The influence of snoring, mouth breathing and apnoea on facial morphology in late childhood: a three-dimensional study

A Survey Study of the 3D Facial Landmark Detection Techniques Used as a Screening Tool for Diagnosis of the Obstructive Sleep Apnea Syndrome

Obstructive Sleep Apnea (OSA) is a common disorder affecting both adults and children. It is characterized by repeated episodes of apnea (stopped breathing) and hypopnea (reduced breathing), which result in intermittent hypoxia. We recognize pediatric and adult OSA, and this paper focuses on pediatric OSA. While adults often suffer from daytime sleepiness, children are more likely to develop behavioral abnormalities. Early diagnosis and treatment are important to prevent negative effects on children's development. Without the treatment, children may be at increased risk of developing high blood pressure or other heart problems. The gold standard for OSA diagnosis is the polysomnography (sleep study) PSG performed at a sleep center. Not only is it an expensive procedure, but it can also be very stressful, especially for children. Patients have to stay at the sleep center during the night. Therefore, screening tools are very important. Multiple studies have shown that OSA screening tools can be based on facial anatomical landmarks. Anatomical landmarks are landmarks located at specific anatomical locations. For the purpose of the screening tool, a specific list of anatomical locations needs to be identified. We are presenting a survey study of the automatic identification of these landmarks on 3D scans of the patient's head. We are considering and comparing both knowledge-based and AI-based identification techniques, with a focus on the development of the automatic OSA screening tool.

Characterization of craniofacial-based clinical phenotypes in children with suspected obstructive sleep apnea

STUDY OBJECTIVES

We conducted this study to identify phenotypes of obstructive sleep apnea (OSA) in children based on lifestyle, sleep habits, age, obesity, sex, soft tissue facial features, and specific craniofacial abnormalities.

METHODS

Seventy-three children with symptoms of pediatric OSA who underwent overnight observed polysomnography participated in this study. Soft tissue facial features were assessed using a 3-dimensional stereophotogrammetric system. Craniofacial abnormalities were evaluated based on the most common facial features associated with orthodontic treatment needs. Data regarding lifestyle, sleep habits, age, obesity, and sex were also collected. To identify phenotypes of OSA, a sequential analysis was then performed on categories of variables using fuzzy clustering with medoids.

RESULTS

Craniofacial abnormalities and soft tissue facial features defined clusters. Three clusters were identified. Cluster 1 comprised a group of younger children (5.9 ± 3.8 years) without obesity, without craniofacial abnormalities, and with smaller soft tissue facial features dimensions. Cluster 2 comprised a group of older children (9.6 ± 3.9 years) without obesity and with larger mandibular dimensions and mildly arched palates (71.4%). Cluster 3 comprised a group of older children (9.2 ± 3.9 years) with obesity and a history of health issues (68.4%), excessive lower facial height (63.2%), and midface deficiency (73.7%). No differences were observed across clusters regarding sleep features. A moderate severity of obstructive and mixed respiratory events was observed in all 3 clusters.

CONCLUSIONS

The study results did not identify distinct phenotypes of pediatric OSA based on soft tissue facial features or craniofacial abnormalities alone. Age and body mass index likely modify the effect of soft tissue facial features and craniofacial abnormalities as risk factors for OSA in children.

CITATION

Fernandes Fagundes NC, Loliencar P, MacLean JE, Flores-Mir C, Heo G. Characterization of craniofacial-based clinical phenotypes in children with suspected obstructive sleep apnea. J Clin Sleep Med. 2023;19(11):1857-1865.

The association between dental and facial symmetry in adolescents

INTRODUCTION

Facial aesthetics have become one of the most important objectives of orthodontic treatment. The correction of dental arches should be performed in accordance with the face. This study explored the association between occlusal and facial asymmetries in adolescents, particularly emphasizing a Class II subdivision.

METHODS

Eighty-one adolescents (43 males, 38 females) with a median age of 15.9 (interquartile range, 15.17-16.33) years were enrolled. Of these patients, 30 had a Class II subdivision (right side, n = 12; left side, n = 18). Three-dimensional facial scans were analyzed using surface- and landmark-based methods. Chin asymmetry was determined using the chin volume asymmetry score. Three-dimensional intraoral scans were analyzed to assess occlusal asymmetry.

RESULTS

The surface matching scores were 59.0% ± 11.3% for the whole face and 39.0% ± 19.2% for the chin. Chin volume was larger on the right side than on the left side in most patients (n = 51, 63%), and it was associated with a dental midline shift to the corresponding subdivision side. A correlation between dental and facial asymmetries was noted. In addition, the dental midline shifted to the left in patients with a Class II subdivision, regardless of the side, and to the right in those with a symmetrical Class II subdivision. However, several patients did not possess asymmetrical occlusal traits sufficient for statistical analysis.

CONCLUSIONS

Dental asymmetry was weak but significantly correlated with facial asymmetry.

Transverse Maxillary Deficiency Predicts Increased Upper Airway Collapsibility during Drug-Induced Sleep Endoscopy

OBJECTIVE

To examine the relationship between craniofacial skeletal anatomy and objective measures of pharyngeal collapse obtained during drug-induced sleep endoscopy. We hypothesized that transverse maxillary deficiency and an increased pharyngeal length will be associated with higher levels of pharyngeal collapsibility.

STUDY DESIGN

Cross-sectional analysis in a prospective cohort.

SETTING

University Hospital.

METHODS

A cross-sectional analysis was conducted in a cohort of consecutive patients from the positive airway pressure (PAP) alternatives clinic who underwent computed tomography (CT) analysis and drug-induced sleep endoscopy for characterization of upper airway collapsibility. PAP titration was used to determine pharyngeal critical pressure (PCRIT ) and pharyngeal opening pressure (PhOP). CT metrics included: Transverse maxillary dimensions (interpremolar and intermolar distances) and pharyngeal length (posterior nasal spine to hyoid distance).

RESULTS

The cohort (n = 103) of severe obstructive sleep apnea (Apnea and Hipopnea Index 32.1 ± 21.3 events/h) was predominantly male (71.8%), Caucasian (81.6%), middle-aged (54.4 ± 14.3 years), and obese (body mass index [BMI] = 30.0 ± 4.9 kg/m2 ). Reduced transverse maxillary dimensions were associated with higher PCRIT (intermolar distance: β [95% confidence interval, CI] = -.25 [-0.14, -0.36] cmH2 O/mm; p = .03) and PhOP (Interpremolar distance: β = -.25 [-0.14, -0.36] cmH2 O/mm; p = .02). Longer pharyngeal length was also associated with higher PCRIT (β = .11 [0.08, 0.14] cmH2 O/mm, p = .04) and PhOP (β [95% CI] = .06 [0.03, 0.09] cmH2 O/mm, p = .04). These associations persisted after adjustments for sex, age, height, and BMI.

CONCLUSION

Our results further the concept that skeletal restriction in the transverse dimension and hyoid descent are associated with elevations in pharyngeal collapsibility during sleep, suggesting a role of transverse deficiency in the pathogenesis of airway obstruction.

Adenoid Hypertrophy and Orthodontic Complications: An Assessment of Parental Knowledge in Saudi Arabia

Background Adenoid hypertrophy is a common condition that can cause upper airway obstruction in children and adolescents, leading to various complications, including dental and maxillofacial abnormalities. However, parents may have limited knowledge of the orthodontic complications associated with this condition. Objective This study aimed to assess the knowledge and attitude of parents toward the orthodontic complications of untreated adenoid hypertrophy and to promote their awareness about this problem. Method This descriptive cross-sectional study involved 824 parents from all regions of Saudi Arabia. An online questionnaire was used to collect data on parents' demographics, their children's information, and their general knowledge about adenoid hypertrophy, including its symptoms, complications, and treatment. Results The study included 824 parents with a mean age of 36.78 ± 10.87 years, 73.2% of whom were women. Overall, only 6.2% (51.1 parents) had a good level of knowledge about adenoid hypertrophy. Conclusion The study highlights the importance of promoting awareness and educating parents about the orthodontic complications associated with adenoid hypertrophy. Greater awareness and understanding can help parents make better decisions for their children's health and well-being.

The Facial Characteristics of Individuals with Posterior Crossbite: A Cross-Sectional Study

Facial morphology is known to be influenced by genetic and environmental factors. Scientific evidence regarding facial parameters in patients with posterior crossbite is lacking. This study aimed to investigate the association between posterior crossbite and facial parameters. This cross-sectional study included 34 adolescents with and 34 adolescents without posterior crossbite in the age range from 13 to 15 years. Facial surface scans were acquired with a 3dMD imaging system, and landmark-based analysis was performed. Data were analyzed using the Mann-Whitney U test and Spearman's correlations. Individuals in the control group had lower face heights (females: p = 0.003, r = 0.45; males: p = 0.005, r = 0.57). The control group females presented with smaller intercanthal width (p = 0.04; r = 0.31) and anatomical nose width (p = 0.004; r = 0.43) compared with the crossbite group females. The males in the control group had wider nostrils. In the control group, significant correlations among different facial parameters were more common, including the correlations between eye width and other transversal face measurements. On the contrary, the facial width was correlated with nasal protrusion (r = 0.657; p < 0.01) and the morphological width of the nose (r = 0.505; p < 0.05) in the crossbite group alone. In both groups, the philtrum width was linked with the anatomical and morphological widths of the nose. Conclusions: Patients with posterior crossbites have increased face height and different patterns of facial proportions compared with individuals without crossbites.

Age-related hypertrophy of adenoid and tonsil with its relationship with craniofacial morphology

BACKGROUND

When analyzing the relationship between adenotonsillar hypertrophy and craniofacial morphology, researchers generally regarded hypertrophied adenoids and tonsils as a whole. It remains unclear whether different enlarged sites of pharyngeal lymphoid tissue would correlate with multiple craniofacial subtypes. We hypothesized there would be craniofacial subtypes correlated with different locations of hypertrophied adenoid and tonsil.

METHODS

Lateral cephalometric radiographs were obtained from 466 children (171 boys and 295 girls, aged 12.27 ± 2.69 years). They were divided into four groups according to different sites of enlarged pharyngeal lymphoid tissue: adenoid hypertrophy group (AG, n = 126), tonsillar hypertrophy group (TG, n = 59), adenotonsillar hypertrophy group (ATG, n = 69) and control group (CG, n = 212). Five commonly used angles for cephalometric measurements were investigated: SNA (Sella-Nasion-Point A), SNB (Sella-Nasion-Point B), ANB (Point A-Nasion-Point B), mandibular plane angle (MP/SN) and Y-axis angle (SGn/FH).

RESULTS

Children with isolated tonsillar hypertrophy correlated with increased SNA (unstandardized regression coefficient B = 1.38, p = 0.009) and SNB (B = 1.99, p = 0.001) compared with controls. However, children with isolated adenoid hypertrophy correlated with decreased SNB (B=-0.94, p = 0.036), increased ANB (B = 0.74, p = 0.014) and increased MP/SN (B = 2.22, p < 0.001). Similarly, children with adenotonsillar hypertrophy correlated with decreased SNB (B=-1.36, p = 0.015), increased ANB (B = 1.35, p < 0.001) and increased MP/SN (B = 2.64, p = 0.001).

CONCLUSIONS

Isolated adenoid hypertrophy correlated with a retrognathic mandible, an increased maxillo-mandibular sagittal discrepancy, and an increased mandibular plane angle. Isolated tonsillar hypertrophy correlated with maxillary and mandibular protrusion. Adenotonsillar hypertrophy did not show a superimposed craniofacial pattern of the above two but showed the same craniofacial pattern as isolated adenoid hypertrophy.

Translation and cross-cultural adaptation of the sleep-related breathing disorder scale of the Pediatric Sleep Questionnaire into Danish language

OBJECTIVE/BACKGROUND

Sleep-disordered breathing (SDB) is common but often underestimated in children. The gold standard for assessing SDB is polysomnography, but it is expensive and time-consuming. The Paediatric Sleep Questionnaire (PSQ/SRDB) is a validated screening tool for SDB, which represents an efficient and alternative tool for screening SDB among children. However, a translated and validated Danish version of the PSQ/SRDB is not available yet. Our aim was to cross-culturally translate the PSQ/SRDB into Danish language for use in clinical and research settings.

PATIENTS/METHODS

The translation was carried out through forward-backward translation techniques performed by a panel of experts, and the cross-cultural adaptation was achieved by pretesting of the pre-final version. Internal consistency of the Danish PSQ/SRDB version was measured by Cronbach's alpha coefficients, while Cohen's kappa was used to evaluate test-retest reliability. Construct validity was assessed by factor analysis of the principal components.

RESULTS

The Danish PSQ/SRDB was administered to the caregivers of 348 children. An overall Cronbach's alpha of 0.72 was found, confirming the survey's consistency, with the results for the domains ranging 0.52-0.70. The Danish PSQ/SRDB showed moderate to perfect reliability for all items, except for one question (C14). Factor analysis performed on the Danish PSQ/SRDB showed that the predetermined four factors were similar with the original version of the PSQ/SRDB.

CONCLUSIONS

The Danish version of the PSQ/SRDB has been successfully translated and cross-culturally adapted, suggesting that it can be used as an appropriate paediatric screening tool for SDB in Denmark.

Association between upper airway obstruction and malocclusion in mouth-breathing children

Objectives

To evaluate the association between upper airway obstruction and occlusal anomalies in mouth-breathing children.

Methods

356 mouth-breathing children were evaluated by ENT physicians and specialists in orthodontics. ENT examination included nasal endoscopy to assess the adenoidal hypertrophy, tonsillar grading and presence of nasal septum deviation. Clinical orthodontic examination was performed to record occlusal variables. Univariate and multivariable logistic regression were performed to study the association between registered variables.

Results

221 patients (mean age ± sd = 6.2 ± 2.5 years) met inclusion criteria. 81.4% of children presented malocclusion. A significant association between tonsillar grade 2 and the presence of malocclusion, Class II relation and increased overjet was shown. Tonsillar grade 4 showed a significant association with the presence of malocclusion and increased overjet. Adenoidal hypertrophy and nasal septum deviation did not show any association with occlusal findings.

Conclusions

A high frequency of orthodontic problems was seen in mouth-breathing children. Our results suggested that severe tonsillar hypertrophy may determine presence of malocclusion and increased overjet. On the other hand, the association between mild tonsillar hypertrophy and many occlusal anomalies in mouth-breathers suggest an important role of malocclusion in the onset of oral breathing in children.

An exploration of adolescent facial shape changes with age via multilevel partial least squares regression

BACKGROUND AND OBJECTIVES

Multilevel statistical models represent the existence of hierarchies or clustering within populations of subjects (or shapes in this work). This is a distinct advantage over single-level methods that do not. Multilevel partial-least squares regression (mPLSR) is used here to study facial shape changes with age during adolescence in Welsh and Finnish samples comprising males and females.

METHODS

3D facial images were obtained for Welsh and Finnish male and female subjects at multiple ages from 12 to 17 years old. 1000 3D points were defined regularly for each shape by using "meshmonk" software. A three-level model was used here, including level 1 (sex/ethnicity); level 2, all "subject" variations excluding sex, ethnicity, and age; and level 3, age. The mathematical formalism of mPLSR is given in an Appendix.

RESULTS

Differences in facial shape between the ages of 12 and 17 predicted by mPLSR agree well with previous results of multilevel principal components analysis (mPCA); buccal fat is reduced with increasing age and features such as the nose, brow, and chin become larger and more distinct. Differences due to ethnicity and sex are also observed. Plausible simulated faces are predicted from the model for different ages, sexes and ethnicities. Our models provide good representations of the shape data by consideration of appropriate measures of model fit (RMSE and R2).

CONCLUSIONS

Repeat measures in our dataset for the same subject at different ages can only be modelled indirectly at the lowest level of the model at discrete ages via mPCA. By contrast, mPLSR models age explicitly as a continuous covariate, which is a strong advantage of mPLSR over mPCA. These investigations demonstrate that multivariate multilevel methods such as mPLSR can be used to describe such age-related changes for dense 3D point data. mPLSR might be of much use in future for the prediction of facial shapes for missing persons at specific ages or for simulating shapes for syndromes that affect facial shape in new subject populations.

Exploring the midline soft tissue surface changes from 12 to 15 years of age in three distinct country population cohorts

INTRODUCTION

Several studies have highlighted differences in the facial features in a White European population. Genetics appear to have a major influence on normal facial variation, and environmental factors are likely to have minor influences on face shape directly or through epigenetic mechanisms.

AIM

The aim of this longitudinal cohort study is to determine the rate of change in midline facial landmarks in three distinct homogenous population groups (Finnish, Latvian, and Welsh) from 12.8 to 15.3 years of age. This age range covers the pubertal growth period for the majority of boys and girls.

METHODS

A cohort of children aged 12 were monitored for facial growth in three countries [Finland (n = 60), Latvia (n = 107), and Wales (n = 96)]. Three-dimensional facial surface images were acquired (using either laser or photogrammetric methods) at regular intervals (6-12 months) for 4 years. Ethical approval was granted in each country. Nine midline landmarks were identified and the relative spatial positions of these surface landmarks were measured relative to the mid-endocanthion (men) over a 4-year period.

RESULTS

This study reports the children who attended 95 per cent of all scanning sessions (Finland 48 out of 60; Latvia 104 out of 107; Wales 50 out of 96). Considerable facial variation is seen for all countries and sexes. There are clear patterns of growth that show different magnitudes at different age groups for the different country groups, sexes, and facial parameters. The greatest single yearly growth rate (5.4 mm) was seen for Welsh males for men-pogonion distance at 13.6 years of age. Males exhibit greater rates of growth compared to females. These variations in magnitude and timings are likely to be influenced by genetic ancestry as a result of population migration.

CONCLUSION

The midline points are a simple and valid method to assess the relative spatial positions of facial surface landmarks. This study confirms previous reports on the subtle differences in facial shapes and sizes of male and female children in different populations and also highlights the magnitudes and timings of growth for various midline landmark distances to the men point.

Orofacial features and pediatric dentistry in the long-term management of Infantile Pompe Disease children

Background

Glycogen storage disease type II (GSDII) or Pompe disease is a rare autosomal recessive metabolic disorder that leads to intracellular glycogen storage in many tissues, mainly in skeletal muscle, heart and liver. Facial muscle weakness and altered craniofacial growth are very common in Pompe disease children. In this paper we describe the orofacial features in two children affected by GSDII and illustrate a multidisciplinary approach that involved enzyme replace therapy, non-invasive ventilation (NIV) and pediatric dentistry with 5-year follow-up.

Results

Two Infantile Pompe Disease children were examined by a pediatric dentist at the age of 4 and 5 years old respectively. The orofacial examination showed typical facies with similar features: hypotonia of facial and tongue muscles, lip incompetence, narrow palate with reduction in transversal dimension of the upper dental arch, macroglossia, low position of the tip of the tongue, concave profile, Class III malocclusion with hypoplasia of maxillary-malar area and mandibular prognathism. Myofunctional therapy and orthodontic treatment consisted in oral muscle exercises associated to intraoral and extraoral orthodontic devices. NIV facial mask was substituted with a nasal pillow mask in order to avoid external pressure on the mid-face which negatively influences craniofacial growth.

Conclusions

This paper evidences that the pediatric dentist plays an important role in craniofacial growth control, oral function rehabilitation and, therefore, in the improvement of the quality of life of Pompe children and their families. Therefore an early pediatric dental evalutation should be included in the multidisciplinary management of children suffering from Infantile Pompe Disease.

Home Respiratory Polygraphy is Useful in the Diagnosis of Childhood Obstructive Sleep Apnea Syndrome

The utility of home respiratory polygraphy (HRP) was assessed as an alternative to polysomnography (PSG) in the diagnosis of childhood obstructive sleep apnea syndrome (OSAS). PSG was indicated only in patients with concomitant disease or where HRP results were questionable. The follow-up period was 1 year. We recorded clinical and anthropometric data, physical examination findings, respiratory variables, severity level and choice of therapy. We assessed 121 children, 70 boys and 51 girls, with mean age 7 ± 4 years, mean body mass index (BMI) 19 ± 5 kg/m², and mean BMI percentile 62 ± 38%. We included 104 HRP and 24 PSG recordings. Of the latter, 7 were preceded by HRP (false negatives) and 17 were indicated as the first-choice method owing to concomitant disease. Of the initial HRP recordings, 93% were technically valid. All technically valid HRPs and 96% of PSGs resulted in a diagnosis of OSAS (apnea-hypopnea index 9.5 ± 9.1/h). Thirty-three percent of cases were moderate and 22% severe. Apnea-hypopnea index showed no correlation with BMI or BMI percentile. Adenotonsillectomy was indicated in 93 patients (77%), conservative treatment in 17 (14%), and conservative treatment combined with CPAP/BiPAP in 11 (9%). There were no significant differences between children diagnosed by HRP and by PSG in terms of treatment choice. The prevalence of OSAS in our sample was 96.7%. In conclusion, when the probability of OSAS is high, HRP is usually sufficient for diagnosing the syndrome and establishing therapy in children. PSG is advisable in complex or questionable cases.

Multilevel principal components analysis of three-dimensional facial growth in adolescents

BACKGROUND AND OBJECTIVES

The study of age-related facial shape changes across different populations and sexes requires new multivariate tools to disentangle different sources of variations present in 3D facial images. Here we wish to use a multivariate technique called multilevel principal components analysis (mPCA) to study three-dimensional facial growth in adolescents.

METHODS

These facial shapes were captured for Welsh and Finnish subjects (both male and female) at multiple ages from 12 to 17 years old (i.e., repeated-measures data). 1000 "dense" 3D points were defined regularly for each shape by using a deformable template via "meshmonk" software. A three-level model was used here, namely: level 1 (sex/ethnicity); level 2, all "subject" variations excluding sex, ethnicity, and age; and level 3, age. The technicalities underpinning the mPCA method are presented in Appendices.

RESULTS

Eigenvalues via mPCA predicted that: level 1 (ethnicity/sex) contained 7.9% of variation; level 2 contained 71.5%; and level 3 (age) contained 20.6%. The results for the eigenvalues via mPCA followed a similar pattern to those results of single-level PCA. Results for modes of variation made sense, where effects due to ethnicity, sex, and age were reflected in modes at appropriate levels of the model. Standardised scores at level 1 via mPCA showed much stronger differentiation between sex and ethnicity groups than results of single-level PCA. Results for standardised scores from both single-level PCA and mPCA at level 3 indicated that females had different average "trajectories" with respect to these scores than males, which suggests that facial shape matures in different ways for males and females. No strong evidence of differences in growth patterns between Finnish and Welsh subjects was observed.

CONCLUSIONS

mPCA results agree with existing research relating to the general process of facial changes in adolescents with respect to age quoted in the literature. They support previous evidence that suggests that males demonstrate larger changes and for a longer period of time compared to females, especially in the lower third of the face. These calculations are therefore an excellent initial test that multivariate multilevel methods such as mPCA can be used to describe such age-related changes for "dense" 3D point data.

Oral dysfunction as a cause of malocclusion

This narrative review surveys current research demonstrating how oral dysfunction can escalate into malocclusion, acquired craniofacial disorder and contribute to generational dysfunction, disorder and disease.

INTRODUCTION

Baseline orthodontic consultations are generally recommended beginning age seven. However, the dysmorphic changes that result in malocclusion are often evident years earlier. Similarly, following orthodontic treatment, patients require permanent retention when the bite is not stable, and without such retention, the malocclusion can return.

SETTING AND POPULATION

Narrative review article including research on infants, children and adults.

MATERIALS AND METHODS

This review is a brief survey of the symptomology of orofacial myofunctional disorder and outlines 10 areas of oral function that impact occlusal and facial development: breastfeeding, airway obstruction, soft tissue restriction, mouth breathing, oral resting posture, oral habits, swallowing, chewing, the impact of orofacial myofunctional disorder (OMD) over time and maternal oral dysfunction on the developing foetus.

CONCLUSION

Malocclusions and their acquired craniofacial dysmorphology are the result of chronic oral dysfunction and OMD. In order to achieve long-term stability of the face, it is critical to understand the underlying pathologies contributing to malocclusion, open bite and hard palate collapse.

Alveolar Bone Density Reduction in Rats Caused by Unilateral Nasal Obstruction

Background

Oral breathing can cause morphological changes in the oral and maxillofacial regions.

Aims

To investigate whether oral breathing affected structural changes in bone tissues.

Study Design

Animal experimentation.

Methods

A total of 48 8-day-old male Sprague−Dawley rats were divided into two groups: a breathing group and a sham (control) group. All Sprague−Dawley rats were killed at 7 weeks after unilateral nostril obstruction modeling. Then, structural changes in bone tissues were detected by micro-computed tomography, and the expression levels of receptor activator of nuclear factor-κB, osteoprotegerin, and receptor activator of nuclear factor-κB ligand in the signal pathway of bone metabolism within the local alveolar bone and serum of rats were detected by reverse transcription-quantitative polymerase chain reaction and Western blotting.

Results

The results showed that receptor activator of nuclear factor-κB ligand and receptor activator of nuclear factor-κB levels in bone tissues and serum in the oral breathing group were higher than those in the control group [Maxillary alveolar bone: receptor activator of nuclear factor-κB ligand (pRNA=0.009, pprotein=0.008), receptor activator of nuclear factor-κB (pRNA=0.008, pprotein=0.009); Mandibular alveolar bone: receptor activator of nuclear factor-κB ligand (pRNA=0.047, pprotein=0.042), receptor activator of nuclear factor-κB (pRNA=0.041, pprotein=0.007); Serum: receptor activator of nuclear factor-κB ligand (pRNA<0.001, pprotein<0.001), receptor activator of nuclear factor-κB (pRNA<0.001, pprotein<0.001)], along with decreased osteoprotegerin expression (Maxillary alveolar bone: pRNA=0.038, pprotein=0.048; Mandibular alveolar bone: pRNA<0.001, pprotein<0.001; Serum: pRNA=0.009, pprotein=0.006) and elevated receptor activator of nuclear factor-κB ligand/osteoprotegerin. Micro-computed tomography analysis indicated a significant difference in the level of bone volume fraction, as well as trabecular thickness in maxillary alveolar bone between the experimental and control groups (p=0.049, p=0.047). Meanwhile, trabecular thickness, and cortical thickness levels in mandibular alveolar bone also differed significantly between the experimental and control groups (p=0.043, p=0.024).

Conclusion

Structural changes of the respiratory system affect the alveolar bone structure and unilateral nasal obstruction may lead to a change in regional specific bone density.

Prevalence of sleep-disordered breathing and associations with orofacial symptoms among Saudi primary school children

Background

This study aimed to determine the prevalence of sleep-disordered breathing among primary school children in Riyadh, Saudi Arabia, and to evaluate associations between sleep-disordered breathing and respiratory conditions/orofacial symptoms.

Methods

In this cross-sectional study, 1600 questionnaires were distributed to Saudi boys and girls aged 6–12 years from 16 primary schools in Riyadh. The questionnaire covered relevant demographic and personal characteristics, presence of respiratory conditions and orofacial symptoms, and the Pediatric Sleep Questionnaire. The latter was used to assess the prevalence of symptoms of sleep-disordered breathing and was completed by the participating children’s parents.

Results

In total, 1350 completed questionnaires were returned (85% response rate). The children’ mean age was 9.2 ± 1.8 years; 733 (54.3%) were boys and 617 (45.7%) girls. Overall, 21% of children were at high risk of sleep-disordered breathing. The prevalence of snoring was 14.4% and that of sleep apnea 3.4%. Boys were at higher risk of sleep-disordered breathing than girls (P = 0.040). Children with respiratory conditions or orofacial symptoms were at higher risk of sleep-disordered breathing (P < 0.0001) than children without these conditions/symptoms.

Conclusions

Around 21% of Saudi children are at risk of sleep-disordered breathing. There is a strong association between sleep-disordered breathing symptoms and the presence of respiratory conditions or orofacial symptoms.

Stomatognathic system screening in preschoolers and its importance for the elaboration of an intervention program in health

ABSTRACT Purpose: to describe the results obtained in the stomatognathic system screening applied in preschoolers of the public and private school systems. Methods: a cross-sectional, observational study randomly which selected four preschools linked to the Diretoria Regional de Educação. Two municipalities were drawn, and the educational institutions located in the city Center were selected. After submission of the proposal to the secretaries, managers and family members, the consent was granted for the screening involving face structures, muscle tonus, teeth, occlusion, mobility, speech, breathing, chewing and swallowing, by means of a tested and standardized protocol for evaluation of the stomatognathic system in a synthesized way. The results were submitted to descriptive statistical analysis and the chi-square test, with a significance level of 5%. Results: a total of 218 preschoolers, aged between two and six years old, participated in the study. Most of the participants, regardless of the institution attended, presented normality of the aspects surveyed. However, when comparing preschool children results among the institutions, there were significant differences for facial symmetry, speech, swallowing (for students in public schools), structural aspects and muscle tonus (private schools). Conclusion: the results obtained allowed the differentiated planning of health promotion and preventive actions of orofacial myofunctional disorders for preschoolers of distinct institutional systems, determining the importance of epidemiological surveys in health promotion spaces.

What's in a Smile? Initial Analyses of Dynamic Changes in Facial Shape and Appearance

Single-level principal component analysis (PCA) and multi-level PCA (mPCA) methods are applied here to a set of (2D frontal) facial images from a group of 80 Finnish subjects (34 male; 46 female) with two different facial expressions (smiling and neutral) per subject. Inspection of eigenvalues gives insight into the importance of different factors affecting shapes, including: biological sex, facial expression (neutral versus smiling), and all other variations. Biological sex and facial expression are shown to be reflected in those components at appropriate levels of the mPCA model. Dynamic 3D shape data for all phases of a smile made up a second dataset sampled from 60 adult British subjects (31 male; 29 female). Modes of variation reflected the act of smiling at the correct level of the mPCA model. Seven phases of the dynamic smiles are identified: rest pre-smile, onset 1 (acceleration), onset 2 (deceleration), apex, offset 1 (acceleration), offset 2 (deceleration), and rest post-smile. A clear cycle is observed in standardized scores at an appropriate level for mPCA and in single-level PCA. mPCA can be used to study static shapes and images, as well as dynamic changes in shape. It gave us much insight into the question “what’s in a smile?”.

Spatially Dense 3D Facial Heritability and Modules of Co-heritability in a Father-Offspring Design

Introduction: The human face is a complex trait displaying a strong genetic component as illustrated by various studies on facial heritability. Most of these start from sparse descriptions of facial shape using a limited set of landmarks. Subsequently, facial features are preselected as univariate measurements or principal components and the heritability is estimated for each of these features separately. However, none of these studies investigated multivariate facial features, nor the co-heritability between different facial features. Here we report a spatially dense multivariate analysis of facial heritability and co-heritability starting from data from fathers and their children available within ALSPAC. Additionally, we provide an elaborate overview of related craniofacial heritability studies.

Methods: In total, 3D facial images of 762 father-offspring pairs were retained after quality control. An anthropometric mask was applied to these images to establish spatially dense quasi-landmark configurations. Partial least squares regression was performed and the (co-)heritability for all quasi-landmarks (∼7160) was computed as twice the regression coefficient. Subsequently, these were used as input to a hierarchical facial segmentation, resulting in the definition of facial modules that are internally integrated through the biological mechanisms of inheritance. Finally, multivariate heritability estimates were obtained for each of the resulting modules.

Results: Nearly all modular estimates reached statistical significance under 1,000,000 permutations and after multiple testing correction (p ≤ 1.3889 × 10^-3), displaying low to high heritability scores. Particular facial areas showing the greatest heritability were similar for both sons and daughters. However, higher estimates were obtained in the former. These areas included the global face, upper facial part (encompassing the nasion, zygomas and forehead) and nose, with values reaching 82% in boys and 72% in girls. The lower parts of the face only showed low to moderate levels of heritability.

Conclusion: In this work, we refrain from reducing facial variation to a series of individual measurements and analyze the heritability and co-heritability from spatially dense landmark configurations at multiple levels of organization. Finally, a multivariate estimation of heritability for global-to-local facial segments is reported. Knowledge of the genetic determination of facial shape is useful in the identification of genetic variants that underlie normal-range facial variation.

Facial Genetics: A Brief Overview

Historically, craniofacial genetic research has understandably focused on identifying the causes of craniofacial anomalies and it has only been within the last 10 years, that there has been a drive to detail the biological basis of normal-range facial variation. This initiative has been facilitated by the availability of low-cost hi-resolution three-dimensional systems which have the ability to capture the facial details of thousands of individuals quickly and accurately. Simultaneous advances in genotyping technology have enabled the exploration of genetic influences on facial phenotypes, both in the present day and across human history. There are several important reasons for exploring the genetics of normal-range variation in facial morphology.     - Disentangling the environmental factors and relative parental biological contributions to heritable traits can help to answer the age-old question "why we look the way that we do?"     - Understanding the etiology of craniofacial anomalies; e.g., unaffected family members of individuals with non-syndromic cleft lip/palate (nsCL/P) have been shown to differ in terms of normal-range facial variation to the general population suggesting an etiological link between facial morphology and nsCL/P.     - Many factors such as ancestry, sex, eye/hair color as well as distinctive facial features (such as, shape of the chin, cheeks, eyes, forehead, lips, and nose) can be identified or estimated using an individual's genetic data, with potential applications in healthcare and forensics.     - Improved understanding of historical selection and adaptation relating to facial phenotypes, for example, skin pigmentation and geographical latitude.     - Highlighting what is known about shared facial traits, medical conditions and genes.

Prevalence of malocclusion in children with obstructive sleep apnoea

OBJECTIVES

To describe the prevalence of malocclusions in 2- to 10-year-old children suffering from obstructive sleep apnoea (OSA) and to evaluate the association between occlusal variables and OSA.

SETTING AND SAMPLE POPULATION

A total of 2101 consecutive patients referred to an otorhinolaryngology unit were considered for the study. One hundred and fifty-six children (range 2-10 years) with suspected OSA were selected for a sleep study. The final sample consisted of 139 children suffering from OSA and a control group of 137 children.

MATERIALS AND METHODS

All patients included in the study underwent a clinical orthodontic examination to record the following occlusal variables: primary canine relationship, presence of a posterior crossbite, overjet and overbite. Odds ratios and 95% confidence intervals, comparing the demographic characteristics and dental parameters in OSA vs non-OSA children, were computed. Multivariable logistic regression models were developed to compare independent variables associated with OSA to non-OSA children.

RESULTS

The prevalence of malocclusions in children with OSA was 89.9% compared to 60.6% in the control group (P < 0.001). Factors independently associated with OSA compared to the control group were posterior crossbite (OR = 3.38; 95%CI:1.73-6.58), reduced overbite (OR = 2.43; 95%CI:1.15-5.15.), increased overbite (OR = 2.19; 95%CI:1.12-4.28) and increased overjet (OR = 4.25; 95%CI:1.90-9.48).

CONCLUSIONS

This study showed a high prevalence of malocclusion in children with OSA compared to the control group. The posterior crossbite and deviations in overjet and overbite were significantly associated with OSA. The presence of these occlusal features shows the importance of an orthodontic evaluation in screening for paediatric OSA.

Gravitational forces, negative pressure and facial structure in the genesis of airway dysfunction during sleep: a review of the paradigm

The recent and distant literature has extensive discussion of how sleep apnea, adeno-tonsillar growth, and facial structural deformity are related. Conventionally, the order of cause and effect is as follows: (1) Inflammatory/infectious process→tonsillar/adenoid tissue growth→(2) airway obstruction and mouth breathing/Obstructive Sleep Apnea (OSA)→(3) altered facial structure (adenoid facies). Using this same reasoning, adenotonsillectomy is the first line of treatment in the prevention of structural abnormalities. However, through a lifetime of clinical research Christian Guilleminault and his colleagues have challenged this paradigm. Through multiple articles and studies, Guilleminault et al., teach that even slight (subclinical) facial structure/muscle tone variations may be the inciting event triggering mouth-breathing and the eventual adenotonsillar growth in most patients. Essentially, this is the reverse of the conventional paradigms. Initial treatments therefore shift from simplified removal of inflammatory tissue to limiting mouth-breathing via musculo-skeletal modification. The purpose of this paper is to synthesize and analyze the recent (and distant) relevant literature to provide support for, and provide a potential anatomic mechanism for Guilleminault et al.'s paradigm-questioning clinical observations.

Impact of pediatric obstructive sleep apnea on the development of Class II hyperdivergent patients receiving orthodontic treatment: A pilot study

OBJECTIVES

To conduct a pilot study to determine if the presence of obstructive sleep apnea (OSA) influences the orthodontic treatment outcome of Class II hyperdivergent patients receiving comprehensive orthodontic treatment.

MATERIALS AND METHODS

Patients between the ages of 12 and 14 who received orthodontic treatment at the Hospital of Stomatology, Wuhan University, China, were included in this study. Patients were divided into two groups: the OSA group and the control group, based on the outcome of pretreatment polysomnography findings and lateral cephalometric radiograph examination. Patients in the control group were matched with the OSA group for age, sex, ethnicity, weight, and height. Cephalometric measurements were used to record the skeletal and dental changes from before to after treatment. Data were analyzed using the t-test.

RESULTS

Twenty three OSA patients and 23 control patients were included. After comprehensive orthodontic treatment, the mandibular plane angle (SN-GoMe), articular angle (SArGo), sum of Jarabak angles (SUM) and the lower gonial angle (NGoMe) were found to increase significantly in the OSA group but remained unchanged or decreased slightly in the control group ( P < .05). In the non-OSA group, the growth pattern became more horizontal. In contrast, in the OSA group the growth pattern became more vertical. Otherwise, similar treatment results were obtained for both groups in terms of sagittal change and occlusion.

CONCLUSIONS

The presence of OSA in pediatric patients has a deleterious effect on the development of hyperdivergent malocclusions. Early diagnosis and management of pediatric OSA can affect the orthodontic treatment outcome of these patients.

Unilateral Nasal Obstruction during Later Growth Periods Affects Craniofacial Muscles in Rats

Nasal obstruction can occur at different life stages. In early stages of life the respiratory system is still under development, maturing during the growth period. Previous studies have shown that nasal obstruction in neonatal rats alters craniofacial function. However, little is known about the effects of nasal obstruction that develops during later growth periods. The aim of this study was to investigate the effects of nasal obstruction during later periods of growth on the functional characteristics of the jaw-opening reflex (JOR) and tongue-protruding muscles. In total, 102 6-day-old male Wistar rats were randomized into either a control or experimental group (both n = 51). In order to determine the appropriate timing of nasal obstruction, the saturation of arterial oxygen (SpO₂) was monitored at 8 days, and at 3, 5, 7, 9, and 11 weeks in the control group. Rats in the experimental group underwent unilateral nasal obstruction at the age of 5 weeks. The SpO₂ was monitored at 7, 9, and 11 weeks in the experimental group. The electromyographic responses of JOR and the contractile properties of the tongue-protruding muscles were recorded at 7, 9, and 11 weeks. In the control group, SpO₂ decreased until 5 weeks of age, and remained relatively stable until 11 weeks of age. The SpO₂ was significantly lower in the experimental group than in the control. In the experimental group, JOR changes included a longer latency and smaller peak-to-peak amplitude, while changes in the contractile properties of the tongue-protruding muscles included larger twitch and tetanic forces, and a longer half-decay time. These results suggest that nasal obstruction during later growth periods may affect craniofacial function.