Morphology of the Second Mesiobuccal Canal in the Maxillary Second Molar

SUMMARY: Failure to locate a complete canal system affects the prognosis of root canal treatment. A missed root canal is one of the most common reasons for failed root canal treatment. The prevalence of the second mesiobuccal canal in the maxillary second molar is relatively high and has a variety of configurations. Therefore, knowledge of its morphology is required in clinical endodontics. This review presented the canal in terms of its prevalence, classification, anatomical features, and the method for locating the second mesiobuccal canal in the maxillary second molar. Root canal treatment requires knowledge of tooth morphology, appropriate access preparation, and a thorough examination of the tooth's interior. Thus, clinicians should carefully employ various methods for assessing the anatomy of the entire root canal system to prevent failure in locating the second mesiobuccal canal. This canal can be located by modifying the access cavity design and utilizing specific instruments to improve the second mesiobuccal canal system visualization.

La falta de localización de un sistema completo de canal afecta el pronóstico del tratamiento de éste. La omisión de un tratamiento de canal es uno de los motivos más frecuentes por las que el tratamiento de canal fracasa. La prevalencia del segundo canal mesiovestibular en el segundo molar superior es relativamente alta y tiene una variedad de configuraciones. Por tanto, el conocimiento de su morfología es necesario en endodoncia clínica. Esta revisión presentó el canal en términos de su prevalencia, clasificación, características anatómicas y el método para localizar el segundo canal mesiovestibular en el segundo molar superior. El tratamiento de canal requiere conocimiento de la morfología del diente, una preparación adecuada del acceso y un examen exhaustivo del interior del diente. Por lo tanto, los dentistas deben emplear cuidadosamente varios métodos para evaluar la anatomía de todo el sistema de canales radiculares para evitar fallas en la localización del segundo canal mesiovestibular. Este canal se puede localizar modificando el diseño de la cavidad de acceso y utilizando instrumentos específicos para mejorar la visualización del sistema del segundo canal mesiovestibular.

Radiological measurement and analysis of trans-inferior alveolar nerve implantation / 口腔医学

Objective@#To measure the position of the mandibular nerve canal at the mandibular second molar by CBCT image data, analyze the theoretical implantation range of trans-alveolar implantation, and provide a theoretical solution to insufficiency of posterior mandibular bone volume in clinical practice. @*Methods@#Eighty patients with missing mandibular second molars whose vertical bone height of the edentulous area was less than 9 mm were selected for CBCT image measurement, and the distances from the mandibular nerve canal to the buccal cortex, lingual cortex, and alveolar crest were measured to simulate trans-inferior alveolar nerve implantation. The angular range of the buccolingual inclination of the implant was also measured.@*Results@#The distances from the mandibular nerve canal to the buccal cortex, lingual cortex and alveolar crest at the mandibular second molar were(6.913±1.222)mm, (2.859±0.891)mm and (7.991±0.783)mm, respectively. The distance from the mandibular nerve canal to the buccal cortex was significantly greater than that to the lingual cortex. And, 75% of the patients could be implanted by the inferior alveolar nerve. The minimum angle of buccolingual inclination of the simulated implant was 19.360°±7.086°, and the maximum angle was 39.462°±6.924°. @*Conclusion@#The mandibular nerve canal at the mandibular second molar is inclined toward the lingual side, which ensures sufficient buccal bone volume. Most patients with severe mandibular atrophy can still adopt implants of conventional length by trans-inferior alveolar nerve implantation to keep a safe distance from the nerve canal.

Intentional replantation for the retreatment of mandibular second molar: a case report / 华西口腔医学杂志

When the use of root canal retreatment and apical surgery experiences difficulty in treating endodontic diseases, intentional replantation is an optional clinical technique used to retain the tooth. A 28-year-old female complained of chewing discomfort at the mandibular second molar after undergoing root canal treatment 3 month ago. History record and radiographic examination revealed that a C-shaped root canal system was filled with gutta-percha in the mandibular second molar. A radiolucency area existed at the root furcal area with a thin canal wall in the distal and mesial roots. Intentional replantation was used to treat this tooth. The clinical and radiographic results showed that intentional replantation and nano-biomaterial application facilitated infection control, tooth retention, and periodontal tissue regeneration.

Comparison of panoramic radiography and cone-beam computed tomography images for detecting external root resorption of mandibular second molar associated with third molar impaction / 口腔医学

Objective@# To compare the diagnostic performance between panoramic radiography(PR)and cone beam computed tomography(CBCT)in the assessment of external root resorption(ERR)of mandibular second molars associated with impacted third molars. @*Methods@# A total number of 832 patients with 1 074 mesially and horizontally impacted mandibular third molars treated at our institution from January 2019 to December 2020 were retrospectively analyzed. Presence of ERR on the adjacent second molar was investigated with PR and CBCT. Factors affecting the diagnostic accuracy of PR were determined. @*Results@# The overall incidence of ERR in second molars was 33.15%(356/1 074)as detected by CBCT images. The accuracy of PR was 66.39%. Multivariate Logistic regression analyses further revealed that middle and Class Ⅲ impaction, crown contact or overlap with the root of adjacent tooth were risk factors for inaccurate diagnosis of PR(P<0.05). @*Conclusion@#The accuracy of detection on ERR of mandibular second molar associated with impacted third molar using panoramic radiography is lower. CBCT is recommended for this clinical scenario.

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.

Comparison of diagnosing the relationship between the root of maxillary posterior tooth and maxillary sinus between panoramic radiography and cone beam computer tomography / 口腔疾病防治

Objective@#To study the diagnostic accuracy and the distance between the root of maxillary posterior tooth and the maxillary sinus using panoramic radiography and cone beam computer tomography; to provide basic information for clinicians to treat diseases in the maxillary posterior region. @* Methods@#Eighty patients were included in this study. A total of 671 specimens were measured for the distance between the root tip and the maxillary sinus floor in both imaging modalities.@*Results @#The roots that did not contact the sinus floor or contacted but did not project into the sinus cavity showed an agreement of 82% and 70% when using panoramic radiography. Forty-eight percent of the roots that projected into the sinus cavity in panoramic radiography showed protrusion into the sinus with cone beam computer tomography (CBCT). For panoramic radiography and CBCT showing root projections into the sinus cavity, the average distances were 2.19 ± 1.82 mm and 1.47 ± 1.01 mm, respectively. There was a significant difference between the two values (P ＜ 0.05).@*Conclusion@# Panoramic radiography is more accurate when roots of maxillary posterior teeth do not contact the sinus floor or contact it. However, it has a lower accuracy rate when the tooth roots protrude into the sinus.

CBCT study of the root and root canal morphology of mandibular second molars in a population in western Guangxi / 口腔疾病防治

Objective@#To observe the root and root canal morphology of mandibular second molars in Western Guangxi by CBCT, to provide a reference for clinical diagnosis and treatment.@*Methods@#In total, 564 patients′ 1 128 mandibular second molars that satisfy the inclusion criteria were analyzed with a planmecaromexis CBCT machine and its own image analysis software. The patients′ gender, age and ethnic differences in the root and canal morphology and the symmetry of the bilateral root and canal were statistically analyzed. @*Results@# Among the 1 128 mandibular second molars, 662 were the Zhuang ethnic group and 384 were the Han ethnic group, and 82 were other ethnic groups; the double root type and C-shaped root type accounted for a relatively high proportion: 73.94% and 24.47%, respectively. The detection rates of the double root type were higher in males than in females (P < 0.05); the detection rates of the C-shaped root type were higher in females than in males (P <0.05); the root type of the teeth was mainly double-rooted in the Zhuang ethnic group (P<0.01). The incidence of type IV in the mesial root of the double root type mandibular second molar was the highest (P < 0.01), and the incidence of type I in the distal root was the highest (P < 0.01). The C-shaped root canal is more continuous at the mouth of the root canal, more downward corresponds to a worse continuity: in three different levels of root canal orifice, root middle and root apex, the root canal orifice is dominated by the C1 type, and both root middle and root apex are mainly C3-type (P < 0.01). The difference in symmetry of bilateral roots and root canals was statistically significant among different gender groups, age groups, and ethnic groups (P < 0.05): there were more males than females, the results in the 18-35-year-old group and the Zhuang ethnic group were higher.@*Conclusion@# The root and root canal morphology of mandibular second molars in western Guangxi people are complex and changeable. The roots are mainly double root type in the Han ethnic group and the Zhuang ethnic group. C-shaped roots are also common. The detection rate of C-shaped roots in the Zhuang ethnic group was higher, and the symmetry rate of bilateral roots and that of bilateral root canals was higher in the Zhuang ethnic group than in the Han ethnic group.

Root canal treatment of maxillary second molar with three mesial buccal root canals: a case report and literature review / 口腔疾病防治

Objective@#To explore the key points of clinical diagnosis and treatment of three mesiobuccal root canals.@*Methods@# In the procedure of endodontic therapy for the upper left second molar with pulpitis, through root canal exploration under a dental microscope and cone beam CT (CBCT)-assisted imaging examination, it was confirmed that the left upper second molar contained 3 roots and 5 root canals, among which the third root canal existed in the mesiobuccal root. Combined with perfect root canal preparation, cleaning, disinfection, filling and minimally invasive inlay repair, the clinical symptoms were eliminated. The patients were followed up and the related literatures were reviewed. @* Results @# One- and two-year follow-ups showed that the tooth had no discomfort and could be used normally. X-ray revealed that the filling was complete, and the periapical tissue was normal. The results of the literature review showed that the incidence of three mesiobuccal root canals in maxillary second molars was 0.11%-4.2%. It is difficult to find additional root canals only by X-ray imaging. Dentists should further determine the number and anatomical shape of root canals by CBCT and operating microscopy. When there are three mesiobuccal root canals in maxillary molars, dentists should avoid overpreparation. Healthy tooth tissue is the key to good prognosis. @* Conclusion@#During root canal therapy, clinicians should consider the anatomical variation of the root canal, should always be alert to the existence of an extra root canal, and should use CBCT, operating microscopy, ultrasound and various auxiliary instruments to locate and treat the variant root canal.

Scleral Dellen after Routine Uneventful Pterygium Surgery.

Occurrence of Scleral Dellen is rare but serious complication with stromalinflammation with tissue loss and scarring. Scleral dellen results from localdehydration & thinning of scleral tissues with exposure of underlying uvea leading toblueish colour. Occular surgical causes of occurrence of scleral dellen are strabismussurgery, pterygium excision (with or without use of adjunctive treatment like betaradiation, conjunctival autograft and Mitomycin C), cataract extraction.1,2 Patientscomplain of foreign body sensation & mild discomfort. Treatment consists ofreduction or elimination of contributing perilimbal elevation, & rapid rehydrationwith artificial tears, eye ointment and patching3. If treated properly dellen usuallyresolves completely without permanent sequelae. We report a case of severe scleraldellen that occurred 14 days after the uneventful surgical excision of primarypterygium without adjuvant therapy. We describe a patient with scleral dellen, whichoccurred after an uneventful pterygium excision without adjunctive therapy.

ViVan Ratio for Maxillomandibular Tooth Material Discrepancy.

According to the guidelines of the American and Indian Boards of Orthodontics, it is essential to include second molars, while managing an orthodontic case. Therefore, the present study was planned to determine maxilla-mandibular tooth material discrepancy.METHODSThe study sample consisted of study casts of 300 subjects in the age range of 18-30 years. Samples having a full complement of teeth with Angle’s Class I molar and canine relationships, good intercuspation, normal overjet and overbite and minimal crowding and spacing were included in the study. Tooth dimensions were measured using digital vernier caliper (accurate to 0.01 mm) and overall ratio was calculated. The data was statistically analysed for range, mean, standard deviation and coefficient of variation.RESULTSViVan ratio was found to be 90.79 with standard deviation of 3.13, variance of 9.81 and range was 83.55 - 95.82.CONCLUSIONSIdeal tooth proportions play an important role in achieving good occlusion at the end of orthodontic treatment. The ViVan ratio obtained in the study included second molars and this would benefit the orthodontist in proper treatment planning. This ratio will add importance for improved results at the finish of orthodontic treatment.

Retenciones múltiples. Reporte de un caso / Multiple retention. Case report

RESUMEN La retención dentaria es común encontrarla en la clínica de ortodoncia, los caninos maxilares son los de mayor solicitud de tratamiento por su importancia estética. Sin embargo, no es frecuente la retención de dientes temporales. Su etiología no está bien definida pero se considera de carácter multifactorial. Se presentó una paciente del sexo femenino de 12 años y medio de edad, con ausencia de 15 y 13, presencia de 53 y mesogresión del 16. Al examen radiográfico se observó retención de 55, 15 y 13, este último en transposición incompleta con el 12. Después de un profundo análisis se decidió exéresis del 55 y alineación al arco dentario de 15 y 13, mediante colocación de un dispositivo, con el empleo del sistema de cementado directo en el acto quirúrgico. Se estableció una oclusión funcional y estética aceptable, con particular cuidado de la integridad de los dientes vecinos y sus tejidos blandos. Las retenciones constituyen maloclusiones dentarias complejas y de difícil pronóstico y tratamiento, más aún cuando son múltiples. Se requiere de estudio y tratamiento multidisciplinario (AU).

ABSTRACT It is common to find teeth retention in Orthodontics clinic; maxillary canines, due to their esthetical importance, are the ones the patients ask to be treated more frequently. Nevertheless, temporary teeth retention is not frequent. Its etiology is not clear, but it is considered multifactorial. The authors present the case of a female patient, aged 12 years and a half, without 15 and 13 teeth, presence of 53 and mesogression of 16. At the radiographic examination, the retention of 55, 15 and 13 was found, and also the incomplete transposition of 13 and 12. After deeply analyzing the case, the orthodontists decided the removal of 55 and aligning 15 and 13 to dental arch, placing a device with the system of direct cementing at the moment of the surgery. It was established a functional occlusion and an acceptable esthetics, particularly caring for the neighboring teeth and their soft tissues. Retentions are complex dental malocclusions, of difficult prognosis and treatment, mainly when they are multiple. They require study and multidisciplinary treatment (AU).

Three-dimensional analysis of the mandible with impacted mandibular second molar / 华西口腔医学杂志

OBJECTIVE@#To study the developmental and morphological characteristics of the mandible in patients with impacted mandibular second molar and to predict the possible trend of mandibular development via three-dimensional (3D) measurement and analysis.@*METHODS@#A total of 88 cases of impacted group and 88 cases of control group were screened out. 3D measurements were performed by using Mimics software. A total of 23 landmark points and 17 measurements were determined. The measurements were analyzed by t-test.@*RESULTS@#The mandible length, the space between the first molars, the space between mandibular angles, and the width between the first molars in the impacted group were lower than those in the control group (P<0.05). Moreover, the value of the submandibular angle was higher than that in the control group (P<0.05).@*CONCLUSIONS@#The impacted mandible of patients with mandibular second molar showed lack of sagittal and width development, and the impacted mandibular second molar was a manifestation of its degeneration.

Anatomical morphology of the root and root canal system of the second permanent molar in the Uygur people / 口腔疾病防治

Objective @#To study the anatomical characteristics of the root and root canal system of the mandibular second permanent molar in the Uygur people and provide a reference for clinical practice.@*Methods @#A total of 125 mandibular second permanent molars were extracted from Uygur patients in hospitals in the Xinjiang Uygur Autonomous Region. Three-dimensional reconstruction was performed after micro-CT scanning. The number of root canals, the root canal type (Weine classification and Fan′s C-shaped canal classification) and the occurrence of lateral accessory canals were observed.@*Results @#A sex difference was not detected in the root number or root form (χ2 = 1.277, P = 0.259). The incidence of 2-rooted molars was 70.4% (n = 88); type 2-1 canals were most common in the mesial root, with an incidence of 29.5%, followed by type 1-1 and 2-2 canals (each with an incidence of 26.1%), and the distal root mostly had a type 1-1 canal (96.6%). The incidence of single-rooted molars was 28.8%, and the frequency of C-shaped (n = 28) and non-C-shaped (n = 8) single-rooted molars was 22.4% and 6.4%, respectively. A three-rooted molar was detected in one case. The incidence of accessory canals was 65.2%.@*Conclusion @# Uygur mandibular second molars are mainly composed of two roots, and the incidence of a single root and root canal fusion is low (including C-shaped canals). Two-rooted molars frequently have two mesial canals and one distal canal.

Dens invaginatus of right maxillary second molar: A case report and literature review / 吉林大学学报(医学版)

Objective: To explore the process of diagnosis and treatment of the patients with dens invaginatus of right maxillary second molar, to analyze the clinical features, the radiographic features and the pathological features of the dens invaginatus, and to make a reasonable treatment plan. Methods: The clinical data, imaging findings and pathological data of a patient with dens invagination were collected. The clinical diagnostic criteria and treatment methods of these cases were summarized with relevant literature review. Results: The patient, female, 28 years old, was diagnosed with a hole in the upper right posterior teeth for 6 months. The special examination results showed that the 17-toothed face was flat, the crown was huge, and the occlusal surface was seen in the sag and sputum; the medullary cavity was not reached. The radiograghic examination results showed that the enamel density image of the 17-toothed surface was sunken to the root, with a depth of about 7. 7 mm, diagnosed as dens invaginatus. At the time of initial treatment, the humus was removed and the sag received sedative treatment. The spontaneous pain still existed during the follow-up examination, and the problem of food embolism was not solved. Considering the poor recovery after treatment, the patient agreed to remove the tooth. The isolated tooth was observed by pathological grinding, and the enamel and dentin structures of the invaginatus were abnormal observed under microscope. Conclusion: The patients with dens invagination occurs in the molar area are rare; the type of disease and treatment plan should be determined by imaging examination during the process of diagnosis and treatment; it suggests that the patients with poor recovery after treatment should remove the teeth.

Construction of Age Estimation Model of 18-Year-Olds in the Northern Chinese Population Based on the Development of Mandibular Second and Third Molars / 法医学杂志

Objective To establish a linear relationship between age and the development process of the mandibular second, third molars in a northern Chinese population and test its accuracy in inferring whether the subject is over 18 years old. Methods The orthopantograms （OPGs） of 960 northern Chinese people aged between 10.00 to 25.99 years were selected. The gender, birth date, and date of the orthopantograms of each sample were recorded. The development stages of left mandibular second and third molars were divided with Demirjian method. The experimental group （760 individuals） constructed a Logistic regression equation to infer whether the subject is over 18 years old. The validation group （200 individuals） tested the accuracy of the equation. Results When only using third molar, the formula obtained for inferring whether the subject's age is over 18 years is： logit P1=-18.276+0.494 x1+2.953 x3. When combining the second and the third molars, the formula is： logit P2=-21.045+3.177 x1+0.619 x2+2.088 x3. （x1 stands for gender, male is marked as 1 and female is marked as 2; x2 and x3 stand for the development stage of second molar and third molar, respectively）. The accuracy rates of this equation in estimating whether ages of subjects from the validation group were over 18 years old for males and females were 88.0%-92.0% and 85.0%-88.0%, respectively. Conclusion The age estimation formulas based on the development of mandibular second and third molars have important value in judging whether the individual is over 18 years old. Meanwhile, the accuracy of age estimation can be improved by combining the development of second and third molars together.

C-shaped root canals of mandibular second molars in a Korean population: a CBCT analysis

OBJECTIVES: The purpose of this study was to investigate the C-shaped root canal anatomy of mandibular second molars in a Korean population. MATERIALS AND METHODS: A total of 542 teeth were evaluated using cone-beam computed tomography (CBCT). The canal shapes were classified according to a modified version of Melton's method at the level where the pulp chamber floor became discernible. RESULTS: Of the 542 mandibular second molars, 215 (39.8%) had C-shaped canals, 330 (53%) had 3 canals, 17 (3.3%) had 2 canals, 12 (2.2%) had 4 canals, and 8 (1.7%) had 1 canal. The prevalence of C-shaped canals was 47.8% in females and 28.4% in males. Seventy-seven percent of the C-shaped canals showed a bilateral appearance. The prevalence of C-shaped canals showed no difference according to age or tooth position. Most teeth with a C-shaped canal system presented Melton's type II (45.6%) and type III (32.1%) configurations. CONCLUSIONS: There was a high prevalence of C-shaped canals in the mandibular second molars of the Korean population studied. CBCT is expected to be useful for endodontic diagnosis and treatment planning of mandibular second molars.

Cone-beam computed tomography evaluation of the distance between the root apex of mandibular molars and the inferior alveolar nerve canal in adults / 口腔疾病防治

Objective@# To evaluate the spatiotemporal relationship between the root apex of mandibular molars and the inferior alveolar nerve canal (IANC) in adults. @*Methods@#Cone-beam computed tomography (CBCT) images were collected in 236 patients, and the distances from the root apexes of mandibular molars to the IANC were measured in NNT 4.6 software. The relationship between distance and gender was evaluated. @*Results@#In two-rooted mandibular first molars, the distances from the mesial root and distal root to the IANC were 7.34 ± 2.07 mm and 6.69 ± 2.08 mm, respectively, in males and 6.47 ± 2.22 mm and 5.94 ± 2.11 mm in females. In three-rooted mandibular first molars, the distances from the mesial root, distobuccal root, and distolingual to the IANC were 7.29 ± 1.30 mm, 7.40 ± 2.33 mm, and 9.97 ± 2.19 mm, respectively, in males and 6.08 ± 2.57 mm, 6.35 ± 2.40 mm, and 9.01 ± 2.90 mm, respectively, in females. In one-rooted mandibular second molars, the distance from the root to the IANC was 4.09 ± 1.64 mm in males and 3.89 ± 1.76 mm in females. In two-rooted mandibular second molars, the distances from the mesial root and distal root to the IANC were 5.14 ± 2.08 mm and 4.39 ± 1.85 mm, respectively, in males and 3.78 ± 1.69 mm and 3.24 ± 1.72 mm, respectively, in females. There were no significant with in-gender differences between the left and right side in the distances from the root apexes to the IANC (P>0.05). The distances from the mandibular first molar were greater in males than in females. The longest average distance was from the distolingual root apexes of three-rooted mandibular first molars to the IANC, and the distances were longer from the distobuccal root apexes of three-rooted mandibular first molars to the IANC than from the distal root apexes of two-rooted mandibular first molars to the IANC (P<0.05). There was no within-gender difference in the distances from the root apexes of single-rooted mandibular second molars to the IANC (P>0.05), but the distances in two-rooted mandibular second molars were larger in males than in females (P<0.05). The distances from the root apexes to the IANC were smaller in mandibular second molars than in mandibular first molars (P<0.05). @*Conclusion @#There are significant differences between adult males and females in the distance from the root apex to the IANC for mandibular first molars and two-rooted mandibular second molars. The distances from the root apexes to the IANC were smaller in mandibular second molars than in mandibular first molars.

A case report of a geminated mandibular second molar / 实用口腔医学杂志

Geminated teeth is a double-tooth deformity which is rare in clinical practice. Geminated teeth are usually found in anterior dentition, more in deciduous and fewer in permanent dentition. This pater reports a case of a geminated mandibular second molar.

Diagnóstico de conducto radicular en C en segundos molares mandibulares mediante la evidencia del ángulo obtenido: estudio piloto de validación / Diagnosis of C-shaped root canals in mandibular second molars through the evidence of the obtained angle: a pilot validation study

Antecedentes: El estándar dorado para diagnosticar segundos molarescon conducto radicular en C antes del inicio de un tratamiento endodóntico restaurador es la tomografía cone beam. La difi cultad para accedera los servicios tomográfi cos y su baja distribución en los consultorios odontológicos nos han llevado a diseñar una técnica alternativa enradiografías panorámicas nombrada «evidencia del ángulo obtenido¼(EAO). Objetivo: El objetivo de este trabajo fue crear un punto de cortey estimar la precisión diagnóstica del mismo mediante un estudio pilotocuyo resultado será utilizado en una futura investigación de validación de pruebas diagnósticas...

Background: The gold standard to diagnose second molars withC-shaped root canals prior to beginning an endodontic and restorative treatment is cone-beam tomography. Tomographic services are hard to access and have a low distribution in dental clinics this has led usto design an alternative technique in panoramic radiographs named«evidence of the obtained angle¼ (EAO). Objective: The aim of thisstudy was to create a breakpoint and estimate its diagnostic accuracy through a pilot study; its results will be used in a future investigation of validation of diagnostic tests...

Orthodontic upright treatment for mesioangular impacted lower second molar

The lower 2(nd) molar eruption is beginning to mesiolingually, then rotate to distobuccally so it has a tendency to be tilted and impacted mesially. Signs and symptoms of impacted 2(nd) molar are similar to impacted 3(rd) molar's. However, treatment plan for impacted 2nd molar is different from that of impacted 3(rd)'s. The former is the preservation and uprighting of 2(nd) molar so that it could act to recovery of mastication, symmetrical facial growth, maintaining the symmetry of dental arch, stable occlusion, while the latter is the extraction of tooth. If the uprighting treatment is planned, most proper protocol of treatment and the additional treatment opition should be applied with consideration for it's crown exposure, present of 3(rd) molar which interrupt the uprighting process, extrusion of opposite tooth. Although it could not improve the esthetic result, it could prevent many dental problems. Therefore, uprighting for impacted lower 2(nd) molar is meaningful treatment.