Influences of Adenoid Hypertrophy on Children's Maxillofacial Development.

This study aims to investigate the association between adenoid hypertrophy and facial development. A total of 388 children aged 1-13 years old who had undergone head MRI in Foshan Maternal and Child Health Hospital were collected, including 196 hypertrophic cases and 192 normal cases. The maxillofacial soft tissue indicators were measured and compared. The A/N ratio and adenoid thickness consistently increased with age in the hypertrophic group and the A/N ratio reached a maximum value three years earlier than the normal group. The pharyngeal airway space, vallecula of epiglottis to anterior plane distance of the third/fourth cervical vertebrae, angle of convexity, total angle of convexity, and the nasolabial angle in the hypertrophy group were smaller than those in the control group (p < 0.05). The thickness of adenoids, palate height, palate length, and tongue length in the hypertrophy group exceeded that of the control group (p < 0.05). To conclude, adenoid hypertrophy was associated with craniofacial features such as a convex facial profile, a narrowed nasopharyngeal airway, an elongated and heightened palate, a lengthened tongue or a lower tongue position. These findings emphasize the importance of early intervention for children with adenoid hypertrophy to mitigate potential adverse effects on maxillofacial development.

Tomographic evaluation of mandibular buccal shelf in patients with different vertical growth pattern / Evaluación de la placa ósea mandibular en pacientes con diferente patrón de crecimiento vertical

The purpose of this research was the tomographic evaluation of the Mandibular Buccal Shelf (MBS) in orthodontic patients with different vertical growth pattern. An observational, descriptive, cross-sectional and retrospective study was conducted. Tomographic images of patients aged 14 to 40 years were observed and a database was formed with those that met the inclusion criteria. The sample size was 10 for each group according to vertical growth pattern (hypodivergent, normodivergent and hyperdivergent). Then four zones of frequent insertion of extralveolar mini-screws were selected in the MBS, taking as a reference the mesial and distal roots of the first and second mandibular molar. When comparing the characteristics of MBS between vertical growth patterns, between sexes and hemiarchs, no statistically significant differences were found. However, when the characteristics of MBS were compared according to the reference root, it was found that there were statistically significant differences. The vestibular area to the distal root of the second mandibular molar presented the highest values in terms of angulation, height and thickness. There are no significant differences in the bone characteristics of MBS according to vertical growth patterns, sexes or hemiarchs. Angulation, height and thickness progressively increase from the vestibular bone of the mesial root of the first mandibular molar to the distal root of the second molar.

El propósito de esta investigación fue la evaluación tomográfica de la placa ósea mandibular (POM) en pacientes de ortodoncia con diferente patrón de crecimiento vertical. Se realizó un estudio de tipo observacional, descriptivo, transversal y retrospectivo. Se observó imágenes tomográficas de pacientes de 14 a 40 años de edad y se formó una base de datos con las que cumplían los criterios de selección. El tamaño de muestra fue de 10 para cada grupo según patrón de crecimiento vertical (hipodivergentes, normodivergentes e hiperdivergentes). Luego se seleccionaron cuatro zonas de inserción frecuente de minitornillos extralveolares en la POM, tomando como referencia las raíces mesial y distal del primer y segundo molar mandibular. Al realizar la comparación de las características de la POM entre patrones de crecimiento vertical, entre sexos y hemiarcadas no se encontraron diferencias estadísticamente significativas. Sin embargo, cuando se comparó las características de la POM según la raíz de referencia se encontró que había diferencias estadísticamente significativas. La zona vestibular a la raíz distal de la segunda molar mandibular presento los mayores valores en cuanto angulación, altura y grosor. No existen diferencias significativas en las características óseas de la POM según patrones de crecimiento vertical, sexos o hemiarcadas. La angulación, la altura y el grosor aumenta progresivamente desde el hueso vestibular de la raíz mesial del primer molar mandibular hacia la raíz distal del segundo molar.

Craniofacial morphology of patients with unilateral cleft lip and palate at two stages of skeletal maturation

Abstract The aim of this retrospective cross-sectional investigation was to perform a 3D analysis of craniofacial morphology of patients with unilateral cleft lip and palate (UCLP) at two stages of skeletal maturation. Cone-beam computed tomography (CBCT) scans of 52 UCLP patients (34 prepubertal; 18 pubertal) were collected from an outpatient referral center for the treatment of craniofacial deformities. In total 15 multiplanar craniofacial landmarks were identified, 3D virtual surface models were created, and 13 variables were measured to assess the 3D Euclidean distances between landmarks and spatial position of the landmarks in the projected X, Y and Z components. Maxillary and mandibular pitch (clockwise, counterclockwise) rotation relative to the cranial base was also evaluated. The significance level was set at 5%. Maxillary retrusion value relative to the cranial base was higher and statistically significant greater (p = 0.028) in pubertal (SNA, 77.4° ± 6.2; N-ANS Y, 3.3 mm ± 3.1) than in prepubertal patients (SNA 81.0° ± 5.2; N-ANS Y, 5.8 mm ± 2.7). The posterior cranial base length (S-Ba Y) was significantly longer (p = 0.013) in pubertal (20.7 mm ± 3.4) than in prepubertal patients (18.4 mm ± 2.7). The upper facial height (N-ANS Z) was significantly greater (p = 0.01) in pubertal (46.9 mm ± 4.5) than in prepubertal patients (43.4 mm ± 3.0). Prepubertal and pubertal UCLP patients presented distinct patterns of craniofacial morphology, mainly in the sagittal component of the maxilla and in the posterior cranial base length. Pubertal patients had greater maxillary retrusion and posterior cranial base length.

Circadian clock-A promising scientific target in oral science.

The oral and maxillofacial organs play vital roles in chewing, maintaining facial beauty, and speaking. Almost all physiological processes display circadian rhythms that are driven by the circadian clock, allowing organisms to adapt to the changing environment. In recent years, increasing evidence has shown that the circadian clock system participates in oral and maxillofacial physiological and pathological processes, such as jaw and tooth development, salivary gland function, craniofacial malformations, oral carcinoma and other diseases. However, the roles of the circadian clock in oral science have not yet been comprehensively reviewed. Therefore, This paper provides a systematic and integrated perspective on the function of the circadian clock in the fields of oral science, reviews recent advances in terms of the circadian clock in oral and maxillofacial development and disease, dialectically analyzes the importance of the circadian clock system and circadian rhythm to the activities of oral and maxillofacial tissues, and focuses on analyzing the mechanism of the circadian clock in the maintenance of oral health, affecting the common diseases of the oral and maxillofacial region and the process of oral-related systemic diseases, sums up the chronotherapy and preventive measures for oral-related diseases based on changes in tissue activity circadian rhythms, meanwhile, comes up with a new viewpoint to promote oral health and human health.

Dermal Matrix Graft Effects on Facial Growth in a Veau-Wardill-Kilner Palatoplasty Model: An Experimental Study in Rats.

The primary goal of palatoplasty is the restoration of normal speech, that can be aimed by, among many procedures, lengthening the palate through the pushback technique; one of its complications is abnormal maxillary growth. The main factor affecting facial growth in CLP patients is believed by many to be the palatoplasty-due to the large scar retraction resulting from some surgical techniques. The non-crosslinked two-layer bioabsorbable collagen matrix Mucograft™ (Geistlich Pharma AG, Wolhusen, Switzerland) is a potential tool to aid in wound closure in a second-intention healing situation.The objective of this work was to test the use of an acellular dermal matrix (Mucograft®) in an experimental model of Veau-Wardill-Kilner palatoplasty, as a tool to reduce scar retraction of the denuded palatine mucosa.Twenty-four 3-week-old male Wistar rats were used. The animals were randomly divided into two groups. In the control group, an excision was made with bone exposure in the palate, simulating the defect left in the Veau-Wardill-Kilner palatoplasty. In the intervention group, the same procedure was performed, and the area of denuded palatine bone was treated with a bioabsorbable collagen matrix (Mucograft®). For data collection, 9 weeks after surgery (12 weeks of life), the animals were euthanized by excessive anesthetic dosage. Maxillary growth, macroscopic appearance of the scar, pain, and bleeding were evaluated.There were significant statistical differences between the groups for palate length growth (7.6 mm + -0.38 mm vs 5.5 mm + -0.36 mm, P = .009) and for palate width growth (1.47 mm + -0.8 mm vs -0.09 mm + -0.55 mm, P = .001), favoring dermal matrix group compared to controls. Whereas for pain and bleeding, there were no differences between the groups.The use of dermal matrix in rats with an area of bone denudation on the palate increases maxillary length and width growth patterns. Besides, it does not increase pain, bleeding, or post-operative complications.

The impact of mouth breathing on dentofacial development: A concise review.

Mouth breathing is one of the most common deleterious oral habits in children. It often results from upper airway obstruction, making the air enter completely or partially through oral cavity. In addition to nasal obstruction caused by various kinds of nasal diseases, the pathological hypertrophy of adenoids and/or tonsils is often the main etiologic factor of mouth breathing in children. Uncorrected mouth breathing can result in abnormal dental and maxillofacial development and affect the health of dentofacial system. Mouth breathers may present various types of growth patterns and malocclusion, depending on the exact etiology of mouth breathing. Furthermore, breathing through the oral cavity can negatively affect oral health, increasing the risk of caries and periodontal diseases. This review aims to provide a summary of recent publications with regard to the impact of mouth breathing on dentofacial development, describe their consistencies and differences, and briefly discuss potential reasons behind inconsistent findings.

Anatomical and immunohistochemical analyses of the fusion of the premaxillary-maxillary suture in human fetuses.

PURPOSE: The development of the premaxillary-maxillary suture (PMS) in human fetuses and a possible association between the fusion time of the PMS and maxillary deficiency were investigated. Expression of transforming growth factor beta (TGF-ß1 and TGF-ß3) and of fibulins (fibulin­1 and fibulin-5) were also investigated. METHODS: We analyzed 36 human fetus cadavers (19 males, 17 females; average age 23.97 ± 2.57 gestational weeks [gws], range 11-35 gws). Two cases, diagnosed with Down syndrome (DS), were characterized with maxillary deficiency; 34 fetus cadavers did not show any craniofacial abnormalities. The PMS was analyzed anatomically, followed by semi-quantitative immunohistochemical (IHC)-based expression analyses (i.e., TGF-ß1/-ß3, fibulin-1/-5). Spearman correlation test was conducted to investigate correlations. RESULTS: In the fetuses without DS, the labial region of the PMS was open at 11 gws, after which it began to ossify from the middle to the upper and lower ends of the suture, typically fusing completely at 27 gws. Fetuses with DS demonstrated complete fusion of the labial region of PMS with a spongy bone structure at 23 gws and those without DS at 27 gws. IHC revealed similar patterns of TGF-ßs and fibulins expression in the PMS during the human fetal period. There were significant positive correlations between the expression of TGF-ß1 and TGF-ß3 (r = 0.64, p = 0.009), TGF-ß1 and fibulin­1 (r = 0.66, p = 0.008), and TGF-ß3 and fibulin­1 (r = 0.67, p = 0.006). CONCLUSION: Premature fusion of the PMS in the labial region during the human fetal period may be associated with maxillary deficiency, which is related to a class III malocclusion. Overall, the similar expression patterns of TGF-ß1, TGF-ß3 and fibulin­1 suggested a close relationship between these factors in regulating the development of the PMS.

A semi-automatic three-dimensional technique using a regionalized facial template enables facial growth assessment in healthy children from 1.5 to 5.0 years of age.

Objectives: To develop a semi-automatic technique to evaluate normative facial growth in healthy children between the age of 1.5 and 5.0 years using three-dimensional stereophotogrammetric images. Materials and Methods: Three-dimensional facial images of healthy children at 1.5, 2.0, 2.5, 3.0, 4.0 and 5.0 years of age were collected and positioned based on a reference frame. A general face template was used to extract the face and its separate regions from the full stereophotogrammetric image. Furthermore, this template was used to create a uniform distributed mesh, which could be directly compared to other meshes. Average faces were created for each age group and mean growth was determined between consecutive groups for the full face and its separate regions. Finally, the results were tested for intra- and inter-operator performance. Results: The highest growth velocity was present in the first period between 1.5 and 2.0 years of age with an average of 1.50 mm (±0.54 mm) per six months. After 2.0 years, facial growth velocity declined to only a third at the age of 5.0 years. Intra- and inter-operator variability was small and not significant. Conclusions: The results show that this technique can be used for objective clinical evaluation of facial growth. Example normative facial averages and the corresponding facial growth between the age 1.5 and 5.0 years are shown. Clinical Relevance: This technique can be used to collect and process facial data for objective clinical evaluation of facial growth in the individual patient. Furthermore, these data can be used as normative data in future comparative studies.

A Non-Linear Osteometric Modeling Method for Three-Dimensional Mandibular Morphological Changes During Growth: One-Year Monitoring of Miniature Pigs Using Cone-Beam Computed Tomography.

Knowledge of mandibular growth and development is essential for diagnosis of malformation and early interception. A previous method of quantifying mandibular growth using the distances between selected anatomical landmarks over the growth period does not provide a complete, quantitative description of the continuous growth patterns. The current study aimed to bridge the gap by measuring the 3D continuous growth of the mandible in miniature pigs using cone-beam computerized tomography (CBCT). The mandibles of the pigs were CBCT-scanned monthly over 12 months, and the 3D mandibular models were reconstructed. A new non-linear, time-dependent osteometric modeling approach was developed to register two consecutive mandible models by searching for the corresponding points with the highest likelihood of matching the anatomical and morphological features so that the morphological changes patterns for each month could be described using color maps on the models. The morphological changes of the mandible were found to decrease anteriorly, with the condyle region and the posterior part of the ramus growing faster than the rest of the mandible. The condyle region showed the fastest growth rate and the posterior ramus the second during the growth period, while the middle and anterior corpus regions showed the slowest growth rates. In conclusion, the current results revealed the non-linear patterns and rates of morphological changes in different growth regions and the whole mandible. The new approach may also be useful for future studies on the growth of the mandible in other animals.

Effects of mouth breathing on maxillofacial and airway development in children and adolescents with different cervical vertebral maturation stages: a cross-sectional study.

BACKGROUND: To examine the influence of mouth breathing on maxillofacial and airway development in children and adolescents with different cervical vertebral maturation stages. METHODS: Lateral cephalometric radiograph of a total of 120 children and adolescents, 64 girls and 56 boys (7-15 years old), diagnosed with mouth breathing were examined. Maxillofacial hard tissue, soft tissue and airway measurements were obtained using both manual and digital techniques. Independent samples t-test was performed to compare the difference between the measured indexes and the standard values. RESULTS: As for maxillofacial hard tissue, SNB (CS1-CS5), GoGn (CS1-CS5), ArGoNa (CS1-CS5), ArGo (CS1-CS2) and SNA (CS1-CS2) in mouth breathing children and adolescents were below the standard values (P < 0.05). NGoMe (CS1-CS5), SN-MP (CS1-CS4), SN-PP (CS1-CS4), PP-MP (CS1-CS3) and SN-GoGn (CS1-CS2) in mouth breathing children and adolescents were above the standard values (P < 0.05). As for maxillofacial soft tissue measurements, H angle (CS1-CS5), lower lip length (CS1-CS5), upper lip protrusion (CS1-CS5), upper lip length (CS1-CS4), lower lip protrusion (CS1-CS3), surface Angle (CS2-CS3) and nasolabial angle (CS2) in mouth breathing children and adolescents were above the standard values with statistically significance (P < 0.05). As for airway measurements, PAS (CS1, CS2, CS5) in mouth breathing children and adolescents was above the standard value with statistical significance (P < 0.05). CONCLUSIONS: Mouth breathing had a real effect on maxillofacial and airway development, which differed among mouth breathing children and adolescents with different cervical vertebral maturation.

Oral and cephalometric characteristics of hypohidrotic ectodermal dysplasia: Case report / Características orales y cefalométricas de la displasia ectodérmica hipohidrótica: Reporte de caso

ABSTRACT Hypohydrotic ectodermal dysplasia (HED) is a genetic disorder that affects the development of ectodermal tissues. This study reports a case of a 5-year-old male patient, with clinical extra and intraoral characteristics of HED. The intraoral clinical examination revealed a generalized absence of teeth, panoramic radiograph revealed the presence of permanent first molars with taurodontism, and confirm the oligodontia. Cephalometric analysis revealed a class III skeletal relationship, due to deficiency in the sagittal development of the maxilla and an anti-clockwise growth tendency. Alterations in craniofacial development require multidisciplinary treatment and long-term follow-up to monitor craniofacial growth.

RESUMEN La displasia ectodérmica hipohidrótica (DEH) es un trastorno genético que afecta el desarrollo de los tejidos ectodérmicos. Se realiza el reporte de caso de un paciente masculino de 5 años, con características clínicas extra e intraorales de DEH. El examen clínico intraoral reveló una ausencia generalizada de dientes, la radiografía panorámica reveló la presencia de primeros molares permanentes con taurodontismo y confirmó la oligodoncia. El análisis cefalométrico reveló una relación esquelética de clase III, debido a la deficiencia en el desarrollo sagital del maxilar y una tendencia de crecimiento en sentido antihorario. Las alteraciones en el desarrollo craneofacial requieren un tratamiento multidisciplinario y un seguimiento a largo plazo para controlar el crecimiento craneofacial.

China experts' consensus on preventive and interceptive orthodontic treatments of malocclusions of children.

Malocclusion is one of the three most common oral diseases reported by World Health Organization(WHO). In China, its incidence rate is rising. Malocclusion seriously affects the dental and maxillofacial function, facial appearance and growth development of nearly 260 million children in China, and what is more, it affects their physical and mental health development. Malocclusion occurrence is related to genetic and environmental factors. Early treatment of malocclusion can create a good dental and maxillofacial development environment, correct abnormal growth and control the adverse effects of abnormal genetic factors. It can effectively reduce the prevalence of children's malocclusion and enhance their physical and mental health. This is an urgent need from the economic perspective of our society, so it has great practical and social significance. Experts from the project group "standard diagnose and treatment protocols for early orthodontic intervention of malocclusions of children" which initiated by China National Health Institute of Hospital Administration wrote the "China Experts' Consensus on Preventive and Interceptive Orthodontic Treatments of Malocclusions of Children", which aims to guide and popularize the clinical practice, improve the clinical theory and practice level, and accelerate the disciplinary development of early treatment of children's malocclusion in China. The consensus elaborates the harmfulness of malocclusion and the necessity of early treatment, and brings up the principles and fundamental contents. Based on the law of dental and maxillofacial development, this paper puts forward the guiding suggestions of preventive and interceptive treatments in different stages of dental development ranging from fetus to early permanent dentition. It is a systematic project to promote and standardize the early treatment of malocclusion. Through scientific and comprehensive stratified clinical practice and professional training, the clinical system of early treatment of malocclusion in China will eventually be perfected, so as to comprehensively care for children's dental and maxillofacial health, and improve their oral and physical health in China.

Differential behaviour and gene expression in 3D cultures of femoral- and calvarial-derived human osteoblasts under a cyclic compressive mechanical load.

The aim of the study was to compare the response of calvarial and femoral osteoblasts cultured in a 3D hydrogel environment to cyclic compressive mechanical loading. Human foetal femoral and calvarial osteoblasts were encapsulated in a semi-synthetic thiol-modified hyaluronan gelatin polyethylene glycol diacrylate (PEGDA) cross-linked HyStemC hydrogel. Constructs were subjected to a cyclic compressive strain of 33.4 kPa force every second for 5 s every hour for 6 h per day using FlexCell BioPress culture plates and compared to non-compressed constructs. Cell viability, mineralisation, and morphological changes were observed over 21 days. BMP2, ALP, COL1A1, COL2A1, and OCN gene expression levels were quantified. Encapsulated osteoblast numbers increased and formed hydroxyapatite over a 21-day period. Cell viability decreased under a cyclical strain when compared to cells under no strain. Femoral osteoblasts under strain expressed increased levels of BMP2 (53.9-fold) and COL1A1 (5.1-fold) mRNA compared to no strain constructs. Surprisingly, no BMP2 mRNA was detected in calvarial osteoblasts. Osteoblasts derived from endochondral (femoral) and intra-membranous (calvarial) processes behaved differently in 3D-constructs. We therefore recommend that site-specific osteoblasts be used for future bone engineering and bone replacement materials and further research undertaken to elucidate how site-specific osteoblasts respond to cyclic compressive loads.

Morfología cefalométrica de la sínfisis del mentón en individuos jóvenes de la ciudad de Quito-Ecuador / Cephalometric morphology of chin symphysis in young individuals from the city of Quito-Ecuador

Resumen Introducción: La sínfisis del mentón aporta equilibrio, simetría y armonía al rostro. Por ser una estructura anatómica mandibular muy importante y altamente modificable en cirugía estética, se considera indispensable conocer su morfología y así obtener una correcta interacción en el diagnóstico, pronóstico y terapéutica médico-odontológica. Objetivo: Determinar la morfología sínfisis del mentón en jóvenes adultos de la ciudad de Quito- Ecuador, año 2019, mediante la identificación de las longitudes sagitales y coronales. Metodología: Este estudio tuvo un enfoque cuantitativo, tipo descriptivo-observacional, con temporalidad retrospectiva. Se calibraron, analizaron y trazaron 384 radiografías digitales laterales de adultos jóvenes de la ciudad de Quito-Ecuador, año 2019 en el software AutoCAD-2019. Resultados: Existió una elevada frecuencia de la forma geométrica cuadrada (60%) con respecto a la rectangular (40%), adicionalmente se identificó que la figura cuadrada es más frecuente en individuos de sexo femenino y sujetos clase I (56%) y II (70%), además de todos los patrones de crecimiento vertical hipodivergentes (58%), normodivergentes (64%) e hiperdivergentes (57%). Conclusiones: La forma cuadrada de la sínfisis del mentón es mayor que la forma rectangular. Por la originalidad de los resultados, se sugiere realizar nuevos estudios que correlacionen la morfología mentoniana con las diferentes estructuras cráneo-maxilofaciales.

Abstract Introduction: The chin symphysis contributes to the balance, symmetry and harmony of the face. Since it is an important anatomical jaw structure and highly modifiable in aesthetic surgery, it is considered crucial to know its morphology and, thus, obtain a correct interaction in the diagnosis, prognosis and medical-dental therapy. Objective: To determine the symphysis morphology of the chin in young adults in the city of Quito, Ecuador, in the year 2019, through the identification of sagittal and coronal lengths. Methodology: This study had a quantitative approach, descriptive-observational type, with retrospective temporality. We calibrated, analyzed and plotted 384 lateral digital radiographs of young adults from the city of Quito-Ecuador, year 2019 in the software AutoCAD-2019. Results: There was a high frequency of the square geometric shape (60%) in comparison to the rectangular one (40%). Additionally, it was identified that the square figure is more frequent in female individuals and class I (56%) and II (70%) subjects, in addition to all the hypodivergent (58%), normodivergent (64%) and hyperdivergent (57%) vertical growth patterns. Conclusions: The square shape of the chin symphysis is larger than the rectangular shape. Due to the originality of the results, it is suggested to carry out new studies that correlate chin morphology with the different cranio-maxillofacial structures.

The Special Developmental Biology of Craniofacial Tissues Enables the Understanding of Oral and Maxillofacial Physiology and Diseases.

Maxillofacial hard tissues have several differences compared to bones of other localizations of the human body. These could be due to the different embryological development of the jaw bones compared to the extracranial skeleton. In particular, the immigration of neuroectodermally differentiated cells of the cranial neural crest (CNC) plays an important role. These cells differ from the mesenchymal structures of the extracranial skeleton. In the ontogenesis of the jaw bones, the development via the intermediate stage of the pharyngeal arches is another special developmental feature. The aim of this review was to illustrate how the development of maxillofacial hard tissues occurs via the cranial neural crest and pharyngeal arches, and what significance this could have for relevant pathologies in maxillofacial surgery, dentistry and orthodontic therapy. The pathogenesis of various growth anomalies and certain syndromes will also be discussed.

Evaluation of facial aesthetics by laypersons in patients undergoing intraoral quadrangular Le Fort II osteotomy compared with conventional Le Fort I osteotomy.

In this study we compared the aesthetic outcome of (1) Le Fort I (LFI) osteotomy and (2) intraoral quadrangular Le Fort II (IQLFII) osteotomy for surgical correction of skeletal class III dysgnathia involving midfacial deficiency. The aim was to investigate whether laypersons see differences in facial changes that occur due to variations of the osteotomy cuts. The patient collectives consisted of 23 patients in each group. Pre- and postoperative photographs were presented in a random sequence to 40 layperson raters. The rating procedure was conducted with a four-point Likert scale. Assessed characteristics were 'attractiveness' ('Attraktivität'), 'likeability' ('Sympathie'), 'intelligence' ('Intelligenz'), 'aggressiveness' ('Aggressivität') and 'dominance' ('Dominanz'). For preoperative photographs we found a significant difference for 'likeability' with lower ratings for the IQLFII group; all other criteria were rated similarly. For the IQLFII group we found a significantly larger shift from lower to higher ratings for 'attractiveness' and 'likeability' and a significantly larger shift from higher to lower ratings for 'aggressiveness' and 'dominance' than for the LF I group. Our study shows that lay raters detect significant differences between the two surgical groups. Thus, IQLFII osteotomy, when indicated, represents a favourable alternative to conventional LFI osteotomy, if patients desire the expectable change in recognition by their social circle.

Mirror-image unilateral condylar hyperplasia in monozygotic twins.

Unilateral condylar hyperplasia (UCH) is an abnormal growth process that results in the development of mandibular asymmetry. The aetiopathogenesis of this entity is still unclear. Various factors including hormonal influences, intrauterine factors, trauma, infection, and genetics have been speculated to lead to the development of UCH. In genetic epidemiology, twins have been a valuable resource for investigating the genetic basis of complex traits and diseases. We present a case of mirror-image UCH in a pair of monozygotic twins, providing evidence of a possible genetic link for this mandibular growth disorder. The concordance in the monozygotic twins appears to be reflected by the precise mirror-image presentation of the congenital dentofacial anomalies. Further twin studies would be useful in clarifying the contributions of genetic and environmental factors to the presence and development of UCH.

Correlation between craniofacial structures, anthropometric measurements, and nasopharyngeal dimensions in black adolescents.

OBJECTIVES: To evaluate the correlation between craniofacial structures, anthropometric measurements, and bony and soft tissue nasopharyngeal dimensions in African Black adolescents. METHODS: This retrospective cross-sectional study was conducted on 483 healthy adolescents (250 females and 233 males), randomly selected from one dental clinic. The inclusion criteria were skeletal and dental Class I, Black ethnicity, pubertal growth period as determined by the Greulich and Pyle atlas criteria, and no history of orthodontic treatment. Anthropometric measurements (stature, upper body height, lower body height, and BMI) and radiographic records (hand-wrist radiographs, and lateral cephalograms) were obtained. One investigator traced and analysed all cephalograms to determine three skeletal craniofacial parameters (maxillary length [Ar- ANS], mandibular length [Ar-Gn], and lower anterior facial height [ANS-Me]), and 14 (8 skeletal and 6 soft tissue) nasopharyngeal parameters. Pearson correlation coefficients and stepwise multiple linear regression analyses were conducted. RESULTS: The mean skeletal ages of females and males were 11.31±2.31y and 12.66±1.85y, respectively. Multiple linear regression analyses showed that stature, posterior height of nasal cavity (S-PNS), length of nasal floor (AA-PNS), and mean area of bony nasopharynx (Area 1) were significantly correlated with maxillary length, P<.001. Stature, BMI, S-PNS, vertical angle of nasopharynx (Ba-S-PNS), Area 1, adenoid height (AD), and linear hyoid bone measurements (H-AA, H-RGN, H-Ax) were all correlated with mandibular length, P<.05. Lower facial height showed sexual dimorphism and was significantly associated with vertical nasopharyngeal measurements, BMI and upper body height. CONCLUSIONS: Craniofacial structures were significantly associated with stature and upper body height. Maxillary growth was associated with bony nasopharyngeal variables. Mandibular growth and lower facial height were associated with bony and soft tissue nasopharyngeal variables. The sexual dimorphism in lower facial height warrants future studies to fully understand and manage the craniofacial complex and nasopharyngeal airway in African Black adolescents.

Symmetry of palatal shape during the first year of life in healthy infants.

OBJECTIVES: The purpose of this study was to quantify the symmetry of the alveolar process of the maxilla and palate during the first year of life in healthy infants with the help of a semiautomatic segmentation technique. MATERIALS AND METHODS: Maxillary plaster models of seventy healthy babies at 0, 3, 6, 9, and 12 months were collected and digitized. A semiautomatic segmentation tool was used to extract the alveolus and palate. The resulting model was aligned within a reference frame and mirrored on its medial plane. Distance maps were created and analyzed to compare and quantify the differences between the two hemispheres. Additional hemispherical width and area measurements were performed. An ANOVA test with additional post hoc tests was performed to check if the symmetry changed during development. Finally, the results were tested on intra- and interobserver variability. RESULTS: The absolute mean inter-surface distance between the original and mirrored models in each age group ranged between 0.23 and 0.30 mm. Width and area analysis showed a small but significant larger left palatal hemisphere. ANOVA and post hoc tests showed no significant difference in symmetry between groups. Reliability analysis showed no significant differences between observers. CONCLUSIONS: This study showed that in this infant population, only a small degree of palatal asymmetry was present, which can be considered as normal and clinically irrelevant. CLINICAL RELEVANCE: The data from this study can be used in future comparative studies as reference data. Furthermore, modeling of these data can help in predicting the growth pattern, which may lead to improved treatment protocols for children with craniofacial anomalies.

China experts' consensus on preventive and interceptive orthodontic treatments of malocclusions of children / 华西口腔医学杂志

Malocclusion is one of the three most common oral diseases reported by World Health Organization(WHO). In China, its incidence rate is rising. Malocclusion seriously affects the dental and maxillofacial function, facial appearance and growth development of nearly 260 million children in China, and what is more, it affects their physical and mental health development. Malocclusion occurrence is related to genetic and environmental factors. Early treatment of malocclusion can create a good dental and maxillofacial development environment, correct abnormal growth and control the adverse effects of abnormal genetic factors. It can effectively reduce the prevalence of children's malocclusion and enhance their physical and mental health. This is an urgent need from the economic perspective of our society, so it has great practical and social significance. Experts from the project group "standard diagnose and treatment protocols for early orthodontic intervention of malocclusions of children" which initiated by China National Health Institute of Hospital Administration wrote the "China Experts' Consensus on Preventive and Interceptive Orthodontic Treatments of Malocclusions of Children", which aims to guide and popularize the clinical practice, improve the clinical theory and practice level, and accelerate the disciplinary development of early treatment of children's malocclusion in China. The consensus elaborates the harmfulness of malocclusion and the necessity of early treatment, and brings up the principles and fundamental contents. Based on the law of dental and maxillofacial development, this paper puts forward the guiding suggestions of preventive and interceptive treatments in different stages of dental development ranging from fetus to early permanent dentition. It is a systematic project to promote and standardize the early treatment of malocclusion. Through scientific and comprehensive stratified clinical practice and professional training, the clinical system of early treatment of malocclusion in China will eventually be perfected, so as to comprehensively care for children's dental and maxillofacial health, and improve their oral and physical health in China.