Home / Archives / Vol. 12 No. 1 (2024) / Articles SPATIAL DISTRIBUTION OF MOLAR INCISOR HYPOMINERALIZATION (MIH) OPACITIES IN FIRST PERMANENT MOLARS

Aim: To evaluate the spatial distribution of MIH opacities in first permanent molars (FPM). Materials and methods: an analysis of intraoral photographs of FPM with demarcated MIH opacities was conducted. The presence of opacity was computed in a digital matrix, discriminating the anatomical regions of the FPM surfaces. The frequencies of distribution of the opacities were descriptively analyzed through 227 FPM digital images of 89 children built in GIMP and Python and by Spearman correlation (= 0,05). Results: the occlusal surface was the most affected one (94% to 100%). In the upper FPM, the palatine surface was the second most affected one (84%-91%). In the lower FPM, the vestibular surface was the second most affected one (85%-80%). A similar pattern of opacity distribution was observed in the contralateral teeth. On smooth surfaces, opacities were more frequent in the regions closer to the occlusal surface than to the cervical one. Conclusion: MIH opacities were mostly present on occlusal, vestibular, and lingual/palatine surfaces, respectively. There is a possibility that the occurrences are in accordance with the chronology of dental formation.

Impacto de la agenesia de incisivos laterales maxilares en la oclusión: revisión bibliográfica

Objetivo: describir el impacto de la agenesia no sindrómica de incisivos laterales maxilares permanentes en la oclusión. Material y método: se realizó una búsqueda de la evidencia disponible de manera electrónica en las bases de datos PubMed, Cochrane Library, EBSCOhost, SciELO y Epistemonikos, con filtro de búsqueda de artículos publicados entre los años 2005 y 2022, y con disponibilidad de texto completo. Resultados: se seleccionaron 9 estudios publicados entre los años 2010 y 2021; 3 estudios genéticos, 4 estudios transversales y 2 revisiones sistemáticas. Conclusión: la agenesia no sindrómica de incisivos laterales maxilares permanentes se relaciona con alteraciones esqueléticas y dentales que inciden en la oclusión dental. Un diagnóstico temprano y un tratamiento oportuno, según las necesidades de cada paciente, son importantes por las repercusiones funcionales y estéticas que genera esta alteración.

Objective: to describe the impact of non-syndromic agenesis of permanent maxillary lateral incisors on occlusion. Material and method: a search of the electronically available evidence was carried out in the PubMed, Cochrane Library, EBSCOhost, SciELO and Epistemonikos databases, with a search filter for articles published between 2005 and 2022, and with full text availability. Results: 9 studies were selected, published between 2010 and 2021: 3 genetic studies, 4 cross-sectional studies and 2 systematic reviews. Conclusion: Non-syndromic agenesis of permanent maxillary lateral incisors is related to skeletal and dental abnormalities that affect dental occlusion. Because of the functional and aesthetic repercussions of this alteration, early diagnosis and timely treatment, according to the needs of each patient, are essential.

Occlusion development after premature loss of deciduous anterior teeth: preliminary results of a 24-month prospective cohort study

ABSTRACT Objective: This study aimed to evaluate occlusion development after premature loss or extraction of deciduous anterior teeth, by means of a prospective cohort study. Methods: Fifteen infants and children aged 1 to 5 years old were longitudinally assessed (with loss or extraction of deciduous anterior teeth [n = 9], and without tooth losses [n = 6]). Photographs and dental casts at the baseline and after 24 months of follow-up were performed. Dental casts were scanned, and linear measurements were made on the digitalized models (missing tooth space, arch perimeter, arch length, arch width, intercanine length and intercanine width). The t-test was used for groups comparisons (α = 0.05). Results: Individuals' mean age at baseline was 2.93 (± 1.18) years. No statistically significant differences were observed in the missing tooth space in the group with tooth loss during the 24 months of follow-up (p > 0.05). Arch perimeter, arch length, arch width, intercanine length and intercanine width did not show differences between the groups (p > 0.05). Qualitative photographic evaluation revealed other changes in the dental arches and occlusion, such as exfoliation and eruption of deciduous teeth, eruption of permanent teeth, self-correction or establishment of malocclusion, among others. Conclusion: The results suggest that the premature loss of deciduous anterior teeth does not affect the perimeter, length and width of the dental arches; however, other alterations that lead to malocclusion could be established.

RESUMO Objetivo: Este estudo teve como objetivo avaliar o desenvolvimento da oclusão após perda prematura ou extração de dentes decíduos anteriores, por meio de um estudo de coorte prospectivo. Métodos: Quinze bebês e crianças de 1 a 5 anos foram avaliados longitudinalmente (com perda ou extração de dentes anteriores decíduos [n = 9] e sem perdas dentárias [n = 6]). Foram realizadas fotografias e modelos dentais no início e após 24 meses de acompanhamento. Os modelos dentários foram escaneados e medidas lineares foram feitas nos modelos digitalizados (espaço dentário perdido, perímetro da arcada, comprimento da arcada, largura da arcada, comprimento intercaninos e largura intercaninos). O teste t foi utilizado para comparações entre grupos (α = 0,05). Resultados: A média de idade dos indivíduos no início do estudo foi de 2,93 (± 1,18) anos. Não foram observadas diferenças estatisticamente significativas no espaço dentário perdido no grupo com perda dentária durante os 24 meses de acompanhamento (p > 0,05). O perímetro da arcada, comprimento da arcada, largura da arcada, comprimento intercaninos e largura intercaninos não apresentaram diferenças entre os grupos (p> 0,05). A avaliação fotográfica qualitativa revelou alterações nas arcadas dentárias e na oclusão, como: esfoliação e erupção de dentes decíduos, erupção de dentes permanentes, autocorreção ou estabelecimento de má oclusão, entre outras. Conclusão: Os resultados sugerem que a perda prematura de dentes anteriores decíduos não afeta o perímetro, comprimento e largura das arcadas dentárias; entretanto, outras alterações que levam à má oclusão poderiam ser estabelecidas.

CBCT analysis of the relative position between maxillary central incisors and alveolar bone in Southern Chinese adults / 口腔疾病防治

Objective@#Exploring the position and bone wall thickness characteristics of the maxillary central incisors in Southern Chinese adults to provide a clinical reference for the design of immediate maxillary central incisor implantation surgery.@*Methods@#The hospital ethics committee approved the study, and the patients provided informed consent. CBCT images of 990 adult patients (aged 20-79 years) from the Stomatology Hospital (January 2018 to December 2021) were categorized based on the dental arch form and age-sex groups. Sagittal CBCT images of the maxillary central incisors were used to measure the labial and palatal bone thickness wall at 4 mm the CEJ to apical, the middle of the root, and the angle between the tooth long axis and the long axis of the alveolar process, to compare the thickness of the labial and palatal bone walls in samples of male and female patients, and to explore the relationship between the angle between the tooth long axis and the alveolar process long axis in samples of male and female patients in different age groups (20-39 years; 40-59 years; 60-79 years).@*Results@#Significant differences were found in the labiopalatine side of the alveolar bone of the maxillary incisor root position. A total of 95.8% (948/990) of the maxillary incisors were positioned more buccally, 4.1% (41/990) were positioned more midway, and 0.1% (1/990) were positioned more palatally. The thicknesses of the bone wall at the CEJ of 4 mm below the palatal side, the middle of the root, and at the apex were greater (1.82 ± 0.56 mm, 3.20 ± 1.10 mm, and 7.70 ± 2.00 mm, respectively) than those at the labial side (1.21 ± 0.32 mm, 0.89 ± 0.35 mm, and 1.86 ± 0.82 mm, respectively), with statistical significance (P<0.05). Male bone wall thickness was generally greater than female bone wall thickness (P<0.05). The angle between the long axis of male teeth and the alveolar bone was 14.77° ± 5.66°, while that of female teeth was 12.80° ± 5.70°, with a statistically significant difference (P<0.05). The angle between the long axis of teeth and the alveolar bone in the 40-59-year-old group and the 60-79-year-old group was greater than that in the 20-39-year-old group, and the difference was statistically significant (P<0.05).@*Conclusion@#A total of 95.8% of adults in South China have maxillary central incisors with root deviation toward the labial bone cortex. The thickness of the labial bone wall is much thinner than that of the labial bone wall, which is the middle of the thickness of the root. In Southern Chinese adults, the angle between the upper central incisor and the long axis of the alveolar bone in males is greater than that in females, and the degree of the angle increases with age. It is recommended to pay attention to the thickness of the bone wall around the root and the angle between the teeth before immediate implantation surgery to choose a reasonable implantation plan.

Intentional replantation for the treatment of a double-rooted maxillary lateral incisor with periodontal-endodontic lesions: a case report and literature review / 口腔疾病防治

Objective@#To investigate the clinical characteristics, diagnosis and treatment of severe combined periodontal-endodontic lesions in a double-rooted maxillary lateral incisor with a palatal radicular groove and to provide a reference for clinical diagnosis and treatment.@*Methods@#A patient with a double-rooted left maxillary lateral incisor with a palatal radicular groove and severe combined periodontal-endodontic lesions underwent complete root canal therapy and intentional replantation, and a retrospective analysis of the management of this type of patient was performed based on the literature.@*Results@#The 3-year follow-up examination revealed no discomfort, good healing of the upper left lateral incisor, no pathological loosening, and a palatal gingival sulcus was found at a depth of approximately 1 mm. Review of the literature showed that the prognosis of the affected tooth and the choice of treatment plan were correlated with the length and depth of extension of the lingual groove toward the root, the periodontal condition and the pulpal status of the affected tooth. For minor PRGs or for affected teeth with no loss of pulpal viability, flap surgery and odontoplasty can be used to avoid endodontic treatment or retreatment. For deep or long lingual grooves that result in significant loss of periodontal tissue, endodontic treatment, odontoplasty, or closure of the grooves and guided tissue regeneration are needed. In the case of PRGs with double root formation, the affected tooth can be preserved via root canal therapy, removal of the small root and filling with apical restorative material, and intentional replantation.@*Conclusion@#In cases of severe combined periodontal-endodontic lesions due to palatal radicular grooves occurring in double-rooted maxillary lateral incisors, clinical presentation and imaging can prevent missed diagnoses, and appropriate treatment should be based on the length and depth of lingual grooves extending toward the roots, periodontal conditions, and pulpal status of the affected teeth.

Clinical study of polyetheretherketone resin-bonded bridge for restoring anterior missing teeth in patients with periodontitis / 口腔疾病防治

Objective@#To study the clinical effect of a polyetheretherketone (PEEK) bonding bridge on the loss of 3 internal incisors in patients with periodontitis.@*Methods@#This study was reviewed and approved by the ethics committee, and informed consent was obtained from the patients. Thirty-eight patients with periodontitis and 3 missing central or lateral teeth were selected to undergo restoration with a PEEK bonding bridge and then returned to the hospital 3, 6, 12, and 24 months after the restoration was completed. The survival rate of the restorations was assessed by the modified USPHS/Ryge criteria. The plaque index, gingival index, periodontal probing depth and attachment loss of the abutments were recorded, and the changes in periodontal tissues after restoration were observed and compared.@*Results@#Over 24 months of clinical follow-up observation of 38 patients, only 1 patient underwent secondary bonding after partial debonding (evaluated as grade B), while bonding was successful in the other 37 cases (evaluated as grade A). The plaque index, gingival index and periodontal probing depth were significantly lower after restoration than before (P<0.05). There was no significant change in attachment loss between before and after restoration (P>0.05).@*Conclusion@#For periodontitis patients missing 3 internal incisors, short-term PEEK bonding bridge repair has good clinical efficacy.

Distancia de la raíz a las tablas óseas y piso nasal de dientes anteriores maxilares con indicación de microcirugía apical / Root to bone table and nasal floor distance of maxillary anterior teeth with indication for apical microsurgery / Tabela raiz-osso e distância do pavimento nasal dos dentes anteriores superiores com indicação para microcirurgia apical

RESUMEN Objetivo: Evaluar la distancia de la raíz a las tablas óseas y piso nasal de dientes anteriores maxilares con indicación de microcirugía apical. Material y métodos: La muestra fue de 44 imágenes tomográficas computarizadas de haz cónico previas al procedimiento de microcirugía apical; además, se seleccionaron 31 imágenes para la comparación con los dientes contralaterales sin indicación de microcirugía apical. Se midió la distancia de la raíz a las tablas óseas y al piso nasal. Resultados: La distancia de la superficie radicular a las tablas óseas vestibular y palatina a 3 mm del ápice fue de 0,98 ± 0,67 mm y 4,26 ± 2,97 mm para el incisivo central; 0,77 ± 0,50 mm y 2,12 ± 1,22 mm para el incisivo lateral; y 0,52 ± 0,63 mm y 5,31 ± 1,38 mm para el canino, respectivamente. La distancia más corta del ápice al piso nasal fue de 9,56 ± 2,88 mm para el incisivo central; 10,33 ± 2,97 mm para el incisivo lateral; y 5,73 ± 2,57 mm para el canino. Solo se encontró una distancia mayor, estadísticamente significativa, del ápice al piso nasal del incisivo lateral con indicación de microcirugía apical en comparación con el incisivo lateral sin indicación de microcirugía apical. Conclusiones: La distancia de la raíz a la tabla ósea vestibular es menor que la distancia de la misma a la tabla ósea palatina. El ápice más próximo al piso nasal fue del canino. Los dientes anteriores maxilares con y sin indicación de microcirugía apical mostraron distancias similares de la raíz a las tablas óseas y piso nasal.

ABSTRACT Objective: To evaluate the distance from the root to the bone tables and nasal floor of maxillary anterior teeth with indication for apical microsurgery. Material and methods : The sample consisted of 44 cone beam computed tomographic images prior to the apical microsurgery procedure; in addition, 31 images were selected for comparison with contralateral teeth without indication for apical microsurgery. The distance from the root to the bone tables and nasal floor was measured. Results: The distance from the root surface to the vestibular and palatal bone tables 3 mm from the apex was 0.98 ± 0.67 mm and 4.26 ± 2.97 mm for the central incisor; 0.77 ± 0.50 mm and 2.12 ± 1.22 mm for the lateral incisor; and 0.52 ± 0.63 mm and 5.31 ± 1.38 mm for the canine, respectively. The shortest distance from the apex to the nasal floor was 9.56 ± 2.88 mm for the central incisor, 10.33 ± 2.97 mm for the lateral incisor, and 5.73 ± 2.57 mm for the canine. A statistically significant greater distance from the apex to the nasal floor was found only for the lateral incisor with indication for apical microsurgery compared to the lateral incisor without indication for apical microsurgery. Conclusions: The distance from the root to the vestibular bone table is less than from the root to the palatal bone table. The apex closest to the nasal floor was that of the canine. Maxillary anterior teeth with and without indication for apical microsurgery showed similar distances from the root to the bone tables and nasal floor.

RESUMO Objetivo: avaliar a distância da raiz às tábuas ósseas e ao assoalho nasal de dentes anteriores superiores com indicação de microcirurgia apical. Material e métodos: a amostra foi composta por 44 imagens de tomografia computadorizada de feixe cônico antes do procedimento de microcirurgia apical; além disso, 31 imagens foram selecionadas para comparação com dentes contralaterais sem indicação de microcirurgia apical. Foi medida a distância da raiz até as tábuas ósseas e o assoalho nasal. Resultados: a distância da superfície radicular às tábuas ósseas vestibular e palatina, a 3mm do ápice, foi de 0,98mm ± 0,67mm e 4,26mm ± 2,97mm para o incisivo central; 0,77mm ± 0,50mm e 2,12mm ± 1,22mm para o incisivo lateral; e 0,52mm ± 0,63mm e 5,31mm ± 1,38mm para o canino, respetivamente. A menor distância entre o ápice e o assoalho nasal foi de 9,56 ± 2,88 mm para o incisivo central; 10,33 ± 2,97 mm para o incisivo lateral; e 5,73 ± 2,57 mm para o canino. Uma distância estatisticamente significativa maior do ápice ao assoalho nasal foi encontrada apenas para o incisivo lateral com indicação de microcirurgia apical em comparação com o incisivo lateral sem indicação de microcirurgia apical. Conclusões: a distância da raiz até a tábua óssea vestibular é menor do que a distância da raiz até a tábua óssea palatina. O ápice mais próximo do assoalho nasal foi o do canino. Os dentes anteriores superiores com e sem indicação de microcirurgia apical apresentaram distâncias semelhantes da raiz às tábuas ósseas e ao assoalho nasal.

Posición del incisivo inferior en pacientes de clase esqueletal I y II según su biotipo facial en una muestra de una clínica privada, Cali 2014 - 2020 / Position of the lower incisor in patients of skeletal class I and II according to their facial biotype in a sample from a private clinic, Cali 2014 - 2020

Introducción: la sínfisis mentoniana es la articulación cartilaginosa medial de los huesos mandibulares, su posición se relaciona con los diferentes biotipos y puede influir en la posición del incisivo inferior. Objetivo: determinar si existen variaciones en la posición del incisivo inferior, en pacientes clase II con diferentes biotipos. Materiales y métodos: se evaluaron la totalidad de tomografías de pacientes clase I y II esquelética que asistieron entre 2014 y 2020 a una clínica privada, teniendo una muestra total de 74 pacientes, caracterizándolos por sexo y edad. Se determinó biotipo facial, Incisor Mandibular Plane Angle, distancias a la sínfisis como el ACV-ACL y altura desde el ápice. Para el análisis se utilizó I-CAT Visión Q, para las medidas de las tomografías digitales y para el análisis estadístico Stata 17. Resultados: se en- contró un Incisor Mandibular Plane Angle mayor en pacientes clase II en los tres biotipos; los dolicofaciales clase II mostraron menor valor en corticales ACV-ACL, los pacientes mostraron mayor proinclinación en la clase II. La posición del incisivo en pacientes clase II presenta una proinclinación significativa en braquifaciales (p = 0.04). Conclusión: se encontraron variaciones entre los tres biotipos faciales en las diversas mediciones en pacientes clase I y II, el sexo femenino evidenció diferencias significativas en las clases en las medidas del Incisor Mandibular Plane Angle y la altura de la sínfisis a nivel del ápice; estos hallazgos son relevantes en el momento de realizar un tratamiento ortodóntico ya que puede limitar el movimiento de los incisivos inferiores.

Introduction: the mental symphysis is the medial cartilaginous joint of the mandibular bones, its position is related with the different biotypes and can influence the position of the lower incisor. Objective: to determine if there are variations in the position of the lower incisor, in class II patients with different biotypes. Materials and methods: all the tomography of skeletal class I and II patients who attended a private clinic between 2014 and 2020 were evaluated, having a total sample of 74 participants, characterizing the patients by sex and age. Facial biotype, Incisor Mandibular Plane Angle, distances to the symphysis such as the ACV-ACL and height from the apex were determined. For the analysis, I-CAT Vision Q was used for the measurements of the digital tomography and for the statistical analysis Stata 17. Results: a greater Incisor Mandibular Plane Angle in class II patients in the three biotypes was evident; class II dolichofacials showed a lower value in both cortical ACV-ACL, with the narrowest and longest measurement of the symphysis, the patients showed proclination in class II for both sexes, being higher for the male. The position of the incisor within the symphysis in class II patients presents a significant proclination in brachyfacial patients (p=0.04), despite presenting greater proclination, it maintains its apices centered within the symphysis. Conclusion: variations were found between the three facial biotypes in class I and II patients, it is relevant when performing orthodontic treatment since it can limit the movement of the lower incisors.

Tratamiento de la transposición de incisivos inferiores / Treatment of transposition of lower incisors

La transposición es el intercambio de la posición de dos dientes adyacentes durante los primeros años de la dentición mixta. El objetivo de la investigación fue evaluar los cambios clínicos de un caso con transposición parcial bilateral de incisivos laterales mandibulares. Se atendió una paciente de 8 años de edad, femenina, de raza blanca, síndrome de Clase II división 1, con transposición de los incisivos laterales con caninos inferiores. Fue tratada con un arco lingual de cierre horizontal, de alambre 0,032 y dos muelles de NiTi comprimidos desde el cierre horizontal del arco hasta una armella soldada a la banda que se colocó en ambos incisivos laterales. Se recuperó el espacio necesario para la erupción de los caninos inferiores y así mejoró la estética dental y facial de la paciente.

Transposition is the exchange of the position of two adjacent teeth during the first years of the mixed dentition. The objective of this research is to evaluate the clinical changes of a case with partial bilateral transposition of mandibular lateral incisors. We present an 8-year-old white female patient with Class II Division 1 malocclusion and transposition of the lateral incisors with lower canines. She was treated with a 0.032 wire horizontal closure lingual arch and two NiTi springs compressed from the horizontal closure of the arch to an eyebolt welded to the band that was placed on both lateral incisors. The necessary space for the eruption of the lower canines was recovered, thus improving her dental and facial aesthetics.

Prevalencia del segundo conducto en dientes anteroinferiores usando Tomografía Computadorizada Cone Beam / Second root canal prevalence in lower anterior teeth using Cone Beam Computed Tomography

Introducción: Es un error común pensar que los dientes anteroinferiores, por lo general, tienen un solo conducto radicular con una sola raíz. Sin embargo, un estudio realizado por Vertucci et. al., (1974), mostraron una alta prevalencia (13%) de dos conductos radiculares en los dientes anteroinferiores, lo que estimuló más investigaciones. Objetivo: El propósito de este estudio fue determinar la prevalencia del segundo conducto radicular en los dientes anteroinferiores en una población nicaragüense, estos fueron detectados por medio de tomografía computadorizada (Cone Beam). Materiales y Métodos: En el estudio se analizaron 293 piezas dentales, de canino a canino de la arcada inferior. Para realizar el análisis se utilizó el software libre Radiant DICOM Viewer 2021.2.2, se realizaron cortes sagitales, axiales y coronales para ver la prevalencia del segundo conducto radicular. Resultados: De las 293 piezas dentarias analizadas se encontró que 259 presentaban un solo conducto que correspondía al 88.4% y 34 dientes presentaban dos conductos que correspondían al 11.6%. De acuerdo con el análisis tomográfico, se encontró que en los cortes axiales y sagitales fue donde se observó la presencia del segundo conducto. Con respecto a la presencia del segundo conducto de acuerdo al tercio del canal radicular se identificó que la mayoría se presentó en el tercio medio (52.94%), seguido por coronal (29.41%) y por último el tercio apical (17.65%). De acuerdo con la clasificación de Vertucci se encontró que se presenta un mayor porcentaje del tipo I con 88.40%, seguido por el tipo III con 4.44%, después el tipo V con 3.41%, y el tipo II con 2.39%. El de menor porcentaje fue el tipo VI con 1.37%, mientras que, en las piezas analizadas, no se encontraron los tipos IV, VII y VIII. Conclusión: Basados en los resultados obtenidos en este estudio, la prevalencia de un segundo conducto en dientes anteroinferiores fue de 11.6%.

Title The prevalence of a second root canal in mandibular anterior teeth using Cone Beam Computed Tomography. Abstract Introduction: It is a common misconception that the mandibular anterior teeth usually have a single root canal with a single root. However, a study by Vertucci et. al., (1974), showed a high prevalence (13%) of two root canals in the lower anterior teeth, which stimulated further investigations. Objective: The purpose of this study was to determine the prevalence of the second root canal in the mandibular anterior teeth in a Nicaraguan population, these were detected by means of computed tomography (Cone Beam). Materials and methods: In the study, 293 teeth were analyzed, from canine to canine of the mandibular teeth. To perform the analysis, the free software Radiant DICOM Viewer 2021.2.2 was used, sagittal, axial and coronal views were made to see the prevalence of the second root canal. Results: Of the 293 teeth analyzed, it was found that 259 had a single root canal corresponding to 88.4%, and 34 teeth had two root canals corresponding to 11.6%. According to the tomographic analysis, it was found that the presence of the second root canal was observed only in the axial and sagittal views. Regarding the presence of the second canal according to the third of the root canal, it was identified that the majority presented in the middle third (52.94%), followed by coronal (29.41%) and finally the apical third (17.65%). According to the Vertucci classification, it was found that there is a higher percentage of type I with 88.40%, followed by type III with 4.44%, then type V with 3.41%, and type II with 2.39%. The one with the lowest percentage was type VI with 1.37%, while in the pieces analyzed, types IV, VII and VIII were not found. Conclusion: Based on the results obtained in this study, the prevalence of a second root canal in lower anterior teeth was 11.6%.

Concordance of the vestibular bone thickness at the level of point a between teleradiography and cone beam computed tomography / Concordancia del espesor óseo vestibular a nivel del punto a entre telerradiografía y tomografía computarizada de haz cónico

Objective: The aim of this study was to determine the concordance of the vestibular bone thickness measured at the level of point A between Teleradiography and Cone Beam Computed Tomography (CBCT). Materials and Methods: This study consisted of a cross-sectional analytical design of concordance that evaluated the teleradiographies and CBCTs of 32 patients. The measurements were performed by three evaluators, specialists in orthodontics. Two of them measured the CBCTs and one evaluated the teleradiographs. The concordance of both tests was determined using the Concordance Correlation Coefficient. Results: When evaluating the value of the vestibular bone thickness at the level of point A between the CBCT and the teleradiography, it was observed that the mean value of the absolute difference between the two was 0.95±0.74, 95%CI [0.68­1.22], being statistically significant (p=0.0027). When the concordance between both tests was analyzed, it was observed that it was poor (CCC=0.204 95%CI [0.014­0.394]), although statistically significant (p<0.00001). Conclusions: It was possible to conclude that there is no concordance in the measurement of the vestibular bone thickness at the level of Point A between the Teleradiography and the CBCT.

Objetivo: El objetivo de este estudio fue determinar la concordancia del espesor óseo vestibular medido a nivel del punto A entre la Telerradiografía y la Tomografía computarizada de haz cónico (CBCT). Materiales y Métodos: Esta investigación presentó un diseño analítico transversal de concordancia en el que se evaluaron las telerradiografías y CBCT de 32 pacientes. Las mediciones fueron realizadas por tres evaluadores especialistas en ortodoncia, dos de ellos midieron los CBCT y uno las telerradiografías. La concordancia de ambos exámenes fue medida mediante Coeficiente de Correlación de Concordancia. Resultados: Al evaluar el valor del grosor óseo vestibular a nivel del punto A entre el CBCT y la telerradiografía, se observó que el valor promedio de diferencia absoluta entre ambos fue de 0,95±0,74 IC95% [0,68­1,22], siendo estadísticamente significativas (p=0,0027). Cuando se analizó la concordancia entre ambos exámenes se observó que esta fue pobre (CCC=0,204 IC95 % [0,014­0,394]), aunque estadísticamente significativa (p<0,00001). Conclusión: Se pudo concluir que no existe concordancia en la medición del espesor óseo vestibular medido a nivel del Punto A entre la Telerradiografía y el CBCT.

Estimation of dental age using the kvaal method with digital panoramic radiographs in peruvian adults / Estimación de la edad dental según el método de Kvaal con radiografías panorámicas digitales en adultos peruanos

To determine the accuracy of the Kvaal method in the estimation of dental age through the analysis of digital panoramic radiographs of patients between 20 and 47 years of age who attended the stomatological clinic of the Universidad Científica del Sur, (2018 to 2019), Lima-Perú. 289 digital panoramic radiographs belonging to individuals of both sexes, aged 20 to 47 years were analyzed. Length and width measurements were obtained in the dental and pulp chamber in the upper central incisors. These data were subsequently evaluated by calculating the proportions between the pulp and root length of the upper central incisor by applying the formula of the method of Kvaal et al. to obtain the accuracy of the method in estimating dental age. Applying the formula of Kvaal et al. indicates that the relationship between the width of the pulp and the length of the root has a higher level of significance in relation to others proportions: M mean value of all ratios except T (-0.659) and W-L difference between W and L (-0.643). The coefficient of determination (r²) and standard error of estimation (SEE) using the original Kvaal formula is r²: 0.70, SEE: 4.90 years, then a modified Kvaal formula was proposed for the Peruvian population. The Method of Kvaal et al. has an accuracy of 1.24 in estimating the dental age of individuals, using the upper central incisor in digital panoramic radiographs.

Determinar la precisión del método de Kvaal en la estimación de la edad dental mediante el análisis de radiografías panorámicas digitales de pacientes entre 20 a 47 años atendidos en la clínica estomatológica de la Universidad Científica del Sur, (2018 a 2019), Lima-Perú. Se analizaron 289 radiografías panorámicas digitales pertenecientes a individuos de ambos sexos, de 20 a 47 años. Se obtuvo medidas de longitud y anchura en la cámara dental y pulpar en los incisivos centrales superiores. Estos datos se valoraron posteriormente al calcular las proporciones entre la pulpa y longitud de la raíz del incisivo central superior aplicando la fórmula del método de Kvaal et al. para obtener la precisión del método en la estimación de la edad dental. Al aplicar la fórmula de Kvaal et al. indica que la relación entre la anchura de pulpa y la longitud de la raíz presentan un nivel de significancia mayor en relación a otras proporciones: M valor medio de todas las proporciones excepto T (-0.659) y W-L: diferencia entre los valores de W y L (-0.643). El coeficiente de determinación (r²) y el error estándar de la estimación (SEE) utilizando la fórmula original de Kvaal es de r²: 0.70, SEE: 4.90 años, después se propuso una fórmula modificada de Kvaal para la población peruana. El Método de Kvaal et al. tiene una precisión del 1.24 en la estimación de la edad dental de los individuos, utilizando el incisivo central superior en radiografías panorámicas digitales.

Ethnic variation in the most common shade of anterior teeth among malaysian students: a cross-sectional study / Variación del tono más común de los dientes anteriores entre estudiantes malasios de diferentes etnias: un estudio transversal

Aim: Determination of the most common shade of anterior teeth in Malaysian students of different ethnicities. Materials and Methods: A total of 120 subjects, 40 each from different ethnicities (Malay, Chinese, and Indian) aged 18-22 years were evaluated for tooth shade using the VITA Classical shade guide. The subject was asked to sit in an up-right position with teeth at the clinician's eye level and the subject was instructed to remove makeup or tinted eyewear which may affect the result. The procedure was done in natural daylight. The shade tabs were positioned adjacent to the maxillary central incisor and the middle 1/3rd of the facial surface was assessed by experts to determine the correct tooth shade. The data was statistically analysed. Results: The differences in tooth shade were seen among the subjects of different ethnicities. The Malay ethnicity has B1 (37%) as the most common tooth shade whereas Chinese has C1 (27%) and Indian C1 (40%). Conclusions: Under the limitation of the study, it was found that there is a relationship between tooth color and ethnic background. Malay students tend to have brighter teeth as compared to Chinese and Indian students.

Objetivo: Determinar el tono más común de los dientes anteriores en estudiantes malasios de diferentes etnias. Materiales y Métodos: Se evaluó el color de los dientes de un total de 120 sujetos, 40 de diferentes etnias (malayos, chinos e indios) de edades comprendidas entre 18 y 22 años, utilizando la guía de colores VITA Classical. Se pidió al sujeto que se sentara en posición vertical con los dientes al nivel de los ojos del médico y se le indicó que se quitara el maquillaje o las gafas teñidas, lo que podría afectar el resultado. El procedimiento se realizó con luz natural. Las pestañas de color se colocaron adyacentes al incisivo central superior y expertos evaluaron el tercio medio de la superficie facial para determinar el tono correcto del diente. Los datos fueron analizados estadísticamente. Resultados: Se observaron diferencias en el color de los dientes entre los sujetos de diferentes etnias. La etnia malaya tiene el B1 (37%) como el color de dientes más común, mientras que los chinos tienen el C1 (27%) y los indios C1 (40%). Conclusión: Bajo las limitaciones del estudio, se encontró que existe una relación entre el color de los dientes y el origen étnico. Los estudiantes malayos tienden a tener dientes más brillantes en comparación con los estudiantes chinos e indios.

Cephalometric Evaluation of Maxillary Incisors Torque and Vertical Changes Utilizing Standard Edgewise Mechanics

In 1995 Gebeck & Merrifield studied a successful and unsuccessful treated Class I and Class II's samples; they found a -1.33 mm intrusion in the former and a 0.80 mm extrusion in the latter. The purpose of this article was to perform a cephalometric evaluation of maxillary incisors torque and vertical changes. We studied a sample of 129 patients, 30 males and 99 females, taken from The Charles H. Tweed Foundation Long Term Study, at pretreatment mean age 12.93 years, posttreatment mean age 16.19 years and follow up post retention mean age 29.83 years, a 13.88 years interval. The records were collected from private practitioners across the North American continent who used Standard Edgewise Mechanics and were members of the Charles H. Tweed Foundation. All patients were Class I and II American whites treated with the extraction of 4 premolars. We found an Upper anterior incisal edge to PP vertical linear measurement 28.7 and 29.2 mm, +0.53 mm (p<0.019) from pretreatment to posttreatment. The average Upper 1 to SN angle was 103.2 ° at pretreatment and 100.1° at posttreatment, -3.2° (p<0.000), Upper 1 to PP 111.0° and 108.9°, -2.2° (p<0.000), the three of them statistically significant. Conversely, Upper 1 to commissure was not. The four measurements were also statistically significant posttreatment to follow up, upper anteriors kept losing torque after posttreatment, and less upper anteriors surface was below the commissure. Some torque loss and vertical extrusion can be expected while treating patients with extractions of four premolars, therefore, upper incisor inclination increase and vertical change by itself cannot determine the success of treatment.

En 1995, Gebeck y Merrifield estudiaron muestras de Clase I y Clase II tratadas con éxito y sin éxito; encontraron una intrusión de -1,33 mm en el primero y una extrusión de 0,80 mm en el segundo. El propósito de este artículo fue realizar una evaluación cefalométrica del torque y los cambios verticales de los incisivos maxilares. Estudiamos una muestra de 129 pacientes, 30 hombres y 99 mujeres, tomados del estudio a largo plazo de la Fundación Charles H. Tweed, con una edad media previa al tratamiento de 12,93 años, una edad media posterior al tratamiento de 16,19 años y una edad media de seguimiento posterior a la retención de 29,83 años, con un intervalo de de 13,88 años. Los registros se recopilaron de médicos privados en todo el continente norteamericano que utilizaron Standard Edgewise Mechanics y eran miembros de la Fundación Charles H. Tweed. Todos los pacientes eran blancos americanos Clase I y II tratados con extracción de 4 premolares. Encontramos una medida lineal vertical del borde incisal anterior superior a PP de 28,7 y 29,2 mm, +0,53 mm (p<0,019) desde el pretratamiento hasta el postratamiento. El promedio del ángulo Superior 1 a SN fue de 103,2° en el pretratamiento y 100,1° en el postratamiento, -3,2° (p<0,000), Superior 1 a PP 111,0° y 108,9°, -2,2° (p<0,000), los tres estadísticamente significante. Por el contrario, Superior 1 a la comisura no lo era. Las cuatro mediciones también fueron estadísticamente significativas para el seguimiento después del tratamiento, los dientes anteriores superiores siguieron perdiendo torsión después del tratamiento y se observó menor superficie de los dientes anteriores superiores debajo de la comisura. Se puede esperar cierta pérdida de torque y extrusión vertical al tratar a pacientes con extracciones de cuatro premolares, por lo tanto, el aumento de la inclinación del incisivo superior y el cambio vertical por sí mismos no pueden determinar el éxito del tratamiento.

An atypical presentation of talon cusp: Double talon cusps

Talon cusp is an uncommon developmental anomaly resulting in an extra cusp or cuspal projection on an anterior tooth consisting of normal enamel, dentin, and varying degrees of pulp tissue. Talon cusp shows varied presentations of which the palatal talon cusp has been the most common of all. The management requires an extensive understanding of this clinical entity and the complications associated with its occurrence. In this case series, we are reporting double talon cusps which is a rarity itself, involving the palatal aspect of maxillary central incisors

Effects of Implant Sites and Axial Direction on Stress of Maxillary Central Incisors with Immediate Implantation under Immediate Weight-Bearing: A Three-Dimensional Finite Element Analysis / 医用生物力学

Objective To investigate the influence of implant location and axial direction on stress distributions at the implant bone interface of maxillary central incisors with different alveolar fossa morphology by immediate implantation under immediate weight-bearing. Methods With reference to dental cone beam computed tomography (CBCT) image data from a healthy adult, the three-dimensional ( 3D) finite element models of maxillary central incisors with three types of alveolar fossa ( buccal, mediate, and palatal type) by immediate implatation under immediate weight-bearing were established. Different implant sites ( apical site, palatal / labial site) and axial directions (long axis of the tooth, long axis of the alveolar bone) were simulated. The established models were subjected to 100 N force at different angles (0°, 30°, 45°, 60°, 90°). The stresses in the alveolar bone around the implant were analyzed by the ANSYS software. Results Twelve 3D finite element models of maxillary central incisors with different alveolar fossa morphology by immediate implantation under immediate weight-bearing were successfully established. When alveolar fossa with buccal and mediate shape was applied with immediate implantation under immediate weight-bearing, it was easier to obtain good biomechanical properties of the implant-bone interface when implants were placed at palatal site along long axis of the alveolar bone. When alveolar fossa with palatal shape was applied with immediate implantation under immediate weight bearing, the equivalent stresses on peri-implant alveolar bone were much smaller than those on apical site, regardless of whether the implant was placed along long axis of the tooth or the long axis of the alveolar bone. Conclusions Different alveolar fossa morphology, implant location and axial direction will affect characteristics of implant-bone interface of maxillary central incisors with immediate implantation under immediateweight-bearing. In clinical practice, surgical planning on different axial direction and location of implantation should be developed for alveolar fossa with different morphology.

Histological study of platelet-rich fibrin combined with MTA for direct pulp capping of rabbit teeth / 口腔疾病防治

Objective @# To investigate the outcomes of a novel direct pulp capping agent containing platelet-rich fibrin (PRF) and mineral trioxide aggregate (MTA). @*Methods @# A total of 32 New Zealand rabbits were randomly divided into 4 groups, namely, the PRF+MTA group (P+M group), PRF group (P group), MTA group (M group) and blank control group (BC group), with 8 rabbits per group. Dental pulp exposure and direct pulp capping were performed, and complete crown square sealing was performed on 2 mandibular central incisor teeth of each rabbit. Four rabbits from each group were euthanized after each observation period (7 and 28 days). The experimental teeth were subjected to HE staining. Inflammatory cell infiltration, calcified bridge formation and pulp tissue disorganization were observed and graded. @*Results@#Inflammatory cell infiltration: on the 7th day, group P+M and group M were lighter than group BC (P<0.05); on the 28th day, group P+M was lighter than group P and group BC (P<0.05); group P+M and group M did not significantly differ (P>0.05). Calcified bridge formation: on the 7th and 28th days, group P+M was lighter than group P, group M and group BC (P<0.05); on the 28th day, group M was higher than group BC (P<0.05). Under microscope, the calcified bridge contained cellular components and was surrounded by odontoblast-like cells, sharing a structure resembled osteodentin; dentin tubule-like structure could not be observed in calcified bridge, and the calcified bridge resembled certain points of osteodentin. Pulp tissue disorganization: on the 7th day, group P+M and group M were lighter than group BC (P<0.05); on the 28th day, group P+M was lighter than group P and group BC (P<0.05). group P+M and group M did not significantly differ (P>0.05). @*Conclusion @# The combination of PRF and MTA for direct pulp capping provided light inflammatory cell infiltration, stable pulp status and a strong ability of pulp tissue to form calcified bridge, and the calcified bridge resembled certain points of osteodentin.

Multidisciplinary treatment of Class I Angle Malocclusion with severe crowding and peg lateral incisor: A case report

@#Class I malocclusions with severe crowding and tooth size discrepancies may be successfully treated orthodontically with extraction therapy, and co-management with other specialists. Correction of the discrepancies will optimize occlusal result (overjet, overbite, midline shift, and smile esthetics). This is a case of a 19-year-old male with severe crowding in upper and lower teeth and peg lateral incisor. The patient had malocclusion Class I. This case was treated comprehensively and successfully using fixed orthodontic appliances with extraction of four premolars, and veneer composite for peg lateral incisor with the help of a conservative dentist at the end of orthodontic treatment.

Study on the ideal sagittal position of the lower third of the face in high-angle patients with different forehead forms / 口腔疾病防治

Objective@#To explore the ideal sagittal position of the lower third of the face in high-angle patients with different forehead forms and to provide a reference for clinical treatment. @*Methods@#Informed consent and portrait authorization were obtained from all patients, and the study passed the ethical review of the unit. We categorized forehead forms into four types: straight, rounded, type I angular (angled at the middle third of the forehead) and type II angular (angled at the upper third of the forehead). Profiles of high-angle patients with different forehead forms were collected. The initial position was when the facial axis point (FA point) was positioned at the goal anterior-limit line (GALL). After being silhouetted, the lower third of the face was moved forward and backward by 1 mm, 2 mm, 3 mm, and 4 mm each, plus the initial silhouetted picture, to obtain 9 images for each patient. A survey was created with these lateral profile silhouettes, and the silhouette images were ranked by 30 orthodontists and 30 laypersons. @*Results@# There were significant differences in profile scores at different movement distances of the lower third of the face among high-angle patients with different forehead shapes (P<0.05). Overall, high-angle patients with straight or type II angular foreheads had higher scores when the lower third of the face did not move. For high-angle patients with a rounded forehead, orthodontists and laypersons gave the highest scores when the lower third of the face was moved backward by 2 mm and 4 mm, respectively. For high-angle patients with a type I angular forehead, orthodontists thought the scores of backward movement of 4 mm were the highest, and laypersons thought the scores of backward movement of 3 mm were the highest. No significant difference was found in scores between orthodontists and laypersons (P>0.05). @*Conclusion @#The forehead forms and the sagittal position of the lower third of the face will affect the face’s profile aesthetics. Patients with straight and type Ⅱ angular foreheads has the best profile when the FA point is located on the GALL line. For patients with rounded and type Ⅰ angular foreheads, a posterior location of the lower third of the face is more desirable than the initial position.

Cognition about emergency management of avulsed incisor in children among dentists in Guangdong province / 华西口腔医学杂志

OBJECTIVES@#This study aimed to evaluate and analyze the current situation of dentists in Guangdong pro-vince regarding the management of avulsed incisors, thereby providing a reference for making treatment strategies for avulsed incisors in the future.@*METHODS@#A total of 712 dentists with different educational backgrounds and working conditions in Guangdong province were randomly selected to conduct an online questionnaire survey on the cognition of children with avulsed incisors from April 2022 to May 2022. The data were recorded by Excel software and statistics were analyzed on Stata/SE 15.1.@*RESULTS@#A total of 712 dentists were investigated and 701 questionnaires were collected (98.46%). In addition, 65.9% of investigators came from the Department of Stomatology in a First-class Hospital or Stomatological Hospital. The results showed that the average number of avulsed teeth consulted by dentists was less than 20 per year. Although 99.7% of respondents considered normal saline as a suitable storage medium, 3.1% and 23.8% of them had a misunderstanding that the tap/alcohol could be used for root cleaning. Moreover, 93.4% was the correct selection rate of the treatment plan for processing on root surfaces before replanting by investigators. The correct selection rate of the duration using elastic fixation was only 10.7%. Meanwhile, 42.9% of investigators refused to inoculate tetanus immunoglobulin after teeth replanting. Emergency management of dental avulsion (EM) and clinical management of dental avulsion (CM) answered correctly with average scores of 14.60±11.85 and 14.48±2.67, respectively. Multivariate linear regression analysis revealed that working years were negatively correlated with EM and CM scores (P<0.05). There was a positive correlation between CM and EM scores with the number of avulsion cases treated by physicians each year (P<0.05). In terms of the EM score of dentists' learning attitude, investigators who had received enough knowledge were higher than those who had not and insufficient knowledge reserved, and the difference was statistically significant (P<0.05). The scores of investigators who thought they had a certain degree of knowledge about dental trauma were higher than those who thought they "did not understand", and the difference was statistically significant (P<0.05). In terms of CM scores, investigators who thought the knowledge of dental trauma was "very helpful" had higher scores than those who thought it was "not helpful", and the difference was statistically significant (P<0.05). The scores of the investigators who thought they had "relatively sufficient knowledge" of dental trauma were higher than those who thought they had "no knowledge" or "insufficient know-ledge", and the difference was statistically significant (P<0.05).@*CONCLUSIONS@#The overall accuracy of the management of avulsed incisors among dentists was low in Guangdong province. Dentists were more likely to have a higher rate of accuracy choice in treatment options for luxation injury and avulsion to enhance the prognosis of replanted teeth.