Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.956
Filtrar
1.
Int. j. morphol ; 38(3): 714-719, June 2020. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1098310

RESUMEN

The morphological variations of the mental foramen (MF) and mandibular foramen (MBF) have been studied for several years, and the prevalence and morphometric characteristics of double and triple foramina have been reported. The objective of this study was to establish the prevalence of variations in the MF and MBF, and to carry out a morphometric analysis of a Chilean population using digital panoramic radiographs. The study included 927 radiographs; the observed prevalence of double MF was 2.58 %, while the prevalence of double MBF was 1.51 %. No cases of triple foramina were found. In men, double MF was found more frequently in the left hemiarch (64.28 % of cases), while in women it was more frequent in the right hemiarch (80 %). Double MBF was found more frequently in the right hemiarch in women (80 % of cases), while the distribution between left and right in men was even. The mean area, width and height of the double MF were 5.46 mm2, 2.77 mm and 2.57 mm respectively. The means of the same morphometric measurements in double MBF were 6.37 mm2, 2.27 mm and 3.19 mm respectively. In both foramina, statistically significant differences were only found between the height of the foramen and the age of the subjects, with the observation that the greater the subject's age, the smaller the height. Dental surgeons must take these anatomical variants into consideration in clinical and surgical actions; timely diagnosis by radiograph is important to avoid possible complications.


Las variaciones morfológicas del foramen mental (FM) y mandibular (FMB) han sido estudiadas durante varios años, reportándose su prevalencia y las características morfométricas de forámenes dobles y triples. El objetivo de este estudio fue establecer la prevalencia de variaciones de los FM y FMB y realizar un análisis morfométrico a través de radiografías panorámicas digitales de una muestra de población chilena. En el estudio se incluyeron 927 radiografías y se observó una prevalencia de FM doble de 2,58 %, mientras que la prevalencia de FMB doble fue de 1,51 %. No se encontraron casos de forámenes triples. En hombres, el FM doble se encontró mayoritariamente en la hemiarcada izquierda (64,28 % de los casos), mientras que en mujeres fue en la hemiarcada derecha (80% de los casos). Para el caso de los FMB dobles, en mujeres se presentó mayoritariamente en la hemiarcada derecha (80 % de los casos), mientras que en hombres fue equitativo en ambos lados. El promedio del área, ancho y alto de los FM dobles fue de 5,46 mm2, 2,77 mm y 2,57 mm, respectivamente. Asimismo, los promedios de estas medidas morfométricas para el FMB doble fueron 6,37 mm2, 2,27 mm y 3,19 mm, respectivamente. Para ambos forámenes sólo se encontraron diferencias estadísticamente significativas entre el alto y la edad de los sujetos, observando que, a mayor edad menor era el alto del foramen. Los cirujanos dentistas deben tener en consideración estas variantes anatómicas para la realización de distintas acciones clínicas y quirúrgicas, su diagnóstico radiográfico oportuno es importante para prevenir posibles complicaciones.


Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Adulto Joven , Variación Anatómica , Foramen Mental/anatomía & histología , Foramen Mental/diagnóstico por imagen , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Radiografía Panorámica , Prevalencia , Estudios Transversales , Distribución por Edad y Sexo
2.
Head Face Med ; 16(1): 13, 2020 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-32513223

RESUMEN

BACKGROUND: The bone thickness of the human mandibular ramus is an important parameter in mandibular surgeries. The aim of this study was to systematically measure the bicortical bone thickness, the ramus dimensions and the position of the lingula. The measurements were tested on significant correlations to the patients' parameters. METHODS: Based on CBCT scans 150 rami were reconstructed as 3D polygon surfaces. An anatomical grid was adapted to the ramus surface to mark the bone thickness measurement points and to achieve comparability between the measurements on different mandibles. The bone thickness, ramus height, ramus width and the gonion angle were measured. A cluster analysis was performed with these parameters to identify clinically relevant groups with anatomical similarities. RESULTS: The median distribution of the bone thickness was calculated and visualized in a pseudo-colour map. The mean ramus height was 44.78 mm, the mean width was 31.31 mm and the mean gonion angle was 124.8°. The average distance from the lingula to the dorsal tangent was 53% of the total width and its distance to the caudal tangent was 65% of the total height. Significant correlations between the bone thickness and the ramus proportions could be identified. Age and sex had no significant influence on the mean bone thickness. The measured rami could be divided into two groups by cluster analysis. CONCLUSION: The dimensions of the human mandibular ramus can be determined from 3D reconstructed surface models from CBCT scans. Measurements could be made comparable by applying an anatomically oriented grid. A cluster analysis allowed the differentiation of two groups with different bone thickness distributions and geometries, which can be used for the optimization of osteosynthesis systems and their precision of adaptation to different ramus morphologies.


Asunto(s)
Mandíbula , Procedimientos Quirúrgicos Ortognáticos , Tomografía Computarizada de Haz Cónico Espiral , Diente , Proteínas Adaptadoras Transductoras de Señales , Humanos , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen
3.
J Appl Oral Sci ; 28: e20190399, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32348443

RESUMEN

Objectives To evaluate the acoustic properties of the /s/ sound in individuals with different occlusion types and to investigate relationships between these properties and cephalometric measurements. Methodology Sixty patients were divided into three groups based on malocclusion. Group 1 included 20 patients (mean age: 14.85±2.01 years) with Class I skeletal and dental relationships. Group 2 included 20 patients (mean age: 13.49±1.78 years) with Class II skeletal and dental relationships. Group 3 included 20 patients (mean age: 12.46±2.62 years) with Class III skeletal and dental relationships. Cephalometric tracings were obtained from cephalometric radiographs. All included patients were native speakers of Turkish. The /s/ sound was selected for center of gravity analysis. Correlations between cephalometric values and acoustic parameters were also investigated. Results The center of gravity of the /s/ sound had the lowest value in Group 2 (p<0.05). For the /s/ sound in Group 3, moderate positive correlations were found between center of gravity and Sella-Nasion to Gonion-Gnathion angle (p<0.05, r=0.444) Lower incisor to Nasion-B point (p<0.023, r=0.505), and Lower incisor to Nasion-B point angle (p<0.034; r=0.476). No correlation was found in other cephalometric measurements. Conclusions The /s/ sound was affected by malocclusion due to the changing place of articulation. Therefore, referral to an orthodontist for malocclusion treatment especially patients with class III in the early period is suggested for producing acoustically ideal sound.


Asunto(s)
Cefalometría , Maloclusión/fisiopatología , Acústica del Lenguaje , Trastornos del Habla/fisiopatología , Adolescente , Niño , Femenino , Humanos , Masculino , Maloclusión/complicaciones , Maloclusión/diagnóstico por imagen , Mandíbula/anatomía & histología , Mandíbula/fisiopatología , Maxilar/anatomía & histología , Maxilar/fisiopatología , Estudios Prospectivos , Radiografía , Valores de Referencia , Trastornos del Habla/diagnóstico por imagen , Trastornos del Habla/etiología , Estadísticas no Paramétricas , Lengua/anatomía & histología , Lengua/fisiopatología , Turquia
4.
Plast Reconstr Surg ; 145(5): 963e-974e, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32332545

RESUMEN

BACKGROUND: The aim of this study was to evaluate the effects of the use of computer-aided design and manufacturing cutting and drilling guides with prebent titanium plates for the correction of skeletal class III malocclusion. METHODS: In this prospective, randomized, controlled clinical trial, 46 patients with skeletal class III malocclusion were randomly assigned into two groups. The patients underwent bimaxillary surgery with computer-aided design and manufacturing cutting and drilling guides with prebent titanium plates (experimental group) or computer-aided design and manufacturing splints (control group). Preoperative and postoperative imaging data were collected and then analyzed using Mimics Research 19.0, Geomagic Studio, and IBM SPSS Version 21.0. RESULTS: Deformity evaluation and posttreatment assessment were performed for all patients. The experimental group had fewer postoperative complications. Comparison of the linear and angular differences to facial reference planes revealed more accurate repositioning of the mandible and condyles in the experimental group, although the position of several landmarks still requires small adjustments. CONCLUSION: Computer-aided design and manufacturing cutting and drilling guides with prebent titanium plates effectively corrected skeletal class III malocclusion, providing positional control of segments with reasonable surgical accuracy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.


Asunto(s)
Diseño Asistido por Computadora , Maloclusión de Angle Clase III/cirugía , Procedimientos Quirúrgicos Ortognáticos/instrumentación , Osteotomía Le Fort/instrumentación , Cirugía Asistida por Computador/instrumentación , Adulto , Puntos Anatómicos de Referencia , Placas Óseas , Cefalometría/métodos , Femenino , Humanos , Imagenología Tridimensional , Masculino , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Mandíbula/cirugía , Maxilar/anatomía & histología , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Procedimientos Quirúrgicos Ortognáticos/métodos , Osteotomía Le Fort/métodos , Estudios Prospectivos , Férulas (Fijadores) , Cirugía Asistida por Computador/métodos , Titanio , Tomografía Computarizada Espiral , Resultado del Tratamiento , Adulto Joven
5.
PLoS One ; 15(4): e0230440, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32236122

RESUMEN

Immature remains are critical for understanding maturational processes in hominin species as well as for interpreting changes in ontogenetic development in hominin evolution. The study of these subjects is hindered by the fact that associated juvenile remains are extremely rare in the hominin fossil record. Here we describe an assemblage of immature remains of Homo naledi recovered from the 2013-2014 excavation season. From this assemblage, we attribute 16 postcranial elements and a partial mandible with some dentition to a single juvenile Homo naledi individual. The find includes postcranial elements never before discovered as immature elements in the sub-equatorial early hominin fossil record, and contributes new data to the field of hominin ontogeny.


Asunto(s)
Huesos/anatomía & histología , Fósiles/anatomía & histología , Mandíbula/anatomía & histología , Animales , Evolución Biológica , Hominidae , Sudáfrica
6.
Int. j. morphol ; 38(1): 126-128, Feb. 2020. tab
Artículo en Inglés | LILACS | ID: biblio-1056409

RESUMEN

The current International Terminologia Anatomica is written in latin and from it, the translation into the corresponding language is carried out. There are terms of greek origin that sometimes do not fully describe the anatomical structure. In this context, the mylos root, present in mylohyoid word, is defined in greek " like a mill" or "resembling a tooth". However, this definition does not accurately represent the mylohyoid structures that it describes. Therefore the question arises: is the mylos root the most appropriate one for naming these structures?.


La actual Terminologia Anatomica (TA), se encuentra redactada en latín y a partir de ella se realiza la traducción al idioma correspondiente. Existen en ella términos de origen griego que en ocasiones no describen a cabalidad la estructura anatómica. En este contexto la raíz mylos, presente en milohioideo(a), se define en griego "como de un molino" o "semejante a una muela", sin embargo, esta definición no precisa las estructuras milohioideas que se desean describir. Entonces surge la interrogante, ¿es la raíz mylos la más adecuada para denominar esas estructuras?.


Asunto(s)
Humanos , Mandíbula/anatomía & histología , Diente Molar/anatomía & histología , Terminología como Asunto
7.
J Appl Oral Sci ; 28: e20190103, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32049131

RESUMEN

OBJECTIVE: This study aimed to assess the association between tooth size and root canal morphology by using CBCT analysis. METHODOLOGY: In this retrospective study, tooth anatomic lengths (crown and root lengths, buccolingual and mesiodistal dimensions) of 384 patients were assessed and correlated with Vertucci's root canal morphology classification. Data was analyzed for gender-related differences using the independent sample t-test, ANOVA, and the Pearson's correlation for a possible relation between anatomic lengths and canal morphology. RESULTS: The maxillary first and second premolars showed a greater predilection for Type IV and II variants, respectively, while the mandibular first premolar showed a greater predilection for Type II canal system. The root canal system of the mandibular second premolar showed maximal diversity (47% Type I, 30% Type II, and 20% Type III). The dimensions were greater in men regardless of tooth type. The most significant relation (p<0.05) between the anatomic size and canal morphology was observed in the maxillary first premolars, followed by the mandibular canines (buccolingual dimension) and the lower second premolars (crown length). Negative correlations existed between the crown length and the patient's age for the anterior teeth and mandibular second premolar (r=-0.2, p<0.01). CONCLUSIONS: The most common canal formation for anterior teeth was the Type I. The anatomic lengths had the strongest influence on the canal configuration of the maxillary first premolar, with Type IV being the most common root canal system. The mandibular second premolars showed maximal diversity in the canal classification terms and had a significant correlation with their crown lengths. CLINICAL RELEVANCE: The complex relationship between the canal morphology and anatomic tooth sizes need meticulous awareness and recognition during endodontic procedures, in conjunction with the demographic variabilities.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Cavidad Pulpar/anatomía & histología , Diente/anatomía & histología , Adulto , Anciano , Análisis de Varianza , Cavidad Pulpar/diagnóstico por imagen , Femenino , Humanos , Masculino , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Maxilar/anatomía & histología , Maxilar/diagnóstico por imagen , Persona de Mediana Edad , Odontometría/métodos , Valores de Referencia , Estudios Retrospectivos , Factores Sexuales , Diente/diagnóstico por imagen , Estados Unidos
8.
J Appl Oral Sci ; 28: e20190148, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32049133

RESUMEN

OBJECTIVE: The site of the sinus tract depends on the rate of resistance against abscess exudate drainage, bone morphology, and distance from the root apex to the outer cortical bone. To assess apical bone thickness in buccal and palatal/lingual aspects of maxillary and mandibular teeth, using a high-resolution cone-beam computed tomography (CBCT) system. METHODOLOGY: In total, 422 CBCT examinations were included in the study, resulting in a sample of 1400 teeth. The scans were acquired by PreXion 3D, with a high-resolution protocol. The bone thickness was taken as the distance between the center of the apical foramen and the buccal and lingual/palatal cortical bone. The quantitative variables were expressed as mean values±standard deviation. The independent samples were analyzed using the t-test or the Mann-Whitney test (p<0.05). RESULTS: The lowest mean value of bone thickness was observed in the buccal cortical bone of the upper canines (1.49 mm±0.86) and in the upper central incisors (1.59 mm±0.67). In premolar teeth, the lowest values were found in the buccal cortical bone of upper first premolars (1.13 mm±0.68). In the posterior teeth, the lowest values were found in the buccal cortical bone of upper first molars (1.98 mm±1.33). In the lower second molar region, the buccal cortical bone (8.36 mm±1.84) was thicker than the lingual cortical bone (2.95 mm±1.16) (p<0.05). CONCLUSIONS: The lowest mean values of bone thickness are in the buccal cortical bone of the maxillary teeth. In the mandible, bone thickness is thinner in the buccal bone around the anterior and premolar teeth, and in the lingual aspect of mandibular molars. All these anatomic characteristics could make the occurrence of the sinus tract more susceptible in these specific regions of the maxillary and mandibular alveolar bone.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Mandíbula/anatomía & histología , Maxilar/anatomía & histología , Diente/anatomía & histología , Adulto , Femenino , Humanos , Masculino , Mandíbula/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Odontometría/métodos , Valores de Referencia , Estadísticas no Paramétricas , Diente/diagnóstico por imagen
9.
J Appl Oral Sci ; 28: e20190393, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32049137

RESUMEN

OBJECTIVES: This study assessed the incidence and variability features of root canals system (RCS) and their ramifications according to Pucci & Reig (PR) (1944) and the American Association of Endodontists (AAE) (2017) by micro-computed tomography (µCT). METHODOLOGY: 500 representative extracted human teeth of each tooth group (n=50) (maxillary/mandibular central and lateral incisors, canines, first and second premolars and molars) were scanned by µCT with a resolution of 26.70 µm. The reconstructed cross-sections images and the visualization of the continuous slices in the transversal axis were performed using DataViewer software. RCS were classified according to Pucci & Reig (main canal, collateral canal, lateral canal, secondary canal, accessory canal, intercanal, recurrent canal) and AAE (main canal, accessory canal, lateral canal). The apical deltas were assessed for both classifications. The prevalence of apical deltas was evaluated using the Chi-squared test (p<0.05). RESULTS: According to PR, a higher incidence of lateral canals was observed in maxillary canines (10%), central incisors (8%) and first premolars (6%). Using AAE, the highest incidence of lateral canals was observed in the mandibular first premolars (85%), first and second molars (84%), lateral incisors (67%), canines (59%), and in maxillary first premolars (52%). Regarding accessory canals, the PR showed a frequency in 2% of the maxillary lateral incisors and maxillary and mandibular first premolars and 3% of mandibular first and second molars. On the other hand, the AAE showed the highest incidence of accessory canals in 86% of the maxillary first premolars, 71% in mandibular lateral incisors, 69% in mandibular first premolars, 65% in mandibular canines, and 56% in maxillary canines. The PR showed the lowest incidence of apical deltas for all dental groups when compared with AAE (p=0.004). Interestingly, distal canals in maxillary molars showed a significant discrepancy between classifications (p=0.027). CONCLUSIONS: µCT enabled accurately describing the RC system and related ramifications, adding to the PR and AAE classifications, with some discrepancies reported for maxillary molars. Clinical Relevance This µCT study enabled a thorough description of the variability among root canals and their ramifications, including clinically relevant details on the presence and location of lateral canals and accessories in all human tooth groups, beyond the currently existing classification systems.


Asunto(s)
Cavidad Pulpar/anatomía & histología , Microtomografía por Rayos X/métodos , Cavidad Pulpar/diagnóstico por imagen , Humanos , Imagenología Tridimensional , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Maxilar/anatomía & histología , Maxilar/diagnóstico por imagen , Valores de Referencia , Estadísticas no Paramétricas , Ápice del Diente/anatomía & histología , Ápice del Diente/diagnóstico por imagen
10.
Niger J Clin Pract ; 23(2): 232-239, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32031099

RESUMEN

Aims: To evaluate the prevalence, correlation, and differences of C-shaped canal morphology in mandibular premolars and molars by means of cone-beam computed tomography (CBCT). Materials and Methods: A total of 1433 mandibular premolars and molars CBCT scans from the Saudi population were evaluated. Axial sections of the roots were acquired at coronal, middle, and apical levels to evaluate C-shaped canals types. The prevalence, correlation, differences of C-shaped canals, bilateral/unilateral presence, gender differences, and location of external grooves on roots were assessed. Results: The prevalence of C-shaped canals in the first premolars was 1.5%, 0.80% in second premolars and 7.9% in second molars, whereas C-shaped canals were absent in first molars. No correlation was found between the presence of C-shaped canals within premolars and molars and between the two groups in the same individual. Both premolars and molars exhibited different types of C-shaped canals, C2 being predominant in premolars and C3 in second molars. Longitudinal external grooves were mostly located on mesiolingual (ML) surface in premolars and lingual in molars. Females showed more prevalence of C-shaped canals in second molars and no differences in premolars. Bilateral symmetry and unilateral presence in premolars and second molars were not significant. Conclusions: Although the prevalence of C-shaped canals is significantly higher in mandibular second molars, they are also found in mandibular premolars but in small percentages. No significant differences were found between both genders and both sides. Since they exhibit unpredictable morphology and differences across the root length, the use of small field CBCT is recommended when such anatomy is presented in a tooth indicated for root canal treatment for better management.


Asunto(s)
Diente Premolar/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico/métodos , Cavidad Pulpar/diagnóstico por imagen , Mandíbula/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Raíz del Diente/diagnóstico por imagen , Adolescente , Adulto , Diente Premolar/anatomía & histología , Estudios Transversales , Cavidad Pulpar/anatomía & histología , Femenino , Humanos , Masculino , Mandíbula/anatomía & histología , Persona de Mediana Edad , Diente Molar/anatomía & histología , Prevalencia , Arabia Saudita , Factores Sexuales , Raíz del Diente/anatomía & histología , Adulto Joven
11.
Medicine (Baltimore) ; 99(2): e18069, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31914012

RESUMEN

This study aims to find and locate foramens exactly in maxilla and mandible in case of complications during surgeries.Computer topographic angiography (CTA) images of 120 cases were reviewed. The measurements were performed on coronal, sagittal and axial planes after the 3 dimension volume reconstruction. The distances among foramens, bony landmarks, teeth, and facial artery were all measured with the angles as adjustments.The incisive foramen (IF) was measured 20.55 ±â€Š2.81 mm to margo inferior of incisor, and 45.27 ±â€Š5.27 degree from the axial midline. The greater palatine foramen located 43.17 ±â€Š2.55 mm from the IF, while 21.08 ±â€Š3.75 degree from the midline in axial plane. The lesser palatine foramina located 44.56 ±â€Š5.74 mm from the IF and 20.05 ±â€Š3.59 degree to the midline. The Mandibular foramen (MBF) was 91.15 ±â€Š1.86 mm horizontally to the margo inferior of incisor. The angle that the MBF-margo inferior of incisor line made with the axial midline was 31.25 ±â€Š2.89 degree. The shortest horizontal distance from the mental foramen (MF) to the facial artery in sagittal plane was 21.90 ±â€Š1.86 mm, while it became 13.00 ±â€Š2.05 mm in coronary section. The horizontal distance from the MF to the margo inferior of incisor in sagittal plane was 22.04 ±â€Š3.22 mm. It turned out to be 25.78 ±â€Š5.23 mm between MF and mid-sagittal line in coronary section. The vertical distance was 25.20 ±â€Š3.06 mm from the upper margin of the second premolar to the MF.The foramens were clearly seen through CTA. Moreover, linear and angular measurements were presented, which makes it safer and wiser for surgeons to consider the biometric data before operations.


Asunto(s)
Puntos Anatómicos de Referencia/diagnóstico por imagen , Angiografía por Tomografía Computarizada/métodos , Mandíbula/anatomía & histología , Foramen Mental/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Arterias , Huesos/diagnóstico por imagen , Huesos/cirugía , Niño , Cara/irrigación sanguínea , Cara/diagnóstico por imagen , Femenino , Humanos , Incisivo/anatomía & histología , Incisivo/diagnóstico por imagen , Masculino , Mandíbula/diagnóstico por imagen , Mandíbula/patología , Mandíbula/cirugía , Foramen Mental/cirugía , Persona de Mediana Edad , Adulto Joven
12.
Eur. j. anat ; 24(1): 37-48, ene. 2020. ilus, tab
Artículo en Inglés | IBECS | ID: ibc-186063

RESUMEN

Paralysis of the facial nerve is a common complication during the surgical removal of parotid gland tumors (parotidectomies). This may be due to the close relationship of the tumor and the facial nerve (along its extracranial course). This study aimed to explore the extracranial course of the facial nerve in terms of branching patterns, bony anatomical landmarks and variations. The sample comprised of 40 facial nerve specimens. The parameters identified and recorded were facial nerve trunk division, branching patterns and variations in terms of connections, course and branching. The parameters were classified and compared according to sex and laterality. Bifurcation of the facial nerve trunk occurred in 90% of cases, whilst trifurcation occurred in only 10%. The cases of trifurcation displayed variations. The frequency of each type of branching pattern was: Type I = 7.5%, Type II = 12.5%, Type III = 25%, Type IV = 15%, Type V = 27.5% and Type VI =12.5%. The six types were further categorized into three subtypes based on the origin of the buccal branch. The distance fromthe facial nerve trunk to bony anatomical landmarks was measured viz. mastoid process, angle of the mandible and external auditory canal. Only the distance to the angle of the mandible displayed significant differences according to sex (p-value < 0.001) and laterality (p- value = 0.002). All three landmarks displayed good-excellent reliability (ICC values ranged from 0.82 to 0.95) with regard to bony anatomical landmarks for the localization of the facial nerve trunk. The present study proposes the use of the three subtypes in conjunction with the classification system. Anatomical knowledge of the extracranial course of the facial nerve and its relation to bony anatomical landmarks are of im-portance to surgeons during procedures such as parotidectomies


No disponible


Asunto(s)
Humanos , Masculino , Femenino , Nervio Facial/anatomía & histología , Glándula Parótida/anatomía & histología , Glándula Parótida/cirugía , Puntos Anatómicos de Referencia/inervación , Cadáver , Apófisis Mastoides/anatomía & histología , Neoplasias de la Parótida/patología , Neoplasias de la Parótida/cirugía , Disección/métodos , Mandíbula/anatomía & histología
13.
Acta Cir Bras ; 34(9): e201900906, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31826098

RESUMEN

PURPOSE: To develop 3D anatomical models, and corresponding radiographs, of canine jaw fractures. METHODS: A base model was generated from a mandibular bone scan. With this model it was possible to perform fracture planning according to the anatomical location. RESULTS: The 3D base model of the canine mandible was similar in conformation to the natural bone, demonstrating structures such as canine tooth crowns, premolars and molars, mental foramina, body of the mandible, ramus of the mandible, masseteric fossa, the coronoid process, condylar process, and angular process. It was not possible to obtain detail of the crown of the incisor teeth, mandibular symphysis, and the medullary channel. Production of the 3D CJF model took 10.6 h, used 150.1 g of filament (ABS) and cost US$5.83. CONCLUSION: The 3D canine jaw fractures models, which reproduced natural canine jaw fractures, and their respective radiographic images, are a possible source of educational material for the teaching of veterinary medicine.


Asunto(s)
Educación en Veterinaria/métodos , Imagenología Tridimensional/veterinaria , Fracturas Mandibulares/veterinaria , Modelos Anatómicos , Impresión Tridimensional , Animales , Perros , Imagenología Tridimensional/métodos , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Fracturas Mandibulares/diagnóstico por imagen , Radiografía/veterinaria , Reproducibilidad de los Resultados , Factores de Tiempo
14.
Biomed Res Int ; 2019: 3069347, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31815128

RESUMEN

Objective: This study investigates the effects of using a twin inclined plane device (TIPD) on the remolding and ultrastructure variation of mandibular condyle in growing rats. Materials and Methods: Forty-eight male Wistar rats (six weeks old, body weight of approximately 190-210 g) were divided into experimental group (wearing appliance, n = 32) and control group (no appliance, n = 16). Samples were collected on days 3, 14, 30, and 60. The immunohistochemical analysis for vascular endothelial growth factor (VEGF) and type II collagen was carried out. Tartrate-resistant acid phosphatase (TRAP) reaction was performed to evaluate the osteoclastic activity. Three-dimensional morphometric images were reconstructed for morphometric analysis by microcomputed tomography (micro-CT). The ultrastructure of the condylar surface was observed by scanning electron microscopy (SEM). Results: The expression of VEGF significantly increased, while the expression of type II collagen decreased in the experimental group at days 30 and 60. Furthermore, the enhanced osteoclast activity was observed under the subchondral bone, which was highest at day 30, and decreased to the lowest at day 60 in the experimental group. In addition, adaptive subchondral bone remolding in the posterior part of the condyle was observed at day 60 in the experimental group, and the SEM revealed the ultrastructure variations after installation of the TIPD. However, these changes began to reverse after 30 days. Conclusion: Condylar tissue changes point to the osteoclastic activity in the posterior region of the condyle. These adaptive changes point to bone resorption in the posterior condyle. Type II collagen and VEGF contribute to the MCC remolding induced by the TIPD. The ultrastructural changes in the posterior condylar area in response to mechanical stresses are recoverable at the initial stage.


Asunto(s)
Adaptación Fisiológica , Diseño de Prótesis Dental , Cóndilo Mandibular/anatomía & histología , Cóndilo Mandibular/metabolismo , Cóndilo Mandibular/ultraestructura , Animales , Resorción Ósea , Colágeno Tipo II/metabolismo , Imagenología Tridimensional , Masculino , Mandíbula/anatomía & histología , Cóndilo Mandibular/diagnóstico por imagen , Masticación , Osteoclastos/metabolismo , Ratas , Ratas Wistar , Estrés Mecánico , Factor A de Crecimiento Endotelial Vascular/metabolismo , Microtomografía por Rayos X
15.
Rev. ADM ; 76(6): 310-314, nov.-dic. 2019. ilus, tab
Artículo en Español | LILACS | ID: biblio-1053538

RESUMEN

Introducción: La región anterior de la mandíbula, ubicada entre los agujeros mentonianos contiene conductos intraóseos con elementos vasculares y ramas nerviosas terminales provenientes del nervio alveolar inferior. El objetivo del trabajo es determinar las variantes anatómicas producidas en el conducto incisivo y las corticales superior, inferior, externa e interna en pacientes edéntulos con respecto a pacientes dentados en tomografía computarizada de haz cónico. Material y métodos: Se realizó un estudio comparativo, retrospectivo y observacional. Se estudiaron 50 tomografías en pacientes edéntulos y 50 en pacientes dentados de ambos sexos desde los 38 hasta los 81 años. En cada corte se realizó una medición en lo alto y ancho del conducto. También se determinó la posición del conducto incisivo mediante la realización de cuatro mediciones. Resultados: Se observaron diferencias significativas en lo que respecta al alto y ancho del conducto incisivo y también entre las distancias hacia la cortical vestibular, lingual, alveolar y basal entre pacientes dentados y desdentados. Conclusión: Se pudo comprobar una mayor resorción ósea en los pacientes desdentados, hallado entre el conducto incisivo y las corticales superior y vestibular y un menor calibre del conducto incisivo con respecto a los pacientes dentados (AU)


Introduction: The previous region of the mandible, located between the mental foramen, contains intraosseous ducts with vascular elements and terminal nervous branches from the inferior alveolar nerve. The objective of the work is to determine the anatomical variants produced in the incisive canal and the superior, inferior, external and internal cortices in edentulous patients with respect to dentate patients in cone beam computed tomography. Material and methods: A retrospective observation al comparative study was carried out. Fifty tomographies were studied in edentulous patients and 50 in dentate patients of both sex es from 38 to 81 years. In each cut a measure men twasmade in height and width of the conduit. The position of the incisive cannel was also determined by performing four measurements. Results: Significant differences were observed regarding the height and width of the incisal canal and also between the distances to the vestibular, lingual, alveolar and basal cortical area between dentate and edentulous patients. Conclusion: A greater bone reabsorption in thee dentulous patients found between the incisive canal and the superior and vestibular cortices and a smaller caliber of the incisive canal with respect to the dentate patient should be verified (AU)


Asunto(s)
Humanos , Masculino , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Boca Edéntula , Tomografía Computarizada de Haz Cónico , Mandíbula/inervación , Mandíbula/diagnóstico por imagen , Mediciones, Métodos y Teorías , Análisis Estadístico , Estudios Retrospectivos , Mandíbula/anatomía & histología
16.
Int. j. morphol ; 37(4): 1486-1492, Dec. 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1040158

RESUMEN

In order to perform local anaesthetic blockade of the mental nerves, it is fundamentally to determine anatomical references, including the precise identification of the mental foramina; however, the literature does not present specific data on such structures in the Hoary Fox. Therefore, the objective was describing the morphometry of the mental foramina of this specie, in order to correlate its topographies with the mandibular anatomical reference points, supporting the effective technique for mental desensitization. For this purpose, four mandibles of adult bodies of Lycalopex vetulus were used. Bilaterally, three mental foramina were observed located on the rostral third of the lateral margin of the mandibular body. One of them is more caudal, positioned ventrally to the lower third premolar tooth; a medium one, is located ventrally to the lower first premolar tooth; and a rostral one, placed ventrally to the lower intermediate incisor tooth. There were no statistically significant differences between the antimeres. Therefore, it is indicated that the local anaesthetic block of the mental nerves in this species should be performed by inserting the needle approximately 4.4 mm in a ventrodorsal direction. It is necessary positioning it perpendicularly to the ventral margin of the mandibular body and juxtaposed to its lateral face, using as anatomical reference the interalveolar space located between the first two lower premolar teeth. Thus, that the point established for anaesthetic injection (caudal limit of the ventral margin of the middle mental foramen), provides greater safety for its realization since, for small animals, the recommendation for blockade is represented by needle penetration on the direction of emergence of the mental nerve and artery from this foramen, which makes these structures more exposed to iatrogenic lesions resulting from the technique.


Para realizar el bloqueo anestésico local de los nervios mentales, es fundamental determinar referencias anatómicas, incluida la identificación precisa de los forámenes mentales; sin embargo, la literatura no presenta datos específicos referente a estas estructuras en el zorro de campo común. Por lo tanto, el objetivo fue describir la morfometría de los forámenes mentales de esta especie, para correlacionar sus topografías con los puntos de referencia anatómicos mandibulares, apoyando la técnica efectiva para la desensibilización mental. Para este propósito, se utilizaron cuatro mandíbulas de Lycalopex vetulus adultos. Bilateralmente, se observaron tres resistencias mentales ubicadas en el tercio rostral del margen lateral del cuerpo mandibular. Uno de ellos es más caudal, posicionado ventralmente hacia el tercer diente premolar inferior; uno mediano, localizado ventralmente hacia el primer diente premolar inferior; y uno rostral, colocado ventralmente al diente incisivo intermedio inferior. No se observaron diferencias estadísticamente significativas entre los antímeros. Por lo tanto, el bloqueo anestésico local de los nervios mentales en esta especie debe realizarse insertando la aguja aproximadamente 4,4 mm en dirección ventrodorsal. Es necesario colocar ésta perpendicularmente al margen ventral del cuerpo mandibular y yuxtapuesto a su cara lateral, utilizando como referencia anatómica, el espacio interalveolar ubicado entre los dos primeros dientes premolares inferiores. De este modo, el punto establecido para la inyección de anestesia (límite caudal del margen ventral del foramen mental medio), proporciona una mayor seguridad para su realización ya que, para los animales pequeños, la recomendación de bloqueo está representada por la penetración de la aguja en la dirección de emergencia del nervio mental y la arteria de este foramen, lo que hace que estas estructuras estén más expuestas a las lesiones iatrogénicas resultantes de la técnica.


Asunto(s)
Animales , Masculino , Femenino , Zorros/anatomía & histología , Anestesia Local/veterinaria , Mandíbula/anatomía & histología , Odontología/veterinaria , Mandíbula/inervación
17.
Int. j. morphol ; 37(4): 1375-1381, Dec. 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1040140

RESUMEN

Determining sex may be more difficult in cases such as natural disasters, accidents or situations in which bodies are subjected to high temperatures, when individuals must be identified from their remains. The mandible is a very strong bone, presents high sexual dimorphism and may be useful in forensic identification. The object of the present study was to determine sex by metrical analysis of macerated mandibles of Brazilian adults. We analysed 113 fully dentate macerated mandibles of Brazilian adults, 47 belonging to women and 66 to men. We took 8 measurements using a digital calliper: bicondilar breadth (BC), bigonial breadth (BG), bimental foramina breadth (BM), distance between mental foramen and mandibular base (MF-MB), mandibular ramus height (MRH), maximum mandibular ramus breadth (MaRB), minimum mandibular ramus breadth (MiRB) and mandibular body length (MBL). The t test was used for statistical analysis of independent samples, and a ROC curve was constructed. Direct and stepwise discriminant analysis was carried out. SPSS v.22 software was used, with a significance threshold of 5 %. We observed that all the measurements presented statistically significant differences between the sexes, with greater mean values for men than for women. BG was the measurement which presented the greatest area under curve (AUC), and the highest correct prediction, followed by MRH and BC. The BM distance presented the smallest AUC and lowest correct prediction. The mean correct prediction was 85 % for direct discriminant analysis and 83.2 % for stepwise discriminant analysis, using the BG and MRH measurements. The measurements analysed in this study can be used to determine the sex of Brazilian individuals.


En casos de desastres naturales, catástrofes o situaciones en las cuales los cuerpos son sometidos a altas temperaturas la identificación sexual queda más difícil, siendo necesaria la identificación de los individuos a partir de restos mortales. La mandíbula es un hueso muy resistente, que presenta gran dimorfismo sexual, pudiendo ser útil en la identificación forense. El objetivo de este estudio fue determinar la predicción sexual mediante el análisis métrico de mandíbulas maceradas de individuos brasileños adultos. Fueron analizadas 113 mandíbulas maceradas completamente dentadas de Brasileños adultos, siendo 47 mujeres y 66 hombres. Con un cáliper digital fueron evaluadas 8 medidas: amplitud bi-condilar (BC), amplitud bi-gonial (BG), amplitud entre forámenes mentonianos (BM), distancia entre el foramen mentoniano y la base de la mandíbula (MF-MB), altura de la rama mandibular (MRH), anchura máxima de la rama mandibular (MaRB), anchura mínima de la rama mandibular (MiRB) y longitud del cuerpo de la mandíbula (MBL). Para análisis estadístico se utilizó la prueba t para muestras independientes. Además se construyó una curva ROC. Se realizó análisis discriminante directo y por pasos. Se utilizó el software SPSS V.22, considerando umbral de significación de 5 %. Se observó que todas las medidas presentaron diferencias estadísticas entre sexos, siendo los valores medios encontrados para hombres mayores que los encontrados para mujeres. La BG fue la medida que presentó mayor área bajo la curva (AUC) y mayor predicción, seguido de la MRH y de la BC. La distancia BM fue la medida que presentó la menor AUC y menor predicción. La correcta predicción para el análisis discriminante directo alcanzó el 85 % y por pasos alcanzó el 83.2 % utilizándose las medidas BG y MRH. Las medidas analizadas en este estudio pueden ser utilizadas en el diagnóstico sexual de individuos Brasileños.


Asunto(s)
Humanos , Masculino , Femenino , Determinación del Sexo por el Esqueleto/métodos , Mandíbula/anatomía & histología , Brasil , Análisis Discriminante , Curva ROC
18.
PLoS One ; 14(12): e0226949, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31881075

RESUMEN

Morphological convergence is an intensely studied macroevolutionary phenomenon. It refers to the morphological resemblance between phylogenetically distant taxa. Currently available methods to explore evolutionary convergence either: rely on the analysis of the phenotypic resemblance between sister clades as compared to their ancestor, fit different evolutionary regimes to different parts of the tree to see whether the same regime explains phenotypic evolution in phylogenetically distant clades, or assess deviations from the congruence between phylogenetic and phenotypic distances. We introduce a new test for morphological convergence working directly with non-ultrametric (i.e. paleontological) as well as ultrametric phylogenies and multivariate data. The method (developed as the function search.conv within the R package RRphylo) tests whether unrelated clades are morphologically more similar to each other than expected by their phylogenetic distance. It additionally permits using known phenotypes as the most recent common ancestors of clades, taking full advantage of fossil information. We assessed the power of search.conv and the incidence of false positives by means of simulations, and then applied it to three well-known and long-discussed cases of (purported) morphological convergence: the evolution of grazing adaptation in the mandible of ungulates with high-crowned molars, the evolution of mandibular shape in sabertooth cats, and the evolution of discrete ecomorphs among anoles of Caribbean islands. The search.conv method was found to be powerful, correctly identifying simulated cases of convergent morphological evolution in 95% of the cases. Type I error rate is as low as 4-6%. We found search.conv is some three orders of magnitude faster than a competing method for testing convergence.


Asunto(s)
Evolución Biológica , Algoritmos , Animales , Gatos/anatomía & histología , Gatos/genética , Gatos/fisiología , Fósiles , Lagartos/anatomía & histología , Lagartos/genética , Lagartos/fisiología , Mandíbula/anatomía & histología , Mandíbula/fisiología , Fenotipo , Filogenia , Indias Occidentales
19.
Niger J Clin Pract ; 22(11): 1611-1616, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31719285

RESUMEN

Aims: To investigate the root canal's anatomy, gender differences, and bilateral symmetry of permanent mandibular incisors using cone-beam computed tomography (CBCT). Materials and Methods: A total of 208 patients with 822 well-developed mandibular incisors were evaluated. CBCT images were retrieved from the database of patients who received treatment in the College of Dentistry and Dental Clinics. The following parameters were evaluated using CBCT: (1) the number of roots; (2) the number of canals; (3) canal configuration according to Vertucci's classification; (4) differences between genders; and (5) bilateral symmetry. Results: Two canals appeared in 26.3% of mandibular central incisors, 30.8% of lateral incisors, and 28.6% of all the 822 mandibular incisors. In the teeth with two canals, Type III configuration was dominant. There were no statistically significant differences found between the central and lateral incisors (P = 0.449). There were gender differences in central incisors, while lateral incisors showed none. Slight bilateral asymmetries appeared in central and lateral incisors in relation to some canals and canals configurations. Conclusion: CBCT can be of great use in locating the second canal and determining canal configuration in mandibular incisors. Knowledge of bilateral asymmetry can be of clinical significance when the clinician is treating contralateral teeth in the same patient.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Cavidad Pulpar/diagnóstico por imagen , Incisivo/diagnóstico por imagen , Mandíbula/diagnóstico por imagen , Raíz del Diente/diagnóstico por imagen , Adulto , Cavidad Pulpar/anatomía & histología , Femenino , Humanos , Incisivo/anatomía & histología , Masculino , Mandíbula/anatomía & histología , Persona de Mediana Edad , Arabia Saudita , Factores Sexuales , Raíz del Diente/anatomía & histología
20.
Dokl Biol Sci ; 488(1): 145-148, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31732900

RESUMEN

The mandible shape of the common vole semi-species from the hybrid zone was studied for the first time using the methods of geometric morphometry. The hybrid specimens were found to display high morphological variability being closer to the parental Microtus obscurus than to M. arvalis form. The main trends of changes in the mandible shape were primarily observed in the horizontal plane.


Asunto(s)
Arvicolinae/anatomía & histología , Arvicolinae/genética , Mandíbula/anatomía & histología , Animales , Especificidad de la Especie
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA