Múltiples Dientes Supernumerarios en Paciente Pediátrico No Sindrómico. Una Revisión de la Literatura y Presentación de Caso Clínico / Multiple Supernumerary Teeth In A Non-Syndromic Pediatric Patient. A Review Of The Literature and Presentation of a Clinical Case

Aquellos casos en que se excede la fórmula dentaria normal primaria de 20 dientes o definitiva de 32 dientes se conocen como dientes supernumerarios o hiperodoncia. Los supernumerarios se pueden presentar de manera única o múltiple y de forma heteromórfica o eumórfica. El supernumerario más prevalente es el mesiodens, se da más en hombres, en dentición permanente y en el maxilar. Su etiología no está confirmada, pero puede deberse a una hiperactividad de la lámina dental. El tratamiento varía de acuerdo a cada paciente según si está afectando a la dentición normal o no y el desarrollo que tengan las estructuras dentarias. El siguiente reporte de caso habla de un paciente de 6 años, no sindrómico, en donde se presentó con un mesiodens erupcionado y se encontraron más supernumerarios gracias a la radiografía complementaria.

Those cases in which the primary normal dental formula of 20 teeth or the final one of 32 teeth is exceeded are known as supernumerary teeth or hyperdontia. The supernumeraries can be presented in a single or multiple way and in a heteromorphic or eumorphic way. The most prevalent supernumerary is the mesiodens, it occurs more in men, in the permanent dentition and in the maxilla. Its etiology is not confirmed, but it may be due to hyperactivity of the dental lamina. The treatment varies according to each patient depending on whether it is affecting the normal dentition or not and the development of the dental structures. The following case report talks about a 6-year-old, non- syndromic patient, who presented with an erupted mesiodens and more supernumeraries were found thanks to the complementary radiography.

Estudio Anatómico y Prevalencia del Canalis sinuosus Evaluado Mediante Cone Beam CT en Pacientes Chilenos / Anatomical Study and Prevalence of Canalis sinuosus Evaluated by Cone Beam CT in Chilean Patients

Canalis sinuosus, canal intraóseo localizado en región maxilar anterior, contiene elementos vasculonerviosos alveolares anterosuperiores. Diversas intervenciones en región maxilar anterior como colocación de implantes, exodoncias, instalación de microtornillos ortodóncicos, procedimientos quirúrgicos, entre otros, pueden comprometer al Canalis sinuosus y/o sus canales accesorios dañando los elementos contenidos en su interior causando complicaciones como hemorragias, parestesia, disestesia, etc. Dado el gran desconocimiento de su existencia, el Canalis sinuosus frecuentemente es confundido con lesiones patológicas y/o endodónticas. Clásicamente la literatura lo describe como una variación anatómica variación anatómica, sin embargo, presenta elevadas prevalencias (51,7 %-100 %), siendo cuestionada esta aseveración. Determinar prevalencia y característica s anatómicas del Canalis sinuosus mediante Cone Beam CT en pacientes chilenos del centro radiológico IMAPROX® entre 2017- 2021. Análisis retrospectivo de 220 CBCT maxilares anonimizados, considerando variables sexo, presencia del Canalis sinuosus, Canalis sinuosus uni/bilateral, diámetro mayor del Canalis sinuosus, presencia/número de accesorios. Análisis estadístico uni y bivariado. 100 % de prevalencia del Canalis sinuosus en ambos sexos, presencia bilateral 100 %. Diámetro mayor promedio del Canalis sinuosus: 2,58 mm. El 76,8 % presentó accesorios, siendo más prevalente la presencia de 2 CA (34,1 %). Una estructura anatómica normal habitual debe presentar sobre 50 % de prevalencia para ser considerada como tal, pero no hay consensos en criterios empleados para definir variación anatómica o estructura anatómica normal habitual. Literatura describe al Canalis sinuosus como variación anatómica, pero estudios actuales muestran elevadas prevalencias: Rusia 67 %, Brasil 88 %, Turquía, Colombia y Chile 100 %. Este estudio encontró 100 % de prevalencia, sugiriendo que Canalis sinuosus es una estructura anatómica normal habitual. Sin embargo, Canalis sinuosus es poco conocido asociándose a numerosas complicaciones por procedimientos odontológicos y/o quirúrgicos en RMA pudiendo generar hemorragias, parestesia/disestesia, dolor agudo, etc. Elevadas prevalencias reportadas sugieren que Canalis sinuosus es una estructura anatómica normal habitual y no una variación anatómica, pero se requieren más estudios y consensos para aseverarlo. Es de relevancia clínica conocer la existencia y localización del Canalis sinuosus para evitar complicaciones.

Canalis sinuosus, an intraosseous canal located in the anterior maxillary region, contains anterosuperior alveolar vascular-nervous elements. Various interventions in anterior maxillary region such as implant placement, extractions, installation of orthodontic microscrews, surgical procedures, among others, can compromise the Canalis sinuosus and/or its accessory canals, damaging the elements contained inside, causing complications such as bleeding, paresthesia, dysesthesia, etc. Given the great ignorance of its existence, Canalis sinuosus is frequently confused with pathological and/or endodontic lesions. Classically, the literature describes it as an anatomical variation, however, it presents high prevalence (51.7 %-100 %), this assertion being questioned. Objective: to determine the prevalence and anatomical characteristics of Canalis sinuosus using Cone Beam CT in Chilean patients from the IMAPROX® radiological center between 2017-2021. Retrospective analysis of 220 anonymous maxillary CBCT, considering variables sex, presence of Canalis sinuosus, uni/bilateral Canalis sinuosus, largest diameter of Canalis sinuosus, presence/number of accessory canals. Univariate and bivariate statistical analysis. The 100 % prevalence of Canalis sinuosus in both sexes, 100 % bilateral presence. Canalis sinuosus average major diameter: 2.58 mm, 76.8 % presented accessory canals, with the presence of 2 accessory canals being more prevalent (34.1 %). A habitual normal anatomical structure must have a prevalence of over 50 % to be considered as such, but there is no consensus on the criteria used to define anatomical variation or normal anatomical structure. Literature describes Canalis sinuosus as anatomical variation, but current studies show high prevalence: Russia 67 %, Brazil 88 %, Turkey, Colombia and Chile 100 %. This study found 100 % prevalence, suggesting that Canalis sinuosus is an normal anatomical structure. However, Canalis sinuosus is little known as it is associated with numerous complications from dental and/or surgical procedures in anterior maxillary region, which can cause bleeding, paresthesia/ dysesthesia, acute pain, etc. High reported prevalences suggest that Canalis sinuosus is an normal anatomical structure and not an anatomical variation, but more studies and consensus are required to confirm this. It is clinically relevant to know the existence and location of Canalis sinuosus to avoid complications.

Effect of various intracanal materials on the diagnostic accuracy of cone-beam computed tomography in vertical root fractures / 北京大学学报(医学版)

OBJECTIVE@#To study the effect of various intracanal materials on the accuracy of oral maxillofacial cone-beam computed tomography (CBCT) for the diagnosis of vertical root fracture (VRF).@*METHODS@#A total of twenty-four structurally intact single root canal dried and isolated teeth extracted for orthodontic treatment or periodontal disease were collected. The teeth were decrowned along the cemento-enamel junction (CEJ) and then used as samples for the study after conventional root canal preparation and post preparation. The 24 samples were divided into two groups with 12 samples in each group. Group A was the control group (no VRF group). According to intracanal materials, they were divided into five subgroups: blank group, fiber post group, gutta-percha point group, titanium post group and gold-palladium post group. Group B was the experimental group (VRF group), and subgroups were grouped as above. The VRF model was prepared by a unified method in the VRF group: the root was completely fractured in the buccolingual direction with a custom root canal nail and then cemented and reset. The control group was not subjected to the simulation of VRF. Titanium post and gold-palladium post were made according to the individuality of the root canal preparation, and the tightness of the post to the root canal wall was confirmed by X-ray radiograph. Then all the samples were scanned by CBCT in the isolate swine mandibular alveolar sockets. The diagnostic accuracy was statistically analyzed via blind interpretation by experienced endodontic specialists and oral and maxillofacial medical imaging specialists.@*RESULTS@#The accuracy of the diagnosis of VRF in the blank group, fiber post group, gutta-percha point group, titanium post group, and gold-palladium post group in CBCT was 95.83%, 91.67%, 87.50%, 79.17%, and 45.83%, respectively. Compared with the blank group, the differences were not statistically significant in the fiber post group (P>0.999), the gutta-percha point group (P=0.500) and the titanium post group (P=0.125). The lowest diagnostic accuracy of VRF was found in the gold-palladium post group, and the difference was statistically significant compared with all other groups (P < 0.001).@*CONCLUSION@#Various intracanal materials have different degrees of influence on the diagnostic accuracy of VRF diagnosis in CBCT. The influence of fiber post, gutta-percha point and titanium post was small, while the influence of gold-palladium post was significant.

A prevalence survey of cone-beam computed tomography use among endodontic practitioners / 北京大学学报(医学版)

OBJECTIVE@#To investigate the clinical application of cone-beam computed tomography (CBCT) among endodontic practitioners, and to analyze the indications and reasonability of CBCT in the diagnosis and treatment of pulpal and periapical diseases.@*METHODS@#The clinical data were collected from patients who visited the Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology and underwent CBCT examination from January to December, 2021. The data with their complete clinical information (including clinical records, radiology request forms/reports, two-dimensional and three-dimensional imaging data) were included. Those who underwent CBCT examination for orthodontic or prosthodontics were excluded. The experience and training background of the endodontic specialists, the number of patients treated in the whole year, the objective and region of interest (ROI) of CBCT examination, technical parameters, such as machine type, field of view (FoV) and radiographic reports were collected and analyzed to evaluate the impact on diagnosis. Wilcoxon and Mann-Whitney tests were used to compare the distribution of CBCT ROI. Chi-squared test and pairwise comparison were used to compare the application of CBCT by endodontic specialists with different clinical experience (senior, middle and junior).@*RESULTS@#In 2021, a total of 3 308 CBCT scans were prescribed by 61 endodontic specialists who treated 34 952 patients throughout the year. 3 218 patients (male ∶female about 1 ∶2) amounting for 10% of the patients treated in the whole year who received CBCT scans with an median age of 35 years (28, 49). Around 98% CBCT examinations were performed after clinical examination and two-dimensional periapical radiographs were taken. The FoV of CBCT scanning less than 10 cm×10 cm accounted for 96% of the total number of the images. Among the 3 308 CBCT scans, 83% of the ROI were in posterior teeth, with a higher number of anterior teeth (Z=-2.278, P < 0.05). Maxillary and mandibular first molars accounted for 35% of the examined teeth. The objectives of CBCT scanning included three aspects: clarifying clinical diagnosis, guiding surgical and non-surgical endodontic treatment (including management of endodontic complications), and outcome assessment, accounting for 1 111 (34%), 1 745 (54%), 311 (10%), respectively. and the others 2%. In the diagnosis process, CBCT was mainly used for the diagnosis of chronic periapical periodontitis, root fracture, root resorption and dental trauma. In the study, 353 CBCT were used in the diagnosis of root fracture, with a positive diagnosis rate of 35% (125/353). 846 CBCT used to reveal the anatomy of the root canal system, of which 297 cases were used to find missed/extra canals after treatment failure, and 58% (171/297) were used to confirm the missed/extra canals. In the management of complications or errors, CBCT was mainly used to assist the diagnosis of perforation and to locate the separated instruments. In the study, 311 CBCT scans were used for outcome assessment, including 240 cases related to non-surgical treatment and 71 cases related to surgical endodontic treatment for follow-up or presence of clinical symptoms, and persistent lesions on 2D films. Among the 61 endodontic specialists who used CBCT, 23 (45%) were with senior experience, 15 (30%) with middle experience, and 23 (25%) with junior experience. The proportion of senior or junior experience prescribing CBCT examination was 10%, higher than that of middle experience (8%, χ12=39.4, χ22=29.1, P < 0.001). The application rate of chief endodontists was 18%, which was higher than that of associate chief endodontists (9%, χ12=139.4, P < 0.001). 31% (1 109/3 308) cases of diagnosis or treatment plans were changed after CBCT was taken.@*CONCLUSION@#Use of CBCT in endodontic practice could provide more clinical information, which is helpful for diagnosis, accurate treatment and prognosis evaluation.

A long-term evaluation of periodontal phenotypes before and after the periodontal-orthodontic-orthognathic combined treatment of lower anterior teeth in patients with skeletal Angle class Ⅲ malocclusion / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the changes of periodontal phenotype (width of keratinized gingiva, thickness and height of alveolar bone) of lower anterior teeth in patients with skeletal class Ⅲ malocclusion before and after the periodontal-orthodontic-orthognathic combined treatment.@*METHODS@#In the study, 20 patients with skeletal class Ⅲ malocclusion (6 males and 14 females) completed the periodontal-orthodontic-orthognathic combined treatment were included from March 2017 to June 2022, with 39 central incisors, 40 lateral incisors and 40 canines. The mean age was (25.40±4.27) years (20-34 years). The mean follow-up time was (3.70±1.05) years from the beginning of periodontal corticotomy regenerative surgery (PCRS) to the end of the combined treatment. Cone-beam computed tomography (CBCT) was used to measure the thickness, area and height of alveolar bone by the same researcher, taken before the PCRS (T0), 6 months after the PCRS (T1), 12 months after the PCRS (T2), before the orthognathic surgery (T3), and after the periodontal-orthodontic-orthognathic combined treatment (T4). The periodontal clinical parameters were used to evaluate changes in the soft tissue by another researcher, measured before the PCRS (T0) and after the combined treatment (T4). Changes of soft and hard tissue were evaluated by the periodontal phenotype.@*RESULTS@#The width of keratinized gingiva increased significantly (all P < 0.001) in lower anterior teeth, the central incisors, lateral incisors and canines increased by (1.82±1.57) mm, (2.03±1.48) mm and (2.05±1.27) mm, respectively. The proportion of thick periodontal biotype in the central and lateral incisors increased significantly (all P < 0.001), while the changes of periodontal biotypes in the lower canines were not obvious. The thickness of labial alveolar bone of lower anterior teeth all increased significantly after periodontal corticotomy regenerative surgery and the combined treatment (all P < 0.001). The area of labial alveolar bone of lower anterior teeth also increased significantly after the combined treatment (all P < 0.001). The whole area of labial and lingual alveolar bone of central and lateral incisors increased (P < 0.001), while the whole area of canines remained the same. All The height of the alveolar bone increased (all P < 0.001) on the labial side after the treatment.@*CONCLUSION@#The periodontal phenotypes of lower anterior teeth were significantly improved after the periodontal-orthodontic-orthognathic combined treatment in patients with skeletal Angle class Ⅲ malocclusion. The improvement was long-termly stable, and the periodontal risk was reduced.

Microcirugía endodóntica: regeneración ósea guiada en defecto óseo tunelizado: caso clínico / Endodontic microsurgery: guided bone regeneration in a through-and-through bone defect: a clinical case

Se presentó a la Cátedra de Endodoncia de la Facultad de Odontología de la Universidad de Buenos Aires un paciente masculino de 62 años de edad que al examen clínico presentaba una fístula vestibular en la zona de la pieza 1.2 y dolor a la percusión. Al examen radiográ-fico se identificó una lesión apical extensa abarcando las piezas dentarias 1.2 y 1.1 endodónticamente trata-das con alteración severa de la anatomía del espacio endodóntico, así como la presencia de postes metáli-cos que no respetaban el eje del canal radicular. Ante el análisis tomográfico se observó una perforación de la pieza 1.2 y una lesión periapical extensa afectando ambas corticales (vestibular y palatina). Se decidió un abordaje microquirúrgico con técnicas de regenera-ción ósea guiada (ROG) y se realizaron los controles clínico-tomográficos a los 6, 12 y 24 meses. Por otro lado, se evaluó con micromografía de rayos X la ana-tomía de los ápices radiculares resecados. La lesión extirpada fue analizada histológicamente (AU)

A 62-year-old male patient attended the Endodontics department of the Buenos Aires University. He was examined clinically and a vestibular fistula in 1.2 area and pain under percussion were found. Radiographic examination identified an extended periapical lesion compromising teeth 1.2 and 1.1 with endodontic treatment severely altering the root canal anatomy, as well as metallic cast posts that did not preserve root canal axis. Regarding the tomographic analysis, a vestibular root perforation was observed (1.2), and both, vestibular and palatal corticals, were affected. We decided to perform a surgical approach with guided bone regeneration techniques (GBR). Clinical-CBCT controls were done at 6, 12 and 24 months. Furthermore, the anatomy of the resected root apex-es was evaluated with X ray microtomography. The removed lesion was histologically analyzed (AU)

Estudio de la morfología de los conductos radiculares de los primeros premolares superiores en tomografía computarizada de haz cónico / Study of the morphology of root canals of the first upper premolars in cone beam computed tomography

Objetivo: analizar, mediante tomografía computarizada de haz cónico (TC o CBCT [Cone Beam Computed Tomograph]) la frecuencia del tipo de morfología interna de los conductos radi- culares según la clasificación de Vertucci y el número de raíces de los primeros premolares superiores. Material y métodos: en una población argentina de 50 pacientes, 30 de sexo femenino y 20 masculino, que concurrieron a la Cátedra de Diagnóstico por Imá- genes de la Facultad de Odontología de la Universidad de Buenos Aires, se evaluaron 100 primeros premolares superiores con CBCT. Se estudiaron las variables: número de raíces, tipo de morfología interna, edad, sexo y lado. Fueron seleccionadas las tomografías de maxilar superior que incluyeron ambos primeros premolares en salud dental, periodontal y con ápice cerrado. Se realizó una adquisición volumétrica 100 × 90 mm y tamaño de vóxel de 150 µm. Se realizó la exploración de las imágenes en el plano axial de los tercios apical, medio y cervical de las piezas 1.4 y 2.4. Se utilizó un corte axial, observando en él, el tercio apical, medio y cervical de las piezas 1.4 y 2.4. Cada premolar fue analizado con 30 cortes transversales. Se utilizó la clasificación de Vertucci para agrupar las distintas variables anatómicas de los conductos radiculares de los primeros premolares superiores, la cual consta de VIII tipolo- gías. Resultados: el tipo más representativo entre los 100 primeros premolares superiores, dentro de la clasificación de Vertucci, fue el tipo IV (dos conductos separados desde la cámara al ápice). La coincidencia de tipos entre los lados derecho (78%; IC 95%: 65 a 87%) e izquierdo (70%; IC 95%: 56 a 81%) fue significativa. La distribución según el número de raíces en el lado derecho (χ 2 = 2.88) e izquierdo (χ2 = 0.72) no presentó una heterogeneidad significativa. La coincidencia del número de raíces entre los lados derecho e izquierdo fue significativa. Conclusión: se comprobó el tipo de morfología interna más frecuente, el número de raíces y su variabilidad de acuerdo al lado, sexo, y edad; lo cual es de una relevante importancia para realizar una correcta instrumentación y obturación del sistema de conductos radiculares (AU)

Objective: to analyze, using cone beam computed tomography (CBCT), the frequency of the type of internal morphology of the root canals according to the Vertucci classification and the number of roots of the first upper premolars. Material and methods: 100 first upper premolars were evaluated with CBCT, which corresponded to 30 female and 20 male patients in the Chair of Diagnostic Imaging of the Faculty of Dentistry, University of Buenos Aires. Variables were studied: number of roots, type of internal morphology, age, sex and side. The tomography of the upper jaw with both first premolars in dental, periodontal and closed apex health, a 100 × 90 mm volumetric acquisition and a voxel size of 150 µm were selected. An axial cut was used, observing the apical, middle and cervical third of pieces 1.4 and 2.4. Each premolar was analyzed with 30 paraxial cuts. The Vertucci classification was used to group the different anatomical variables of the root canals of the first upper premolars which consists of VIII typologies. Results: the most representative type among the top 100 upper premolars within the Vertucci classification was type IV (two separate ducts from the chamber to the apex). The type coincidence between the right (78%; 95% CI: 65 to 87%) and left (70%; 95% CI: 56 to 81%) los primeros premolares superiores, la cual consta de VIII tipolo gías. Resultados: el tipo más representativo entre los 100 primeros premolares superiores, dentro de la clasificación de Vertucci, fue el tipo IV (dos conductos separados desde la cámara al ápice). La coincidencia de tipos entre los lados derecho (78%; IC 95%: 65 a 87%) e izquierdo (70%; IC 95%: 56 a 81%) fue significativa. La distribución según el número de raíces en el lado derecho (χ 2 = 2.88) e izquierdo (χ2 = 0.72) no presentó una heterogeneidad significativa. La coincidencia del número de raíces entre los lados derecho e izquierdo fue significativa. Conclusión: se comprobó el tipo de morfología interna más frecuente, el número de raíces y su variabilidad de acuerdo al lado, sexo, y edad; lo cual es de una relevante importancia para realizar una correcta instrumentación y obturación del sistema de conductos radiculares (AU))

Reabsorción dentinaria interna coronaria: informe de un caso clínico / Coronary internal dentine resorption: report of a clinical case

Objetivo: La reabsorción dentinaria interna es un pro- ceso causado por la actividad odontoclástica asociada princi- palmente a la inflamación pulpar crónica y/o traumatismos, y se caracteriza por la pérdida progresiva de tejido dentinario y la posible invasión al cemento. El presente informe describe el diagnóstico y tratamiento de un molar inferior que presentó un cuadro sintomático de reabsorción dentinaria interna. Caso clínico: Un paciente de 38 años fue derivado a la consulta por presentar una zona de reabsorción interna en un segundo molar inferior. Durante el examen clínico y ra- diográfico se tomó una radiografía preoperatoria periapical con radiovisiógrafo en la que se observó la presencia de un área compatible con el diagnóstico de reabsorción dentinaria interna, el que fue posteriormente confirmado por medio de una tomografía computada de haz cónico. La imagen de la lesión se presentó como una zona radiolúcida deformante de bordes nítidos, localizada a nivel de la cámara pulpar. El tra- tamiento consistió en la extirpación de la pulpa coronaria y de la instrumentación, desinfección y obturación de los conduc- tos radiculares y la cavidad de acceso. En el control clínico y radiográfico realizado luego de 3 años se observó que el paciente estaba asintomático y las estructuras perirradiculares se encontraban dentro de los límites normales. La observación histológica del material removido de la cámara pulpar reveló la presencia de un tejido granulomatoso con numerosos vasos sanguíneos y escasos focos micro hemorrágicos. Hasta el momento, el tratamiento endodóntico es el pro- cedimiento indicado para el tratamiento de la reabsorción dentinaria interna. Se destaca la importancia de la tomografía computada de haz cónico para el diagnóstico y tratamiento temprano de las reabsorciones dentinarias internas a efectos de contar con un pronóstico favorable (AU)

Aim: Internal dentine resorption is aprocess caused by odontoclastic activity, mainly associated with chronic pulpal inflammation and/or trauma, and it'scharacterized by a pro- gressive loss of dentine tissue and the possible invasion of the cementum. This report describes the diagnosis and treatment of a lower molar that presented a symptomatic case of inter- nal dentine resorption. Clinical case: A 38-years old patient was referred to the office because of presenting an area of internal resorption in a lower second molar. During clinical and radiographic exam- ination, a periapical preoperative radiograph with radiovisio- graph was taken, in which the presence of an area compatible with the diagnosis of internal dentine resorption was observed, which was later confirmed by a cone-beam computed tomog- raphy.The image of the lesion was presented as a deforming radiolucent area with sharp edges, located at pulp chamber level. Treatment consisted of the removal of the coronary pulp and the instrumentation, disinfection and filling of the root ca- nals and the access cavity. In the clinical and radiographic control carried out 3 years after procedure, it was observed that the patient was asymptomatic and the periradicular struc- tures were within normal limits. The histological observation of the removed material from the pulp chamber revealed the presence of a granulomatous tissue with numerous blood ves- sels and scarce micro hemorrhagic focus. Until now, the endodontic treatment is the indicated pro- cedure to treat internal dentine resorption. It is necessary to highlight the importance of the cone-beam computerized to- mography for the early diagnosis and treatment of internal dentine resorptions in order to have a favorable outlook (AU)

Lesiones perirradiculares asociadas a primeros molares superiores tratados endodónticamente: estudio a través de tomografías computadas / Periradicular lesions associated with endodontically treated maxillary first molars: study through computed tomography

Objetivos: Estudiar con tomografías computadas de haz cónico (CBCT) las lesiones perirradiculares de primeros molares superiores tratados endodónticamente; evaluar la lo- calización y, en los que tenían lesión en la raíz mesiovestibu- lar (MV), evaluar la frecuencia del conducto MV2. Materiales y métodos: A partir de una muestra de 179 tomografías, que incluían primeros molares superiores, se seleccionaron y analizaron aquellas en las cuales estos ha- bían recibido un tratamiento endodóntico previo, presentaban lesiones perirradiculares y conservaban una restauración co- ronaria. Las variables analizadas fueron: la localización de áreas radiolúcidas compatibles con lesiones perirradiculares de origen endodóntico y la correlación entre diferentes loca- lizaciones y la calidad del tratamiento realizado (adecuado, defectuoso o sin tratamiento). Los datos fueron analizados mediante la prueba de chi-cuadrado y la prueba de Spearman. Resultados: De las 179 CBCT que incluían primeros molares superiores, 90 reunían las condiciones requeridas. La frecuencia de las lesiones perirradiculares fue significativa- mente mayor en la raíz MV al compararla con las raíces disto- vestibular y palatina (p<0,05). El conducto MV1 presentó un tratamiento adecuado en todos los casos. El conducto MV2 recibió un tratamiento adecuado en 4 casos (4,44%), defec- tuoso en 4 casos (4,44%) y no tratado en 82 casos (91,1%); con una diferencia estadísticamente significativa (p<0,05). Conclusiones: En la muestra analizada, la localización de lesiones perirradiculares postratamiento endodóntico en primeros molares superiores se encontró con mayor frecuencia asociada a la raíz mesiovestibular, donde en la mayoría de los casos el con- ducto MB2 no fue tratado o presentó un tratamiento defectuoso (AU)

Aim: To study with cone-beam computed tomography (CBCT) the periradicular lesions of maxillary first molars with endodontical treatment; to evaluate its localization and, in those with a mesiobuccal root (MB) injury, assess the fre- quency of the MB2 root canal. Materials and methods: From a sample of 179 tomog- raphies (CBCT) that included maxillary first molars, those in which they had received previous endodontic treatment, pre- sented periradicular lesions and had a coronary restoration were selected and analyzed. The analyzed variables were: localization of radiolucent areas compatible with periradic- ular lesions of endodontic origin and the correlation between different localizations and quality of the performed treatment (adequate, defective, or untreated). Data were analyzed by the chi-square test and the Spearman test. Results: Of the 179 CBCT that included maxillary first molars, 90 met the required conditions. The frequency of periradicular lesions was significantly higher in the MB root when compared with distobuccal and palatal roots (P<0,05). The MB1 canal presented an adequate treatment in all cas- es. The MB2 canal received adequate treatment in 4 cases (4.44%), a defective one in 4 cases (4.44%) and was untreated in 82 cases (91.1%). The differences among these frequencies were statistically significant (P<0.05). Conclusions: In the analyzed sample, the localization of periradicular lesions after endodontic treatment in maxillary first molars was associated more frequently with the mesio- buccal root in which in the majority of cases the MB2 canal was untreated or presented a defective treatment

Fossa navicularis magna: detección por tomografía computarizada de haz cónico / Fossa navicularis magna: detection by cone-beam computed tomography

Introducción: La identificación, interpretación y manejo de hallazgos incidentales en imagenología dental es imprescindible. Algunos de ellos requieren técnicas de imagen adicionales y remisión a profesionales de experiencia, otros únicamente su descripción. Una de estas variantes anatómicas se halla en el clivus, la fossa navicularis magna, asociada en pocos casos a repercusiones sistémicas. Objetivo: Describir las características de la fossa navicularis magna para su identificación mediante tomografía computarizada de haz cónico. Presentación de los casos: Tres pacientes de sexo femenino, con un rango de edad entre 35-71 años que acuden al Centro Odontológico de la Universidad San Martín de Porres para tratamientos de ortodoncia y rehabilitación oral. En estas áreas, como parte del protocolo se solicita tomografía computarizada de haz cónico por pieza retenida y elaboración de guías quirúrgicas respectivamente. El escaneo permite la identificación de un defecto tipo muesca en el clivus, de límites bien definidos y bordes corticalizados, lo que sugiere fossa navicularis magna. La historia clínica de los pacientes no sugirió implicaciones clínicas. Principales comentarios: Se informa y discute esta variante anatómica cuya presencia no requiere tratamiento y generalmente no tiene repercusiones sistémicas. En contados casos ha estado asociado con cuadros clínicos que amenazan la vida del paciente, precisamente porque puede servir como un trayecto para infecciones intracraneales. De ahí la necesidad de conocer y describir esta variante anatómica(AU)

Introduction: The identification, interpretation and management of incidental findings in dental imaging is essential. Some of them require additional imaging techniques and referral to experienced professionals, others only their description. One of these anatomical variants is found in the clivus, fossa navicularis magna, associated in few cases with systemic repercussions. Objective: Describe the characteristics of fossa navicularismagna for its identification by cone-beam computed tomography. Presentation of cases: Three female patients, with an age range between 35-71 years who come to the Dental Center of San Martín de Porres University for orthodontic treatments and oral rehabilitation. In these areas, as part of the protocol, cone-beam computed tomography per retained piece and development of surgical guides are requested, respectively. The scan allows the identification of a notch-like defect in the clivus, of well-defined boundaries and corticalized edges, suggesting fossa navicularis magna. The patients' medical history did not suggest clinical implications. Main comments: This anatomical variant is reported and discussed and its presence does not require treatment and generally has no systemic repercussions. In rare cases it has been associated with clinical pictures that threaten the patient's life, precisely because it can serve as a path for intracranial infections. Hence the need to know and describe this anatomical variant(AU)

Can the method of cbct interpretation influence endodontic diagnosis? / O método de interpretação da tcfc pode influenciar o diagnóstico endodôntico?

Objetivo: Este estudo avaliou a influência do método de visualização e análise do exame de tomografia computa-dorizada de feixe cônico (TCFC) no diagnóstico de afecções endodônticas. Materiais e métodos: Vinte casos clínicos contendo doze diferentes afecções endodônticas foram ana-lisados por dois especialistas em radiologia odontológica e um especialista em endodontia. Inicialmente, os avaliadores visualizaram os casos em Portable Document Format (PDF) contendo uma seleção de imagens digitais e, por consenso, descreveram suas hipóteses diagnósticas para cada caso. Após uma semana, os avaliadores reavaliaram os casos, desta vez utilizando reconstrução multiplanar em um visualizador de imagens no formato Digital Imaging and Communications in Medicine (DICOM). Novamente, por consenso, eles indicaram suas hipóteses diagnósticas. Resultados: Em 10% dos casos, houve discrepância entre os diagnósticos realizados utili-zando as seleções de imagens digitais em PDF e utilizando a reconstrução multiplanar. A visualização das imagens em PDF obteve sensibilidade de 0.714, especificidade de 0.966, e acurácia de 90%. Discussão: Na maioria destes casos, as afecções endodônticas identificadas utilizando o visuali-zador de imagens DICOM (reconstrução multiplanar) não foram detectadas quando visualizados os PDF de imagens pré-selecionadas. Conclusão: Embora mais estudos sejam necessários, os autores reiteram que a utilização de recons-truções multiplanares sempre são preferíveis comparadas à outras formas de análise da TCFC, para que se atinja o máximo potencial diagnóstico do exame de imagem.

Aim: This study evaluated the influence of the method used for visualization and analysis of cone-beam com-puted tomography (CBCT) on the diagnosis of endodontic conditions. Materials and methods: Twenty clinical cases containing twelve different endodontic conditions were analyzed by two specialists in dental radiology and one specialist in endodontics. Initially, the evaluators viewed the cases in Portable Document Format (PDF) containing a selection of digital images and, by consensus, described their diagnostic hypotheses for each case. One week la-ter, the evaluators reassessed the cases, this time using multiplanar reconstructions with a Digital Imaging and Communications in Medicine (DICOM) format image viewer. Once more, by consensus, they recorded their diagnostic hypotheses. Results: In 10% of the cases there was a discrepancy between the diagnoses made using preselected digital images in PDFs and by viewing multiplanar reconstructions. The visualization of the PDF images obtained a sensitivity of 0.714, specificity of 0.966, and 90% accuracy. Discussion: In the majority of these cases, endodontic conditions identified using the DICOM image viewer (multiplanar reconstruction) were not detected using the PDFs of preselected images. Conclusion: Although more studies are needed, the au-thors reiterate that using multiplanar reconstructions should always be preferred to other forms of analysis for CBCT, so that the maximum diagnostic potential of the imaging exam can be achieved.

Ruptura de aguja dental con migración al espacio pterigomaxilar. Resolución mediante abordaje intrabucal laterofaríngeo / Rupture of dental needle with migration to the pterygomaxillary space. Resolution by intraoral lateropharyngeal approach

Introducción: La ruptura de una aguja dental es una complicación infrecuente y sucede generalmente por el movimiento repentino y/o cierre bucal inesperado del paciente, por doblar la aguja en forma inadecuada, por insertarla completamente o moverla dentro del tejido blando, por elegir agujas de calibre y longitud inadecuados y al realizar técnicas anestésicas inapropiadas. Cuando la aguja no puede ser recuperada al instante, debe establecerse su ubicación imagenológica tridimensional y decidir el manejo. Ante tal situación, su eliminación quirúrgica es la propuesta más recomendable por la posibilidad de que migre y lesione estructuras anatómicas importantes. Objetivo: Realizar una revisión de la literatura y presentar un caso clínico de ruptura de aguja dental localizada en el espacio pterigomaxilar, resuelto con un abordaje intrabucal laterofaríngeo. Presentación de caso: Paciente masculino de 8 años de edad, que acude a consulta por presentar ruptura de una aguja dental. Para obtener su ubicación se utilizó una tomografía computarizada de haz cónico con reconstrucción tridimensional a boca cerrada y abierta. Esta prueba ofreció mayor precisión y correspondencia anatómica, considerando que la eliminación quirúrgica podría realizarse mediante un abordaje intrabucal. Así fue hecho y durante la intervención quirúrgica se advirtió que la aguja había migrado a una ubicación superior y posterior, al espacio pterigomaxilar. Ante tal situación, resultó de mayor complejidad su recuperación, que ya presentaba riesgos por el procedimiento complejo al que se sometió. Conclusiones: La anestesia local intrabucal no está exenta de complicaciones propias como la ruptura de la aguja dental. Cuando este evento se presenta, el resultado puede ser de muy difícil manejo(AU)

Introduction: The rupture of a dental needle is an uncommon complication and usually happens due to the sudden movement and / or unexpected oral closure of the patient, by bending the needle improperly, by inserting it completely or moving it into the soft tissue, by choosing needles of inadequate caliber and length and by performing inappropriate anesthetic techniques. When the needle cannot be recovered instantly, its three-dimensional imaging location must be established and handling decided. In such a situation, its surgical elimination is the most recommended proposal due to the possibility of migrating and injuring important anatomical structures. Objective: Conduct a literature review and present a clinical case of dental needle rupture located in the pterygomaxillary space, resolved with a lateropharyngeal intraoral approach. Case presentation: An 8-year-old male patient, who comes to the consultation for a ruptured dental needle. To obtain its location, a cone-beam computed tomography with three-dimensional reconstruction was used at closed and open mouth. This test offered greater precision and anatomical correspondence, considering that surgical removal could be performed by an intraoral approach. This was done and during the surgical intervention it was noticed that the needle had migrated to an upper and posterior location, to the pterygomaxillary space. Faced with this situation, his recovery was more complex, in addition to the one that this procedure represents by itself. Conclusions: Intraoral local anesthesia is not exempt from its own complications such as the rupture of the dental needle. When this event occurs, the result can be very difficult to manage(AU)

Consentimiento informado en radiología odontológica: un asunto pendiente / Informed consent in dental radiology: a pending matter

Introducción: En el ámbito odontológico es muy común el uso de radiografías intraorales, extraorales e incluso de tomografías computarizadas volumétricas. Las radiografías intraorales presentan una baja dosis de radiación en comparación con las tomografías computarizadas volumétricas que pueden emitir una mayor dosis de radiación con cierto grado de riesgo para los pacientes. A pesar de que se conoce sobre la importancia del uso del consentimiento informado y los riesgos durante estos procedimientos, muy poco se ha reportado sobre la utilización del consentimiento informado en radiología oral y maxilofacial. Objetivo: Analizar los beneficios y los retos de usar el consentimiento informado en radiología odontológica. Comentarios principales: Actualmente, no existe un consenso claro en la comunidad odontológica sobre si se debe obtener el consentimiento informado del paciente antes de que se someta a un examen de imagen con radiación ionizante. Su aplicación de manera repetitiva o prolongada podría afectar al paciente a largo plazo. Consideraciones globales: Existe un consenso universal en resaltar la importancia del consentimiento informado en todo el ámbito de la salud. Sin embargo, en la práctica, su realización puede conllevar ciertas dificultades, tales como la identificación del responsable de su realización, el tiempo que lleva ejecutarla y la preocupación por causar un miedo innecesario en el paciente. Si estas dificultades logran ser superadas, podremos ver los beneficios de tener un consenso claro para la utilización de un consentimiento informado en el área odontológica(AU)

Introduction: In the dental field, the use of intraoral, extraoral and even volumetric computed tomography is very common. Intraoral X-rays have a low dose of radiation compared to volumetric CT scans that can emit a higher dose of radiation with some degree of risk to patients. Although the importance of the use of informed consent and the risks during these procedures are known, very little has been reported about the use of informed consent in oral and maxillofacial radiology. Objective: Analyze the benefits and challenges of using informed consent in dental radiology. Main Comments: Currently, there is no clear consensus in the dental community on whether the patient's informed consent should be obtained before they undergo an imaging examination with ionizing radiation. Its application repetitively or prolongedly could affect the patient in the long term. Global considerations: There is a universal consensus to highlight the importance of informed consent in the entire field of health. However, in practice, its realization can lead to certain difficulties, such as the identification of the person responsible for its implementation, the time it takes to execute it and the concern to cause unnecessary fear in the patient. If these difficulties can be overcome, we can see the benefits of having a clear consensus for the use of informed consent in the dental area(AU)

Impact of dental cone-beam computed tomography on diagnostic evaluation and treatment plan for the maxillary sinus in dental implant planning / Impacto de la tomografía computarizada de haz cónico en el diagnóstico y plan detratamiento preimplantologico de senos maxilares

Objective: To determine the impact of CBCT on diagnostic evaluation and treatment plan for the maxillary sinus in dental implant planning. Material and Methods: Diagnostic evaluation and treatment plan for the maxillary sinus were evaluated by eight specialists experienced in dental implant placement. Eight panoramic radiographs (PAN) and CBCT examinations were obtained from five adult patients with a specific clinical need for dental implants. Evaluation was performed first on PAN then, at least 2 weeks later, on CBCT. Residual alveolar ridge height, mucosal thickening, radiographic findings and treatment plan were recorded. The confidence level was evaluated for both diagnostic evaluation and treatment plan. The kappa statistic for intra-observer reproducibility and McNemar test were performed. Results: In the diagnostic evaluation, CBCT showed significant impact on the diagnosis of radiographic findings. Availability of CBCT significantly changed the treatment plan, for less invasive treatment, or no treatment need. Observers had significantly greater confidence when using CBCT than PAN, when indicating presence of mucosal thickening and radiographic findings in the maxillary sinus. In addition, CBCT increased confidence in the treatment plan. Conclusion: The present study suggests that CBCT has an impact on the diagnostic evaluation of radiographic findings in the maxillary sinus and on the decision to place implants, owing to misdiagnosis of pathology and planning of more invasive treatments when using PAN. Availability of CBCT also improves clinician confidence. Further studies at higher levels of diagnostic efficacy should be performed, to justify the use of CBCT, by evaluating the actual treatment performed and its outcome.

Objetivo: Determinar el impacto de la tomografía computarizada de haz cónico (CBCT) en la evaluación diagnóstica y el plan de tratamiento del seno maxilar en la planificación de implantes dentales. Material y Métodos: La evaluación diagnóstica y el plan de tratamiento del seno maxilar fueron evaluados por ocho especialistas con experiencia en la colocación de implantes dentales. Se obtuvieron ocho radiografías panorámicas (PAN) y exámenes CBCT de cinco pacientes adultos con una necesidad clínica específica de implantes dentales. La evaluación se realizó primero en PAN y luego, al menos dos semanas después, en CBCT. Se registraron la altura del reborde alveolar residual, el engrosamiento de la mucosa, los hallazgos radiográficos y el plan de tratamiento. Se evaluó el nivel de confianza tanto para la evaluación diagnóstica como para el plan de tratamiento. Se realizó el estadístico kappa para la reproducibilidad intraobservador y la prueba de McNemar. Resultados: En la evaluación diagnóstica, CBCT mostró un impacto significativo en el diagnóstico de los hallazgos radiográficos. La disponibilidad de CBCT cambió significativamente el plan de tratamiento, para un tratamiento menos invasivo o sin necesidad de tratamiento. Los observadores tuvieron una confianza significativamente mayor al usar CBCT que PAN, al indicar la presencia de engrosamiento de la mucosa y hallazgos radiográficos en el seno maxilar. Además, CBCT aumentó la confianza en el plan de tratamiento. Conclusión: El presente estudio sugiere que la CBCT tiene un impacto en la evaluación diagnóstica de los hallazgos radiográficos en el seno maxilar y en la decisión de colocar implantes, debido al diagnóstico erróneo de la patología y la planificación de tratamientos más invasivos al usar PAN. La disponibilidad de CBCT también mejora la confianza del clínico. Se deben realizar más estudios a niveles más altos de eficacia diagnóstica para justificar el uso de CBCT, evaluando el tratamiento real realizado y su resultado.

Correlation between cortical bone thickness at mini-implant insertion sites and age of patient

ABSTRACT Introduction: Orthodontic mini-implants (MI) are a reliable alternative to provide temporary orthodontic anchorage. Prior to miniscrew insertion, the best approach would be to evaluate each possible insertion site and measure the cortical bone thickness, and verify whether it would provide adequate primary stability. Objective: This study aimed to evaluate the difference in cortical bone thickness in areas of mini-implants insertion in patients of different ages, by means of cone beam computed tomography (CBCT). Methods: The sample of this retrospective study was composed of 123 CBCT scans, which were used to measure cortical bone thickness in the buccal and palatal inter-radicular space in the mesial region of the first permanent molars. These measures were compared by using the Student's t-test, ANOVA/Tukey tests, and Linear regression between male and female subjects, from 12 to 30 years old. Results: No significant difference was found in cortical bone thickness between sex, race and sagittal facial patterns. Significantly higher measurement values were observed in patients older than 12 years of age at all sites evaluated. The coefficient β at the adjusted linear regression analysis showed that at each increment in age, mean cortical thickness values increased by 0.06mm in the mandible, 0.03mm in the buccal region and 0.02mm in the palatal region of the maxilla. Conclusions: The increase in cortical bone thickness was positively associated with age; that is, the more advanced the patient's age was, the less chance there was of failure due to primary stability.

RESUMO Introdução: Os mini-implantes ortodônticos (MI) são uma alternativa confiável para fornecer ancoragem esquelética temporária. Antes da inserção do mini-implante, a melhor abordagem seria avaliar cada local de inserção possível, medir a espessura do osso cortical e verificar se proporcionaria uma adequada estabilidade primária. Objetivo: O presente estudo teve como objetivo avaliar a diferença na espessura do osso cortical em áreas de inserção dos mini-implantes em pacientes de diferentes idades, por meio da tomografia computadorizada de feixe cônico. Métodos: A amostra desse estudo retrospectivo foi composta por 123 tomografias computadorizadas de feixe cônico, que foram utilizadas para medir a espessura do osso cortical nos espaços inter-radiculares vestibular e palatino na região mesial dos primeiros molares permanentes. Essas medidas foram comparadas por meio dos testes t de Student, ANOVA/Tukey e regressão linear entre os sexos masculino e feminino, de 12 a 30 anos. Resultados: Não houve diferença estatisticamente significativa na espessura cortical, quando comparados sexo, cor da pele e padrão facial sagital. Foram verificadas medidas significativamente maiores em pacientes com idade superior a 12 anos em todos os sítios avaliados. O coeficiente β da análise de regressão linear ajustada mostrou que, a cada incremento da idade, os valores médios da espessura cortical aumentaram 0,06 mm na mandíbula, 0,03 mm na região vestibular e 0,02 mm na região palatina da maxila. Conclusão: O aumento da espessura do osso cortical teve associação positiva com a idade, ou seja, quanto mais avançada a idade do paciente, menor a chance de falha, devido à estabilidade primária.

Remoción diferida de un tercer molar superior impulsado a la región infratemporal / Deferred removal of a third upper molar driven to the infratemporal region

La cirugía de los terceros molares retenidos puede ser considerada una intervención de rutina para el cirujano bucomaxilofacial. Como todo procedimien-to quirúrgico, puede presentar complicaciones intra y postoperatorias. Las más frecuentes son el dolor, edema, trismus, hemorragia y fracturas de las piezas dentarias a extraer, o de las tablas óseas. Pero tam-bién se pueden presentar otras complicaciones ines-peradas, como la impulsión o desplazamiento de la pieza dentaria a espacios anatómicos vecinos, entre los que podemos encontrar al espacio pterigomandi-bular, la celda submaxilar, el seno maxilar, el espacio infratemporal, según se trate de terceros molares retenidos inferiores o superiores. En el presente ar-tículo, se describe una situación clínica de un tercer molar superior, que fue accidentalmente impulsado a la región infratemporal, y removido en una segunda cirugía realizada 3 semanas después del primer in-tento de exodoncia. Se analizan también los estudios preoperatorios para su correcto diagnóstico, y las maniobras clínicas e instrumentales tendientes a po-sibilitar su remoción minimizando las complicaciones intra y postquirúrgicas (AU)

Surgery of retained third molars can be considered a routine intervention for the oral surgeon. Like any surgical procedure, it can present intra and posto-perative complications. The most frequent are pain, edema, trismus, hemorrhage and fractures of the teeth to be extracted or of the bone tables. But other unexpected complications can also occur, such as the impulsion or displacement of the tooth to neighbo-ring anatomical spaces, among which we can find the pterygomandibular space, the submaxillary cell, the maxillary sinus, the buccal space, the infratemporal space and the lateral pharyngeal space, depending on whether they are lower or upper retained third mo-lars. In this article, the clinical case of a third upper molar is described, which was accidentally driven to the infratemporal region, which was removed in a second surgery performed 3 weeks after the first attempt at exodontics. It should be noted the impor-tance of diagnostic imaging as an indispensable com-plement to the correct location of the displaced tooth and its subsequent removal (AU)

A cone-beam computed tomography evaluation of three-dimensional changes of circummaxillary sutures following maxillary protraction with alternate rapid palatal expansions and constrictions / 北京大学学报(医学版)

OBJECTIVE@#To assess three-dimensional (3D) changes of circummaxillary sutures following maxillary protraction with alternate rapid palatal expansions and constrictions (RPE/C) facemask protocol in maxillary retrusive children, and to investigate the relationship between the changes of circum-maxillary sutures and zygomaticomaxillary suture (ZMS) maturation, and to explore the factors of maxilla forward movement with RPE/C and facemask.@*METHODS@#In the study (clinical trial registration No: ChiCTR2000034909), 36 maxillary retrusive patients were recruited and block randomized to either the rapid palatal expansion (RPE) group or the RPE/C group. Patients aged 7 to 13 years, Class Ⅲ malocclusion, anterior crossbite, ANB less than 0°, Wits appraisal less than -2 mm, and A-Np less than 0 mm were included in the study. The RPE group received rapid palatal expansion, whereas the RPE/C group received alternate rapid palatal expansions and constrictions, and both with facemask protraction. Head orientations of cone-beam computed tomography (CBCT) images were implemented by Dolphin 11.7. 3D measurements of circummaxillary sutures on CBCT images were evaluated using Mimics 10.01 before (T0) and after treatment (T1). The changes were analyzed with independent t test, two-way ANOVA, Pearson correlation and regression analysis.@*RESULTS@#Two subjects in the RPE/C group were lost to follow-up. A total of 34 patients reached the completion criteria and were analyzed. Compared with the RPE group, sagittal changes of circummaxillary sutures were significantly increased in the RPE/C group with 1.21 mm advancement of zygomaticotemporal suture, 2.20 mm of ZMS, 1.43 mm of zygoma-ticofrontal suture (P < 0.05, respectively). Except for the zygomaticotemporal suture, the rest forward sagittal changes of other circummaxillary sutures showed no major difference in terms of the ZMS maturation. The Spearman's correlation in RPE/C indicated a strong positive correlation of sagittal changes between ZMS and point A (P < 0.01) with a regression analysis R2=42.5%.@*CONCLUSION@#RPE/C might be more effective on the treatment of maxillary retrusive children. As one of the major mechanical loading sutures during orthopedic therapy, ZMS showed a strong positive correlation with point A on sagittal changes.

Mandibular pre-molars endodontic anatomy and role in sex dimorphism for Western Asia population using CBCT 3d imaging technique / Anatomía endodóntica de premolares mandibulares y papel en el dimorfismo sexual para la población de Asia Occidental utilizando la técnica de imagen 3d CBCT

SUMMARY: Cone Beam Computerized Tomography (CBCT) imaging technique can be used for identifying the root canal anatomy and its use in determining sexual dimorphism. The aim of current study was to identify the commonly found root canal morphology and gender dimorphism for mandibular pre-molars in Western Asia population according to Vertucci's classification using CBCT 3D imaging technique. On ethical approval 470 patients from Western Asia population with intact healthy mandibular first and second pre-molars were included in the study. The selected patients were sent to radiology department of Riyadh Elm University, Saudi Arabia for CBCT images. The observations recorded included: i) number of roots; and ii) type of root canal morphology based on Vertucci's classification. All the mandibular first and second pre-molars had single root both in males and females. The type of Vertucci's classification commonly observed was Type I both in males (88.94 %) and females (100 %) in mandibular first pre-molars. Similarly Type I was identified as a common root canal configuration in mandibular second pre-molars for males (82.77 %) and females (100 %). The two canal configurations Type IV and V were only observed in the males. It can be concluded from the results mandibular first and second pre-molars in the Western Asia population are single rooted with common Vertucci's Type I canal configuration in the females with rare evidence of two canals in males. Additionally CBCT is an effective technique and should be used for detection of root canals in the mandibular pre-molars which can aid dentists in providing a successful endodontic therapy.

RESUMEN: La imagen de la tomografía computarizada de haz cónico (CBCT) se puede utilizar para identificar la anatomía del conducto radicular y para determinar el dimorfismo sexual. El objetivo del estudio fue identificar la morfología del conducto radicular y el dimorfismo de sexo, comúnmente encontrados en los premolares mandibulares en la población de Asia occidental, de acuerdo con la clasificación de Vertucci, utilizando la técnica de imágenes CBCT 3D. Tras la aprobación ética, se incluyeron en el estudio 470 pacientes de la población de Asia occidental con primeros y segundos premolares mandibulares sanos intactos. Los pacientes seleccionados fueron enviados al departamento de radiología de la Universidad de Riyadh Elm, Arabia Saudita, para las imágenes CBCT. Las observaciones incluyeron: i) número de raíces; y ii) tipo de morfología del conducto radicular según la clasificación de Vertucci. Se observó solamente una raíz en los primeros y segundos premolares mandibulares tanto en hombres como en mujeres. El tipo de clasificación de Vertucci comúnmente observado fue Tipo I tanto en hombres (88,94 %) como en mujeres (100 %) en los primeros premolares mandibulares. El Tipo I se identificó como una configuración común del conducto radicular en los segundos premolares mandibulares para hombres (82,77 %) y mujeres (100 %). Ambas configuraciones de canal Tipo IV y V solo se observaron en los varones. Se puede concluir a partir de los resultados de los primeros y segundos premolares mandibulares en la población de Asia occidental, que éstos tienen una sola raíz con una configuración de canal de Vertucci Tipo I común en mujeres con una evidencia de dos canales infrecuente en los hombres. La CBCT es una técnica eficaz y debe usarse para la detección de conduc- tos radiculares en los premolares mandibulares, lo que puede ayu- dar a los dentistas a proporcionar una terapia endodóntica exitosa.

Valores de densidad en la escala de grises en Tomografía Computarizada de Haz Cónico: alcances y limitaciones / Grayscale Values in Cone Beam Computed Tomography: Scope and Limitations

ABSTRACT: Cone-beam computed tomography (CBCT) is a 3D imaging technique widely used in maxillofacial diagnosis. The grayscale value (GSV) is a number that represents the amount of attenuation of the X-ray beam by the material contained in each voxel or structural unit of the tomographic volume. Similarly, in computed tomography (CT) used in medical radiology, the attenuation values are standardized in the Hounsfield Unit (HU) scale. Although GSV may have interesting potential applications in maxillofacial diagnosis, it is essential to know that HU differ from GSV. The latter are susceptible to multiple technical factors during the tomographic acquisition, so their value can vary among different CBCT scanners or when technical parameters are modified. Hence, GSV should not be extrapolated between different CBCT machines, and their use should be cautious while more investigation is available considering various equipment and acquisition protocols.

RESUMEN: La tomografía computarizada de haz cónico (CBCT, por sus siglas en inglés) es una técnica de imagen 3D ampliamente usada en diagnóstico maxilofacial. El valor de densidad en la escala de grises (DEG) es una cifra que corresponde al grado de atenuación de los rayos x del material representado en cada vóxel o unidad estructural de la tomografía. De forma similar, en los sistema de tomografía computarizada de uso médico (CT) el valor de atenuación está estandarizado en las Unidades Hounsfield (UH). Aunque los valores de DEG pueden tener interesantes usos potenciales en el apoyo de diagnóstico en el área dentoalveolar, es importante conocer que los valores UH no son los mismos a los valores DEG, y que los valores de DEG son susceptibles a múltiples factores técnicos durante la adquisición de la tomografía, por lo que se pueden obtener resultados distintos entre equipos y al variar parámetros técnicos en las tomas. Por lo tanto sus valores no deben extrapolarse entre equipos y su uso debe ser cauteloso mientras se realiza mayor investigación específica para cada equipo y para cada protocolo de adquisición.