Genetic and environmental contributions to the development of soft tissue facial profile: a twin study.

OBJECTIVES: This study aimed to determine the relative contribution of genetic and environmental factors in the phenotypic variation of the soft tissue facial profile during the mixed dentition and the permanent dentition stages. METHODS: In this retrospective cohort study, standardized facial profile photographs of 139 twin pairs (55 monozygotic and 84 dizygotic) were obtained from archival records at the Adelaide Dental School. Photographic analysis used 12 angular and 14 linear facial profile measurements from the mixed dentition (7-11 years) to the permanent dentition (12-17 years) stages. A genetic analysis was performed using a univariate structural equation model adhering to the normal assumptions of a twin model. RESULTS: In the mixed dentition stage, the additive genetic (A) and unique environment (E) model, AE model, was the most parsimonious in explaining the observed phenotypic variance for all 26 facial traits with the narrow-sense heritability estimates ranging between 0.38 and 0.79. In the permanent dentition, the AE model was the most parsimonious for 20 out of 26 traits, however, the variance of six traits, particularly those in the lower third of the face, was best explained by the shared environmental and unique environmental factors. LIMITATIONS: This study exclusively included twins of European ancestry. CONCLUSIONS: The soft tissue facial profile demonstrated dynamic genetic and environmental influences with a greater additive genetic influence during the mixed dentition and the early stages of the permanent dentition. However, there was evidence of increasing environmental influence in the lower third of the face during the early stages of the permanent dentition.

Does facial growth pattern affect the perception of lower facial asymmetry?

OBJECTIVES: To investigate the influence of vertical facial type on esthetic perception of lower facial asymmetry as evaluated by orthodontists, dentists, and laypeople. MATERIALS AND METHODS: Three adult females were selected with normal growth patterns (NGP), vertical growth patterns (VGP), and horizontal growth patterns (HGP). Frontal photographs were made symmetric and digitally altered, rotating the lower facial third clockwise, ranging from 0° to 6° in 1° increments. A web-based survey was designed with 24 images (eight images for each model) in random order. Each image was rated using a scale ranging from 0 (unattractive) to 10 (the most attractive) by 75 orthodontists, 73 dentists, and 78 laypeople. Kruskal-Wallis test was used to determine whether differences among groups were significant. Pairwise comparisons were made with Mann-Whitney U test. The significance level was set at P = .05. RESULTS: In NGP, orthodontists and dentists could recognize slighter deviations (2°), while deviations in VGP and HGP under 3° were not recognized by all groups. Severe deviations (≥4°) were distinguished better in HGP by orthodontists and laypeople. In VGP and NGP, there was no significant difference over 4°. CONCLUSIONS: Growth pattern has a significant influence on perception of lower facial asymmetry. Less severe asymmetry can be detected better in NGP. In severe degrees, increments of asymmetry can be perceived more in HGP by orthodontists and laypeople.

Effects of bone anchored maxillary protraction on patients with unilateral cleft lip/palate or isolated cleft palate and hypoplastic maxilla: a 6-year follow-up case control study.

OBJECTIVES: To evaluate the effects of bone-anchored maxillary protraction (BAMP) treatment and longterm stability in growing cleft lip and palate and isolated cleft palate (CLP/CP) patients with mild maxillary hypoplasia and to compare maxillary growth patterns of BAMP-treated patients to matched control CLP/CP patients. MATERIALS AND METHODS: Ten patients with CLP/CP were treated with BAMP; they were compared to the maxillary growth pattern of 10 age-matched cleft control patients with no maxillary protraction treatment, who later received surgical Le Fort I maxillary advancement after the growth period. The assessment of maxillary growth and the occlusion started at mean 8 years of age and continued until mean 18 years of age. RESULTS: The use of BAMP orthopedic traction changed the growth pattern of mild hypoplastic maxilla toward a more anterior direction and advanced the face even above the level of Le Fort lll with only a minor effect on dentoalveolar units. The correction of occlusion and facial convexity were stable in the long term. CONCLUSIONS: The using BAMP may improve the position of the maxilla relative to the anterior cranial base for the correction of mild maxillary hypoplasia in adolescent patients with CLP/CP. The achieved results are rather stable in the long term.

[Early treatment of Class â ¢ malocclusion based on craniomaxillofacial growth and development].

More and more attention has been paid to the early treatment of malocclusion, especially the early treatment of class Ⅲ malocclusion. Class Ⅲ malocclusion not only affects maxillofacial growth and development, occlusal function and facial beauty, but also leads to serious physical and mental problems. Focusing on class Ⅲ malocclusion, the definition, classification, etiological mechanism, craniofacial growth and development rule, and the influence of early treatment on craniofacial growth and development were reviewed. In class Ⅲ patients, the craniofacial growth and development should be evaluated and analyzed when the early intervention carried out. The purpose of treatment of class Ⅲ malocclusion is achieved by using the appliance to affect the craniomaxillofacial growth.

[Effect and mechanism of obstructive sleep apnea on maxillofacial development in children].

In recent years, a large number of studies have demonstrated that obstructive sleep apnea （OSA） can lead to the abnormal development of maxillofacial region in pediatric patients, which may result in a 'vicious circle' aggravating OSA, therefore adversely affecting quality of life. Understanding the effect and mechanism of OSA on children's maxillofacial development is helpful to better prevent and treat OSA and maxillofacial dysplasia in children.

Effect of Tongue Position on Facial Morphology of Pakistani Adults and Different Growth Patterns.

OBJECTIVE:  To determine the effect of tongue position on facial morphology of Pakistani adults and different growth patterns. STUDY DESIGN:  Cross-sectional study. Place and Duration of the Study: Department of Orthodontics, Karachi Medical and Dental College, Karachi, Pakistan, from January to April 2021. METHODOLOGY:  The study included individuals aged 17 to 30 years with no history of prior orthodontic treatment, absence of wound, burn, or scar tissue in the neck region, comfortable breathing through the nose, absence of deglutition disorder, and a skeletal Class I or II relationship. The exclusion criteria were a cleft lip or palate, or a history of chronic mouth breathing, snoring, or tonsillectomy. According to their skeletal relationships, the subjects were split into three groups; Group I (low-angle), Group II (normal growth), and Group III (high-angle). Vertical growth pattern was assessed on radiograph by interpreting the values of NS / ML (nasion-sella / mandibular plane) angle, and angle formed between FH / ML (Frankfort horizontal plane / mandibular plane). A predesigned proforma was used to record all the measurements made on pre-treatment lateral cephalograms by the sole investigator. Data were analysed using SPSS 24.0. RESULTS:  Data from the lateral cephalogram of 79 patients, consisting of 18 (22.8%) males and 61 (77.2%) females who met the inclusion criteria, were analysed. The sample included 15 low-angle, 45 normal vertical growth, and 19 high-angle cases. Fifty participants had Class I skeletal relationships, while 29 had Class II relationships. According to the ANOVA test, FH / ML and NS / ML measurements showed no statistically significant variations in tongue position and growth trends. CONCLUSION: There was no statistically significant difference between tongue position and facial morphology of Class I or II subjects with different vertical growth patterns. However, there was a statistically sufficient evidence showing the tongue height was greater in Class I skeletal relationship patients as compared to Class II skeletal cases (p = 0.008). KEY WORDS: Tongue position, Tongue space, Tongue length, Growth pattern.

Charting facial growth and development for Bantu Africans: Central tendencies, variational properties and sexual dimorphisms.

Current studies on facial growth and development have been largely based on European populations. Less studied are African populations, who because of their distinct genetic makeup and environmental conditions, provide deeper insights into patterns of facial development. Patterns of facial shape development in African populations remain largely uncharacterised. Our study aimed to establish facial growth and development trajectories based on a cohort of 2874 Bantu Africans from Tanzania aged 6-18 years, with particular focus on identifying morphogenetic processes that lead to observed developmental shape changes. Procrustes ANCOVA suggested sexually dimorphic patterns of facial shape development (p = 0.0036). The forehead was relatively contracted during development in both sexes. The glabella region was more anteriorly displaced in females due to expansion in the region laterosuperior to the eyes. Nasal protrusion increased with development, which was found to arise from local expansion in the nasal alae and columella. Local expansion in the upper and lower labial regions resulted in forward displaced lips in both sexes, with the effect more pronounced in males. The mentum was displaced more anteriorly in females due to comparatively more expanded mental regions with development. The lateral facial region corresponding to the underlying body of the mandible were developmentally expanded but were posteriorly positioned due to protrusive growth of surrounding structures. Generalised additive modelling of Procrustes variance suggested that facial variation decreased non-linearly with age (p < 0.05). Relative principal component analysis suggested that variations in facial outline shape were developmentally constrained, whereas nasolabial and mental regions, where developmental changes were significant, became morphologically diversified with development. In contrast to simple descriptive illustration of facial shape development, we gained transformative insights into patterns of facial shape development by analysing morphogenetic processes and variational properties. Our analytical framework is broadly applicable to morphometric studies on ontogenetic shape changes.

Comparison of craniomaxillofacial morphology in children with unilateral cleft lip and palate treated with/without presurgical nasoalveolar molding - a retrospective study with a mean age of 5 years.

OBJECTIVES: To three-dimensionally assess differences in craniomaxillofacial skeletal development in patients with operated unilateral cleft lip and palate (UCLP) treated with/without presurgical nasoalveolar molding (PNAM) with a mean age of 5 years. MATERIALS AND METHODS: Cone-beam CT radiographs of 30 patients with UCLP who had undergone PNAM and 34 patients with UCLP who did not receive PNAM were analyzed. The data were stored in DICOM file format and were imported into the Dolphin Imaging program for 3D image reconstruction and landmark identification. 33 landmarks, 17 linear and three angular variables representing craniofacial morphology were analyzed and compared by using the Mann-Whitney U tests. RESULTS: The vast majority of linear variables and 3D coordinates of landmark points reflecting craniofacial skeletal symmetry were not significantly different between the two groups. In terms of craniofacial skeletal development, the PNAM group had a significantly smaller anterior nasal spine offset in the midsagittal plane and a greater maxillary length compared to the non-PNAM group. CONCLUSIONS: Evaluations performed in early childhood showed that treatment with/without PNAM in the neonatal period was not a major factor influencing craniomaxillofacial hard tissue development in patients with UCLP; moreover, PNAM treatment showed significant correction of skeletal deviation at the base of the nose. CLINICAL RELEVANCE: Follow-up in early childhood has shown that PNAM treatment administered during the neonatal stage does not impede maxillary development and has benefits in correcting nasal floor deviation. It is a viable option for improving nasal deformity in children with unilateral cleft lip and palate.

Regulatory role of primary cilia in oral and maxillofacial development and disease.

Primary cilia have versatile functions, such as receiving signals from the extracellular microenvironment, mediating signaling transduction, and transporting ciliary substances, in tissue and organ development and clinical disease pathogenesis. During early development (embryos within 10 weeks) in the oral and maxillofacial region, defects in the structure and function of primary cilia can result in severe craniofacial malformations. For example, mice with mutations in the cilia-related genes Kif3a and IFT88 exhibit midline expansion and cleft lip/palate, which occur due to abnormalities in the fusion of the single frontonasal prominence and maxillary prominences. In the subsequent development of the oral and maxillofacial region, we discussed the regulatory role of primary cilia in the development of the maxilla, mandible, Meckel cartilage, condylar cartilage, lip, tongue, and tooth, among others. Moreover, primary cilia are promising regulators in some oral and maxillofacial diseases, such as tumors and malocclusion. We also summarize the regulatory mechanisms of primary cilia in oral and maxillofacial development and related diseases, including their role in various signaling transduction pathways. For example, aplasia of submandibular glands in the Kif3a mutant mice is associated with a decrease in SHH signaling within the glands. This review summarizes the similarities and specificities of the role of primary cilia in tissue and organ development and disease progression in the oral and maxillofacial region, which is expected to contribute several ideas for the treatment of primary cilia-related diseases.

[Role of Fibroblast Growth Factor 7 in Craniomaxillofacial Development]. / æˆçº¤ç»´ç»†èƒžç”Ÿé•¿å› å­7åœ¨é¢ é¢Œé¢å‘è‚²ä¸­çš„ä½œç”¨.

Craniomaxillofacial development involves a series of highly ordered temporal-spatial cellular differentiation processes in which a variety of cell signaling factors, such as fibroblast growth factors, play important regulatory roles. As a classic fibroblast growth factor, fibroblast growth factor 7 (FGF7) serves a wide range of regulatory functions. Previous studies have demonstrated that FGF7 regulates the proliferation and migration of epithelial cells, protects them, and promotes their repair. Furthermore, recent findings indicate that epithelial cells are not the only ones subjected to the broad and powerful regulatory capacity of FGF7. It has potential effects on skeletal system development as well. In addition, FGF7 plays an important role in the development of craniomaxillofacial organs, such as the palate, the eyes, and the teeth. Nonetheless, the role of FGF7 in oral craniomaxillofacial development needs to be further elucidated. In this paper, we summarized the published research on the role of FGF7 in oral craniomaxillofacial development to demonstrate the overall understanding of FGF7 and its potential functions in oral craniomaxillofacial development.

Review on the Role of IRF6 in the Pathogenesis of Non-syndromic Orofacial Clefts.

Non-syndromic orofacial clefts (NSOCs) are the most common craniofacial malformation. In the complex aetiology and pathogenesis of NSOCs, genetic factors play a crucial role and IRF6, located at chromosome 1q32.2, is the best documented NSOC susceptibility gene. IRF6 is a key factor in oral maxillofacial development and known to contribute the most in NSOCs. It is essential to conduct a complete review of the existing results on IRF6 to further understand its role in the pathogenesis of NSOCs. Thus, the present authors summarised the research progress on the mechanism of IRF6 in NSOCs from both genetic and functional perspectives in this review.

Accuracy of artificial intelligence-assisted growth prediction in skeletal Class I preadolescent patients using serial lateral cephalograms for a 2-year growth interval.

OBJECTIVE: To investigate the accuracy of artificial intelligence-assisted growth prediction using a convolutional neural network (CNN) algorithm and longitudinal lateral cephalograms (Lat-cephs). MATERIALS AND METHODS: A total of 198 Japanese preadolescent children, who had skeletal Class I malocclusion and whose Lat-cephs were available at age 8 years (T0) and 10 years (T1), were allocated into the training, validation, and test phases (n = 161, n = 17, n = 20). Orthodontists and the CNN model identified 28 hard-tissue landmarks (HTL) and 19 soft-tissue landmarks (STL). The mean prediction error values were defined as 'excellent,' 'very good,' 'good,' 'acceptable,' and 'unsatisfactory' (criteria: 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm, respectively). The degree of accurate prediction percentage (APP) was defined as 'very high,' 'high,' 'medium,' and 'low' (criteria: 90%, 70%, and 50%, respectively) according to the percentage of subjects that showed the error range within 1.5 mm. RESULTS: All HTLs showed acceptable-to-excellent mean PE values, while the STLs Pog', Gn', and Me' showed unsatisfactory values, and the rest showed good-to-acceptable values. Regarding the degree of APP, HTLs Ba, ramus posterior, Pm, Pog, B-point, Me, and mandibular first molar root apex exhibited low APPs. The STLs labrale superius, lower embrasure, lower lip, point of lower profile, B', Pog,' Gn' and Me' also exhibited low APPs. The remainder of HTLs and STLs showed medium-to-very high APPs. CONCLUSION: Despite the possibility of using the CNN model to predict growth, further studies are needed to improve the prediction accuracy in HTLs and STLs of the chin area.

Feasibility of spheno-occipital synchondrosis fusion stages as an indicator for the assessment of maxillomandibular growth: A mixed longitudinal study.

OBJECTIVES: This study aimed to assess the relative growth rates (RGRs) of the maxilla and mandible at varying fusion stages of the spheno-occipital synchondrosis (SOS), thereby elucidating the potential of SOS stages in predicting maxillomandibular growth. MATERIALS AND METHODS: A total of 320 subjects (171 boys and 149 girls), aged 6 to 18 years, were retrospectively included. Each subject had a minimum of two longitudinal cone-beam computed tomography (CBCT) images, with no more than one interval of SOS fusion stage change between the two scans. Subjects were categorized based on their SOS fusion stages and genders. The RGRs of the maxilla and mandible at various SOS fusion stages were measured and compared using longitudinal CBCT images. RESULTS: Significant statistical differences were observed in maxillomandibular RGRs across various SOS fusion stages. In girls, the sagittal growth of the maxilla remained stable and active until SOS 3, subsequently exhibited deceleration in SOS 4-5 (compared to SOS 3-4, P < .05) and continued to decrease in SOS 5-6. Whereas in boys, the sagittal growth of the maxilla remained stable until SOS 4, and a deceleration trend emerged starting from SOS 5 to 6 (P < .01 compared to SOS 4-5). Mandibular growth patterns in both genders exhibited a progression of increasing-accelerating-decelerating rates from SOS 2 to 6. The highest RGRs for total mandibular length were observed in SOS 3-4 and SOS 4-5. CONCLUSION: Spheno-occipital synchondrosis fusion stages can serve as a valid indicator of maxillomandibular growth maturation.

The effects of adenoid hypertrophy and oral breathing on maxillofacial development: a review of the literature.

According to modern epidemiological surveys, the prevalence of adenoid hypertrophy in children and adolescents ranges from 42% to 70%. Adenoid hypertrophy can lead to airway obstruction; thus forces a child to breathe through their mouth, thus affecting the normal development of the dental and maxillofacial area, and can lead to malocclusion. Long-term mouth breathing can cause sagittal, vertical and lateral changes in the maxillofacial area. In this article, we review the current research status relating to the association between adenoid hypertrophy, oral breathing and maxillofacial growth and development in children and adolescents. We also discuss the personalized formulation of treatment plans.

[Orthodontic treatment in multidisciplinary sequential treatment of patients with cleft lip and palate].

Cleft lip and palate is the most common congenital maxillofacial defect. The modern treatment of cleft lip and palate is a sequential treatment with multidisciplinary collaboration, which can restore the maxillofacial morphology and function, and rebuild the psychosocial adaptation of the patients. Orthodontic treatment is almost throughout whole process of the sequential treatment. Due to the professional attention to maxillofacial growth and development, orthodontists have become one of the most crucial members during the multidisciplinary treatment of cleft lip and palate. Orthodontists are required in the different stages of maxillofacial growth and development to provide suggestions and necessary treatment. By orthodontic treatment, it can not only solve the problem of malocclusion and promote the maxillofacial growth and development, but also create a favourable condition for other therapies of sequential treatment, such as cleft lip and palate repair, bone grafting, prosthodontics, and even mental health. In order to improve the therapeutic effect of comprehensive treatment and to alleviate the burden of patients, orthodontists should learn more about the treatment of cleft lip and palate. This article mainly introduced the craniofacial deformities of cleft lip and palate and the progress of orthodontic treatment in the multidisciplinary treatment of cleft patients.

Classification of Skeletal Phenotypes of Preadolescent Patients With Isolated Cleft Palate Using Principal Component Analysis and Cluster Analysis.

This study aimed to classify the skeletal phenotypes of preadolescent patients with isolated cleft palate using principal component analysis and cluster analysis. Sixty-four preadolescent female patients with isolated cleft palate (incomplete hard palate and complete soft palate cleft group, n=51; complete cleft of the hard and soft palate group, n=13; the mean age when lateral cephalograms were taken, 7.08±0.76 y) were included. Ten angular and 2 ratio cephalometric variables were measured on a lateral cephalogram. Cluster analysis was performed using 3 representative variables obtained from principal component analysis (SN-GoMe, SNA, and SNB). The differences in the variables among the clusters were characterized using the Kruskal-Wallis test. As a result of the analysis, 6 clusters were obtained from 3 groups: the retrusive maxilla and mandible group: cluster 3 (14.1%, moderately hyperdivergent pattern), cluster 5 (17.2%, severely hyperdivergent pattern); the normal maxilla and mandible group: cluster 1 (23.4%, normodivergent pattern), cluster 4 (12.5%, moderately hyperdivergent pattern), cluster 6 (20.3%, severely hyperdivergent pattern); the normal maxilla and protrusive mandible group: cluster 2 (12.5%, normodivergent pattern). The distribution of isolated cleft palate types did not differ among the 6 clusters ( P >0.05). Two thirds of the patients (68.7%, clusters 1, 2, 4, and 6) had a normal anteroposterior position of the maxilla, while one third of the patients (31.3%, clusters 3 and 5) showed a retrusive mandible. These results indicate that isolated cleft palate patients have diverse maxillo-mandibular growth patterns compared with patients with cleft lip and palate.

[Effects of mouth opening breathing for different reasons on maxillofacial development in children].

Objective:To explore the effects of mouth opening breathing for different reasons on children's maxillofacial development. Methods:One hundred and fifty-one children were selected as the research objects of this experiment. They were divided into 49 cases of adenoid hypertrophy group（group A）, 52 cases of tonsillar hypertrophy group（group B） and 50 cases of adenoid with tonsillar hypertrophy group（Group C）. Healthy children in the same period were selected as the control group, a total of 45 cases. The reflex nasopharyngeal measurement parameters, facial development indexes and cephalometric parameters of group A, group B, group C and control group were analyzed, and the incidence of Angle ClassⅡand Angle Class Ⅲ in group A, group B and group C were studied. Results:Compared with the control group, the reflex nasopharyngeal measurement parameters in group A, group B and group C was significantly different（P<0.05）, and the cephalometric parameters changed with variation in groups（P<0.05）. The incidence of Angle Class Ⅱ facial pattern in group A and group C was higher, but the incidence of Angle Class Ⅲ facial pattern in group B and group C was higher（P<0.05）. Conclusion:Adenoid hypertrophy leads to mandibular retraction; tonsil hypertrophy leads to anterior mandibular arch; adenoid hypertrophy and tonsil hypertrophy are easy to lead to clockwise rotation of the mandible. In clinical practice, to avoid children's uncoordinated maxillofacial development, we should correct the maxillofacial situation of children as soon as possible.

Changes in the Craniomaxillofacial Growth and Development of Sprague Dawley Rats Subjected to Permanent Experimental Unilateral Nasal Obstruction / Cambios en el Crecimiento y Desarrollo Cráneo Maxilo Facial de Ratas Sprague Dawley Sometidas a Obstrucción Nasal Unilateral Experimental Permanente

SUMMARY: Breathing is considered a vital function dependent on factors such as adequate permeability of the nasal route, which is linked to physiological functions, intellectual processes, and craniofacial growth. The aim of this study was to determine the changes in the craniomaxillofacial growth and bone development of Sprague Dawley rats subjected to permanent experimental unilateral nasal obstruction. Twenty-four newborn rats were used, randomized, and divided into experimental and control groups. The right nostril was obstructed, and weight, length, and Lee's index measurements were recorded at 8 and 16 weeks. Craniomandibular x-rays were taken of each animal, obtaining linear neuro- and viscerocranial measurements. Then, a biochemical analysis was performed to measure the alkaline phosphatase concentration. The results were analyzed in the SPSS software, performing a descriptive analysis, using a t-test for independent samples, comparing basal, cephalometric, and biochemical characteristics between the control and experimental groups, considering a significance range of 5%. When comparing the experimental and control groups, the variables length, weight, and Lee's index presented no significant differences. In the x-ray analysis, at 8 weeks, the Co-L1 and Co-Mn measurements were reduced, whereas the Ba-So increased, with significant differences. At 16 weeks, the L1-O, Po-Ba, and E-Mu measurements decreased; however, Co-Gn registered a greater value with significant differences. The alkaline phosphatase levels fell significantly at week 16 in the experimental group. In conclusion, the reduction of permanent nasal respiratory flow is related to modifications in facial growth at 8 and 16 weeks and to the reduction of alkaline phosphatases at 16 weeks.

La respiración se considera una función vital, dependiente de factores como la permeabilidad adecuada de la vía nasal, vinculada con funciones fisiológicas, procesos intelectuales y crecimiento cráneofacial. El objetivo de este estudio fue determinar los cambios en el crecimiento y desarrollo óseo cráneo maxilo facial de ratas Sprague Dawley sometidas a obstrucción nasal unilateral experimental permanente. Se utilizaron 24 ratas macho neonatas, randomizadas y divididas en grupo control y experimental. Fue realizada obstrucción nasal de la narina derecha y realizadas mediciones de peso, longitud e índice de Lee a las 8 y 16 semanas. Se efectuaron radiografías cráneomandibulares a cada animal, obteniendo medidas lineales de neuro y viscerocráneo. Posteriormente se realizó análisis bioquímico, para medir la concentración de fosfatasa alcalina. Los resultados fueron analizados en el software SPSS, realizándose análisis descriptivo, empleando prueba T para muestras independientes comparando características basales, cefalométricas y bioquímicas entre los grupos control y experimental, considerando un umbral de significancia de 5 %. Al comparar los grupos control y experimental, las variables longitud, peso e índice de Lee no presentaron diferencias significativas. En el análisis radiográfico, a las 8 semanas, las medidas Co-L1 y Co-Mn presentaron reducción, mientras que Ba-So aumentó, con diferencias significativas. A las 16 semanas, las medidas L1-O, Po-Ba y E-Mu disminuyeron, sin embargo, Co-Gn registró un mayor valor, con diferencias significativas. Los niveles de fosfatasa alcalina disminuyeron significativamente en la semana 16 en el grupo experimental. En conclusión, la reducción de flujo respiratorio nasal permanente se relaciona con modificaciones del crecimiento facial a las 8 y 16 semanas y con la reducción de ALK en análisis a las 16 semanas.

Factores etiopatogénicos de maloclusión. Parte II: el factor dentario en la organización de la oclusión / Etiopathogenic factors of malocclusion. Part II: the dental effect in occlusal organization

El objetivo de esta publicación es continuar con el tema desarrollado en la primera parte, donde se esbozaron aspectos generales de la organización de la oclusión, como introducción al estudio de la etiopa- togenia de las maloclusiones, con el factor dentario como aspecto central. Probablemente es el que com- parte mayor presencia en maloclusiones, donde el factor principal es de otro origen, es decir, esqueletal o neuromuscular. Se expondrá, a continuación, la condición del espacio en los arcos dentarios, sea por exceso o defecto de material dentario, sea por pérdida de perímetro del arco dentario, en cuanto al diagnóstico y a conductas preventivas. La parte III se centrará en alteraciones de erupción dentaria (AU)

The objective of this publication is to continue with the theme developed in the first part, where general aspects of the organization of the occlusion were outlined, as an introduction to the study of the etiopathogenesis of malocclusions, with the dental factor as a central aspect. It is probably the one that shares the greatest presence in malocclusions where the main factor is of another origin, that is, skeletal or neuromuscular. Next, the condition of the space in the dental arches will be exposed, whether due to excess or defect of dental material or loss of perimeter of the dental arch, in terms of diagnosis and preventive behaviors. Part III will focus on dental eruption disorders (AU)