphometric study

Genetic and environmental factors are essential in occlusal variations and malocclusion and have been of considerable interest to orthodontists. Studies on twin pairs are one of the most effective methods for investigating genetically determined occlusal variables. Many studies have focused on distances between first molars or between canines but malocclusions can also occur in other regions of the dental arch. Aim: To evaluate the characteristics of the dental arch between pairs of Monozygotic (MZ) and Dizygotic (DZ) twins from Southern India. Methods: A random sample of 51 twin pairs (12­18years old) participated in this study. The zygosity of twin pairs was recorded by facial appearance. The occlusion of the first permanent molars was recorded according to Angle's classification. Study models were prepared to assess dental arch characteristics (i.e., arch form, arch perimeter, arch length; intercanine, intermolar width, and teeth size discrepancy). The obtained data was statistically analyzed using SPSS software 19.0. The student's t-test (two-tailed, independent) and Chi-square test was used to determine the significance of studied parameters. Results: Angle's Class I molar relation was more commonly observed followed by the Class II molar relationship among twins. The measured dental arch dimensions did not show a statistically significant difference among twin pairs. The ovoid arch form was commonly observed among Monozygotic and Dizygotic Twins. There was a similarity among MZ and DZ twins in the anterior and overall Bolton's ratio. Conclusion: There were similar occurrences of measured parameters among twins, which showed genetic predominance in the expression of measured dental arch traits

Sex estimation from maxillary arch measurements in Egyptian populations: cross-sectional study / Estimación sexual a partir de mediciones del arco maxilar en poblaciones egipcias: estudio transversal

SUMMARY: Sex estimation is an essential step in personal identification and a cornerstone for developing biological profile from skeletal remains. The present study aimed to evaluate the role of maxillary arch widths and lengths as unique parameters in the estimation of sex in Egyptian populations. Maxillary arch measurements were collected from 1410 subjects where palatal impressions were obtained from each participant. Fourteen maxillary inter-teeth widths and lengths that excluded teeth dimensions were included The current study revealed that among the studied population, Egyptian men showed significant differences (p34.57 mm, it could predict the sex with sensitivity of 69.8 %, specificity of 58.8 % and p<0.05. The first molar could be considered as one of the most valid and reliable teeth in estimating sex in Egyptian populations. These measurements may be used as a reference in different populations in cases of mass disaster or relevant events.

RESUMEN: La estimación del sexo es un aspecto esencial en la identificación personal para desarrollar el perfil biológico a partir de restos óseos. El presente estudio tuvo como objetivo evaluar el papel del ancho y longitud del arco maxilar como parámetros únicos en la estimación del sexo en poblaciones egipcias. Se obtuvieron medidas del arco maxilar de 1410 sujetos, además de las impresiones palatinas de cada participante. El estudio actual reveló que entre la población estudiada, los hombres egipcios mostraron diferencias significativas (p 34,57 mm, podría predecir el sexo con sensibilidad de 69,8 %, especificidad de 58,8 % y p <0,05. El primer molar podría considerarse como uno de los dientes más confiables para estimar el sexo en las poblaciones egipcias. Estas mediciones se pueden utilizar como referencia en diferentes poblaciones en casos de desastres masivos o eventos relevantes.

Prevalence of Tympanostomy Tube Placement in Relation to Cleft Width and Type.

OBJECTIVES/HYPOTHESIS: The prevalence of tympanostomy tube surgery (TTS) in patients with a cleft deformity was investigated, in relation to cleft width and cleft type. STUDY DESIGN: Retrospective review of medical health records. METHODS: Retrospective review of medical health records. Seventy-eight patients with non-syndromic cleft deformity of the palate and/or alveolus and lip between 2003 and 2017 were investigated. All available medical documents were analyzed. The study group was divided into subgroups: 1) patients with isolated cleft palate (CP) and patients with a cleft palate with cleft lip and alveolus (CLP). 2) According to Veau's classification (I-IV), further subgroups were defined. Cleft width was measured using plaster cast models. RESULTS: TTS was performed in 55% of the patients (n = 43). Considering Veau's classification, TTS was conducted as follows: Veau I 65.2% (n = 15/23), Veau II 55.0% (n = 11/20), Veau III 47.6% (n = 10/21), and Veau IV 50.0% (n = 7/14). Cleft classifications, maxillary arch width, and absolute/relative cleft width had no statistical impact on TTS occurrence. Although no significant correlation could be found, patients in our study group with CP (Veau I and II) underwent TTS more often (60.5%, n = 26/43) than patients with CPL (Veau III and IV; 48.6%, n = 17/35) during a three-year follow-up. CONCLUSION: None of the cleft characteristics examined had a significant impact on the proportion of patients who received TTS. Nevertheless, patients with lower Veau classification and CP received tympanostomy tubes more often. Therefore, otolaryngologists and pediatricians treating children with cleft palate should maintain a high level of suspicion for chronic middle ear effusion, even in patients with small clefts. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E2764-E2769, 2021.

Aplicabilidad del método Tanaka-Johnston para la estimación del diámetro mesiodistal de caninos y premolares en pacientes de 12-18 Años / Applicability of the Tanaka-Johnston method for the estimation of the mesiodistal diameter of canines and premolars in patients of 12-18 years old

El método Tanaka-Johnston es utilizado mundialmente para predecir el diámetro de caninos y premolares no erupcionados por la conveniencia de no necesitar tablas ni radiografías para su uso. Sin embargo, durante los últimos años investigadores de varios países han demostrado que al ser utilizado en una población diferente para la que fue diseñado, puede sobrestimar o subestimar los valores. En Cuba, donde el patrón facial de la población difiere del ideal para este método, ha sido muy empleado, pero prácticamente no existen estudios donde se valide la confiabilidad o exactitud de las predicciones de este. Por tanto, el objetivo de esta investigación es determinar la aplicabilidad del método Tanaka-Johnston para la estimación del diámetro mesiodistal de caninos y premolares en pacientes de 12-18 años. Se desarrolló un estudio descriptivo y transversal desde junio de 2019 hasta enero de 2020 con una población de 140 pacientes de ambos sexos de entre 12 y 18 años de Cuba. Se efectuaron las mediciones de los anchos mesiodistales de los incisivos inferiores, todos los caninos y premolares. Se realizaron distribuciones de frecuencia a las variables estudiadas y los resultados se presentaron en tablas estadísticas. Para comprobar la existencia de diferencias significativas se utilizó la prueba estadística t-Student. Los resultados principales obtenidos fueron que el método Tanaka-Johnston tiende a sobrestimar los valores para el sexo femenino y subestimarlos para el masculino, ambos entre los 0,2 y 0,3 mm, pero esta diferencia no resulta significativa. Se concluye que el método Tanaka-Johnston puede ser aplicado en la población estudiada para la predicción del ancho mesiodistal de caninos y premolares no erupcionados.

The Tanaka-Johnston method is used worldwide to predict the diameter of canines and premolars not erupted for the convenience of not needing boards or x-rays for use. However, in recent years researchers from several countries have shown that when used in a different population for which it was designed, it can overestimate or underestimate the values. In Cuba, where the facial pattern of the population differs from the ideal for this method, it has been highly used, but there are very few studies where the reliability or accuracy of the predictions of the same is validated. Therefore, the objective of this research is to determine the applicability of the Tanaka-Johnston method for estimating the mesiodistal diameter of canines and premolars in patients aged 12-18 years. A descriptive and cross-cutting study was conducted from June 2019 to January 2020 with a population of 140 patients of both sexes between 12 and 18 years of age from Cuba. Measurements were made of the mesiodistal widths of the lower incisors, all canines, and premolars. Frequency distributions were made to the variables studied and the results were presented in statistical tables. The t-Student statistical test was used to verify significant differences. The main results obtained were that the Tanaka-Johnston method tends to overestimate the values for the female sex and underestimate them for the male, both between 0,2 and 0,3 mm, but this difference is not significant. It is concluded that the Tanaka-Johnston method can be applied in the population studied for the prediction of the mesiodistal width of unerupted canines and premolars.

Intrauterine maxillary development and maxillary dental arch biometry: a fetal cadaver study.

INTRODUCTION: This study's goal was to determine normal maxillary development on fetal cadavers. MATERIALS AND METHODS: This study was carried out on 45 fetuses aged between the 17th - 40th weeks of gestation (24 male, 21 female). The distance between the widest left and right points of the maxillary dental arch (MDA) on the transverse plane, the distance of the papilla incisiva (PI) to the widest left and right points of the maxillary dental arch (MDAW), and the PI and posterior nasal spine (PNS) were measured. The average arch forms of the MDA were created according to trimester groups using the MATLAB program. The one-way ANOVA test was used to make a comparison between trimester groups, and ANOVA followed by post hoc analysis using the Bonferroni test was applied for comparisons. Pearson's correlation analysis was used for correlation analysis. RESULTS: The data in the present study did not differ between genders. In the comparison between trimester groups, we did not find any difference between the 3rd trimester and full-term groups only in the PI-MDAW measurement. Other parameters increased with age. In the correlation analysis, the measurement values by age showed a strong positive correlation. The MDAW exhibited the best correlation with age (rweek = 0.919). When the average MDA forms created using the MATLAB program were evaluated, it was observed that the PI-MDAW of the average MDA in the 3rd trimester and full-term intersected. CONCLUSIONS: This study provides a basis for a better understanding of fetal maxillary growth processes and can be useful to standardize the detection of malformations or intrauterine growth restrictions.

Valoración de las dimensiones del paladar y su relación con alteraciones verticales / Avaliação das dimensões do palato e sua relação com alterações verticais / Assessment of palate dimensions and its relation with vertical alterations

Objetivos: La presente investigación tuvo como objetivo establecer la correlación entre la presencia de maloclusiones a nivel vertical con el índice del paladar y con la altura palatina. Materiales y Métodos: Estudio de tipo transversal. La población de estudio fue conformada por 134 modelos de yeso con dentición mixta, 81 mujeres y 53 hombres, seleccionados por conveniencia y obtenidos desde el 2014 hasta el 2018 del área de clínica de odontopediatría y ortodoncia en la Escuela Nacional de Estudios Superiores Unidad León. La muestra de estudio fue dividida en 3 categorías según la oclusión; mordida abierta (37), mordida profunda (32) y normoclusión (65). Se realizaron mediciones del ancho intermolar y altura del paladar con el uso de un calibrador digital, posteriormente se obtuvo el índice del paladar y se correlacionó con los parámetros expuestos por Korkhaus mediante la prueba estadística de Spearman. Resultados: La prueba estadística de Spearman refleja que no hay correlación entre la magnitud de los valores del índice del paladar propuestos por Korkhaus con la presencia de maloclusiones a nivel vertical. De igual manera las pruebas estadísticas indican que no existe correlación notable entre la altura del paladar y la oclusión en relación vertical. Conclusiones: El resultado obtenido al usar el índice del paladar no fue capaz de corresponder a los parámetros propuestos por Korkhaus como normales, posiblemente al ser usado durante la etapa de la dentición mixta pues durante este periodo suceden cambios constantes relacionados al crecimiento.

Objetivos: Os objetivos a presente investigação buscou valor uma correlação entre a presença de más oclusões em nível vertical com o índice do palato e com a altura palatina. Materiais e Métodos: Estudo do tipo transversal. A população do estudo foi composta por 134 modelos de gesso com dentição mista, 81 mulheres e 53 homens, selecionados por conveniência e obtidos de 2014 a 2018 na área de Odontopediatria e Ortodontia na Escola Nacional de Ensino Superior Unidade de León. A amostra do estudo foi dividida em 3 categorias de acordo com a oclusão; mordida aberta (37), mordida profunda (32) e normoclusão (65). A medida da largura intermolar e da altura do palato foi feita com o uso de um paquímetro digital, o índice de palato foi posteriormente obtido e relacionado aos parâmetros expostos por Korkhaus por meio do teste estatístico de Spearman. Resultados: O teste estatístico de Spearman mostra que não há correlação entre a magnitude dos valores do índice de palato proposta por Korkhaus e a presença de más oclusões verticais. Da mesma forma, os testes estatísticos indicam que não há correlação notável entre a altura do palato e a oclusão na relação vertical. Conclusões: O resultado obtido com o uso do índice de palato não foi capaz de corresponder aos parâmetros propostos por Korkhaus como normais, possivelmente quando usado durante o estágio de dentição mista, porque durante este período há mudanças constantes relacionadas ao crescimento

Purpose: The aim of the present study is to assess the relation between vertical malocclusions with palatal index and palatal height. Materials and Methods: Transversal study. The sample consisted in 134 stone models within mixed dentition, 81 females and 53 males, they were convenience selected and obtained from the pediatric and orthodontic dentistry medical center at the National School for Superior Studies Unit León since 2014 to 2018. The stone models were divided into three categories according to their kind of occlusion: open bite (37), deep bite (32) and normal bite (65). Palatal width and height were measure by using a digital caliper. Subsequently the palatal index was obtained and it was related with the parameters exposed by Korkhaus using the Spearman statistical test. Results: The Spearman statistical test indicated there is no a clearly relationship between palatal index values exposed by Korkhaus with the presence of vertical malocclusions and in the same way there is no a relationship between palatal height and vertical malocclusions.Conclusions: The result obtained by using the palatal index was no able to indicate an agreement with Korkhaus parameters. Probably this disagreement was due to the constant changes that occur during the period of the mixed dentition.

Influence of the palatine tonsil grade on the morphology of the maxillary and mandibular dental arches / Influencia del grado de las tonsilas palatinas en la morfología de los arcos dentales maxilar y mandibular

SUMMARY: Enlarged palatine tonsils and adenoids are thought to cause obstruction of the upper airway, triggering changes in breathing patterns, which in turn lead to dentofacial alterations, including malocclusions. The object of the present study was to correlate the size (grade) of the palatine tonsil with measurements of the maxillary and mandibular dental arches in children. This was an observational cross-sectional study carried out in 35 children aged between 6 and 11 years. The inter- and intra-arch parameters were measured (horizontal, vertical and sagittal analyses) by making plastercasts and then taking measurements with callipers. The tonsil size was classified in 5 grades from 0-4, using the Brodsky tonsil grading scale. The researcher was calibrated prior to carrying out the measurements. Pearson's chi-squared test was used and Pearson's correlation coefficient was calculated. The SPSS v.22.0 software was used, with a significance threshold of 5 %. Six patients were classified as grade 1, sixteen grade 2, eleven grade 3, two grade 4 and none of the patients presented grade 0.A low positive association was found between tonsil grade and the total length of the mandibular arch, a very low positive association between tonsil grade and maxillary inter-first premolar distance, total length of the maxillary arch and depth of the palatine recess.A very low negative association was found for tonsil grade and overjet, overbite, mandibular inter-permanent first molar distance, mandibular inter-first premolar distance, and mandibular and maxillary intercanine widths. No statistically significant correlation was observed for any of the measurements. No association was found between the tonsil grade and Angle's Classification, canine relationship, overjet and overbite. According to the results of this study there is no significant correlation between the dental arches and the tonsil grade.

RESUMEN: Se ha considerado que el grado del tamaño de las tonsilas palatinas y los adenoides pueden ser factores que generan obstrucción de la vía aérea superior, desencadenando cambios en el patrón de respiración, lo que provoca alteraciones dentofaciales, entre ellas, maloclusiones. El objetivo del presente estudio fue correlacionar el grado tonsilar palatino con medidas de los arcos dentales maxilar y mandibular en niños. Se realizó un estudio observacional de corte transversal. Fueron incluidos 35 niños entre 6 y 11 años de edad. Fueron medidos parámetros interarco e intra-arco (análisis transversal, vertical, sagital). Para eso fueron tomados modelos de yeso y luego las medidas fueron realizadas con un caliper. El grado tonsilar fue clasificado en 5 grados (0-5), de acuerdo a la escala de graduación de Brodsky. Para la realización de las mediciones el evaluador fue previamente calibrado. Se realizó la prueba Chi-cuadrado de Pearson, y coefi- ciente de correlación de Pearson. Se utilizó el software SPSS 22.0, considerándose umbral de significación de 5 %. Seis pacientes fueron clasificados en grado 1, dieciséis grado 2, once grado 3, dos grado 4 y ningún paciente presentó grado 0. Se encontró una asociación positiva baja entre grado tonsilar y la longitud total del arco mandibular, positiva muy baja entre grado tonsilar y distancia inter-primer premolar maxilar, longitud total del arco maxilar y profundidad de la bóveda palatina. Una asociación negativa muy baja fue encontrada para el grado tonsilar y overjet, overbite, distancia inter-primer molar permanente mandibular, distancia inter- primer premolar mandibular, ancho intercanino mandibular y maxilar. Se observó ausencia de correlación estadísticamente significativa para todas las medidas. No se encontró asociación entre el grado tonsilar y clase molar de Angle, relación canina, overjet y overbite. Según los resultados de este estudio no se aprecia una correlación significativa entre los arcos dentales y el grado tonsilar.

Scandcleft randomized trials of primary surgery for unilateral cleft lip and palate. Dental arch relationships in 8 year-olds.

BACKGROUND AND TRIAL DESIGN: The Scandcleft intercentre study evaluates the outcomes of four surgical protocols for treatment of children with unilateral cleft lip and palate (UCLP). Originally 10 cleft centres in Denmark, Finland, Norway, Sweden, and the UK participated in a set of three randomized trials of primary surgery. Three groups of centres (Trials 1, 2, and 3) tested their traditional local surgical protocols (Arms B, C, and D) against a common protocol (Arm A). OBJECTIVES: To evaluate dental arch relationships at age 8 years after four different protocols of primary surgery for UCLP. These results are secondary outcomes of the overall trial. METHODS: Study models of 411 children (270 boys, 141 girls) with non-syndromic UCLP at a mean age of 8.1 (range 7.0-10.0) years were available. Dental arch relationships were analysed using the GOSLON Yardstick by a blinded panel of 11 orthodontists. To assess reliability, Kappa statistics were calculated. The trials were tested statistically with t-tests. RESULTS: Comparisons within each trial showed no statistically significant differences in the mean 8-year index scores or their distributions between the common protocol and the local team protocol. The mean index scores were Trial 1: Arm A 3.03, Arm B 2.82, Trial 2: Arm A 2.78, Arm C 2.64, and Trial 3: Arm A 3.06, Arm D 3.08. Comparisons between the trials detected a significantly (P < 0.005) better mean index score Trial 2 Arm C than in Trial 3 Arm D. The intra- and inter-rater reliabilities were acceptable. CONCLUSION: The results of these three trials do not provide evidence that one surgical protocol is better than the others. TRIAL REGISTRATION: ISRCTN29932826.

Evaluación del Índice de Korkhaus en adultos chilenos con oclusión normal / Evaluation of Korkhaus Index in Chilean adult individuals with normal occlusion

El examen de modelos es una de las múltiples herramientas diagnósticas que posee la ortodoncia y ortopedia dentomáxilofacial. Los valores con que se construyó su norma estadística están basados en poblaciones específicas y no reflejan las diferencias morfológicas existentes en el complejo cráneofacial entre las distintas etnias. El propósito de esta investigación fue identificar las longitudes transversales y sagitales de los maxilares de la población adulta mestiza chilena con oclusión normal y compararlas con el índice de Korkhaus basado en una población adulta caucásica alemana. Se reclutaron 20 estudiantes de pregrado de la Facultad de Odontología de la Universidad de Valparaíso con oclusión normal. Se registraron ambas arcadas dentarias con yeso y se aplicó el índice de Korkhaus: se midió la longitud interpremolar, la longitud intermolar, la longitud anterior superior y la longitud anterior inferior. La comparación entre los valores de la muestra y los valores referenciales del índice de Korkhaus fue hecha con la prueba de rangos de Wilcoxon mediante el software estadístico STATA 15.0 y se consideraron significativos valores de p<0,05. Se encontró una diferencia estadísticamente significativa en el valor de la longitud anterior superior (p-0,013); para la longitud interpremolar (p-0,9552) la longitud intermolar (p-0,8223) y la longitud anterior inferior (p-0,0452) no se hallaron diferencias. La mayor magnitud de la longitud anterior superior de la arcada dentaria respecto a la población adulta caucásica alemana se debe al rasgo de protrusión dentaria presente en la población mestiza chilena, lo cual no altera las características de una oclusión normal.

The model exam is one of many diagnostic tools in orthodontics and dentomaxillofacial orthopedics. The values on which the statistical norm were constructed, are based on specific populations and they do not reflect the morphological differences in the craniofacial complex between the different ethnic groups. The purpose of this study was to identify the transverse and sagittal maxillary and mandibular lengths of the Chilean mestizo adult population with normal occlusion, and compare them with the Korkhaus index based on a German Caucasian adult population. For this study 20 undergraduate students with normal occlusion were recruited from the Faculty of Dentistry of the University of Valparaíso. Both upper and lower dental casts were obtained from each student, and Korkhaus index was applied: the interpremolar length, intermolar length, upper anterior length and lower anterior length were measured. Comparison between the values of the sample and the reference values of the Korkhaus index was made with the Wilcoxon range test using the STATA 15.0 statistical software and significant values of p <0.05 were considered. A statistically significant difference was found in the value of the upper anterior length (p-0.013); for the interpremolar length (p-0.9552) the intermolar length (p-0.8223) and the lower anterior length (p-0.0452) no differences were found. The greater magnitude of the dental arch upper anterior length compared to the German Caucasian adult population is due to dental protrusion present in the Chilean mestizo population, which does not affect the normal occlusion characteristics.

Quantification of maxillary dental midline deviation in 2D photographs: Methodology trial.

INTRODUCTION: Discrepancy of the upper dental midline to the facial midline plays an important role in smile aesthetic assessment. This study presents different reference points to quantify the deviation of upper dental midline to the facial midline in 2D frontal photographs. The aim was to find the most accurate, precise, and practical reference points to measure dental midline discrepancy in 2D photographs. METHODOLOGY: A modified headset with a protractor was developed in order to achieve photographs in nine standardised head positions. Six reference points were used to detect the facial midline in the 2D photographs (eyebrows "EB", inner-canthus of the eyes "ICE", alae of the nose "AN", columella "C", nasolabial folds "NLF", and the philtrum "PH"). The deviation of the maxillary dental midline from the facial midline was measured and compared with clinical measurements. STATISTICAL ANALYSIS: Standard deviations (SD), Root Mean Square Error (RMSE), Method of Moments' Estimator (MME), 2-way repeated measures ANOVA, and multi-level linear model were used to estimate the true errors. RESULTS: The different reference points responded significantly differently to changes in head position and all showed measurement errors, which increased with greater head rotation. Alae of the nose showed the least measurement error and the greatest precision in all head positions. CONCLUSION: The alae of the nose are the recommended reference points to identify the facial midline in order to quantify dental midline deviation from frontal photographs.

Craniofacial and occlusal development in 2.5-year-old children with obstructive sleep apnoea syndrome.

OBJECTIVES: Paediatric obstructive sleep apnoea syndrome (OSAS) is associated with a range of changes in craniofacial and occlusal development. There is, however, little knowledge of how early in life these changes can be found. The aim of the present study was to determine whether changes in dental arch morphology, occlusion, facial profile, tonsil size, breathing habit or body mass index (BMI) can already be found among 2.5-year-old children with OSAS. MATERIALS AND METHODS: Fifty-two children were recruited to the study. Of these, OSAS was diagnosed in 9 children and 18 children did not snore in polysomnography. These two groups were subsequently compared when evaluating polysomnographic, otorhinolaryngological and dental variables. RESULTS: Children with OSAS had narrower inter canine width than non-snoring children (P = 0.032). Furthermore, children with OSAS had larger adenoid size with respect to the nasopharyngeal volume (P = 0.020) and more tendency to mouth breathing (P = 0.002). No statistically significant differences were found when comparing palatine tonsil size, occlusal characteristics, soft tissue profile measurements or BMI. LIMITATIONS: The limitation of the study is the small sample size. CONCLUSION: Children with OSAS had narrower upper inter canine width than non-snoring children at the age of 2.5 years. Larger adenoid size and mouth breathing tendency were also more common among children with OSAS. Further studies with larger sample sizes are needed to determine if other changes in craniofacial and occlusal development can be found in this age group.

Dental arch width in overweight and normal-weight subjects / Comparación de los anchos de los arcos dentarios en sujetos con y sin sobrepeso

Objective: To compare the width of the dental arches between overweight and non-overweight subjects . Materials and Methods: A cross-sectional comparative study was carried out with 54 subjects from 8 to 13 years of age, 27 normal-weight and 27 overweight. The presence of overweight was assessed according to the Quetelet index. To determine the width of the dental arches, measurements of the upper and lower intercanine and intermolar width were obtained with a digital calibrated Vernier caliper. The comparison between the dental arch width of normal-weight and overweight subjects was performed using the Mann-Whitney U test. Results: Statistically significant differences were found in the intercanine and intermolar widths between overweight and non-overweight subjects (p<0.05). Conclusion: The dental arches were wider in overweight subjects compared to those of normal-weight.

Comparar los anchos de los arcos dentarios en sujetos con sobrepeso y sin sobrepeso. Materiales y Método: Se realizó un estudio transversal comparativo. Se evaluaron 54 sujetos de 8 a 13 años de edad, 27 sin sobrepeso y 27 con sobrepeso. La presencia de sobrepeso se evaluó según el índice de Quetelet. Para determinar los anchos de los arcos dentarios, se analizaron, en los modelos de estudio de cada grupo, las medidas de los anchos intercanino e intermolar superior e inferior con un vernier calibrado digital. La comparación de los anchos de los arcos dentarios de los sujetos con sobrepeso y sin sobrepeso se realizó mediante la prueba U de Mann-Whitney. Resultados: Se encontraron diferencias estadísticamente significativas en los anchos intercanino e intermolar entre los sujetos con sobrepeso y sin sobrepeso (p<0.05). Conclusión: Los anchos de los arcos dentarios fueron mayores en sujetos con sobrepeso que en sujetos sin sobrepeso.

Evaluation of conformity of preformed orthodontic archwires and dental arch form

ABSTRACT Introduction: The alterations in the arch form during treatment are dictated by the dimensions of the archwires. Objective: This study aimed to determine the mean arch dimensions of a sample of Pakistani subjects and to evaluate the conformity of preformed archwires with mandibular arch form. Methods: The dental records of 1,500 adult subjects were evaluated. The mandibular casts of 42 subjects (males = females = 21) with balanced facial profile, Class I occlusion, ideal overjet and overbite were included. Brackets were bonded on all teeth. Arch dimensions were evaluated at canines, first premolars, second premolars, first and second molars, with digital vernier calipers. The arch widths at the level of aforementioned teeth were evaluated on the digitized archwires, using the mean arch depths of the subjects. Results: In males, the archwires were found to be wider at canines and premolars, and significantly narrower at first (p< 0.001, 95% CI = 2.03 - 5.74) and second molars (p< 0.001, 95% CI = 2.29 - 7.73) as compared to the arch dimensions of the mandibular casts. In females, the archwires were significantly narrower at canines (p< 0.001, 95% CI = 1.4 - 3.97), and first (p= 0.02, 95% CI = 0.402 - 4.41) and second molars (p< 0.001, 95% CI = 1.76 - 6.13). Conclusion: No single commercially available archwires evaluated in the present study conformed to the arch dimensions of our subjects. Utilization of the currently available archwires may result in unwarranted modification of arch form, which may lead to unstable post-treatment teeth position.

RESUMO Introdução: as alterações no formato da arcada dentária durante o tratamento são ditadas pelas dimensões do arco ortodôntico. Objetivo: o presente estudo teve como objetivos determinar a dimensão média das arcadas dentárias de pacientes paquistaneses e avaliar a conformidade entre diferentes arcos ortodônticos pré-fabricados e o formato da arcada inferior. Métodos: os registros odontológicos de 1.500 pacientes adultos foram analisados e, desses, foram selecionados modelos de gesso de 42 pacientes (21 de cada sexo, masculino e feminino) com perfil facial equilibrado, Classe I de Angle, sobressaliência e sobremordida adequadas. Foram, então, colados braquetes ortodônticos em todos os dentes. Utilizando um paquímetro digital, as dimensões das arcadas foram avaliadas nos seguintes dentes: caninos, primeiros pré-molares, segundos pré-molares, primeiros e segundos molares. Utilizando-se a profundidade média das arcadas dos pacientes, as larguras das arcadas, no nível dos dentes acima mencionados, foram comparadas aos arcos ortodônticos digitalizados. Resultados: nos homens, a largura do arco ortodôntico, em comparação às dimensões dos modelos de gesso inferiores, foi maior nos caninos e pré-molares e significativamente menor nos primeiros molares (p< 0,001, IC 95% = 2,03 - 5,74) e segundos molares (p< 0,001, IC 95% = 2,29 - 7,73). Nas mulheres, os arcos ortodônticos foram significativamente mais estreitos nos caninos (p< 0,001, IC 95% = 1,4 - 3,97), primeiros molares (p= 0,02, IC 95% = 0,402 - 4,41) e segundos molares (p< 0,001, IC 95% = 1,76 - 6,13). Conclusão: nenhum dos arcos ortodônticos comercialmente disponíveis avaliados no presente estudo esteve em conformidade com as dimensões das arcadas dos pacientes da amostra. O uso dos arcos ortodônticos atualmente disponíveis pode resultar em modificações indesejáveis no formato da arcada, e pode levar à instabilidade na posição dos dentes após o tratamento.

Dentoalveolar Arch Dimensions in UCLP Boys After Neonatal Cheiloplasty or After Lip Surgery at the Age of 3 or 6 Months.

OBJECTIVE: To compare the influence of 3 different time protocols of cleft lip and palate operations on the growth of the dentoalveolar arch in patients with unilateral cleft lip and palate (UCLP). MATERIALS AND METHODS: We evaluated 64 plaster casts of 8-year-old boys with UCLP operated on according to 3 different time protocols: lip repair at the age of 6 months and palate repair at 4 years, lip repair at 3 months and palate repair at 9 months, and neonatal lip repair and palate repair at 9 months. The control group contained 13 plaster casts of 8-year-old boys. The dentoalveolar arch width was measured between deciduous canines and between the second deciduous molars; the length was measured between incisive papilla and the line connecting both tuber maxillae. RESULTS: All measured distances were statistically significantly smaller in boys with UCLP than in the control group. Intercanine width was not statistically significantly different between the patients operated on according to the different time protocols. In comparison to the lip repair at 6 months and palate repair at 4 years, the intermolar width was statistically significantly smaller in the group with neonatal lip repair; the alveolar arch length was statistically significantly shorter in both groups with lip repair performed neonatally or at 3 months. CONCLUSIONS: The length of the dentoalveolar arch is shorter after surgical repair of cleft lip neonatally or at the age of 3 months. Cleft palate repair at 9 months can contribute to a reduction in the width of the dentoalveolar arch.

[Relationships between the size of the adenoids and the dental arch measurements]. / Corrélations entre les dimensions des végétations adénoïdes et les mensurations des arcades dentaires.

INTRODUCTION: Enlarged adenoids are often associated with oral breathing. The latter can impact the dental arches. The purpose of this study was to determine the relationships between dental arch measurements and the size of adenoids. MATERIALS AND METHODS: A cross-sectional study was carried out on 86 children. The dimensions of the adenoids were determined from nine radiographic evaluation methods and the dental arch measurements made on the casts. The association between the grade of adenoids and the dental arch measurements was sought by Spearman correlation. That between the quantitative variables assessing adenoids and dental arch measurements was sought by Pearson correlation. The strength of these associations was analyzed using Cohen's values in 1988. The significance was set at p = 0.05. RESULTS: Palatal depth was significantly and positively correlated with adenoid grade according to the method of Holmberg and Linder-Aronson (rho = 0.55, p = 0.005) and with the adenoid measurements according to the methods of Kemaloglu, Fujioka, Johannesson, De Menezes and Maran with r respectively equal to 0.65, 0.59, 0.63, 0.47, 0.74; and p respectively equal to 0.001, 0.002, 0.001, 0.019, and < 0.001. It was also significantly but negatively correlated with the adenoids measurements according to Hibbert's method (r = -0.52, p = 0.008). Overbite was significantly and negatively correlated with adenoid dimension using the De Menezes method (r = -0.541, p = 0.006). DISCUSSION: The strength of the associations shows that using respectively Maran and De Menezes methods can allow to better highlight the association between the dimensions of the adenoids and the palatal depth and the overbite.

Correlation between tooth size-arch length discrepancy and interradicular distances measured on CBCT and panoramic radiograph: an evaluation for miniscrew insertion

Abstract Introduction: The selection of appropriate sites for miniscrew insertion is critical for clinical success. Objectives: The aim of the present study was to evaluate how interradicular spaces measured on panoramic radiograph compare with Cone-Beam Computed Tomography (CBCT), and how crowding can influence the presence of available space for miniscrew insertion, in order to define a new "safe zones" map. Methods: A total of 80 pre-treatment panoramic radiographs and 80 CBCT scans with corresponding digital models were selected from the archives of the department of Dentistry, Aarhus University. Crowding was measured on digital models, while interradicular spaces mesial to the second molars were measured on panoramic radiographs and CBCTs. For panoramic radiographs, a magnification factor was calculated using tooth widths measured on digital models. Statistical analyses were performed to investigate the correlation between the amount of crowding and the available interradicular space. Visual maps showing the amount of interradicular spaces measured were drawn. Results: The most convenient interradicular spaces are those between the second molar and the first premolar in the mandible, and between the central incisors in the maxilla. However, some spaces were revealed to be influenced by crowding. Conclusions: Calibration of panoramic radiographs is of utmost importance. Generally, panoramic radiographs underestimate the available space. Preliminary assessment of miniscrew insertion feasibility and the related selection of required radiographs can be facilitated using the new "safe zone" maps presented in this article.

Resumo Introdução: a seleção de locais apropriados para a inserção de mini-implantes é crítica para o sucesso clínico. Objetivo: os objetivos do presente estudo foram avaliar as medições de espaços inter-radiculares feitas em radiografias panorâmicas e compará-las com as medições feitas com tomografia computadorizada de feixe cônico (TCFC), além de avaliar como o apinhamento pode influenciar na disponibilidade de espaços para inserção dos mini-implantes, no intuito de definir um novo mapa de "áreas seguras". Métodos: foram selecionadas, nos arquivos do departamento de Ortodontia da Aarhus University, 80 radiografias panorâmicas pré-tratamento e 80 imagens de TCFC com os modelos digitais correspondentes. O apinhamento foi medido nos modelos digitais, enquanto os espaços inter-radiculares mesiais aos segundos molares foram medidos nas radiografias panorâmicas e na TCFC. O fator de magnificação das radiografias panorâmicas foi calculado utilizando-se as larguras dentárias medidas nos modelos digitais. Análises estatísticas foram realizadas para investigar a correlação entre a quantidade de apinhamento e o espaço inter-radicular disponível. Foram desenhados mapas visuais mostrando a quantidade dos espaços inter-radiculares medidos. Resultados: os espaços inter-radiculares mais adequados são aqueles entre o segundo molar e o primeiro pré-molar inferior, e entre os incisivos centrais superiores. Porém, verificou-se que alguns espaços são influenciados pelo apinhamento. Conclusões: A calibração das radiografias panorâmicas é de suma importância, pois, geralmente, as radiografias panorâmicas subestimam o espaço disponível. A avaliação preliminar da viabilidade de inserção dos mini-implantes e a seleção das radiografias necessárias para isso podem ser facilitadas utilizando-se os novos mapas de "áreas seguras" aqui apresentados.

Mandibular anterior crowding: normal or pathological?

ABSTRACT The teeth become very close to each other when they are crowded, but their structures remain individualized and, in this situation, the role of the epithelial rests of Malassez is fundamental to release the EGF. The concept of tensegrity is fundamental to understand the responses of tissues submitted to forces in body movements, including teeth and their stability in this process. The factors of tooth position stability in the arch - or dental tensegrity - should be considered when one plans and perform an orthodontic treatment. The direct causes of the mandibular anterior crowding are decisive to decide about the correct retainer indication: Should they be applied and indicated throughout life? Should they really be permanently used for lifetime? These aspects of the mandibular anterior crowding and their implication at the orthodontic practice will be discussed here to induct reflections and insights for new researches, as well as advances in knowledge and technology on this subject.

RESUMO Os dentes ficam muito próximos quando estão apinhados, mas suas estruturas permanecem individualizadas e, nessa situação, o papel dos restos epiteliais de Malassez é fundamental para liberar o EGF. A tensigridade é um conceito chave para compreender as respostas dos tecidos submetidos às forças nos movimentos corporais, incluindo os dentes e sua estabilidade nesse processo. Os fatores da estabilidade de posição de um dente na arcada dentária — ou tensigridade dentária — devem ser considerados quando se planeja e finaliza um caso na prática clínica ortodôntica. As causas diretas do apinhamento dentário anteroinferior são determinantes para se refletir se a contenção deve ser mesmo indicada e aplicada por toda a vida e se, necessariamente, deve ser usada de forma permanente. Esses aspectos do apinhamento dentário anteroinferior e suas implicações na prática clínica serão aqui abordados para induzir reflexões e insights de novas pesquisas, bem como avanços no conhecimento e tecnologia sobre esse assunto.

O gênero e a idade influenciam as dimensões do palato duro? Revisão sistemática da literatura / Do gender and age influence hard palate dimensions? A systematic review

RESUMO Objetivo Analisar a influência do gênero e da idade nas dimensões do palato duro, bem como verificar os parâmetros de referência disponíveis na literatura. Estratégia de pesquisa Dois examinadores realizaram a pesquisa de forma independente nas bases de dados Cochrane Library, PubMed-Medline e Web of Knowledge utilizando os descritores de acordo com as regras de sintaxe de cada banco de dados. Critérios de seleção Estudos em humanos observacionais ou experimentais, que avaliaram as dimensões do palato duro ou do arco dentário maxilar com pelo menos uma mensuração no plano transversal, vertical ou sagital em oclusões normais ou más oclusões classe I e que realizaram comparações das dimensões entre os gêneros e/ou idades. Análise de dados Análise descritiva, seguindo subdivisões: delineamento, amostra, instrumentos de avaliação, medidas em milímetros e análise estatística. A qualidade dos estudos incluídos foi verificada através da escala "Newcastle - Ottawa Quality". Resultados Foram selecionados 18 estudos. Destes, 11 apresentaram resultados das dimensões do palato duro ou do arco dentário maxilar conforme o gênero, seis em idade e gênero e um somente em idade. Conclusão As medidas foram maiores no gênero masculino e houve um aumento progressivo nas dimensões do nascimento até o período de dentição permanente.

ABSTRACT Purpose Analyze the influence of gender and age on hard palate dimensions and verify the reference parameters available in the literature. Research strategies Two reviewers independently performed a search at the Cochrane Library, PubMed-Medline and Web of Knowledge databases using descriptors according to the syntax rules of each database. Selection criteria Observational or experimental human studies evaluating the dimensions of the hard palate or maxillary dental arch, with at least one transverse, vertical or sagittal plane measurement, in normal occlusions or class I malocclusions, and comparisons of the dimensions between genders and/or ages. Data analysis Descriptive analysis with the following subdivisions: design, sample, evaluation instruments, measurements in millimeters, and statistical analysis. Quality of the included studies was verified by the Newcastle - Ottawa Quality scale. Results Eighteen studies were selected and 11 presented results for hard palate or maxillary dental arch dimensions according to gender, six in age and gender and one in age only. Conclusion The dimensions were larger in males and progressive increase in the measurements was observed from birth to the permanent dentition period.

Digital models: How can dental arch form be verified chairside?

ABSTRACT Introduction: Plaster dental casts are routinely used during clinical practice to access maxillary dental arch form and assist on fabrication of individualized orthodontic archwires. Recently introduced, digital model technology may offer a limitation for the obtainment of a dental physical record. In this context, a tool for dental arch form assessment for chairside use is necessary when employing digital models. In this regard, paper print of the dental arch seems thus to be useful. Methods: In the present study, 37 lower arch models were used. Intercanine and intermolar widths and dental arch length measurements were performed and compared using plaster dental casts, digital models and paper print image of the models. Ortho Insight 3D scanner was employed for model digitalization. Results: No statistically significant differences were noted regarding the measurements performed on the plaster or digital models (p> 0.05). Paper print images, however, showed subestimated values for intercanine and intermolar widths and overestimated values for dental arch length. Despite being statistically significant (p< 0.001), the differences were considered clinically negligible. Conclusion: The present study suggests that paper print images obtained from digital models are clinically accurate and can be used as a tool for dental arch form assessment for fabrication of individualized orthodontic archwires.

RESUMO Introdução: os modelos de gesso são usados rotineiramente, durante a prática clínica, para avaliação da forma da arcada inferior e para auxiliar na confecção de arcos ortodônticos individualizados. A tecnologia dos modelos digitais, introduzida recentemente, pode oferecer uma limitação na obtenção de um registro físico da arcada dentária. Assim, quando se utilizam modelos digitais, faz-se necessária uma ferramenta clínica para obtenção da forma da arcada. Com essa finalidade, poderia-se imprimir, em papel, uma imagem da arcada dentária obtida a partir do modelo de gesso. Métodos: nesse estudo, 37 modelos da arcada inferior foram utilizados, nos quais foram realizadas medições das distâncias intercaninos, intermolares e comprimento da arcada; sendo, então, comparadas entre modelos de gesso, modelos digitalizados com um scanner Ortho Insight 3D e imagens impressas em folha de papel A4. Resultados: não foram encontradas diferenças estatisticamente significativas nas medidas realizadas nos modelos de gesso e modelos digitais (p > 0,05). As imagens impressas, contudo, mostraram valores subestimados para as distâncias intercaninos e intermolares, e superestimados para o comprimento da arcada. Apesar de serem estatisticamente significativas (p< 0,001), as diferenças foram consideradas clinicamente insignificantes. Conclusão: o presente estudo sugere que as imagens obtidas por meio dos modelos digitais e impressas em papel são clinicamente acuradas e podem ser utilizadas como uma ferramenta auxiliar na confecção dos arcos ortodônticos individualizados.

Distances between mandibular posterior teeth and the WALA ridge in Peruvians with normal occlusion

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.