A multi-ancestry GWAS meta-analysis of facial features and its application in predicting archaic human features.

Facial morphology, a complex trait influenced by genetics, holds great significance in evolutionary research. However, due to limited fossil evidence, the facial characteristics of Neanderthals and Denisovans have remained largely unknown. In this study, we conducted a large-scale multi-ethnic meta-analysis of the genome-wide association study (GWAS), including 9674 East Asians and 10,115 Europeans, quantitatively assessing 78 facial traits using 3D facial images. We identified 71 genomic loci associated with facial features, including 21 novel loci. We developed a facial polygenic score (FPS) that enables the prediction of facial features based on genetic information. Interestingly, the distribution of FPSs among populations from diverse continental groups exhibited relevant correlations with observed facial features. Furthermore, we applied the FPS to predict the facial traits of seven Neanderthals and one Denisovan using ancient DNA and aligned predictions with the fossil records. Our results suggested that Neanderthals and Denisovans likely shared similar facial features, such as a wider but shorter nose and a wider endocanthion distance. The decreased mouth width was characterized specifically in Denisovans. The integration of genomic data and facial trait analysis provides valuable insights into the evolutionary history and adaptive changes in human facial morphology.

Face-brain correlates as potential sex-specific biomarkers for schizophrenia and bipolar disorder.

Given the shared ectodermal origin and integrated development of the face and the brain, facial biomarkers emerge as potential candidates to assess vulnerability for disorders in which neurodevelopment is compromised, such as schizophrenia (SZ) and bipolar disorder (BD). The sample comprised 188 individuals (67 SZ patients, 46 BD patients and 75 healthy controls (HC)). Using a landmark-based approach on 3D facial reconstructions, we quantified global and local facial shape differences between SZ/BD patients and HC using geometric morphometrics. We also assessed correlations between facial and brain cortical measures. All analyses were performed separately by sex. Diagnosis explained 4.1 % - 5.9 % of global facial shape variance in males and females with SZ, and 4.5 % - 4.1 % in BD. Regarding local facial shape, we detected 43.2 % of significantly different distances in males and 47.4 % in females with SZ as compared to HC, whereas in BD the percentages decreased to 35.8 % and 26.8 %, respectively. We detected that brain area and volume significantly explained 2.2 % and 2 % of facial shape variance in the male SZ - HC sample. Our results support facial shape as a neurodevelopmental marker for SZ and BD and reveal sex-specific pathophysiological mechanisms modulating the interplay between the brain and the face.

Applications of forensic anthropology methodology: accuracy of virtual face reproductions performed on the Tenchini collection.

Facial reproduction validation uses the methodology typical of forensic anthropology to confirm the accuracy of three-dimensional reproductions of faces. Achieving high accuracy in virtual facial reproductions is still under study. In the present paper, the Tenchini collection, which contains wax reproductions of prisoners' faces and their skulls, was used. By creating facial reproductions on skulls from this collection, the result was compared with the real face of the person to whom the skull belongs. The three-dimensional volume of each examined skull of Tenchini collection was acquired via CT scan and photogrammetry. Subsequently, the virtual reproduction of each skull was processed using three-dimensional graphics software (ZBrush, Pixologic®). The morphological comparison parameters used in the field of personal identification by forensic anthropology were used. The blind procedure required the operator to see the mask subsequent to the facial reproduction phase, so that the facial reproduction cannot exploit the information that knowledge of the mask would have produced. The parameters used in the study of facial reproductions have shown discrepancies between the characteristics of the masks and the facial reproductions, partly expected because due to the lack of soft tissue on the skull. However, a high degree of accuracy in the facial reproductions performed due to the applied methodology was documented. The present study allowed us to observe how these parameters can be useful to study the accuracy of facial reproduction and identify what difficulties are encountered in producing a result close to the real appearance.

De Novo Dissecting the Three-Dimensional Facial Morphology of 2379 Han Chinese Individuals.

Phenotypic diversity, especially that of facial morphology, has not been fully investigated in the Han Chinese, which is the largest ethnic group in the world. In this study, we systematically analyzed a total of 14,838 facial traits representing 15 categories with both a large-scale three-dimensional (3D) manual landmarking database and computer-aided facial segmented phenotyping in 2379 Han Chinese individuals. Our results illustrate that homogeneous and heterogeneous facial morphological traits exist among Han Chinese populations across the three geographical regions: Zhengzhou, Taizhou, and Nanning. We identified 1560 shared features from extracted phenotypes, which characterized well the basic facial morphology of the Han Chinese. In particular, heterogeneous phenotypes showing population structures corresponded to geographical subpopulations. The greatest facial variation among these geographical populations was the angle of glabella, left subalare, and right cheilion (p = 3.4 × 10-161). Interestingly, we found that Han Chinese populations could be classified into northern Han, central Han, and southern Han at the phenotypic level, and the facial morphological variation pattern of central Han Chinese was between the typical differentiation of northern and southern Han Chinese. This result was highly consistent with the results revealed by the genetic data. These findings provide new insights into the analysis of multidimensional phenotypes as well as a valuable resource for further facial phenotype-genotype association studies in Han Chinese and East Asian populations. Supplementary Information: The online version contains supplementary material available at 10.1007/s43657-023-00109-x.

Automated reconstruction: Predictive models based on facial morphology matrices.

Forensic Facial Approximation (FFA) has evolved, with techniques advancing to refine the intercorrelation between the soft-tissue facial profile and the underlying skull. FFA has become essential for identifying unknown persons in South Africa, where the high number of migrant and illegal labourers and many unidentified remains make the identification process challenging. However, existing FFA methods are based on American or European standards, rendering them inapplicable in a South African context. We addressed this issue by conducting a study to create prediction models based on the relationships between facial morphology and known factors, such as population affinity, sex, and age, in white South African and French samples. We retrospectively collected 184 adult cone beam computed tomography (CBCT) scans representing 76 white South Africans (29 males and 47 females) and 108 French nationals (54 males and 54 females) to develop predictive statistical models using a projection onto latent structures regression algorithm (PLSR). On training and untrained datasets, the accuracy of the estimated soft-tissue shape of the ears, eyes, nose, and mouth was measured using metric deviations. The predictive models were optimized by integrating additional variables such as sex and age. Based on trained data, the prediction errors for the ears, eyes, nose, and mouth ranged between 1.6 mm and 4.1 mm for white South Africans; for the French group, they ranged between 1.9 mm and 4.2 mm. Prediction errors on non-trained data ranged between 1.6 mm and 4.3 mm for white South Africans, whereas prediction errors ranging between 1.8 mm and 4.3 mm were observed for the French. Ultimately, our study provided promising predictive models. Although the statistical models can be improved, the inherent variability among individuals restricts the accuracy of FFA. The predictive validity of the models was improved by including sex and age variables and considering population affinity. By integrating these factors, more customized and accurate predictive models can be developed, ultimately strengthening the effectiveness of forensic analysis in the South African region.

Elastic Chain Premaxillary Retraction Appliance Does Not Increase Inter-Canthal Dimension in Patients with Bilateral Cleft Lip and Palate.

OBJECTIVE: To determine if the elastic chain premaxillary retraction (ECPR) appliance increases inter-medial and inter-lateral canthal dimension in patients with bilateral complete cleft lip and palate (BCLP). DESIGN: Retrospective cohort study. SETTING: Specialized tertiary care facility. PATIENTS, PARTICIPANTS: 126 patients with BCLP; 75 had ECPR, 51 had no pre-surgical manipulation. INTERVENTIONS: Three-dimensional facial photographs were obtained prior to insertion of appliance (T0), post-appliance therapy prior to appliance removal/labial repair (T1), and several months after labial repair (T2) for a longitudinal ECPR group, and were obtained after age 4 years (T3) for a non-longitudinal ECPR group and for the non-ECPR group. MAIN OUTCOME MEASURES: Inter-medial and inter-lateral canthal dimension (en-en, ex-ex) was determined for all groups/time-points. Measurements were compared between groups and to norms. RESULTS: The mean en-en and ex-ex was 32.6 ± 3.2 mm and 84.4 ± 6.3 mm for the ECPR group and 33.5 ± 3.1 mm and 86.7 ± 7.2 mm for the non-ECPR group at T3. Inter-medial and inter-lateral canthal dimensions were significantly greater than normal (P < .05) in both groups; there was no significant difference between groups (P > .05). The mean en-en and ex-ex for the Longitudinal ECPR group was 27.5 ± 2.4 mm and 66.7 ± 3.7 mm at T0, 29.6 ± 2.4 mm and 70.4 ± 2.9 mm at T1, and 29.2 ± 2.3 mm and 72.3 ± 3.8 mm at T2. en-en and ex-ex increased significantly from T0-T1 (P < .05), decreased at T2 (P > .05) and was significantly larger than normal at all time-points (P < .05). CONCLUSIONS: Inter-medial and inter-lateral canthal dimension increased after ECPR but returned to baseline growth trajectory. These dimensions were above normal at all time-points. There was no difference between those that did and did not have dentofacial orthopedic manipulation.

Cleft Lip With Ankyloblepharon Filiforme Adnatum: A Case Report.

Ankyloblepharon filiforme adnatum (AFA) is a rare, benign congenital anomaly. Notably, it is characterized by the adhesion of the ciliary edges of the upper and lower eyelids at the trabecular line. AFA is usually a solitary malformation of sporadic occurrence; however, it can occur in conjunction with other congenital diseases. Herein, we report a case of cleft lip with AFA. A patient was referred to the ophthalmology department of our hospital. The ophthalmic diagnosis was AFA in both the eyes. The left eye was observed to have a fibrous adhesion in the center, and she underwent surgery to excise the fibrous adhesion of tissue with scissors. The right eye was observed to have a fibrous adhesion in the external canthus and was excised during lip plasty. After surgery, her eyes were able to fully open, and no other apparent disease was diagnosed. AFA is thought to be caused by an ectodermal-derived developmental abnormality. Notably, cases of AFA with a cleft lip are rare. Diagnosis and surgery should be performed promptly to minimize any risk of amblyopia and for the early detection of congenital diseases, including glaucoma.

Morfología ósea facial en cirugía ortognática. ¿existe tendencia hacia el avance facial? / Facial morphology in orthognathic surgery: is there a facial advance trend?

RESUMEN: El objetivo de esta investigación fue determinar los movimientos preferidos en maxila y mandíbula para obtener normalidad en morfología facial utilizando técnicas de superimposición en análisis 3D. Se realizó un estudio descriptivo para evaluar el desplazamiento óseo bimaxilar y del hueso hioides en sujetos clase facial tipo II y clase facial tipo III sometidos a cirugía ortognática. Para la superimposición se utilizó como puntos fijos Nasion - Silla - Porion y la sutura cigomática-maxilar. Estos puntos se superpusieron en CBCT pre quirúrgico y postquirúrgico y se evaluó el desplazamiento de la espina nasal anterior, Punto A, Punto B, mentón y del hueso hioides. Para la evaluación y comparación de las variables continuas antes y después de la cirugía ortognática se utilizó la prueba T de Student. Para la correlación entre las variables, se utilizó el Test de Spearman considerando un valor p<0,05 como diferencia significativa. 44 sujetos de entre 18 y 40 años de ambos sexos, fueron incluidos en esta investigación. En el 90 % de los sujetos se realizó un movimiento sagital de avance de la maxila. El movimiento sagital de avance mandibular se realizó en el 100 % de los sujetos con clase facial tipo II, mientras que el 100 % de los sujetos con clase facial tipo III se realizó se le retroceso mandibular. El hueso hioides presentó un avance en 26 de los 27 sujetos con clase facial tipo III. Es posible concluir que existe una tendencia al avance maxilar independiente de la deformidad facial.

ABSTRACT: The objective of this research was to determine the preferred movements in the maxilla and mandible to obtain normality in facial morphology using superimposition techniques in 3D analysis. A descriptive study was carried out to evaluate bimaxillary bone displacement and hyoid bone in subjects facial class II and facial class III undergoing orthognathic surgery. were used as fixed points for superimposition: Nasion (N) - Silla (S) - Porion (Po) and the zygomatic-maxillary suture (Z). These points were superimposed in pre-surgical and post- surgical CBCT and was evaluated to displacement of the anterior nasal spine, Point A, Point B, Chin and the hyoid bone. For the evaluation and comparison of continuous variables before and after orthognathic surgery, was used the Student's t test. For the correlation between the variables, the Spearman test is used, considering a p value <0.05 as a significant difference. 44 subjects between 18 and 40 years old of both sexes were included in this research. A 90% of subjects a was performed a maxillay sagittal movement. The sagittal movement of mandibular advancement was performed in 100% with facial class type II, while 100 % of the subjects with with facial class type III had a mandibular recession. The hyoid bone advanced in 26 of the 27 subjects with facial class type II. It is possible to conclude that there is a tendency for maxillary advancement, independent of facial deformity.

Cone beam computed tomography evaluation of the relationship between atlantodental interval and skeletal facial morphology in adolescents / Avaliação por tomografia computadorizada de feixe cônico da relação entre o intervalo atlantodental e a morfologia esquelética facial em adolescentes

Abstract Introduction: In the pediatric population, computed tomography examination of the upper cervical spine plays an important role in the diagnosis of neurological injuries involving that region. Due to the interconnected nature of the craniofacial structures, a structural change in one is expected to also cause changes in the other structures. Objective: The aim of this study was to evaluate relationships between atlantodental interval, cervical vertebral morphology, and facial structure in healthy adolescents using cone beam computed tomography. Methods: Thirty subjects aged 14-20 years (10 males, mean age: 17.2 years; 20 females, mean age: 17.9 years) were included in the study. The anterior, lateral and posterior atlantodental intervals, and vertical and anteroposterior dimensions of the first and second cervical vertebrae were evaluated from cone beam computed tomography images. Facial morphology was evaluated using 7 parameters on lateral cephalometric cone beam computed tomography images and 6 parameters on posteroanterior images. The Mann-Whitney U test and Wilcoxon test were used for statistical analyses. Results: Comparisons between males and females showed that most parameters were larger in males, with significant differences in vertical facial dimensions (anterior lower face height: p= 0.05; anterior upper face height: p= 0.001), (distance between the most internal point of the frontozygomatic suture and midsagittal reference plane; p= 0.01), (the distance between the deepest point of the right alveolar maxillar process and midsagittal reference plane; p= 0.001), and C2 vertebral dimensions. The anterior and lateral atlantodental interval values correlated with maxilla position relative to the mandible angle, and the anterior atlantodental interval correlated with lower anterior facial height (p= 0.05). Dimensional measurements of the C1 and C2 vertebrae were correlated with both anterior facial heights and some posteroanterior parameters. Conclusion: Sagittal, vertical, and transverse facial dimensions and positions were strongly associated with C1 and C2 vertebral dimensions, and the maxillomandibular relationship may affect atlantodental interval. Therefore, including craniofacial features in assessment of the atlantodental area and vertebral distances in adolescents may be beneficial.

Resumo Introdução: Na população pediátrica, a tomografia computadorizada da coluna cervical alta tem um importante papel no diagnóstico de lesões neurológicas que envolvem essa região. Devido à natureza interconectada das estruturas craniofaciais, espera-se que uma mudança estrutural em uma delas também cause alterações nas outras estruturas. Objetivo: Avaliar as relações entre o intervalo atlantodental, a morfologia vertebral cervical e a estrutura facial em adolescentes saudáveis com a tomografia computadorizada de feixe cônico. Método: Trinta indivíduos entre 14 e 20 anos (10 homens, média de 17,2 anos; 20 mulheres, média de 17,9 anos) foram incluídos no estudo. O intervalo atlantodental anterior, lateral e posterior e as dimensões vertical e anteroposterior da primeira e segunda vértebras cervicais foram avaliados a partir de imagens de tomografia computadorizada de feixe cônico. A morfologia facial foi avaliada utilizando-se sete parâmetros em imagens de tomografia computadorizada de feixe cônico cefalométricas laterais e seis parâmetros em imagens posteroanteriores. O teste U de Mann-Whitney e o teste de Wilcoxon foram utilizados para as análises estatísticas. Resultados: As comparações entre homens e mulheres mostraram que em sua maioria os parâmetros foram maiores no sexo masculino, com diferenças significantes nas dimensões faciais verticais (altura facial anterior inferior: p = 0,05; altura facial anterior superior: p = 0,001), distância entre o ponto mais interno da sutura fronto-zigomática e plano de referência médio-sagital; p = 0,01distância entre o ponto mais profundo do processo alveolar do maxilar direito e o plano de referência médio-sagital; p = 0,001) e as dimensões do corpo vertebral C2. O intervalo atlantodental anterior e lateral correlacionaram-se com o ângulo da posição da maxila em relação à mandíbula e o intervalo atlantodental anterior correlacionou-se com altura facial anterior inferior (p = 0,05). Medidas das dimensões das vértebras C1 e C2 foram correlacionadas com as alturas faciais anteriores e alguns parâmetros póstero-anteriores. Conclusão: As dimensões e posições faciais sagitais, verticais e transversais foram fortemente associadas às dimensões dos corpos vertebrais C1 e C2 e a relação maxilomandibular pode afetar o intervalo atlantodental. Portanto, incluir características craniofaciais na avaliação da área atlantodental e das distâncias vertebrais em adolescentes pode ser benéfico.

Three-dimensional analysis of nasolabial soft tissues while smiling using stereophotogrammetry (3dMDTM) / Análisis tridimensional de los tejidos blandos nasolabiales en sonrisa utilizando estereofotogrametría (3dMDTM)

SUMMARY: The nasolabial region is the central esthetic unit of the face and is considered one of the most important determinants of the facial esthetic. The facial morphometry of soft tissues is a very important tool in facial surgery. Advances have been made recently in the capture and analysis of 3D images, which offer great development potential in the diagnosis and treatment of facial deformities. The aim of this study was to characterize the nasolabial region of patient candidates for orthognathic surgery using 3D facial captures. A study was conducted to characterize the width of the nasal base and the nasolabial angle in adult patients through 3D photographs. 30 subjects were included, taking two 3D photos each, one in a resting position and the other smiling. The three-dimensional capture was done with the 3dMDface System. The measurements were taken with the 3dMD Vultus software. The length of the alar base was an average of 34.3 ± 2.6 mm at rest, and 39.1 ± 2.9 mm smiling. The mean of the nasolabial angle was 104.6 ± 9.6° at rest and 105.4 ± 14.3º smiling. Additionally, the distance of the alar base smiling compared to its distance at rest increased an average of 4.83 mm, whereas the nasolabial angle smiling increased an average of 0.8º compared to at rest. In this study, the nasolabial angle did not present any significant changes so that its assessments in the case of facial modifications can be standard; the width of the nasal base is significantly modified with the smile and thus a more intense study of any type of modification in this area is required.

RESUMEN: La región nasolabial es la unidad estética central de la cara y se considera uno de los determinantes más importantes de la estética facial. La morfometría facial en tejidos bandos, es una herramienta de gran importancia en Cirugía Facial. En el último tiempo, se han realizado avances en captura y análisis de imágenes 3D, las cuales ofrecen un gran potencial de desarrollo en el diagnóstico y tratamiento de las deformidades faciales. El objetivo de éste trabajo fue caracterizar mediante capturas faciales 3D la región nasolabial de pacientes candidatos a cirugía ortognática. Se realizó un estudio para caracterizar a través de fotografías tridimensionales de pacientes adultos el ancho de la base nasal y el ángulo nasolabial. Se incluyeron 30 sujetos, tomando 2 fotografías 3D a cada uno, una en posición de reposo y otra en sonrisa. Se realizó la captura tridimensional con la camara facial 3dMDface System. Las mediciones fueron realizadas con el software 3dMD Vultus. La longitud de base alar en reposo, fue en promedio de 34,3 ± 2,6 mm, y de 39,1 ± 2,9 mm, en sonrisa. Por otra parte, la media del ángulo nasolabial en reposo fue de 104,6 ± 9,6° y en sonrisa, de 105,4 ± 14,3º. Por otro lado, la distancia de la base alar en sonrisa respecto a su distancia en reposo, aumentó un promedio de 4,83 mm, mientras que el ángulo nasolabial en sonrisa, aumentó en promedio 0,8º respecto a la posición de reposo. En esta investigación, el ángulo nasolabial no presentó cambios significativos de forma que su valoración frente a modificaciones faciales puede ser estándar; el ancho de base nasal se modifica significativamente con la sonrisa de forma que su estudio debe ser más agudo frente a cualquier tipo de modificación en esta zona.

Comparación entre las técnicas de Ricketts y Mcnamara para la determinación de la posición del maxilar y la mandíbula en jóvenes del Ecuador / Comparison between Ricketts and Mcnamara techniques for the determination of the maxilla and mandible position in Ecuadorian youths

RESUMEN: Los análisis cefalométricos, a partir de una radiografía lateral de cráneo, son amplios y variados considerando tanto los patrones funcionales como los de estética facial. Entre las técnicas de medición en cefalometría, Ricketts y de McNamara son ampliamente utilizados; ambas le entregan importancia a determinar la posición del maxilar y de la mandíbula con diferentes relaciones esqueletales. El objetivo de esta investigación es comparar ambas técnicas en una población joven de Ecuador; se realizó un análisis de concordancia utilizando el índice kappa de Cohen entre los resultados de las mediciones correspondientes a 44 radiografías cefálicas laterales de sujetos jóvenes entre 18 y 27 años de edad, de ambos sexos. En relación a la posición maxilar, el 56,82 % (IC 95 %: 42,18 % - 71,45 %) coinciden en el diagnóstico de protrusión maxilar; el índice de concordancia kappa de Cohen fue de 0,599 (IC 95 %: 0,354 - 0,854) con un valor p<0,05. En relación a la posición mandibular, el 50,0 % (IC 95 %: 35,23 % - 64,77 %) coinciden en el diagnóstico de retrusión mandibular; el índice kappa de Cohen fue de 0,460 (IC 95 % 0,229 - 0,691) con un valor p<0,05. Se concluye que, a pesar de manejar puntos de referencia cefalométricos diferentes, las dos técnicas de medición cráneo-facial son útiles para el estudio de posición de maxila y mandíbula. Existen diferencias entre algunos analisis de ambos estudios que pueden incidir en la selección terapéutica de potenciales pacientes.

SUMMARY: The cephalometric analyses from a lateral cranial radiograph, are wide and varied considering both functional and facial aesthetic patterns. Among the measurement techniques in cephalometry, Ricketts and McNamara are widely used; they both give importance to determine the position of the maxilla and mandible with different skeletal relationships. The objective of this research is to compare both techniques in a young population of Ecuador. A concordance analysis was performed using Cohen's kappa index between the results of the measurements corresponding to 44 lateral cephalic radiographs of young subjects between 18 and 27 years of age, of both sexes. In relation to the maxillary position, 56.82 % (95 % CI: 42.18 % - 71.45 %) coincide in the diagnosis of maxillary protrusion. Cohen's kappa concordance index was 0.599 (95 % CI: 0.354-0.854) with a p-value < 0.05. In relation to the mandibular position, 50.0 % (95% CI: 35.23 % 64.77 %) coincide in the diagnosis of mandibular retrusion. Cohen's kappa index was 0.460 (95 % CI 0.229 - 0.691) with a p-value < 0.05. It is concluded that, despite handling different cephalometric reference points, the two craniofacial measurement techniques are useful for the study of maxilla and mandible position. There are differences between some analyses of both studies that may affect the therapeutic selection of potential patients.

Relações entre potenciais elétricos dos músculos temporais e masseteres, força de mordida e índice morfológico da face / Relationship between electrical activity of the temporal and masseter muscles, bite force, and morphological facial index

RESUMO Objetivo Verificar e analisar possíveis correlações entre a atividade elétrica dos músculos temporais e masseteres, a força de mordida e os índices morfológicos da face, em indivíduos adultos. Método Participaram 43 indivíduos, adultos jovens de ambos os gêneros, entre 18 e 37 anos, submetidos à mensuração da face para cálculo do Índice Morfológico da Face (IMF), Eletromiografia de Superfície (EMGs) de Masseteres Direitos e Esquerdos (MD e ME), Temporais Direitos e Esquerdos (TD e TE) e obtenção da Força de Mordida (FM) nas regiões de pré-molares direitos, pré-molares esquerdos e incisivos. As provas eletromiográficas realizadas foram em repouso, Contração Voluntária Isométrica Máxima (CVIM) e mastigação habitual de uva-passa. Foi realizada análise estatística pelo coeficiente de correlação de Spearman com significância no nível de 5%. Resultados Os valores de repouso em TD e TE foram significativamente maiores que os de MD e ME. Foi encontrada correlação direta significativa entre IMF e a EMGs na prova de CVIM para o TE (rs=36, p=0,017). Observou-se correlação direta significativa entre o IMF com a EMGs durante a FM em Incisivos para os músculos TD, TE e Masseter Direito (MD). Durante as provas de força, foi possível observar correlação direta significativa entre a FM em pré-molares direitos com a EMGs do TE, MD, ME. Conclusões Não foi verificada correlação entre as respostas elétricas dos músculos temporais e masseteres, a força de mordida e os índices morfológicos da face, em indivíduos adultos a partir das provas realizadas. A atividade elétrica dos músculos temporais e masseteres parece associar-se apenas à força de mordida. Como dado de característica postural habitual, a atividade elétrica dos músculos temporais é maior que a atividade de masseteres, também independente do IMF.

ABSTRACT Purpose To analyze possible correlations between the electrical activity of masseter and temporal muscles, Bite Force (BF), and Morphological Facial Indices (MFI). Methods The study involved 43 young adults, both genders, 18 to 37 years old. The individuals were submitted to: face measurement to calculate MFI; Masseter and Temporal Surface Electromyography (sEMG) and BF measurements on right and left premolars and incisors. The following electromyographic tests were conducted: at rest position; Maximal Voluntary Isometrical Contraction (MVIC) and usual chewing of raisins. Statistical analysis was conducted using the coefficient of Spearman correlation with significance level of 5%. Results The values at rest in the temporal muscles were significantly higher than those in the masseter muscles. A meaningful correlation was found between MFI and sEMG in the MVIC test for the Left Temporal (rs=36, p=0.017). A significant correlation was observed between FMI and sEMG during BF in incisors for temporal muscles and the Right Masseter. During the force tests, it was possible to observe a meaningful correlation between BF in right premolars and the sEMG of the Left Temporal and Masseters. Conclusion No correlation was found between the sEMG of temporal and masseter muscles, BF, and FMI in adult individuals based on the tests performed. The SEMG of temporal and masseter muscles seems to be associated only with BF. As a datum of habitual postural characteristic, the electrical activity of temporal muscles is higher than the activity of masseters, also regardless of MFI.

Nasal deformity in subjects with class III facial deformities / Deformidad nasal en sujetos con deformidad facial clase III

Dentofacial deformities present some shades and variations that determine the inclusion of different anatomical components as part of the disease; the aim of this study was to ascertain the nasal characteristics in patients with a Class III dentofacial deformity. A descriptive study was conducted on 20 patients diagnosed with a Class III facial deformity and a surgical indication; frontal and lateral as well as CT images were taken to analyze variables of nasal morphology and deformities associated with the nasal bridge, tip and septum. The results showed that the nasal angles are outside normal parameters and that the basal width of the nose is approximately 3 mm smaller than the intercanthal width; 45% of the subjects have lateral deviations, 50% bridge deformity and 80% septum deviation. It is concluded that there are nasal deformities in subjects with a Class III facial deformity and that this component must be carefully evaluated in the preoperative stage.

Las deformidades dentofaciales presentan algunos matices y variaciones que determinan la inclusión de diferentes componentes anatómicos dentro de la enfermedad; el objetivo de esta investigación es conocer las características de la nariz en pacientes con deformidad dentofacial de clase III. Se desarrollo un estudio descriptivo en 20 pacientes con diagnóstico de deformidad facial declase III e indicación quirúrgica; se estudiaron análisis fotográficos frontales y laterales así como tomografías computadorizadas para analizar variables de morfología nasal y deformidades asociadas al puente nasal, punta nasal y septo nasal. Los resultados demostraron que los ángulos nasales se encuentran fuera de los parámetros de normalidad y que el ancho basal de la nariz es aproximadamente 3 mm menor que el ancho intercantal; el 45% de los sujetos presentó desviación lateral, 50% deformidad del puente nasal y el 80% desvío de septo nasal. Se concluye que existen deformidades nasales en sujetos con deformidad facial de clase III y que este componente debe ser evaluado criteriosamente en la etapa preoperatoria.

Relaciones de forma y proporción del incisivo central maxilar con medidas faciales, línea mediana dentaria y facial en adultos / Relationships between shape and proportion of the maxillary central incisor with facial measurements, dental and facial midline in adults

El propósito de este estudio fue relacionar la forma y proporción del incisivo central maxilar (ICM) derecho con la forma facial y ubicación de las líneas medianas dentarias y facial. Se realizó un estudio de corte transversal sobre una muestra por conveniencia constituida por 118 pacientes de ambos sexos, con una edad promedio de 25,09±7,71 años, escogidos según criterios de inclusión. En cada caso, fueron medidos el largo y ancho del ICM derecho, proporción dentaria resultante entre estas medidas, líneas medianas dentarias en relación a la línea mediana facial. Estas medidas se correlacionaron con las medidas faciales para forma y clase facial. Los resultados revelaron que la forma dentaria más frecuente encontrada fue la ovoide; las medidas promedio de largo y ancho para el ICM fueron de 10,28±0,91 mm y 8,69±0,57 mm, respectivamente. En mujeres fue 9,98 mm y 8,55 mm, y en hombres de 10,62 mm y 8,86 mm. La proporción dentaria fue de un 85%. Se encontraron coincidencias de las líneas medianas dentarias maxilar, mandibular y facial sólo en un 18% de los casos, y los tipos de contornos gingivales más frecuentes fueron de tipo estético (97%). No hubo relación entre medidas dentarias y faciales para las distintas clases faciales (análisis de varianza, y pruebas de comparaciones múltiples de Scheffe), sin embargo, encontramos que en todas las clases faciales de ambos sexos, predominó el tipo mesofacial y la clase I facial (57%). No se puede establecer una correlación entre forma dentaria y forma facial de manera significativa, por lo que otros parámetros también deben ser tomados en cuenta.

The purpose of this study was to relate the shape and proportion of the right maxillary central incisor with facial shape and location of dental and facial median lines. Cross-sectional study on a convenience sample consisting of 118 patients of both sexes was performed, with an average age of 25.09±7.71 years, selected according to inclusion criteria. In each case, were measured the length and width of right maxillary central incisor, tooth ratio resulting of these measures and medium tooth lines in relation to the midline. These measures were correlated with measures of facial shape and facial class. The results revealed that the most common tooth shape found was ovoid; average length and width for the maxillary central incisor were 10.28±0.91 mm and 8.69±0.57 mm, respectively; of 9.98 mm and 8.55 mm in women, and 10.62 mm and 8.86 mm in men. The dental proportion was 85%. Matches between the median lines of maxillary teeth, jaw and face were only found in 18% of cases, and the most common types of gingival contours were aesthetic (97%). There was no relationship between dental and facial for different facial types (analysis of variance and multiple comparison tests of Scheffe) measures, however, we found that all facial classes in both sexes, prevailed mesofacial and class I facial types (57%). Unable to establish a correlation between tooth shape and facial shape significantly, so other parameters should also be taken into account.

Facial soft tissue in subjects with class II and class III facial deformities: preliminary results / Tejido blando facial en sujetos con deformidad facial clase II y clase III: resultados preliminares

Class II and class III skeletal anomalies require treatments that are both esthetic and functional, so the purpose of this investigation was to study the relationship between facial soft and hard tissues of patients with class II and class III deformities in the lower third of the face. A descriptive study was designed which included class II subjects with a SNB angle less than 78 and class III with a SNA angle less than 80. The soft tissue width was analyzed in relation to the Pg point, A point, B point, and upper and lower incisor cervical points. The naso-labial angle and interincisal angle were also analyzed. The studies were done using cone beam computerized tomography and analyzed with the software Simplant O&O (Materialise, Belgium). The results revealed similarities in the measurements of the facial width soft tissues with differences of less 1 mm in the Pg point, A point, B point, upper incisor point; the greatest differences were observed between the two groups in thelower incisor cervical point, with almost 5 mm difference in tissue size. The naso-labial angle also presented differences between the two groups, being more closed in the class III than in the class II subjects (approximate difference of 6). It can be concluded that there are minimal differences in the soft tissue width in class II and class III subjects; other parameters can be analyzed to search for differences that influence treatment planning and strategies for these patients.

Las anomalías esqueletales de clase II y clase III requieren tratamientos que asocian estética y función. El objetivo de esta investigación fue estudiar la relación entre tejidos blandos y duros faciales de pacientes con clase II y clase III facial, a nivel del tercio inferior facial. Se diseño un estudio descriptivo donde se incluyeron sujetos clase II con un ángulo SNB menor de 78 y clase III con un ángulo SNA menor de 80. Se analizó el ancho de tejidos blandos en relación a los putos Pg, punto A, punto B, y puntos cervicales de dientes incisivos maxilar y mandibular; también se analizaron los ángulos nasolabial e interincisivo; los estudios se realizaron en tomografía computadorizada cone beam y analizados en el software Simplant O&O (Materialise, Belgium). Los resultados demostraron semejanzas en las mediciones obtenidas en el ancho facial de tejidos blandos con diferencias menores a 1 mm en los puntos Pg, punto A, punto B y cervical incisivo maxilar; en relación al punto cervical del incisivo mandibular se observaron las mayores diferencias entre ambos grupos, cercanas a 5 mm de diferencia de tamaño en los tejidos; el ángulo nasolabial también presento diferencias entre ambos grupos, siendo en los sujetos clase III mas cerrado que en sujetos clase II (diferencia aproximada de 6). Se puede concluir que existen mínimas diferencias en el ancho de tejidos blandos en sujetos de clase II y clase III; otros parámetros pueden ser analizados para búsqueda de diferencias que influyan en planificaciones y estrategias terapéuticas para estos sujetos.

Association between maximum bite force and craniofacial morphology in an Amazonian population with normal dental occlusion / Associação entre força máxima de mordida e morfologia craniofacial em população Amazonense com oclusão normal

The aim of this study was to determine the maximum bite force (MBF) in Amazonian children and young adolescents with normal dental occlusion, the average craniofacial morphology, and investigate associations between craniofacial morphology and body mass with MBF. Ninety-seven children and young adolescents, 21 with primary dentition and 76 with permanent dentition and normal dental occlusion were included in the study. Subjects were from Amazonian tribes studying at three schools in Leticia, Amazonas, Colombia. MBF was determined by means of a digital hydraulic pressure gauge. Body mass index (BMI), facial morphology index, and dental arches transverse dimensions were computed in each subject. Mann Whitney test, a one-tailed non-parametric statistical analysis, was used to contrast MBF between primary dentition and permanent dentition. The same statistical analysis was used to determine MBF statistical differences between the various facial morphologies. Pearson correlation statistical analysis was used to evaluate associations between MBF with BMI, dental arches transverse dimensions or facial morphology. Statistical significance was determined at 95 percent level of confidence. A significant difference was found for the MBF between subjects in primary dentition (incisors: 116.57 ± 48.30; right molars: 368.38 ± 105.52; left molars: 322.76 ± 83.77) and those in permanent dentition (incisors: 260.88 ± 85.73; right molars: 459.63 ± 167.11; left molars: 645.67 ± 170.60). In addition, an association was observed between MBF and facial morphology index. It was concluded that MBF significantly increases from primary to permanent dentition in subjects with normal dental occlusion. Furthermore, this study agrees with other reports stating that MBF is associated with the morphology of the face, but not with BMI or dental arches transverse dimensions.

O presente estudo teve como objetivo determinar a força máxima de mordida (FMM) e morfologia craniofacial média de crianças e adolescentes da região do Amazonas com oclusão dentária normal, e investigar associações entre índice de massa corpórea (IMC), morfologia craniofacial e FMM. Participaram do estudo 97 crianças e adolescentes, 21 deles com dentição primária e 76 com dentição permanente, todos com oclusão dentária normal. Os indivíduos pertencentes a tribos amazônicas estudavam em três escolas em Leticia, Amazonas e Colombia. A FMM foi determinada utilizando medidor de pressão hidráulica digital. Índice de massa corporal (IMC), índice morfológico, e dimensões transversais dos arcos dentários de cada indivíduo foram registrados. O teste de Mann Whitney, análise unicaudal não paramétrica, foi aplicado na comparação da força máxima de mordida em dentição decídua e permanente. A mesma análise estatística foi utilizada para determinar as diferenças estatísticas acerca da FMM entre as diferentes características da morfologia facial. O coeficiente de correlação de Pearson foi empregado para avaliar as associações entre FMM e IMC, dimensão transversal dos arcos dentários ou morfologia facial. A significância estatística foi determinada com intervalos de 95% de confiança. Diferença significativa foi observada para FMM entre sujeitos com dentição decídua (incisivos: 116.57 ± 48.30; molares direitos: 368.38 ± 105.52; molares esquerdos: 322.76 ± 83.77) e aqueles com dentição permanente (incisivos: 260.88 ± 85.73; molares direitos: 459.63 ± 167.11molares esquerdos: 645.67 ± 170.60).