Craniofacial identification standards: A review of reliability, reproducibility, and implementation.

There are numerous anatomical and anthropometrical standards that can be utilised for craniofacial analysis and identification. These standards originate from a wide variety of sources, such as orthodontic, maxillofacial, surgical, anatomical, anthropological and forensic literature, and numerous media have been employed to collect data from living and deceased subjects. With the development of clinical imaging and the enhanced technology associated with this field, multiple methods of data collection have become accessible, including Computed Tomography, Cone-Beam Computed Tomography, Magnetic Resonance Imaging, Radiographs, Three-dimensional Scanning, Photogrammetry and Ultrasound, alongside the more traditional in vivo methods, such as palpation and direct measurement, and cadaveric human dissection. Practitioners often struggle to identify the most appropriate standards and research results are frequently inconsistent adding to the confusion. This paper aims to clarify how practitioners can choose optimal standards, which standards are the most reliable and when to apply these standards for craniofacial identification. This paper describes the advantages and disadvantages of each mode of data collection and collates published research to review standards across different populations for each facial feature. This paper does not aim to be a practical instruction paper; since this field encompasses a wide range of 2D and 3D approaches (e.g., clay sculpture, sketch, automated, computer-modelling), the implementation of these standards is left to the individual practitioner.

Cephalometric Characteristics in Chilean Latino Population with Normal Occlusion and Harmonic Profiles in Permanent Dentition. A Retrospective Study / Características Cefalométricas en Población Latina Chilena con Oclusión Normal y Perfiles Armónicos en Dentición Permanente. Un Estudio Retrospectivo

SUMMARY: Malocclusion is usually treated based on clinical decisions complemented with a cephalometric analysis, allowing the comparison of an individual with standard reference norms. Cephalometric standards have mostly been obtained from Caucasian population, but may not be appropriate for other ethnic groups, becoming a clinically relevant problem in multicultural and multiracial societies. The present study aimed to establish cephalometric norms for Chilean-Latino population, using a representative sample of class I individuals in permanent dentition. A sample of 72 cephalometric x-rays of class I growing individuals (47 women and 25 men) between 10 and 20 years of age with class I occlusion and harmonic profile was obtained from the records of the Universidad de los Andes taken between 2012 and 2019, including 1164 individuals. The radiographs were classified according to their cervical vertebral maturation status, and cephalometrically analyzed, obtaining vertical and sagittal parameters in soft and hard tissues, which were compared with Caucasian cephalometric norms. The statistical analysis was performed using descriptive and inferential statistics (T-test, ANOVA and Bonferroni tests). Cephalometric norms were obtained for hard and soft tissues. Upon comparison with Caucasian norms, the subjects included in the sample present a tendency towards a convex profile, significant incisal proclination, dental protrusion, labial biprotrusion and an acute nasolabial angle. There are cephalometric differences between the Caucasian cephalometric norms and those observed Chilean Latino population, displaying differences at a hard and soft tissue level that should be taken into account for clinical decision making in Orthodontics.

La maloclusión generalmente se trata con base en decisiones clínicas complementadas con un análisis cefalométrico, lo que permite la comparación de un individuo con normas de referencia estándar. Los estándares cefalométricos se han obtenido en su mayoría de población caucásica, pero pueden no ser apropiados para otros grupos étnicos, convirtiéndose en un problema clínicamente relevante en sociedades multiculturales y multirraciales. El presente estudio tuvo como objetivo establecer normas cefalométricas para población chileno-latina, utilizando una muestra representativa de individuos clase I en dentición permanente. Se obtuvo una muestra de 72 radiografías cefalométricas de individuos en crecimiento clase I (47 mujeres y 25 hombres) entre 10 y 20 años de edad con oclusión clase I y perfil armónico de los registros de la Universidad de los Andes tomados entre 2012 y 2019, incluidas 1164 personas. Las radiografías se clasificaron según su estado de maduración vertebral cervical, y se analizaron cefalométricamente, obteniendo parámetros verticales y sagitales en tejidos blandos y duros, que se compararon con normas cefalométricas caucásicas. El análisis estadístico se realizó mediante estadística descriptiva e inferencial (T-test, ANOVA y pruebas de Bonferroni). Se obtuvieron normas cefalométricas para tejidos duros y blandos. En comparación con las normas caucásicas, los sujetos incluidos en la muestra presentan una tendencia hacia un perfil convexo, proinclinación incisal significativa, protrusión dental, biprotrusión labial y un ángulo nasolabial agudo. Existen diferencias entre las normas cefalométricas caucásicas y las observadas en población latina chilena, mostrando diferencias a nivel de tejidos duros y blandos que se deben considerar para la toma de decisiones clínicas en Ortodoncia.

The reliability of analytical reference lines for determining esthetically pleasing lip position: An assessment of consistency, sensitivity, and specificity.

INTRODUCTION: This study aimed to identify a simple yet reliable soft-tissue parameter for the clinical determination of esthetic lip position by investigating the most consistent reference lines and assessing their sensitivity and specificity. METHODS: A total of 5745 records from Chinese patients aged >18 years were screened. In part I of the study, lateral view photographs of 96 subjects (33 males, 63 females) with esthetic facial profiles were selected. The profile esthetics of each photograph was first scored by 52 dental students, followed by 97 laypeople on a 5-point attractiveness scale. For the top 25% of photographs with the highest score for each sex (8 males, 16 females), the consistency of 6 commonly used reference lines were assessed to determine the esthetic lip position. In part II of the study, lip positions relative to Steiner's (S) and Ricketts' (E) lines in the profile photographs of 86 patients (43 males, 43 females) deemed to have an esthetically unpleasing profile were compared with those in 86 Chinese movie star idols (43 males, 43 females). RESULTS: In part I of the study, the S, E, and Burstone's (B) lines exhibited the lowest standard deviations for the upper and lower lips. B line was excluded from further analysis because of its higher mean absolute values, and S and E lines were used for the subjective assessment in part II of the study. In part II, the S line showed a sensitivity of 86.0% and 86.0% and a specificity of 81.4% and 83.7% for males and females, respectively. In contrast, the E line presented a sensitivity of 88.4% and 93.0% and a specificity of 79.1% and 74.4% for males and females, respectively. CONCLUSIONS: S, E, and B lines were the most consistent soft-tissue parameters among both sexes; however, because of the smaller absolute values, the S line would be more convenient among the 3 for a quick clinical assessment of lip position. Moreover, the performance of both S and E lines was similar among both sexes, which supports using these lines in assessing the esthetic lip position.

Construction of China national newborn growth standards based on a large low-risk sample.

Most published newborn growth references are based on conventional monitoring data that usually included both low- and high-risk pregnancies. We sought to develop a set of neonatal growth standards constructed from only a large sample of low-risk pregnancies. A total of 24,375 naturally conceived singleton live births with gestational ages of 24-42 weeks were collected in 69 hospitals in thirteen Chinese cities between 2015 and 2018. Unhealthy infants or those with high-risk mother were excluded. Smoothed percentile curves of six anthropometric indicators were established using the Generalized Additive Model for Location, Scale and Shape. The 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentile references for birth weight, length, head circumference, weight/length, body mass index, and ponderal index were calculated for neonates with gestational ages of 24-42 weeks. This set of neonatal growth standards with six anthropometric indicators can provide more tools for growth and nutrition assessment and body proportionality in neonatal clinical practice. These standards might also help to show the differences between growth curves based on low-risk and mixed low- and high-risk pregnancies.

Abnormal cranium development in children and adolescents affected by syndromes or diseases associated with neurodysfunction.

Microcephaly and macrocephaly can be considered both cranial growth defects and clinical symptoms. There are two assessment criteria: one applied in dysmorphology and another conventionally used in clinical practice. The determination of which definition or under which paradigm the terminology should be applied can vary on a daily basis and from case to case as necessity dictates, as can defining the relationship between microcephaly or macrocephaly and syndromes or diseases associated with neurodysfunction. Thus, there is a need for standardization of the definition of microcephaly and macrocephaly. This study was designed to investigate associations between abnormal cranial development (head size) and diseases or syndromes linked to neurodysfunction based on essential data collected upon admission of patients to the Neurological Rehabilitation Ward for Children and Adolescents in Poland. The retrospective analysis involved 327 children and adolescents with medical conditions associated with neurodysfunction. Two assessment criteria were applied to identify subgroups of patients with microcephaly, normal head size, and macrocephaly: one system commonly used in clinical practice and another applied in dysmorphology. Based on the results, children and adolescents with syndromes or diseases associated with neurodysfunction present abnormal cranial development (head size), and microcephaly rarely co-occurs with neuromuscular disease. Macrocephaly frequently co-occurs with neural tube defects or neuromuscular diseases and rarely with cerebral palsy (p < 0.05); microcephaly frequently co-occurs with epilepsy and hypothyroidism (p < 0.001). Traditional classification facilitates the identification of a greater number of relationships and is therefore recommended for use in daily practice. There is a need to standardize the definition of microcephaly and macrocephaly and to include them in 'Human Phenotype Ontology' terms.

Machine learning for image-based detection of patients with obstructive sleep apnea: an exploratory study.

PURPOSE: In 2-dimensional lateral cephalometric radiographs, patients with severe obstructive sleep apnea (OSA) exhibit a more crowded oropharynx in comparison with non-OSA. We tested the hypothesis that machine learning, an application of artificial intelligence (AI), could be used to detect patients with severe OSA based on 2-dimensional images. METHODS: A deep convolutional neural network was developed (n = 1258; 90%) and tested (n = 131; 10%) using data from 1389 (100%) lateral cephalometric radiographs obtained from individuals diagnosed with severe OSA (n = 867; apnea hypopnea index > 30 events/h sleep) or non-OSA (n = 522; apnea hypopnea index < 5 events/h sleep) at a single center for sleep disorders. Three kinds of data sets were prepared by changing the area of interest using a single image: the original image without any modification (full image), an image containing a facial profile, upper airway, and craniofacial soft/hard tissues (main region), and an image containing part of the occipital region (head only). A radiologist also performed a conventional manual cephalometric analysis of the full image for comparison. RESULTS: The sensitivity/specificity was 0.87/0.82 for full image, 0.88/0.75 for main region, 0.71/0.63 for head only, and 0.54/0.80 for the manual analysis. The area under the receiver-operating characteristic curve was the highest for main region 0.92, for full image 0.89, for head only 0.70, and for manual cephalometric analysis 0.75. CONCLUSIONS: A deep convolutional neural network identified individuals with severe OSA with high accuracy. Future research on this concept using AI and images can be further encouraged when discussing triage of OSA.

Distortion and magnification of four digital cephalometric units.

OBJECTIVES: To assess the validity of using the calibration ruler for correcting magnification of linear measurements and to explore and compare the vertical and horizontal magnification of four digital cephalometric units. METHODS: An acrylic box was imaged at seven sagittal positions using four digital cephalometric units: Orthopantomograph OC100, Orthopantomograph OC200, Sirona Orthophos CD, and Sirona Orthophos DS. The true linear lengths of the phantom, corrected, and uncorrected linear lengths on the images were measured and compared. The validity of measurements using the calibration ruler was assessed. The magnification values and distortion indices were calculated and compared among the four cephalometric units. RESULTS: For linear measurements on the mid-sagittal plane and averaged linear measurements on bilateral symmetric sagittal planes, the bias 1.96 STD of the calibration ruler ranged from 1% to 2% for the four cephalometric testing units. For linear measurements on the single lateral sagittal plane, the bias 1.96 STD ranged from 3% to 6%. The vertical scanning charge-coupled device cephalometric unit produced the greatest distortion, ranging from 1.029 to 0.964. CONCLUSION: The metal millimeter calibration ruler is an accurate reference for linear measurement magnification correction. Because of unpredictability and machine specificity, the magnification and distortion of a cephalometric unit should be calibrated for the estimation of cephalometric measurement error.

Accuracy of digital dental models using the low-cost DAVID laser scanner.

BACKGROUND: Accurate laser scanning of plaster casts using validated, low-cost hardware represents a key issue in 3D orthodontics. OBJECTIVES: The aim of this study was to compare the accuracy of measurements taken from plaster casts (gold standard) with digital models of those casts created with a low-cost structural light DAVID laser scanner. MATERIAL AND METHODS: Five different measurements were taken on each of 14 plaster casts by 2 independent observers with an electronic caliper. The measurements were repeated 10 times on all 14 plaster casts by each observer, with a 1-week interval between each set of measurements. All 14 plaster casts were digitized using a low-cost DAVID SLS 3 laser scanner. The same 5 measurements were performed on each of the 3D virtual surface models of the 14 plaster casts by 2 independent observers using Meshlab software in a manner similar to that used with the digital caliper. The measurements were repeated 10 times by the 2 observers with 1 week between each set of measurements. RESULTS: The laser-scanned models were more accurate than the plaster cast models in defining measurements based on simple tooth fissures. The accuracy of measurements based on complex tooth fissures were equivalent for the 2 types of model. For measurements based on interproximal dental contacts, the 2 methods of measurement were similar and both were notably poor in terms of accuracy. CONCLUSIONS: Three-dimensional virtual models obtained from the low-cost DAVID laser scanner can be used clinically, but only for certain types of measurements and indications.

Case-Control Study of Cephalometrics in Patients with Moyamoya.

OBJECTIVE: To determine whether cranial metrics consistently differed between patients with moyamoya and age-, sex-, and race-matched controls. METHODS: Patients diagnosed with moyamoya disease by cerebral angiogram were obtained from a prospectively collected database through the Department of Neurosurgery at the University of Kansas Medical Center. Control patients matched by decade of age, sex, and race were collected through a deidentified hospital database by International Classification of Diseases-9 and 10 codes for ischemic stroke to identify patients with computed tomography angiograms. Imaging studies for both groups were analyzed to obtain 6 skull metrics: maximum anterior to posterior distance, maximum biparietal distance, bregma to occiput distance, right carotid canal diameter (CCD), left CCD, and cephalic index. RESULTS: Forty-five patients were identified in each cohort. Measurements of mean anterior to posterior skull diameter, mean biparietal skull diameter, bregma to occiput distances, and calculated cephalic index did not demonstrate a statistically significant difference between patients with moyamoya and control patients. Right carotid canal mean diameter was 4.8 mm for the moyamoya group and 5.4 mm for the control group, with a significant raw mean difference of -0.61 mm (95% confidence interval, -0.95 to -0.27). Left CCD was 4.7 mm for the moyamoya group and 5.5 mm for the control group, resulting in a significant raw mean difference of -0.76 mm (95% confidence interval, -1.09 to -0.43). CONCLUSIONS: This study identified 2 skull parameters as statistically different in patients with moyamoya compared with a matched control group of patients with ischemic stroke: right CCD and left CCD.

Second-trimester fetal head circumference in more than 350 000 pregnancies: Outcome and suggestion for sex-dependent cutoffs for small heads.

OBJECTIVE: To explore the relationship between small fetal second-trimester head circumference (HC) and pregnancy outcome and identify a cutoff point for offering genetic testing. METHOD: Data from second-trimester scans in Denmark were linked to national registers. Fetuses with anomalies diagnosed before this scan were excluded. Fetuses were grouped according to HC z-score. RESULTS: We included 352 515 singleton fetuses. The mean HC was significantly larger among males than among females with z-scores averaging 0.52 more in males. Small HC was associated with chromosomal anomaly, malformations of the CNS and heart, miscarriage/perinatal death, termination, preterm delivery, and intrauterine growth restriction (test for trend: P < .001 for all outcomes). Fetuses in the group with z-score less than -3 had the highest incidence of adverse outcome, irrespective of fetal sex. In the groups with z-scores between -3 and -2.5, and between -2.5 and -2, risk of adverse outcome was lower for females than males for all outcome categories. CONCLUSION: Small HC in second trimester is a prognostic marker for adverse outcome. The smaller the HC, the higher the risk of adverse outcome. We suggest an HC cutoff point of -2 SD for males and -2.5 SD for females for offering genetic testing.

The turricephaly index: A validated method for recording turricephaly and its natural history in Apert syndrome.

INTRODUCTION: We present the CT scan-derived turricephaly index (TI) as a quotient of the maximal occipito-frontal length of the skull to the distance from the centre of the sella to the highest point on the vertex as a validated tool for assessing turricephaly and evaluating surgical techniques aimed at reducing it. MATERIALS AND METHODS: Measurements taken from CTs of non-operated children with Apert syndrome and age-matched controls were analysed using Centricity PACS system (from the lateral scout image) and the thick-sliced Osirix tool. CTs from non-operated children with Apert syndrome were used to investigate the natural history of their turricephaly both as a group and individually. RESULTS: There was statistically significant agreement between measurements taken from the CT scout and Osirix for 42 control children (R2 = 0.97) and 42 children with Apert syndrome (R2 = 0.98) and between two separate observers. There was a statistically significant difference (p < 0.001) between CT scout-derived TI value between controls (1.73 ± 0.12, range 1.46-1.99) and Apert children (1.42 ± 0.15, range 1.13-1.73). Analysis of 113 CTs of 65 non-operated children with Apert syndrome showed a decrease in turricephaly with age (positive spearman correlation: r = 0.50, p < 0.001). Analysis of 37 CTs of those with multiple (>2) CT's showed a similar decrease in turricephaly in the individual child (p < 0.001). CONCLUSIONS: TI derived from the CT scout view provides a simple, objective and validated method for assessing turricephaly. We recommend it for monitoring and for the prospective evaluation of reconstructive techniques in children with complex/syndromic craniosynostosis.

Validation of Reference Charts for Mid-Trimester Fetal Biometry.

OBJECTIVE: The aim of our study was to assess charts proposed for international use in the Intergrowth-21st Project. METHODS: Ultrasound data were collected from 43,923 healthy singleton pregnancies examined at 18-23 weeks of gestation in the Netherlands. Fetal measurements were converted into Z-scores using previous and current Dutch reference charts and Intergrowth charts. The distributions of the Z-scores were compared with the expected standard normal distribution. RESULTS: In the Dutch population, Intergrowth curves perform well for head circumference and biparietal diameter, but not for abdominal circumference (AC, Z- score = 0.43) and femur length (FL, Z-score = 0.26). Similar findings have been reported in other European countries. Compared with the population in the Intergrowth study, Dutch women are relatively tall (170 vs. 162 cm) and sturdy (67 vs. 61 kg) with a moderately high BMI. Maternal size, in particular maternal height, is positively correlated with birthweight. CONCLUSIONS: Whilst the establishment of the Intergrowth charts is an important step towards worldwide uniformity, for now locally derived charts still perform better, especially for AC and FL. Results from our validation study indicate that distinction between normal and pathologically small babies may be improved by taking maternal size into account.

The Cephalometry of the Yoruba Ethnic Group of Southwestern Nigeria.

Cephalometry of an ethnic population is determined by sex, diet, geographic location and genetics. Quantitative facial morphometry is necessary in today's contemporary society because of the globalization of crime and justice. The objective of this study is to determine Yoruba ethnic population's cephalofacial uniqueness for gender identification. A total of 222 adults (155 females and 67 males) participants from 10 local government areas in 5 states of the South-west Nigeria were randomly selected. Pre-defined set of cephalometric parameters were measured using standard requirement for anthropometry. Statistical analysis was calculated for gender differences using SPSS 20. Overall, gender differences (male vs female) was exhibited in head length, head width, upper facial height, lower facial height and facial width. Sexual differences were also exhibited in head modulus index (41.43±1.72 cm Vs 42.87±2.18 cm) and the index of the size of head (2361.89±444.53 cm3 vs 2147.78±316.13 cm3). Both genders exhibited dolichocephalic/mesocephalic type. Gender identification in this ethnic group may concentrate on five facial morphometry.

Standardization of Cranial Index Measurement in Sagittal Craniosynostosis.

: Cranial index is a widely used 2-dimensional measure of skull form. It has traditionally been calculated as a ratio of the maximal cranial width divided by the maximal skull length. Nevertheless, the points of maximal skull length change dramatically in sagittal craniosynostosis due to variable degrees of frontal and occipital bossing. Therefore, such anatomical changes influence the calculated cranial index. METHOD: This is a retrospective comparative study of 2 methods of measuring cranial index; the traditional method that measures the skull length from glabella to opithcranion versus a modified method that measures the maximal skull length from the most anterior point of the frontal bossing to opithcranion. Cranial indices for 115 patients of radiologically and clinically diagnosed nonsyndromic sagittal craniosynostosis were calculated using both methods. Correlation and Agreements Limits were calculated for comparison between the 2 methods. RESULTS: Males constituted 74.8% (n = 86) of the total sample size with the remaining 29 participants identified as female. The mean age of the study participants was 4.8 months (range 8 days-12 months). The 2 methods were strongly correlated (r = 0.94). The Agreement Limits were calculated to be between 4.02% and 0.18%. CONCLUSION: Typical anatomical changes such as variable degrees of frontal and occipital bossing influence the accuracy of cranial index measurement in sagittal craniosynostosis. Traditional method of cephalic index measurement could underestimate the severity of scaphocephaly.

Diagnostic validity of different cephalometric analyses for assessment of the sagittal skeletal pattern.

INTRODUCTION: Numerous cephalometric analyses have been proposed to diagnose the sagittal discrepancy of the craniofacial structures. OBJECTIVE: This study aimed at evaluating the reliability and validity of different skeletal analyses for the identification of sagittal skeletal pattern. METHODS: A total of 146 subjects (males = 77; females = 69; mean age = 23.6 ± 4.6 years) were included. The ANB angle, Wits appraisal, Beta angle, AB plane angle, Downs angle of convexity and W angle were used to assess the anteroposterior skeletal pattern on lateral cephalograms. The sample was classified into Class I, II and III groups as determined by the diagnostic results of majority of the parameters. The validity and reliability of the aforementioned analyses were determined using Kappa statistics, sensitivity and positive predictive value (PPV). RESULTS: A substantial agreement was present between ANB angle and the diagnosis made by the final group (k = 0.802). In the Class I group, Downs angle of convexity showed the highest sensitivity (0.968), whereas ANB showed the highest PPV (0.910). In the Class II group, ANB angle showed the highest sensitivity (0.928) and PPV (0.951). In the Class III group, the ANB angle, the Wits appraisal and the Beta angle showed the highest sensitivity (0.902), whereas the Downs angle of convexity and the ANB angle showed the highest PPV (1.00). CONCLUSION: The ANB angle was found to be the most valid and reliable indicator in all sagittal groups. Downs angle of convexity, Wits appraisal and Beta angle may be used as valid indicators to assess the Class III sagittal pattern.

Diagnostic validity of different cephalometric analyses for assessment of the sagittal skeletal pattern

Abstract Introduction: Numerous cephalometric analyses have been proposed to diagnose the sagittal discrepancy of the craniofacial structures. Objective: This study aimed at evaluating the reliability and validity of different skeletal analyses for the identification of sagittal skeletal pattern. Methods: A total of 146 subjects (males = 77; females = 69; mean age = 23.6 ± 4.6 years) were included. The ANB angle, Wits appraisal, Beta angle, AB plane angle, Downs angle of convexity and W angle were used to assess the anteroposterior skeletal pattern on lateral cephalograms. The sample was classified into Class I, II and III groups as determined by the diagnostic results of majority of the parameters. The validity and reliability of the aforementioned analyses were determined using Kappa statistics, sensitivity and positive predictive value (PPV). Results: A substantial agreement was present between ANB angle and the diagnosis made by the final group (k = 0.802). In the Class I group, Downs angle of convexity showed the highest sensitivity (0.968), whereas ANB showed the highest PPV (0.910). In the Class II group, ANB angle showed the highest sensitivity (0.928) and PPV (0.951). In the Class III group, the ANB angle, the Wits appraisal and the Beta angle showed the highest sensitivity (0.902), whereas the Downs angle of convexity and the ANB angle showed the highest PPV (1.00). Conclusion: The ANB angle was found to be the most valid and reliable indicator in all sagittal groups. Downs angle of convexity, Wits appraisal and Beta angle may be used as valid indicators to assess the Class III sagittal pattern.

Resumo Introdução: numerosas análises cefalométricas foram propostas para diagnosticar a discrepância sagital das estruturas craniofaciais. Objetivo: este estudo teve como objetivo avaliar a confiabilidade e validade de diferentes análises esqueléticas para a identificação do padrão esquelético sagital. Métodos: foram incluídos 146 indivíduos (homens = 77; mulheres = 69; idade média = 23,6 ± 4,6 anos). O ângulo ANB, a avaliação de Wits, o ângulo Beta, o ângulo do plano AB, o ângulo de convexidade de Downs e o ângulo W foram utilizados para avaliar o padrão esquelético anteroposterior em cefalogramas laterais. A amostra foi classificada nos grupos Classe I, II e III, conforme os resultados diagnósticos da maioria dos parâmetros. A validade e a confiabilidade das análises acima mencionadas foram determinadas usando estatísticas Kappa, sensibilidade e valor preditivo positivo (VPP). Resultados: foi encontrada uma concordância significativa entre o ângulo ANB e o diagnóstico feito pelo grupo final (k = 0,802). No grupo Classe I, o ângulo de convexidade de Downs mostrou a maior sensibilidade (0,968), enquanto o ANB apresentou o maior VPP (0,910). No grupo Classe II, o ângulo ANB mostrou a maior sensibilidade (0,928) e o maior VPP (0,951). No grupo Classe III, o ângulo ANB, a avaliação de Wits e o ângulo Beta apresentaram a maior sensibilidade (0,902), enquanto o ângulo de convexidade de Downs e o ângulo ANB apresentaram o maior VPP (1,00). Conclusão: o ângulo ANB foi considerado o indicador mais válido e confiável em todos os grupos sagitais. O ângulo de convexidade de Downs, a avaliação de Wits e o ângulo Beta podem ser usados como indicadores válidos para avaliar o padrão sagital de Classe III.

Cephalometric Norms in an Omani Adult Population of Arab Descent.

OBJECTIVES: This study aimed to establish cephalometric norms for an Omani population of Arab descent and to compare these with established cephalometric values for Caucasians. METHODS: This cross-sectional study was conducted at the Military Dental Centre and Oman Dental College in Muscat, Oman, between May 2014 and October 2016. A total of 150 Omani patients between 20-29 years old seeking orthodontic treatment were included. All participants had a symmetrical face, class I molar and canine relationships, proper intercuspation, a normal overjet/overbite (<3 mm) and mild spacing/crowding of the teeth (≤3 mm). Lateral cephalography was performed in centric occlusion with the lips relaxed and the head in a natural position. Cephalometric measurements were then compared with Eastman Standard norms. RESULTS: The Omani subjects were found to have a slightly retrusive maxilla, an increased angle between the maxillary and mandibular planes and shorter facial heights in comparison to the Eastman Standard norms. Furthermore, incisor relations were edge-to-edge in nature and the interincisal angle was reduced, suggesting that the Omani subjects had more proclined incisors. In addition, the lips were more protrusive and the nasolabial angle was more obtuse. CONCLUSION: In the Omani sample, increased proclination of the incisors was observed in comparison to Eastman Standard norms. As such, slightly more proclined incisors should be considered acceptable and natural among Omani patients of Arab descent. The cephalometric findings of this study may be helpful in the diagnosis and treatment planning of orthodontic problems among Omanis of Arab descent.

Intervalo de confianza para las normas del cefalograma resumido de Ricketts en niños de cubanos / Confidence interval for the standards of the Ricketts´summarized cephalogram in Cuban children

Introducción: en hallazgos cefalométricos de diferentes países en poblaciones conpatrones de crecimientos y oclusión normal, se reportan diferencias estadísticamentesignificativas a los valores dados en los cefalogramas de Ricketts, Steiner, Downs,Jarabak y otros. En Cuba no existen estudios de estos patrones en niños con denticiónmixta los que favorecerían un mejor diagnóstico de las anomalías dento-maxilofaciales.Objetivo: proponer el perfeccionamiento de las normas del cefalograma resumido deRicketts para los niños.Materiales y Métodos: investigación observacional, descriptiva en cuatropoblaciones pertenecientes a las siguientes zonas del país: Matanzas, Cárdenas,Camagüey y Sancti Spíritus. El universo estuvo constituido por 1 657 niños de 9 añosde edad. La muestra 163 niños, seleccionados por el método estratificado porconglomerados con oclusión dentaria normal. Se utilizó el análisis del cefalogramaresumido de Ricketts y la prueba t de media para determinar los valores de las variables estudiadas y se hicieron estimaciones puntuales y por intervalos deconfianza.Resultados: tres variables mostraron medias iguales a las normas de Ricketts: ejefacial (90°), profundidad facial (87°) y profundidad maxilar (90°). En las restantesfueron comprobadas diferencias significativas. Se obtuvo un intervalo de confianzapara cada una de las variables del cefalograma resumido de Ricketts.Conclusiones: solamente tres variables presentaron valores similares a los planteadospor Ricketts, las restantes presentaron valores que difieren significativamente de losplanteados por Ricketts. Se propone utilizar el intervalo de confianza obtenido en estainvestigación en las variables del cefalograma resumido de Ricketts para diagnosticarlas anomalías dento-maxilofaciales en niños cubanos (AU).

Introduction: in cephalometric findings from different countries in populations withnormal growing and occlusion patterns, significant statistic differences are reported inrelation to the values given in the cephalograms of Ricketts, Steiner, Downs, Jarabak,and others. In Cuba there are not studies of these patterns in children with mixeddentition that might allow a better diagnosis of dental, maxilla-facial anomalies.Objective: to propose the improvement of the standards of the Ricketts abridgecephalogram for children.Materials and methods: descriptive, observational research in four populationsbelonging to different regions of the country: Matanzas, Cárdenas, Camagüey andSancti Spíritus. The universe was formed by 1675 children aged 9 years old; thesample, 163 children with normal dental occlusion, was chosen by the stratifiedmethod per conglomerate. The analysis of the Ricketts summarized cephalogram andthe mean T test were used to determine the values of the studied variables; punctualestimates and estimates by confidence interval were carried out.Results: three variables showed equal means than Ricketts standards: facial axis(90o), facial depth (87o) and maxillary depth (90o). In the remaining variables therewere found significant differences. A confidence interval was obtained for every one ofthe Ricketts summarized cephalogram variable.Conclusions: only three variables showed values similar to those given by Ricketts.The remaining ones presented values significantly differing from those established byRicketts. The proposition is using the confidence interval obtained in this research inthe variables of the Ricketts summarized cephalogram to diagnose the dental-maxillafacial anomalies in Cuban children (AU).

Intervalo de confianza para las normas del cefalograma resumido de Ricketts en niños de cubanos / Confidence interval for the standards of the Ricketts´summarized cephalogram in Cuban children

Introducción: en hallazgos cefalométricos de diferentes países en poblaciones con patrones de crecimientos y oclusión normal, se reportan diferencias estadísticamente significativas a los valores dados en los cefalogramas de Ricketts, Steiner, Downs, Jarabak y otros. En Cuba no existen estudios de estos patrones en niños con dentición mixta los que favorecerían un mejor diagnóstico de las anomalías dento-maxilofaciales. Objetivo: proponer el perfeccionamiento de las normas del cefalograma resumido de Ricketts para los niños. Materiales y Métodos: investigación observacional, descriptiva en cuatro poblaciones pertenecientes a las siguientes zonas del país: Matanzas, Cárdenas, Camagüey y Sancti Spíritus. El universo estuvo constituido por 1 657 niños de 9 años de edad. La muestra 163 niños, seleccionados por el método estratificado por conglomerados con oclusión dentaria normal. Se utilizó el análisis del cefalograma resumido de Ricketts y la prueba t de media para determinar los valores de las variables estudiadas y se hicieron estimaciones puntuales y por intervalos de confianza. Resultados: tres variables mostraron medias iguales a las normas de Ricketts: eje facial (90°), profundidad facial (87°) y profundidad maxilar (90°). En las restantes fueron comprobadas diferencias significativas. Se obtuvo un intervalo de confianza para cada una de las variables del cefalograma resumido de Ricketts. Conclusiones: solamente tres variables presentaron valores similares a los planteados por Ricketts, las restantes presentaron valores que difieren significativamente de los planteados por Ricketts. Se propone utilizar el intervalo de confianza obtenido en esta investigación en las variables del cefalograma resumido de Ricketts para diagnosticar las anomalías dento-maxilofaciales en niños cubanos (AU).

Introduction: in cephalometric findings from different countries in populations with normal growing and occlusion patterns, significant statistic differences are reported in relation to the values given in the cephalograms of Ricketts, Steiner, Downs, Jarabak, and others. In Cuba there are not studies of these patterns in children with mixed dentition that might allow a better diagnosis of dental, maxilla-facial anomalies. Objective: to propose the improvement of the standards of the Ricketts abridge cephalogram for children. Materials and methods: descriptive, observational research in four populations belonging to different regions of the country: Matanzas, Cárdenas, Camagüey and Sancti Spíritus. The universe was formed by 1675 children aged 9 years old; the sample, 163 children with normal dental occlusion, was chosen by the stratified method per conglomerate. The analysis of the Ricketts summarized cephalogram and the mean T test were used to determine the values of the studied variables; punctual estimates and estimates by confidence interval were carried out. Results: three variables showed equal means than Ricketts' standards: facial axis (90o), facial depth (87o) and maxillary depth (90o). In the remaining variables there were found significant differences. A confidence interval was obtained for every one of the Ricketts' summarized cephalogram variable. Conclusions: only three variables showed values similar to those given by Ricketts. The remaining ones presented values significantly differing from those established by Ricketts. The proposition is using the confidence interval obtained in this research in the variables of the Ricketts' summarized cephalogram to diagnose the dental-maxillafacial anomalies in Cuban children (AU).

A simple and accurate craniofacial midsagittal plane definition.

INTRODUCTION: In this article, we aimed to establish an ideal definition for the craniofacial midsagittal plane (MSP) by first finding an optimal "plane of best fit" and then deriving a simple approximation for clinical use that is highly accurate. METHODS: For 60 adolescent patients, 3-dimensional coordinates of 8 central landmarks and 6 pairs of lateral landmarks were collected. Across all patients, the coplanarity of the central landmarks was compared with that of the midpoints of the lateral landmarks. The MSP of best fit was then found by minimizing the mean square distance of the 8 central landmarks to a plane. Across all patients, each possible 3-point plane was compared with the MSP of best fit with respect to both orientation and proximity. RESULTS: The central landmarks were more coplanar and thus more accurate than the midpoints of the lateral pairs. The plane defined by nasion, basion, and incisive foramen was the closest to the MSP of best fit in both orientation and proximity. CONCLUSIONS: The nasion-basion-incisive foramen plane should be used for skull orientation and 3-dimensional cephalometric analyses because it approximates the MSP of best fit with high accuracy, avoids the use of horizontal reference planes, avoids influence from upper and midface asymmetry, uses easily identifiable relevant landmarks, and is simple to define.