Dental arch morphology in children with sleep-disordered breathing

Candidate genes for obstructive sleep apnea in non-syndromic children with craniofacial dysmorphisms - a narrative review

Pediatric obstructive sleep apnea (POSA) is a complex disease with multifactorial etiopathogenesis. The presence of craniofacial dysmorphisms influencing the patency of the upper airway is considered a risk factor for POSA development. The craniofacial features associated with sleep-related breathing disorders (SRBD) - craniosynostosis, retrognathia and micrognathia, midface and maxillary hypoplasia - have high heritability and, in a less severe form, could be also found in non-syndromic children suffering from POSA. As genetic factors play a role in both POSA and craniofacial dysmorphisms, we hypothesize that some genes associated with specific craniofacial features that are involved in the development of the orofacial area may be also considered candidate genes for POSA. The genetic background of POSA in children is less explored than in adults; so far, only one genome-wide association study for POSA has been conducted; however, children with craniofacial disorders were excluded from that study. In this narrative review, we discuss syndromes that are commonly associated with severe craniofacial dysmorphisms and a high prevalence of sleep-related breathing disorders (SRBD), including POSA. We also summarized information about their genetic background and based on this, proposed 30 candidate genes for POSA affecting craniofacial development that may play a role in children with syndromes, and identified seven of these genes that were previously associated with craniofacial features risky for POSA development in non-syndromic children. The evidence-based approach supports the proposition that variants of these candidate genes could lead to POSA phenotype even in these children, and, thus, should be considered in future research in the general pediatric population.

Association of Sleep-Disordered Breathing and Developing Malocclusion in Children: A Cross-Sectional Study

Background Sleep Disordered Breathing (SDB) in children and its role in health has received renewed interest in the recent past. Malocclusion is one of the most common multifactorial craniofacial disturbances widely prevalent in children. The primary objective of this study was to assess the association of SDB with developing malocclusion in six to 12-year-old children and the effect of modifiers like age, gender, and tonsillar enlargement. Materials and method One hundred and seventy-seven children aged six to 12 years were assessed for developing malocclusion using Angle classification and Index of Orthodontic Treatment Needs (IOTN) comprising of 5 grades. Their parents were administered a pre-validated Pediatric Sleep Questionnaire (PSQ) for assessing SDB, by a single, calibrated examiner. The primary outcomes were SDB score, Angle class of malocclusion, and IOTN grade, assessed as categorical variables. The modifying variables assessed were age, gender, and tonsillar enlargement (Brodsky's criteria). The data were subject to statistical analysis using Fischer's test and the odds ratio (OR) was estimated. The modifiers were assessed using logistic regression. Results The prevalence of SDB was 69%. SDB has significantly associated with angle class II and class III malocclusion (x² = 9.475, p < 0.05 OR=3.79) and with higher IOTN grades (x² = 109.799, p < 0.05, OR=53.64). Logistic regression revealed that gender and tonsillar enlargement had a significant modifying effect (p<0.05). Conclusion SDB had a significant association with developing malocclusion, the odds being higher in angle class II and III malocclusions and higher IOTN grades. Clinical relevance Both SDB and developing malocclusion are quite commonly seen in children, though the relation between the two has not been adequately explored. This study shows that they are strongly associated with each other and one could act as a marker for the other.

3D Evaluation of Upper Airway Morphological Changes in Growing Patients with Class II Malocclusion Using Sander Bite Jumping Appliance

Class II malocclusion due to mandibular retrognathia is associated with a posterior positioning of the tongue and the hyoid bone, reducing the oropharyngeal volume. This could be a contributing factor to the development of respiratory and cardiovascular problems. This study evaluates the oropharyngeal volume variation in 13 patients with class II malocclusion undergoing functional orthopedic treatment with Sander Bite Jumping Appliance (SBJ). CBCT scans were performed before treatment (T0) and approximately after 12.5 months (T1): the retropalatal volume and retroglossal volume were quantified in mm3 using a segmentation software. At T1, the retropalatal volume increased in 2523 ± 2088 mm3, and the retroglossal volume increased in 2258 ± 1717 mm3. Both values were statistically significant (p < 0.05). This widening of the airways may allow prevention and treatment of sleep-disordered breathing, including obstructive sleep apnea syndrome.

The dental and craniofacial characteristics among children with obstructive sleep apnoea: a systematic review and meta-analysis

BACKGROUND

Paediatric obstructive sleep apnoea (OSA) is a sleep breathing disorder which may have dramatic effects on childhood behaviour, neurodevelopment, metabolism, and overall health in children. Malocclusion and craniofacial morphology may be related to paediatric OSA, and therefore provide information for clinicians to recognize, evaluate and treat patients with this sleeping disorder.

OBJECTIVE

The aim of this systematic review was to summarize evidence regarding the association between paediatric OSA and children's dental and craniofacial characteristics.

SEARCH METHODS

PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from inception to 1 June 2022.

SELECTION CRITERIA

Cross-sectional studies, comparing dental or craniofacial characteristics using clinical dental examinations or radiographic findings between OSA children (less than 18 year, diagnosed with overnight polysomnography) and healthy children, were included.

DATA COLLECTION AND ANALYSIS

The Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross-Sectional Studies was used to assess the quality of included studies. RevMan software was used for performing the Meta-analyses.

RESULTS

Sixteen studies were included. Meta-analyses showed that the overjet (MD = 0.86, 95% CI: 0.20 to 1.51; P = 0.01), the saggital skeletal jaw discrepancy (ANB; MD = 1.78, 95% CI: 1.04 to 2.52; P < 0.00001) and mandibular plane angle (FH-MP; MD = 3.65, 95% CI: 2.45 to 4.85; P < 0.00001) were greater in OSA-affected children. In contrast, the upper molar arch width (upper first deciduous molar width; MD = -1.86, 95% CI: -3.52 to -0.20; P = 0.03), (Upper second deciduous molar width; MD = -1.06, 95% CI: -1.88 to -0.24; P = 0.01), SNB (MD = -2.10, 95% CI: -3.11 to -1.09; P < 0.0001), and maxillary length (ANS-PNS; MD = -1.62, 95% CI: -2.66 to -0.58; P = 0.002) were smaller in the OSA group.

CONCLUSIONS

This review shows that OSA-affected children tend to present with mandibular retroposition or retrognathia, increased mandibular plane angle and excess anterior overjet. However, these findings need to be viewed with caution as the corresponding differences may not be significant clinically.

REGISTRATION

PROSPERO (CRD42020162274).

Craniofacial and upper airway morphological characteristics associated with the presence and severity of obstructive sleep apnea in Chinese children

Objectives

To identify craniofacial and upper airway morphological characteristics associated with the presence and severity of obstructive sleep apnea (OSA) in children.

Methods

This study consisted of 82 OSA children and 77 controls (age 5-10 years). All subjects underwent cephalograms and were divided into a 5-7 age group and an 8-10 age group. Cephalometric variables were compared between OSA children and controls, and hierarchical regression analysis was performed to examine the relationship between cephalometric variables and OSA severity [expressed by the obstructive apnea-hypopnea index (OAHI)] in different age groups.

Results

Increased A/N ratio, narrowed posterior airway space, decreased SNA and SNB angles, and shortened ramus height were observed among OSA children in different age groups. In the 5-7 age group, the A/N ratio and a lower gonial angle explained 40.0% and 14.7% of the variance in the OAHI, respectively. In the 8-10 age group, the BMI z-score and A/N ratio explained 25.2% and 6.6% of the variance in the OAHI, followed by a lower gonial angle and the hyoid-retrognathion distance (19.1% in total).

Conclusions

Adenoid hypertrophy was a major factor associated with OSA in preschool children, whereas obesity replaced adenoid hypertrophy as the main contributor to OSA in late childhood. Several craniofacial skeletal variables such as the SNB angle, ramus height, lower gonial angle, and hyoid position are also associated with the presence and/or severity of OSA, which could be used to help recognize children at a higher risk for OSA.

Craniofacial Sleep Medicine: The Important Role of Dental Providers in Detecting and Treating Sleep Disordered Breathing in Children

Obstructive sleep apnea (OSA) is a clinical disorder within the spectrum of sleep-related breathing disorders (SRDB) which is used to describe abnormal breathing during sleep resulting in gas exchange abnormalities and/or sleep disruption. OSA is a highly prevalent disorder with associated sequelae across multiple physical domains, overlapping with other chronic diseases, affecting development in children as well as increased health care utilization. More precise and personalized approaches are required to treat the complex constellation of symptoms with its associated comorbidities since not all children are cured by surgery (removal of the adenoids and tonsils). Given that dentists manage the teeth throughout the lifespan and have an important understanding of the anatomy and physiology involved with the airway from a dental perspective, it seems reasonable that better understanding and management from their field will give the opportunity to provide better integrated and optimized outcomes for children affected by OSA. With the emergence of therapies such as mandibular advancement devices and maxillary expansion, etc., dentists can be involved in providing care for OSA along with sleep medicine doctors. Furthermore, the evolving role of myofunctional therapy may also be indicated as adjunctive therapy in the management of children with OSA. The objective of this article is to discuss the important role of dentists and the collaborative approach between dentists, allied dental professionals such as myofunctional therapists, and sleep medicine specialists for identifying and managing children with OSA. Prevention and anticipatory guidance will also be addressed.

Craniofacial features in children with obstructive sleep apnea: a systematic review and meta-analysis

STUDY OBJECTIVES

This review aimed to evaluate the association between craniofacial features in children and adolescents with pediatric obstructive sleep apnea (OSA).

METHODS

Seven databases were searched to fulfill our research objectives. Clinical studies that included participants younger than 18 years with fully diagnosed OSA or without OSA and that evaluated skeletal, soft craniofacial features, or dental arch morphology were considered for this review. The risk of bias and certainty of evidence were assessed. A meta-analysis was performed when low methodological and clinical heterogeneity were detected. This review followed the protocols recommended by the Preferred Reporting Items for a Systematic Review and Meta-analysis (PRISMA-2020) guidelines.

RESULTS

Nine studies were identified at the end of the selection process, from which 5 did not report differences. Four studies reported differences between craniofacial features when OSA was compared to an asymptomatic control group. Mandibular retrognathia, reduced anteroposterior linear dimensions of the bony nasopharynx (decreased pharyngeal diameters at the levels of the adenoids), longer facial profile, and a narrower intercanine width were described among children with OSA. A meta-analysis was performed considering the studies with a similar methodological approach, and no differences were observed in all the considered cephalometric angles (SNA, SNB, ANB, NSBa, U1-L1, U1-SN). All the included studies were considered at low risk of bias even though some limitations were noted.

CONCLUSIONS

Due to the very low to moderate level of certainty, neither an association nor a lack thereof between craniofacial morphology and pediatric OSA can be supported by these data.

CITATION

Fagundes NCF, Gianoni-Capenakas S, Heo G, Flores-Mir C. Craniofacial features in children with obstructive sleep apnea: a systematic review and meta-analysis. J Clin Sleep Med. 2022;18(7):1865-1875.

Children and adolescents with speech sound disorders are more likely to have orofacial dysfunction and malocclusion

Background

Children with speech sound disorders (SSD) form a heterogeneous group that differs in terms of underlying cause and severity of speech difficulties. Orofacial dysfunction and malocclusions have been reported in children with SSD. However, the association is not fully explored.

Objectives

Our aims were to describe differences in orofacial function and malocclusion between a group of children and adolescents with compared to without SSD and to explore associations between those parameters among the group with SSD.

Methods

A total of 105 participants were included, 61 children with SSD (6.0–16.7 years, mean age 8.5 ± 2.8, 14 girls and 47 boys) and 44 children with typical speech development (TSD) (6.0–12.2 years, mean age 8.8 ± 1.6, 19 girls and 25 boys). Assessments of orofacial function included an orofacial screening test and assessment of bite force, jaw stability, chewing efficiency, and intraoral sensory‐motor function. Possible malocclusions were also assessed.

Result

Children with SSD had both poorer orofacial function and a greater prevalence of malocclusion than children with TSD. Furthermore, children with SSD and poorer orofacial function had a greater risk of malocclusion.

Conclusion

Our result suggests that children with SSD are more prone to having poorer orofacial function and malocclusion than children with TSD. This illustrates the importance of assessing coexisting orofacial characteristics in children with SSD, especially since orofacial dysfunction may be linked to an increased risk of malocclusion. This result highlights the need for a multiprofessional approach.

Sleep-disordered breathing in children and adolescents seeking paediatric dental care in Dubai, UAE

PURPOSE

This study aimed to evaluate the severity of high-risk SDB in children and adolescents seeking paediatric dental care. Sleep-disordered breathing (SDB) has many untoward consequences that may interfere with children's health and is associated with several risk factors.

METHODS

In this cross-sectional study, the convenience sample included 65 healthy children and adolescents aged 7-16. High-risk SDB breathing was assessed using the Paediatric-Sleep-Questionnaire consisting of 22 questions. High-risk was defined as a positive response to 33% or more of the questions. The clinical examination included: tonsils' size, Body-Mass Index, orthodontic examination, and enamel defects.

RESULTS

In this sample of 65 children with a mean age of 9.75 (± 2.60) years; 36 (55.4%) were boys, and 29 (44.6%) were girls. Overall, 12.3% of children in the sample were at high-risk of SDB, and this was significantly associated with tonsils' size (P = 0.001), Body-Mass Index (P = 0.03), Class-II molar relationship (P = 0.03), and posterior crossbite/s (P = 0.02).

CONCLUSIONS

This study suggested that approximately 12% of the sample studied were potentially at risk of SDB. Tonsils' size, Body-Mass Index, Class-II molar relationship, and posterior crossbite/s were positively associated with the risk of SDB. Therefore, the importance of investigating the risk for sleep-disordered breathing should not be disregarded.

Clinical and anatomical characteristics associated with obstructive sleep apnea severity in children

PURPOSE

To determine the clinical and anatomical characteristics associated with obstructive sleep apnea severity in children with adenotonsillar hypertrophy.

METHODS

The authors conducted a cross-sectional multidisciplinary survey and selected 58 Brazilian children (4‒9 years old) with adenotonsillar hypertrophy, parental complaints of snoring, mouth-breathing, and witnessed apnea episodes. The authors excluded children with known genetic, craniofacial, neurological, or psychiatric conditions. Children with a parafunctional habit or early dental loss and those receiving orthodontic treatment were not selected. All children underwent polysomnography, and three were excluded because they showed an apnea-hypopnea index lower than one or minimal oxygen saturation higher than 92%. The sample consisted of 55 children classified into mild (33 children) and moderate/severe (22 children) obstructive sleep apnea groups. Detailed clinical and anatomical evaluations were performed, and anthropometric, otorhinolaryngological, and orthodontic variables were analyzed. Sleep disorder symptoms were assessed using the Sleep Disturbance Scale for Children questionnaire. All children also underwent teleradiography exams and Rickett's and Jarabak's cephalometric analyses.

RESULTS

The mild and moderate/severe obstructive sleep apnea groups showed no significant differences in clinical criteria. Facial depth angle, based on Ricketts cephalometric analysis, was significantly different between the groups (p = 0.010), but this measurement by itself does not express the child's growth pattern, as it is established by the arithmetic mean of the differences between the obtained angles and the normal values of five cephalometric measurements.

CONCLUSIONS

The clinical criteria and craniofacial characteristics evaluated did not influence the disease severity.

Relationship between dental and basal arch forms in mandibular anterior crowding

INTRODUCTION

Positive correlations between the mandibular dental and basal arch forms in patients with minimum crowding have been observed; however, the relationship in orthodontic patients with mandibular anterior crowding (MnAC) remains unclear. Therefore, we evaluated this relationship in patients with MnAC requiring premolar extraction.

METHODS

Thirty women with normal occlusion (mean age, 20.6 ± 2.5 years) and 30 women with Class I MnAC (mean age, 20.3 ± 2.9 years) were selected as control and MnAC groups, respectively. The widths and depths of the mandibular dental and basal arches at the FA and WALA points were measured and compared between groups. Relationships between the arch widths at the FA and WALA points were analyzed by Pearson correlation coefficient.

RESULTS

Larger variances were found for dental arch widths at canine and premolars and depth at canine in the MnAC group. Positive correlations were observed between dental and corresponding basal arch widths for both groups, except at the canine in the MnAC group, and higher correlations were observed between dental arch widths for all teeth except the first molar and basal arch widths for posterior adjacent teeth when comparing the corresponding basal arch widths.

CONCLUSIONS

The positive correlations observed between the dental and basal arch widths suggest the basal arch widths at the posterior adjacent tooth can be used as an additional reference to create an individualized postorthodontic dental arch form for MnAC patients.

Nasal obstruction during the growth period modulates the Wnt/β-catenin pathway and brain-derived neurotrophic factor production in association with tyrosine kinase receptor B mRNA reduction in mouse hippocampus

There is accumulating evidence that nasal obstruction induces high‐level brain dysfunction, including memory and learning deficits. We previously demonstrated that unilateral nasal obstruction (UNO) during the growth period increases the expression of brain‐derived neurotrophic factor (BDNF). The expression of BDNF is regulated by the Wnt/β‐Catenin pathway, which is linked to neuronal differentiation, proliferation, and maintenance. However, little is known about whether Wnt3a protein expression could be an index for modulations analyses in the Wnt/β‐Catenin pathway caused by UNO during the growth period. This study aimed to investigate the effects of UNO during the growth period on the Wnt/β‐Catenin pathway in the hippocampus using combined behavioural, biochemical, and histological approaches. Male BALB/C mice were randomly divided into the control (CONT; n = 6) and experimental (UNO; n = 6) groups. Blood oxygen saturation (SpO₂) levels were measured, and a passive avoidance test was performed in mice aged 15 weeks. Brain tissues were subjected to immunohistochemistry, real‐time reverse transcription‐polymerase chain reaction, and western blot analysis. Compared with control mice, UNO mice had lower SpO₂ levels and exhibited memory/learning impairments during behavioural testing. Moreover, Wnt3a protein, BDNF mRNA, and tyrosine kinase receptor B (TrkB) mRNA expression levels were significantly lower in the hippocampus in the UNO group than in the CONT group. Our findings suggested that UNO during the growth period appeared to modulate the hippocampal Wnt/β‐catenin pathway and BDNF production in association with TrkB mRNA reduction, thereby resulting in memory and learning impairments.

The role of the dentist in the diagnosis and management of pediatric obstructive sleep apnea

The objective of this article is to review the role of the dentist in the early diagnosis of pediatric obstructive sleep apnea (OSA) and to provide an in-depth review of the best evidence-based practices available to treat and/or to refer these patients for intervention.

Material and methods

A narrative review was performed using indexed data bases (PubMed, Medline, EMBASE, OVID, Scopus and Cochrane) up to year 2020, and approximately 1000 articles were reviewed. The articles included were those with the best information provided.

Results

Detailed review of the literature suggests that the role of the dentist has been redefined owing to their expertise in the orofacial region. Every patient consulting a dental practice is not merely a dental patient; he/she also requires a comprehensive medical review. The role of the dentist is pivotal in pediatric patients once diagnosed with OSA; as the patients grow, growth modification can be achieved, and future management will be easier. Initiating dental treatments during growth can benefit patients two-fold, saving them from malocclusion, and intervening in orofacial structural growth can help to avoid cumbersome treatments, such as CPAP and various surgeries. Proper diagnosis and management of systemic illnesses can prevent compromised quality of life, delays in treatment, morbidity and, in some cases, mortality.

Dental and dentoalveolar dimensions in individuals with osteogenesis imperfecta

OBJECTIVE

This cross-sectional study compared tooth and dental arch dimensions of individuals with Osteogenesis imperfecta (OI) and healthy controls.

MATERIAL AND METHODS

The 37 OI patients and 37 controls were aged 10 to 74 years. Mesio-distal tooth size, dental arch dimensions, and palatal height were measured from dental models. The differences between the patient and control groups were analysed statistically with a t-test, chi-square test, and Mann-Whitney U test.

RESULTS

The average mesio-distal tooth size of individuals with OI was smaller by 0.1 to 0.8 mm, corresponding to 1.4 to 7.3% of the size of the tooth. The patients and controls showed similar anterior-posterior lengths of maxillary and mandibular arches. The OI patient group exhibited increasingly wider maxillary dental arches posterior to the canines and a shallow palate.

CONCLUSIONS

Reduced tooth size is a developmental feature of OI and a shallow palate a characteristic possibly associated with previously documented imparity of vertical jaw development. Observed posterior widening of the dental arches may follow from altered tongue position. Smaller tooth size can be favourable from orthodontic point of view in alleviating crowding, but it might further predispose to fracturing of teeth which is a considerable risk associated with dentine abnormality. The shallow jawbones may initiate development of posterior open bite, rare in general population but relatively often encountered in OI.

Dental malocclusion among children with attention deficit hyperactivity disorder

INTRODUCTION

Children with attention deficit hyperactivity disorder (ADHD) have more sleep breathing problems and parafunctional oral habits than individuals without ADHD. However, there is scarce information on the correlation between their dental malocclusion and these functional disorders. The objective of this study was to assess the severity of malocclusion in patients with and without ADHD and to evaluate the correlation between their functional disorders and dental malocclusion.

METHODS

Eighty-eight patients aged 6-17 years were divided into 2 groups: ADHD (n = 44) and control (n = 44). A medical questionnaire to assess functional disorders and an orthodontic examination to evaluate malocclusion were completed for each patient. Distribution of the data was evaluated using Shapiro-Wilk test, whereas the 2 groups were compared with a t test, Mann-Whitney U test, Fisher exact test, and Spearman correlation. The association between parafunctional oral habits, ADHD drug intake, and malocclusion severity were assessed with a t test and Mann-Whitney U test.

RESULTS

Patients with ADHD had significantly higher severity of malocclusion (P = 0.042), more dental rotation (P = 0.021) and more parafunctional oral habits (P = 0.001), specifically bruxism (P = 0.005), and a history of pacifier use (P = 0.009), than the control group.

CONCLUSIONS

It is important to be aware of the increased risk of parafunctional oral habits and dental malocclusion among ADHD patients to develop preventive programs, as well as therapeutic strategies for them.

Combined Surgical and Orthodontic Treatments in Children with OSA: A Systematic Review

Obstructive sleep apnea (OSA) is a sleeping breathing disorder. In children, adenotonsillar hypertrophy remains the main anatomical risk factor of OSA. The aim of this study was to assess the current scientific data and to systematically summarize the evidence for the efficiency of adenotonsillectomy (AT) and orthodontic treatment (i.e., rapid maxillary expansion (RME) and mandibular advancement (MA)) in the treatment of pediatric OSA. A literature search was conducted in several databases, including PubMed, Embase, Medline, Cochrane and LILACS up to 5th April 2020. The initial search yielded 509 articles, with 10 articles being identified as eligible after screening. AT and orthodontic treatment were more effective together than separately to cure OSA in pediatric patients. There was a greater decrease in apnea hypoapnea index (AHI) and respiratory disturbance index (RDI), and a major increase in the lowest oxygen saturation and the oxygen desaturation index (ODI) after undergoing both treatments. Nevertheless, the reappearance of OSA could occur several years after reporting adequate treatment. In order to avoid recurrence, myofunctional therapy (MT) could be recommended as a follow-up. However, further studies with good clinical evidence are required to confirm this finding.

Is securing normal dentofacial development an indication for tonsil surgery in children? A systematic review and meta-analysis

OBJECTIVE

Tonsil surgeries are common operations in the field of paediatric otorhinolaryngology. Often, the indication for these operations is hypertrophied tonsils. Paediatric sleep-disordered breathing and mouth-breathing are conventional situations caused by the hypertrophied tonsils. Both of these are further associated with dentofacial development alterations. Securing normal dentofacial development, or restoring it, is often used as an indication for tonsil surgery. In this review and meta-analysis, we assessed the contemporary literature to clarify whether tonsil surgery has an effect on dentofacial development in children.

METHODS

Studies with children aged 3-10 years who underwent tonsil surgery and were compared to non-operated controls using dentofacial parameters were included to the review. Search strategies were planned for specific databases. The Newcastle-Ottawa scale was used to assess the risk of bias. A meta-analysis was performed when the data was methodologically homogenous enough to be pooled.

RESULTS

The inclusion criteria for the review were fulfilled in 8 studies. The overall quality of the individual studies was judged to be moderate at best. The data were methodologically homogenous enough to be pooled for the meta-analysis in only 2 studies. The results of the meta-analysis revealed that tonsil surgery has a positive effect on the growth direction of the mandible (p < 0.001).

CONCLUSIONS

There is modest evidence that suggests that tonsil surgery has a positive effect on the dentofacial development in children with hypertrophied tonsils. Securing normal dentofacial development should be one component, but not the only one, when the indications for tonsil surgery in children are considered.

Prevalence of sleep-related breathing disorders in children with malocclusion

Background

The paediatric population has a high incidence of sleep-related breathing disorders (SRBD). A notable risk factor is the presence of craniofacial abnormalities. The objective of the study was therefore to survey the prevalence of SRBD in patients presenting for interceptive treatment.

Material and Methods

Prospective study with a sample of 249 healthy patients. The "Paediatric Sleep Questionnaire" and "Sleep Disturbance Scale for Children" were completed by the children's parents and the results were evaluated. All patients had their medical records reviewed and underwent orthodontic diagnosis by oral examination, as well as dental cast and cephalometric analysis. Finally, we compared the results of the pre- and post-treatment questionnaires of 50 patients in the sample.

Results

Based on the results of the questionnaires, 22.8% of the study sample had SRBD. No statistically significant correlation was found between SRBD and the anthropometric characteristics and occlusal variables assessed. According to the cast analysis, patients with SRBD had a smaller maxillary width (p<0.003), and according to the cephalometric study, less overbite (p<0.003). Furthermore, the prevalence of SRBD was higher among patients with a history of adenotonsillectomy (p<0.02). Comparison of the results of pre- and post-treatment questionnaires revealed significant differences after orthodontic treatment (p<0.0005).

Conclusions

It is necessary to identify the presence of SRBD in orthodontic patients given its high prevalence. Patients with SRBD have a smaller maxillary width and less overbite. Key words:Sleep-related breathing disorders, paediatric sleep questionnaire, cephalometry.

Effects of Maxillary Skeletal Expansion on Upper Airway Airflow: A Computational Fluid Dynamics Analysis

The effect of maxillary skeletal expansion (MSE) on upper airway in adolescent patients is not clear. The purpose of this study was to determine the upper airway airflow with MSE treatment using computational fluid dynamics analysis. Three-dimensional upper airway finite element models fabricated from cone beam computed tomography images were obtained before and after treatment in an adolescent patient with maxillary constriction. Turbulent analyses were applied. The nasal cavity (NC) was divided into 6 planes along the y-axis and the pharynx was divided into 7 planes in the z-axis. Changes in cross-sectional area, airflow velocity, pressure, and total resistance at maximum expiration and maximum inspiration were determined at each plane after MSE treatment. The greatest increase in area occurred in the oropharynx which was around 40.65%. The average increase in area was 7.42% in the NC and 22.04% in the pharynx. The middle part of pharynx showed the greatest increase of 212.81 mm and 217.99 mm or 36.58% and 40.66%, respectively. During both inspiration and expiration, airflow pressure decreased in both the NC and pharynx, which ranged from -11.34% to -23.68%. In the NC, the average velocity decrease was -0.18 m/s at maximum expiration (ME) and -0.13 m/s at maximum inspiration (MI). In the pharynx, the average velocity decrease was -0.07 m/s for both ME and MI. These results suggest that treatment of maxillary constriction using MSE appliance may show positive effects in improvement of upper airway cross-sectional areas and reduction of upper airway resistance and velocity.

Association between snoring and deciduous dental development and soft tissue profile in 3-year-old children

INTRODUCTION

The aim was to study the association between snoring and development of occlusion, maxillary dental arch, and soft tissue profile in children with newly completed deciduous dentition.

METHODS

Thirty-two (18 female, 14 male) parent-reported snorers (snoring ≥3 nights/week) and 19 (14 female, 6 male) nonsnorers were recruited. Breathing preference (nose or mouth) was assessed at the mean age of 27 months by otorhinolaryngologist. At the mean age of 33 months, an orthodontic examination was performed, including sagittal relationship of second deciduous molars, overjet, overbite, and occurrence of crowding and lateral crossbite. Bite index was obtained to measure maxillary dental arch dimensions (intercanine and intermolar width, arch length). A profile photograph was obtained to measure facial convexity.

RESULTS

No significant differences were found between nonsnorers and snorers in any of the studied occlusal characteristics or in measurements of maxillary dental arch dimensions. Snorers were found to have a more convex profile than nonsnorers. Occurrence of mouth breathing was more common among snorers.

CONCLUSIONS

Parent-reported snoring (≥3 nights/week) does not seem to be associated with an adverse effect on the early development of deciduous dentition, but snoring children seem to have more convex profile than nonsnorers. Snoring is a mild sign of sleep-disordered breathing, and in the present study its short time lapse may not have had adequate functional impact on occlusion.

[Orthodontic management of obstructive sleep-disordered respiratory disorders]

Through his/her knowledge of cranio-facial growth, the orthodontist plays a leading role within the multidisciplinary team that tracks and treats sleep-disordered breathing (SDB) in children. Correction of craniofacial risk factors (maxillary deficiency and retrognathia) is commonly used by practitioners alongside orthodontic treatment such as OMA and RME in the optimal conditions afforded by childhood growth. Myofunctional therapies are performed to restore correct stomatognathic function and play a central role in the management of SDB in children. The orthodontist is therefore a key player in the medical treatment chain of these children.

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.

Craniofacial, dental arch morphology, and characteristics in preschool children with mild obstructive sleep apnea

Background/purpose

Pediatric obstructive sleep apnea (OSA) might be a serious cause of neurocognitive deficits, behavioral changes, and craniofacial disharmony in children at very young age with mild type of OSA. This study aims to examine the effect of mild OSA on craniofacial morphology as well as dental arch morphology and characteristics in preschool children.

Materials and methods

The test group comprised 16 preschool children (11 boys, 5 girls; mean age: 5.14 years old; mean AHI: 2.02) with confirmed polysomnographic diagnosis of mild OSA. Ten control subjects also underwent polysomnography (5 boys, 5 girls; mean age: 5.18 years old; median AHI: 0.43). Lateral cephalometric radiographs and dental arch impressions were obtained and measured. A survey on characteristics and quality of life (OSA-18) was filled out by study participants' caregivers.

Results

For craniofacial morphology, a significant increase in ANB angle, a decrease in SNB angle, and larger overjet size were seen in the group with mild OSA, compared with the control group. More frequent sleep disturbances and mood swing were also found in children with mild OSA, based on the OSA-18 assessment.

Conclusion

Preschool children with mild OSA present the following: skeletal Class II pattern with a more retrognathic mandible, increased overjet size, and more pronounced symptoms in the domains of sleep and emotion. Dental arch constriction is not a typical feature in our sample of Asian preschool children with mild OSA.

Obstructive sleep apnea severity and dental arches dimensions in children with late primary dentition: An observational study

Objective: The aim of this study was to compare the dimensions of the upper and lower arches in children affected by OSAS with different levels of severity of obstruction.Methods: Twenty-seven Caucasian children (14 males, 13 females; mean age 6, range 5.2-6.1 years) with a diagnosis of OSAS determined by polysomnography were enrolled in this study. The dimensions of both dental arches were measured, and the data were compared among children affected by severe, moderate, and mild OSAS.Results: Statistically significant differences among the three groups revealed that children with severe OSAS had the highest values of upper intercanine and intermolar distances in the sample.Discussion: A severe OSAS grade (AHI > 10) is associated with statistically significantly higher upper intercanine and intermolar distances compared with mild and moderate grades. An early approach to OSAS in children with late primary dentition is auspicated in order to prevent an influence on dental arches growth.

Comparison of dental arch measurements according to the grade and the obstructive character of adenoids

INTRODUCTION

Obstructive adenoid hypertrophy is cited as one of the causes of mouth breathing and leads to disharmony in the development of orofacial structures. The objective of this study was to compare the measurements of dental arches according to the grade and the obstructive character of adenoids.

MATERIALS AND METHODS

A cross-sectional study was carried out with 86 children. The grade and the obstructive character of adenoids were determined from Holmberg and Cohen's radiographic methods respectively. Dental arch measurements were taken on dental casts. A t-test and a Chi² test were performed respectively to compare the quantitative and qualitative variables of dental arches according to the obstructive character. An Anova test made it possible to compare the quantitative variables according to the grade as Holmberg defined it. For variables that showed significant differences, a Post Hoc test was used. The significance level was set at P=0.05.

RESULTS

Subjects with obstructive adenoids had a shorter posterior mandibular length (P=0.04) and a greater overbite (P=0.04) than those with non-obstructive adenoids. Those with grade 4 had a greater arch depth (P=0.02) and were more prone to open bite(P=0.03).

CONCLUSION

A prevention program involving the otorhinolaryngologist and the orthodontist for subjects with obstructive adenoids or grade 4 is necessary to minimize their influence on dental arch relationships.

Oral Health and Oral Health-Related Quality of Life in Children With Obstructive Sleep Apnea

STUDY OBJECTIVES

This aim of this study was to evaluate oral health and oral health-related quality of life (OHRQoL) in children with obstructive sleep apnea (OSA).

METHODS

This cross-sectional study involved 31 children who had baseline polysomnography studies and in whom a diagnosis of OSA was made by a sleep physician. They were evaluated against 36 control patients who, based on parent responses to the Pediatric Sleep Questionnaire, were at very low risk for having sleep problems. The mean age of the cohort was 12.3 ± 2.7 years. The oral health status was examined clinically and recorded using caries and periodontal indices. OHRQoL was measured using the Child Oral Health Impact Profile (COHIP) questionnaires.

RESULTS

Children with OSA had significantly worsened oral health compared to control patients as evidenced by more caries (15.2 and 3.2, respectively; P < .001) and more periodontitis. Periodontitis severity was measured by the presence of bleeding on probing, (87% versus 30%, P < .001) and higher number of sites with abnormally deep periodontal probing depths (2.7 versus 0.3, P < .001). The COHIP scores were significantly higher among children with OSA compared to control patients, (29.7 versus 11.8, P < .001) consistent with poorer OHRQoL.

CONCLUSIONS

This study suggests that in children OSA may have a significant association with poorer oral health when compared to control patients without sleep problems, and that their oral health status may have a negative effect on their quality of life. Increased awareness regarding the oral health effects of sleep-disordered breathing in the medical and dental community is needed.

[Relationships between the size of the adenoids and the dental arch measurements]

INTRODUCTION

Enlarged adenoids are often associated with oral breathing. The latter can impact the dental arches. The purpose of this study was to determine the relationships between dental arch measurements and the size of adenoids.

MATERIALS AND METHODS

A cross-sectional study was carried out on 86 children. The dimensions of the adenoids were determined from nine radiographic evaluation methods and the dental arch measurements made on the casts. The association between the grade of adenoids and the dental arch measurements was sought by Spearman correlation. That between the quantitative variables assessing adenoids and dental arch measurements was sought by Pearson correlation. The strength of these associations was analyzed using Cohen's values in 1988. The significance was set at p = 0.05.

RESULTS

Palatal depth was significantly and positively correlated with adenoid grade according to the method of Holmberg and Linder-Aronson (rho = 0.55, p = 0.005) and with the adenoid measurements according to the methods of Kemaloglu, Fujioka, Johannesson, De Menezes and Maran with r respectively equal to 0.65, 0.59, 0.63, 0.47, 0.74; and p respectively equal to 0.001, 0.002, 0.001, 0.019, and < 0.001. It was also significantly but negatively correlated with the adenoids measurements according to Hibbert's method (r = -0.52, p = 0.008). Overbite was significantly and negatively correlated with adenoid dimension using the De Menezes method (r = -0.541, p = 0.006).

DISCUSSION

The strength of the associations shows that using respectively Maran and De Menezes methods can allow to better highlight the association between the dimensions of the adenoids and the palatal depth and the overbite.

Risk factors associated with obstructive sleep apnea-hypopnea syndrome in Chinese children: A single center retrospective case-control study

Pediatric obstructive sleep apnea-hypopnea syndrome is caused by multiple factors. The present study aimed to investigate the potential risks of pediatric obstructive sleep apnea hypopnea syndrome (OSAHS) and their correlation with the disease severity. A total of 338 pediatric patients with OSAHS (polysomnography (PSG) diagnosis) were enrolled between June 2008 and October 2010. These pediatric patients were divided into mild, moderate and severe subgroups according to the obstructive apnea index (OAI) and/or apnea hypoventilation index (AHI). A total of 338 pediatric patients with vocal nodules who were without obstruction of the upper respiratory tract were enrolled as the control group. The patients were analyzed retrospectively. The average number of upper respiratory tract infections each year and tonsil hypertrophy, adenoid hypertrophy, positive serum tIgE, chronic sinusitis, nasal stenosis, craniofacial features and obesity were significantly higher in OSAHS compared with controls (P<0.01). The parameters the average number of upper respiratory tract infections each year (OR: 1.395, 95% CI: 1.256–1.550), adenoid hypertrophy (OR: 8.632, 95% CI: 3.990–18.672), tonsil hypertrophy (OR: 9.138, 95% CI: 4.621–18.073), nasal stenosis (8.023, 95% CI: 3.633–17.717) and chronic sinusitis (OR: 27.186, 95% CI: 13.310–55.527) were independent factors of pediatric OSAHS (P<0.01). The distribution of chronic sinusitis, nasal stenosis, craniofacial features and obesity indicated a gradual increasing trend in the severity of OSAHS (P<0.01). Number of upper respiratory tract infections per year, adenoid hypertrophy, tonsil hypertrophy, chronic sinusitis, nasal stenosis, infections, allergic reactions, craniofacial features and obesity may be potential risk factors of pediatric OSAHS.

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.

Prevalence of upper respiratory tract infections in habitually snoring and mouth breathing children

OBJECTIVES

The aim of the study was to investigate the prevalence of upper respiratory tract infections (URI) - as indicated by rhinosinusitis (RS), ear infections (EI), and antibiotic consumption - in a general pediatric population and evaluate the relationship between these conditions and habitual snoring and mouth breathing during sleep.

METHODS

A population-based cross-sectional study was performed in three medium-sized Polish cities from 2011 to 2015.

RESULTS

4837/6963 questionnaires (69.5%) were completed, returned and analyzed. Mean age of studied group was 7.07 ± 0.72 and 7.14 ± 0.73 in girls and boys, respectively. Habitual mouth breathing during sleep (MB) was reported in 907 (18.7%) children and habitual snoring (HS) in 290 (6.0%). 230/290 (79.3%) of children with HS were also MB. Both HS and MB were more prevalent in boys than in girls (p = 0.027 and p < 0.0001, respectively) and neither was associated with BMI (p = 0.11 and p = 0.07, respectively). Habitual snoring and habitual mouth breathing were highly associated with more frequent bouts of rhinosinusitis, ear infections, and antibiotic use (p < 0.0001 for each parameter).

CONCLUSIONS

Higher rates of rhinosinusitis, ear infections, and antibiotic consumption were similarly associated with HS and MB. MB is over three times more prevalent in the pediatric population relative to HS, therefore it might be considered as a risk factor for URI and may be included in history of URI.

Intermittent hypoxia causes mandibular growth retardation and macroglossia in growing rats

INTRODUCTION

In this study, we aimed to examine the role of intermittent hypoxia (IH) in dentofacial morphologic changes in growing rats.

METHODS

Seven-week-old male rats were exposed to IH at 20 cycles per hour (nadir of 4% oxygen to peak of 21% oxygen) for 8 hours per day for 6 weeks. Control rats were exposed to normoxia (N). Maxillofacial growth was compared between the 2 groups by linear measurements on cephalometric radiographs. To examine the dental arch morphology, study models and microcomputed tomography images of the jaws were taken. Additionally, tongue size was measured.

RESULTS

The gonial angle and the ramus of the mandible were smaller in the IH group than in the N group, whereas the body weights were not different between the 2 groups. Morphometric analysis of the dentition showed a significantly wider mandibular dentition and narrower maxillary dentition in the IH than in the N group. The relative width (+4.2 %) and length (tongue apex to vallate papillae, +3.5 %) of the tongue to the mandible were significantly greater in the IH group than in the N group.

CONCLUSIONS

IH induced dentofacial morphologic discrepancies in growing rats.

Pediatric Obstructive Sleep Apnea: Consensus, Controversy, and Craniofacial Considerations

Pediatric obstructive sleep apnea, characterized by partial or complete obstruction of the upper airway during sleep, is associated with multiple adverse neurodevelopmental and cardiometabolic consequences. It is common in healthy children and occurs with a higher incidence among infants and children with craniofacial anomalies. Although soft-tissue hypertrophy is the most common cause, interplay between soft tissue and bone structure in children with craniofacial differences may also contribute to upper airway obstruction. Snoring and work of breathing are poor predictors of obstructive sleep apnea, and the gold standard for diagnosis is overnight polysomnography. Most healthy children respond favorably to adenotonsillectomy as first-line treatment, but 20 percent of children have obstructive sleep apnea refractory to adenotonsillectomy and may benefit from positive airway pressure, medical therapy, orthodontics, craniofacial surgery, or combined interventions. For children with impairment of facial skeletal growth or craniofacial anomalies, rapid maxillary expansion, midface distraction, and mandibular distraction have all been demonstrated to have therapeutic value and may significantly improve a child's respiratory status. This Special Topic article reviews current theories regarding the underlying pathophysiology of pediatric sleep apnea, summarizes standards for diagnosis and management, and discusses treatments in need of further investigation, including orthodontic and craniofacial interventions. To provide an overview of the spectrum of disease and treatment options available, a deliberately broad approach is taken that incorporates data for both healthy children and children with craniofacial anomalies.

From oral facial dysfunction to dysmorphism and the onset of pediatric OSA

The upper airway is a collapsible tube, and its collapsibility increases during sleep. Extrinsic factors such as atypical craniofacial features may increase the risks of airway collapse. We review early development of oral-facial structures and the anatomical variants that may be present at birth and can impact nasal breathing. After birth, there is a continuous interaction between orofacial functions and growth of anatomic features. We review the dysfunctions identified to date that may impact orofacial development leading to sleep-disordered-breathing through changes in the orofacial growth. The identification of risk-factors, ultimately leading to full-blown obstructive sleep apnea, may allow early recognition of these factors and the development of treatments to eliminate early problems or at least decrease their impact.

Dental Arch Dimensions of Nigerian Children with Hypertrophied Adenoids

OBJECTIVE

The study objective was to assess the effect of adenoid hypertrophy on the dental arch dimensions of children in Ile-Ife, Nigeria.

METHODS

Ninety patients aged 3-12 years attending the Otorhinolaryngology Clinic at Obafemi Awolowo University Teaching Hospital Ile-Ife diagnosed as having hypertrophied adenoids and 90 children from the Child Dental Health Clinic were recruited as adenoid and control subjects respectively. Arch and palatal vault dimensions, including total arch length; inter-canine, inter-premolar, and inter-molar widths; palatal length; and palatal heights measured at three levels and palatal volume were determined for both groups from dental casts.

RESULTS

Maxillary arch dimensions were shorter in the adenoid group than the control group; however, only total maxillary arch length was significantly shorter (p=0.049). Mandibular arch dimensions with the exception of inter-molar width were significantly shorter in the adenoid group (p<0.05). Adenoid subjects had significantly increased palatal heights at canine, premolar, and molar levels and reduced palatal volume compared to the control subjects (p<0.05).

CONCLUSION

Adenoid subjects demonstrated shorter maxillary and mandibular arch dimensions compared with control subjects, with the differences being more evident in the lower arch. They also exhibited increased palatal heights at all levels and reduced palatal volume compared with control subjects.

The preliminary results of the differences in craniofacial and airway morphology between preterm and full-term children with obstructive sleep apnea

Background/purpose

The prematurely born and obstructive sleep apnea (OSA) could affect craniofacial and airway growth. The purpose of this study is to compare the differences in craniofacial and airway morphology between preterm and full-term children both with OSA problem.

Materials and methods

The differences in craniofacial and airway morphology between preterm children and full-term children both with OSA problem during the prepubertal (age 6–10) and pubertal (age 11–14) period were measured using lateral cephalometric radiograph.

Results

In the prepubertal period, effective maxillary length, and length from Go to Gn were smaller in the preterm group (n = 6) compared to the full-term (n = 8). The length of the soft palate was smaller and the distance soft palate-posterior side of nasopharynx was longer in preterm children. During puberty, (1) position of maxilla relative to cranial base: there was an anteroposterior maxilla and a mandibular discrepancy, a convexity of facial profile, (2) the distance from point A to nasion perpendicular, the distance from Pog to nasion perpendicular, and the ratio of effective maxillary length/effective mandibular length were smaller in the preterm group (n = 5) compare to the full-term (n = 6).

Conclusion

During prepuberty, the preterm children had a significantly shorter effective maxillary and mandibular length but the catch up growth resulted during the pubertal period in reduction in facial profile convexity and more important mandibular vertical growth toward a dolichocephalic profile. Due to preterm birth, OSA children have a different craniofacial morphology compared to the full-term. When using an oral device for passive myofunctional therapy, the treatment outcome maybe different.

[Effect of dental arch length decrease during orthodontic treatment in the upper airway development. A review]

INTRODUCTION

A possible relation between an upper airway space decrease and the development of obstructive sleep apnea syndrom explains the importance to know the effect of the modification of dental arch length on the upper airway during orthodontic treatment.

OBJECTIVES

The aim of this article is to expose recent knowledge about upper airway development and dental arch length decrease factors, to determine the influence of this decrease on upper airway development.

METHODS

A review was done to determine the upper airway normal development, to define dental arch to specify if an ideal position of dental arch on apical base exists. All of the length dental arch decrease factors during orthodontic treatment (dental extraction, dental agenesis and dental malpositions) and their upper airway resounding were searched.

RESULTS

Some authors found a diminution of upper airway space after premolars extractions while others didn't found this diminution after extractions premolars when incisor retraction is finished. A decrease of transversal maxillary diameter and nasal cavity may be due to absence of permanent teeth.

CONCLUSION

The effect of dental arch length decrease during orthodontic treatment in the upper airway development was not scientifically proved. However we had to be vigilant and adapt our orthodontic treatment case by case to avoid an upper airway modification.

Managing obstructive sleep apnoea in children: the role of craniofacial morphology

Obstructive sleep apnoea syndrome is a type of sleep-disordered breathing that affects 1 to 5% of all children. Pharyngeal and palatine tonsil hypertrophy is the main predisposing factor. Various abnormalities are predisposing factors for obstructive sleep apnoea, such as decreased mandibular and maxillary lengths, skeletal retrusion, increased lower facial height and, consequently, increased total anterior facial height, a larger cranio-cervical angle, small posterior airway space and an inferiorly positioned hyoid bone. The diagnosis is based on the clinical history, a physical examination and tests confirming the presence and severity of upper airway obstruction. The gold standard test for diagnosis is overnight polysomnography. Attention must be paid to identify the craniofacial characteristics. When necessary, children should be referred to orthodontists and/or sleep medicine specialists for adequate treatment in addition to undergoing an adenotonsillectomy.

Intermittent Hypoxia Influences Alveolar Bone Proper Microstructure via Hypoxia-Inducible Factor and VEGF Expression in Periodontal Ligaments of Growing Rats

Intermittent hypoxia (IH) recapitulates morphological changes in the maxillofacial bones in children with obstructive sleep apnea (OSA). Recently, we found that IH increased bone mineral density (BMD) in the inter-radicular alveolar bone (reflecting enhanced osteogenesis) in the mandibular first molar (M1) region in the growing rats, but the underlying mechanism remains unknown. In this study, we focused on the hypoxia-inducible factor (HIF) pathway to assess the effect of IH by testing the null hypothesis of no significant differences in the mRNA-expression levels of relevant factors associated with the HIF pathway, between control rats and growing rats with IH. To test the null hypothesis, we investigated how IH enhances mandibular osteogenesis in the alveolar bone proper with respect to HIF-1α and vascular endothelial growth factor (VEGF) in periodontal ligament (PDL) tissues. Seven-week-old male Sprague-Dawley rats were exposed to IH for 3 weeks. The microstructure and BMD in the alveolar bone proper of the distal root of the mandibular M1 were evaluated using micro-computed tomography (micro-CT). Expression of HIF-1α and VEGF mRNA in PDL tissues were measured, whereas osteogenesis was evaluated by measuring mRNA levels for alkaline phosphatase (ALP) and bone morphogenetic protein-2 (BMP-2). The null hypothesis was rejected: we found an increase in the expression of all of these markers after IH exposure. The results provided the first indication that IH enhanced osteogenesis of the mandibular M1 region in association with PDL angiogenesis during growth via HIF-1α in an animal model.

Anthropometric and Dental Measurements in Children with Obstructive Sleep Apnea

STUDY OBJECTIVES

A number of authors have shown that children with OSA are more likely to have certain physical characteristics than healthy controls. With this in mind, our objectives were to collect normative baseline data and determine if there was a significant difference in anthropometric and dental measurements between children with OSA and age-matched nonsnoring controls.

METHODS

Children 2 to 12 y of age, in whom OSA was diagnosed by overnight polysomnography, were recruited to our experimental group. Age-matched nonsnoring controls were screened for signs of sleep-disordered breathing. Anthropometric measurements, including waist, neck, and hip circumferences, and waist-hip and neck-waist ratios, were obtained on all study participants preoperatively. Dental casts were acquired to determine intertooth distances and palatal height.

RESULTS

Sixty-one children (42 with OSA [69%] and 19 controls [31%]) with a mean age of 4.7 y participated in the study. Waist and hip circumferences were significantly larger in children with OSA (p = 0.001 and 0.001, respectively). However, there was no difference in neck circumference and waist-hip ratios between the two groups. Neck-waist ratio in children with OSA was significantly smaller than in controls (p = 0.001). Intertooth distance for the first (p < 0.0001) and second deciduous (p = 0.0002) and first permanent molars (p = 0.022) were significantly narrowed in children with OSA; however, no difference was seen in palatal height between groups. Body mass index was similar between groups (p = 0.76).

CONCLUSIONS

Anthropometric and dental measurements were significantly different in children with OSA compared to nonsnorers. Future studies with a large sample size may allow us to determine if these measurements can be used by clinicians to identify children at risk for OSA.

COMMENTARY

A commentary on this article appears in this issue on page 1213.

Efficacy of a Mandibular Advancement Appliance on Sleep Disordered Breathing in Children: A Study Protocol of a Crossover Randomized Controlled Trial

BACKGROUND

Sleep-Disordered Breathing (SDB) varies from habitual snoring to partial or complete obstruction of the upper airway and can be found in up to 10% of children. SDB can significantly affect children's wellbeing, as it can cause growth disorders, educational and behavioral problems, and even life-threatening conditions, such as cardiorespiratory failure. Adenotonsillectomy represents the primary treatment for pediatric SDB where adeno-tonsillar hypertrophy is indicated. For those with craniofacial anomalies, or for whom adenotonsillectomy or other treatment modalities have failed, or surgery is contra-indicated, mandibular advancement splints (MAS) may represent a viable treatment option. Whilst the efficacy of these appliances has been consistently demonstrated in adults, there is little information about their effectiveness in children.

AIMS

To determine the efficacy of mandibular advancement appliances for the management of SDB and related health problems in children.

METHODS/DESIGN

The study will be designed as a single-blind crossover randomized controlled trial with administration of both an "Active MAS" (Twin-block) and a "Sham MAS." Eligible participants will be children aged 8-12 years whose parents report they snore ≥3 nights per week. Sixteen children will enter the full study after confirming other inclusion criteria, particularly Skeletal class I or class II confirmed by lateral cephalometric radiograph. Each child will be randomly assigned to either a treatment sequence starting with the Active or the Sham MAS. Participants will wear the appliances for 3 weeks separated by a 2-week washout period. For each participant, home-based polysomnographic data will be collected four times; once before and once after each treatment period. The Apnea Hypopnea Index (AHI) will represent the main outcome variable. Secondary outcomes will include, snoring frequency, masseter muscle activity, sleep symptoms, quality of life, daytime sleepiness, children behavior, and nocturnal enuresis. In addition, blood samples will be collected to assess growth hormone changes.

TRIAL REGISTRATION

This study was registered in the Australian New Zealand Clinical Trials Registry (ANZCTR): [ACTRN12614001013651].

Maxillary dentoskeletal changes 1-year after adenotonsillectomy

OBJECTIVE

To measure the maxillary dentoskeletal and soft tissue changes of severely obstructed mouth breathing (MB) young children who had their mode of breathing normalized after adenotonsillectomy (T&A), in comparison with a matched group of severely obstructed untreated MB children (CG).

METHODS

Seventy patients who had an Ear, Nose, and Throat examination (ENT), including flexible nasal endoscopy, to confirm the severe obstruction of the upper airways and the indication of T&A composed the sample. Cephalograms and dental casts were available from the patient's orthodontic records. Treatment group (TG) and CG included 35 children each. Groups were matched by gender (24 males and 11 females in each group), age (TG, 6.7 ± 1.8 years; CG, 6.9 ± 2.3 years), tooth development (TG, 13 primary dentition, 22 mixed dentition; CG, 14 primary dentition, 21 mixed dentition), and skeletal maturation status. Records were taken at baseline (T0) and 1-year after T&A (T1) for TG; while CG records were taken with a 1-year interval. Dentoskeletal measurements were performed in the lateral cephalograms, and dental casts were used to assess the palatal volume and occlusal changes.

RESULTS

TG showed a significant increase (503.3 mm(3), P < 0.001) in the palatal volume (10% of change), while CG palatal volume was stable. No dimensional occlusal changes were detected between T0 and T1 in both groups. Significant downward (point A, 2.1 mm; ANS, 2.1 mm) and forward displacements (point A, 0.7 mm; ANS, 1 mm) of the anterior region of the maxilla were observed in the TG, but CG presented only significant downward displacement (point A, 1.8 mm; ANS, 1.4 mm). The maxillary posterior region (PNS, PTM, and Molar) displaced downward in both groups (P < 0.05), however no sagittal change was found. The palatal plane inclination was stable in both groups.

CONCLUSIONS

TG presented significant increase in the palatal volume and in the forward displacement of the maxilla. No other significant maxillary dentoskeletal changes were found.

Patterns of morphological integration in the dental arches of individuals with malocclusion

OBJECTIVES

In humans, there is a large range of variation in the form of the maxillary and mandibular dental arches. This variation can manifest as either prognathism or retrognathism in either or both arches, which can cause malocclusion and lead to abnormal masticatory function. This study aims to identify aspects of variation and morphological integration existing in the dental arches of individuals with different types of malocclusion.

METHODS

Coordinate landmark data were collected along the gingival margins of 397 scanned dental casts and then analyzed using geometric morphometric techniques to explore arch form variation and patterns of morphological integration within each malocclusion type.

RESULTS

Significant differences were identified between Class II forms (increased projection of upper arch relative to the lower arch) and Class III forms (lower arch projection beyond the upper arch) in symmetrical shape variation, including anteroposterior arch discrepancies and abnormal anterior arch divergence or convergence. Partial least squares analysis demonstrated that Class III dental arches have higher levels of covariance between upper and lower arches (RV = 0.91) compared to the dental arches of Class II (RV = 0.78) and Class I (RV = 0.73). These high levels of covariance, however, are on the lower end of the overall range of possible masticatory blocks, indicating weaker than expected levels of integration.

CONCLUSIONS

This study provides evidence for patterns of variation in dental arch shape found in individuals with Class II and Class III malocclusions. Moreover, differences in integration found between malocclusion types have ramifications for how such conditions should be studied and treated. Am. J. Hum. Biol. 28:879-889, 2016. © 2016Wiley Periodicals, Inc.