Palatal surface and volume in mouth-breathing subjects evaluated with three-dimensional analysis of digital dental casts-a controlled study

Medium-term effects of rapid maxillary expansion on nasal cavity and pharyngeal airway volumes considering age as a factor: A retrospective study

OBJECTIVES

The medium-term effects of rapid maxillary expansion (RME) on nasal cavity (NC) and upper airway (UA) dimensions based on chronological age are still unclear. This retrospective study evaluated the medium-term changes occurring in the NC and pharyngeal airways (PA) after RME in two distinct age-based cohorts of patients.

METHODS

This retrospective study included 48 subjects who underwent RME grouped in two cohorts: a 6-9-year-old group (EEG group: early expansion group - 25 subjects) and an 11-14-year-old group (LEG group: late expansion group - 23 subjects). NC and PA volumes were analyzed from CBCT imaging segmentation before RME (T0) and twelve months after RME (T1). The amount of maxillary expansion (PW) and minimal cross-sectional area (CSmin) were also considered.

RESULTS

All PAs' volumetric sub-regions, CSmin and PW showed a significant volumetric increment (p < 0.05). Inter-group comparisons showed significant differences (p < 0.05) for nasopharynx and CSmin parameters (p < 0.05), while no significant changes were recorded for the other UA's sub-regions and PW (p > 0.05). According to a deviation analysis, part of the UA increase (more marked for the nasopharynx area) may have occurred due to reduced adenotonsillar tissues, which were larger in the EEG group.

CONCLUSIONS

Twelve months after treatment, clinicians should not expect changes in the UAs dimensions to be solely related to treatment effects of RME; instead, normal craniofacial growth changes and spontaneous regression of the adenotonsillar tissue could represent the most significant factors influencing UAs changes.

CLINICAL SIGNIFICANCE

From the clinical perspective, the results of the present study encourage caution when considering the therapeutic effects of RME on airways dimensions.

Evaluation of three-dimensional reconstructed palatal morphology in skeletal class III subjects with different vertical patterns using cone beam computed tomography

BACKGROUND

This study aims to evaluate the difference of three-dimensional (3D) reconstructed palatal morphology between subjects with skeletal Class III and skeletal Class I in different vertical patterns using cone beam computed tomography (CBCT).

METHODS

In this study, 89 subjects with skeletal Class III (49 females, 40 males; 25.45 ± 3.81 years) and 85 subjects with skeletal Class I (45 females, 40 males; 23.95 ± 4.45 years) were collected retrospectively and divided into hyperdivergent, normodivergent and hypodivergent groups. Dolphin software was used to reorient the CBCT images of these subjects. After segmenting 3D object of maxilla from the 3D skull by ProPlan software, Geomagic Studio was used to reconstruct 3D palatal morphology and establish an average 3D palatal morphology for each group. The differences of 3D palatal morphology between different groups were compared by deviation patterns on 3D colored map analysis.

RESULTS

3D colored map analysis showed the posterior part of male's palate was higher and wider than that of female's palate in skeletal Class III subjects. In skeletal Class III subjects, males with hyperdivergent pattern had a higher and narrower palate compared with hypodivergent subjects, while females with hyperdivergent had a higher but not obviously narrower palate compared with hypodivergent subjects. In the similar vertical patterns, skeletal Class III subjects had a flatter but not narrower palate compared with skeletal Class I subjects, along with a smaller palate volume.

CONCLUSIONS

This method allows more intuitive between-group comparisons of the differences of 3D palatal morphology. In skeletal Class III subjects, as the vertical dimension increased, the palate tends to be higher and narrower. Therefore, the influence of vertical patterns on the palatal morphology should be fully considered in the orthodontic and orthognathic treatment of skeletal Class III subjects.

Effects of novel microimplant-assisted rapid palatal expanders manufactured by 3-dimensional printing technology: A finite element study

INTRODUCTION

The expansion effects of several new microimplant-assisted rapid palatal expanders (MARPEs) manufactured by 3-dimensional printing technology were evaluated by finite element analysis (FEA). The aim was to identify a novel MARPE suitable for treating maxillary transverse deficiency.

METHODS

The finite element model was established using MIMICS software (version 19.0; Materialise, Leuven, Belgium). First, the appropriate microimplant insertion characteristics were identified via FEA, and several MARPEs with the above insertion patterns were manufactured by 3-dimensional printing technology. Then, the stress distribution and displacement prediction of the 4 MARPEs and hyrax expander (model E) were evaluated via FEA: bone-borne (model A), bone-tooth-borne (model B), bone-mucous-borne (model C), bone-tooth-mucous-borne (model D).

RESULTS

Monocortical microimplants perpendicular to the cortical bone on the coronal plane resulted in better expansion effects. Compared with a conventional hyrax expander, the orthopedic expansion of each of the 4 MARPEs was far larger, the parallelism was greater, and the posterior teeth tipping rate was lower. Among them, the expansion effects of models C and D were the best; the von Mises peak values on the surfaces of the microimplants were smaller than those of models A and B.

CONCLUSIONS

This study may demonstrate that the 4 MARPEs obtained more advantageous orthopedic expansion effects than a hyrax expander. Models C and D obtained better biomechanical effects and had better primary stability. Overall, model D is the recommended expander for treating maxillary transverse deficiency because its structure acts like an implant guide and is beneficial for the accurate insertion of the microimplant.

Gender and age effects on dental and palatal arch dimensions among full siblings

PURPOSE

This study was conducted to investigate the dental and palatal arch dimensions of male and female siblings in relation to gender and age, using three-dimensional (3D) digital casts.

METHODS

This study involved 54 subjects (27 pairs) of male-female siblings aged 15 to 45 years. Dental casts were digitized and analyzed for tooth size (TS), arch width (AW), arch length (AL), arch length discrepancy (ALD), and palatal arch dimensions (PAD). The data obtained were subjected to t-tests, and the palatal curvature (PC) was modeled using a fourth-order polynomial.

RESULTS

Significant differences (P < 0.05) between the sexes were found in the mesiodistal TS, particularly in all canines, as well as 16, 36, 46, and 41. Maxillary AW and AL were also significantly (P < 0.05) influenced by sexes. Most arch parameters were more prominent in male siblings, and the effect of age on PC differed between the sexes. In addition, the PC of adolescent females was mostly superimposed on adult females relative to males.

CONCLUSION

Among siblings, males were found to have significantly larger dental arch dimensions than females. Furthermore, PC showed some differences between the sexes in both the frontal and sagittal planes.

Application of three-dimensional reconstruction technology in dentistry: a narrative review

BACKGROUND

Three-dimensional(3D) reconstruction technology is a method of transforming real goals into mathematical models consistent with computer logic expressions and has been widely used in dentistry, but the lack of review and summary leads to confusion and misinterpretation of information. The purpose of this review is to provide the first comprehensive link and scientific analysis of 3D reconstruction technology and dentistry to bridge the information bias between these two disciplines.

METHODS

The IEEE Xplore and PubMed databases were used for rigorous searches based on specific inclusion and exclusion criteria, supplemented by Google Academic as a complementary tool to retrieve all literature up to February 2023. We conducted a narrative review focusing on the empirical findings of the application of 3D reconstruction technology to dentistry.

RESULTS

We classify the technologies applied to dentistry according to their principles and summarize the different characteristics of each category, as well as the different application scenarios determined by these characteristics of each technique. In addition, we indicate their development prospects and worthy research directions in the field of dentistry, from individual techniques to the overall discipline of 3D reconstruction technology, respectively.

CONCLUSIONS

Researchers and clinicians should make different decisions on the choice of 3D reconstruction technology based on different objectives. The main trend in the future development of 3D reconstruction technology is the joint application of technology.

Comparative 3D study of dental arches in children with microcephaly associated with congenital Zika syndrome, orofacial cleft, and without craniofacial anomalies

INTRODUCTION

The dentist participates in the treatment protocol for craniofacial anomalies in individuals from the first months of life.

OBJECTIVE

to compare in a retrospective cohort study the morphometry of the edentulous palate of children microcephaly associated with congenital Zika syndrome (CZS), unilateral complete cleft lip and alveolus (UCL), and without craniofacial anomalies.

METHODS

Forty-five digitized dental molds composed the sample divided into three groups: CZS; UCL; and without craniofacial anomalies (control group). The following measurements were evaluated: intercanine and intertuberosity distances; dental arch length, area, volume, and mismatch superimposition. Parametric and non-parametric tests were applied (α = 5%).

RESULTS

CZS group showed the smallest means of intercanine distance and area than those of the other groups (p = .001 and p = .010, respectively). The dental arch length was greater in the CZS group than in the control group (p = .020). The evaluation of the mismatch superimposition showed that the CZS group had the lowest means of maximum distance and root mean square than that of the UCL group (p = .025 and p = .005, respectively).

CONCLUSION

CZS participants tended to palatal narrowing, while UCL individuals had parameters similar to those of the control group, despite the alveolus defect.

Rapid maxillary expansion and nasal patency in mouth breathing children with maxillary atresia due to or not due to allergic rhinitis

AIM

To evaluate the effects of rapid maxillary expansion (RME) on nasal patency in mouth breathing (MB) children with maxillary atresia due to or not due to allergic rhinitis (AR) associated with asthma.

METHODS

Fifty-three MB children/adolescents (aged 7-14 years) with mixed or permanent dentition and maxillary atresia participated, with or without unilateral or bilateral crossbite. They formed the groups: RAD (AR + asthma; clinical treatment, RME); RAC (AR + asthma; clinical treatment, no RME); and D (mouth breathers; RME only). RAD and RAC patients received topical nasal corticosteroid and/or systemic H1 antihistamine (continuous use) and environmental exposure control. All were evaluated before RME (T1) and 6 months after (T2) with the CARATkids score, acoustic rhinometry, and nasal cavity computed tomography (CT). Patients RAD and D underwent RME (Hyrax® orthopedic appliance).

RESULTS

A significant reduction in the CARATkids score occurred in the RAD (-4.06; p < 0.05), similarly when patient and parent/guardian scores were evaluated (-3.28 and -3.16, respectively). Acoustic rhinometry (V5) showed increased nasal volume in all groups, significantly higher in RAD patients than in RAC and D (0.99 × 0.71 × 0.69 cm³, respectively). CT of the nasal cavity documented increased volume in all three groups, with no significant differences between them.

CONCLUSION

In MB patients with AR, asthma, and maxillary atresia, RME increased nasal cavity volume and improved respiratory symptoms. However, it should not be used as the only treatment for managing patients with respiratory allergies.

Analysis of maxillary arch morphology and its relationship with upper airway in mouth breathing subjects with different sagittal growth patterns

OBJECTIVE

This three-dimensional cone beam computed tomography(CBCT) study assessed pharyngeal airway and maxillary arch in mouth breathing subjects with different skeletal classifications and analyzed the factors associated with the upper airway morphological variations in mouth breathing (MB) and nasal breathing (NB) subjects.

METHODS

One hundred and five subjects (52 MB and 53 NB children), divided into three skeletal groups: Class I (1° ≤ ANB° ≤ 5°), Class II (ANB° >5°), and Class III (ANB°<1°). An independent t-test and one-way ANOVA test were utilized in the group analysis of normal distributed data. The linear multiple regression test was applied to create a model for the airway volumes based on the maxillary arch parameters in different skeletal groups.

RESULTS

In three skeletal groups, NB individuals had greater oropharyngeal airway volume (OPV) and total pharyngeal airway volume (TPV) than MB. Maxillary arch parameters of intermolar width (IMW), intercanine width (ICW), and maxillary width of canines (MWC) were larger in NB participants than in MB subjects. In the MB group, we discovered that Class II individuals had lower NPV (nasopharyngeal airway volume) than Class I and Class III. MWC was lower in Class II subjects compared to Class I and Class III in both the NB and MB groups.

CONCLUSION

NB individuals had greater pharyngeal airway and maxillary arch parameters than MB subjects. Our model equation revealed that the inter-molar width (IMW) and palatal area (PA) parameters were the strongest predictors of total pharyngeal airway volume (TPV) in the skeletal Class II and Class I groups.

Uniformity of palatal volume and surface area in various malocclusions

AIMS

To assess palatal volume, surface area and linear dimensions across sagittal and vertical components of malocclusion.

METHODS

Pre-treatment cephalographs and dental casts of 178 non-growing patients (88 males, 90 females, age 25.81 ± 8.23 years) were used for classification in sagittal malocclusion groups: Class I (n = 48), Class II division 1 (n = 42), Class II division 2 (n = 40) and Class III (n = 48); and in vertical divergence groups based on the MP/SN angle: hypodivergent (n = 35), normodivergent (n = 95) and hyperdivergent (n = 48). Dental casts were scanned and palatal measurements recorded: palatal width, depth and interdental distances; palatal surface area (PSA, mm² ) and volume (PV, mm³ ). A 3-way ANOVA was used to compare palatal dimensions across groups. Pearson product-moment correlations were employed to assess associations among variables.

RESULTS

PSA and PV (in both sex groups) were not statistically significantly different across sagittal malocclusions and vertical patterns. Significant differences were depicted more among the vertical divergence groups than sagittal groups. Correlations between PSA and PV and palatal dimensions were low to moderate. Predictability of PSA and PV ranged between 15 and 18%.

CONCLUSION

The finding of similar palatal volume and surface area, on average, across malocclusions possibly underscores the limitations of environmental influences within the inherited orofacial phenotype. The vertical facial pattern seems to be more interactive with palatal dimensions than sagittal relations. Studies of palatal changes following orthodontic and orthognathic treatments are warranted.

Evaluation of nasal airway resistance in a cohort of children with primary snoring and maxillary deficiency

BACKGROUND

The aim of this study was to test whether rapid palatal expansion is effective to improve nasal airway patency in a sample of pediatric patients with primary snoring.

METHODS

A group of 21 subjects, 11 girls (52%) and 10 boys (48%), with a mean age of 7.1 years (SD=1.3; range 4-9 years) were treated with a rapid maxillary expansion (RME) device. Nasal airway resistance was assessed via rhinomanometric exam before (pre-) and 6 months after (post-) the rapid palatal expansion treatment.

RESULTS

Data analysis showed a statistically significant increase in the mean scores of the results of the rhinomanometric exam between the pre- and post-measurements with a significant reduction in total inspiratory and expiratory air resistance values after rapid palatal expansion.

CONCLUSIONS

Our results show that RME treatment is associated with an improvement in nasal airway resistance due to a substantial reduction in nasal resistance associated with the orthopedic action of the orthodontic device.

Three-dimensional evaluation of pharyngeal airway and maxillary arch in mouth and nasal breathing children with skeletal Class I and II

Objective

This study aimed to investigate whether the subjects with mouth breathing (MB) or nasal breathing (NB) with different sagittal skeletal patterns showed different maxillary arch and pharyngeal airway characteristics.

Methods

Cone-beam computed tomography scans from 70 children aged 10 to 12 years with sagittal skeletal Classes I and II were used to measure the pharyngeal airway, maxillary width, palatal area, and height. The independent t-test and the Mann–Whitney U test were used for the intragroup analysis of pharyngeal airway and maxillary arch parameters.

Results

In the Skeletal Class I group, nasopharyngeal airway volume (P < 0.01), oropharyngeal airway volume (OPV), and total pharyngeal airway volume (TPV) (all P < 0.001) were significantly greater in subjects with NB than in those with MB. Furthermore, intermolar width, maxillary width at the molars, intercanine width, maxillary width at the canines, and palatal area were significantly larger in subjects with NB than in those with MB (all P < 0.001). In the Skeletal Class II group, OPV, TPV (both P < 0.05) were significantly greater in subjects with NB than in those with MB. No significant differences in pharyngeal airway parameters in the MB group between subjects with Skeletal Class I and those with Skeletal Class II.

Conclusion

Regardless of sagittal Skeletal Class I or II, the pharyngeal airway and maxillary arch in children with MB differ from those with NB. However, the pharyngeal airway was not significantly different between Skeletal Class I and II in children with MB.

Evaluation of maxillary arch width and palatal volume and depth in patients with maxillary impacted canine by CBCT

Introduction

Canines are the second most common tooth in terms of impaction. Impacted teeth can be associated with some different indices of dental arch and dentoalveolar structures. The aim of this study was to evaluate maxillary arch width as well as volume and depth of palate in patients with maxillary impacted canine by cone beam computed tomography (CBCT).

Methods

In this cross-sectional study, 45 CBCT images of patients with unilateral maxillary impacted canines were examined. All patients had palatally impacted canines. Three parameters of maxillary arch width, palatal volume and palatal depth were assessed using axial and sagittal incisions on the CBCT images. Then all the measurements on the impacted side were compared with the non-impacted side. Data were entered into SPSS software and paired sample t-test and Student's t-test were used to comparison. The significance level of 0.05 was considered.

Results

The maxillary arch width on the impacted side was significantly less than the normal side (P < 0.001). The mean depth of the palate was 14.86 ± 3.53 mm. There was a significant correlation between canine impaction and Palatal volume (R = 0.728 and P-value< 0.001), but no significant correlation between canine impaction and Maxillary arch width was shown (R = 0.15 and p-value = 0.326).

Conclusion

The impacted canine was significantly associated with a reduction in the width of the maxillary arch on the affected side, and it made no difference if the impacted side was left or right. Also, impacted canine teeth were significantly associated with volume reduction on the affected side.

Mother and Daughter Carrying of the Same Pathogenic Variant in FGFR2 with Discordant Phenotype

Craniosynostosis are a heterogeneous group of genetic conditions characterized by the premature fusion of the skull bones. The most common forms of craniosynostosis are Crouzon, Apert and Pfeiffer syndromes. They differ from each other in various additional clinical manifestations, e.g., syndactyly is typical of Apert and rare in Pfeiffer syndrome. Their inheritance is autosomal dominant with incomplete penetrance and one of the main genes responsible for these syndromes is FGFR2, mapped on chromosome 10, encoding fibroblast growth factor receptor 2. We report an FGFR2 gene variant in a mother and daughter who present with different clinical features of Crouzon syndrome. The daughter is more severely affected than her mother, as also verified by a careful study of the face and oral cavity. The c.1032G>A transition in exon 8, already reported as a synonymous p.Ala344 = variant in Crouzon patients, also activates a new donor splice site leading to the loss of 51 nucleotides and the in-frame removal of 17 amino acids. We observed lower FGFR2 transcriptional and translational levels in the daughter compared to the mother and healthy controls. A preliminary functional assay and a molecular modeling added further details to explain the discordant phenotype of the two patients.

The role of craniofacial maldevelopment in the modern OSA epidemic: a scoping review

STUDY OBJECTIVES

There is increasing recognition that environmental factors affect human craniofacial development and our risk for disease. A scoping review of the literature was performed looking at environmental influences on craniofacial development to better understand this relationship and investigate what further study is needed to determine how this relationship may impact obstructive sleep apnea.

METHODS

A comprehensive literature search was performed using the Ovid Medline database from inception to May, 2020 with relevance to craniofacial development in 5 clinically-oriented variables: diet, secular change, breastfeeding/non-nutritive sucking habits (NNSH), nasal obstruction/mouth breathing, and masticatory muscle function. The Oxford Centre for Evidence-Based Medicine Levels of Evidence (LoE) was used to assess studies based on study design.

RESULTS

18,196 articles were initially identified, of which 260 studies were fully reviewed and 97 articles excluded. The remaining 163 articles were categorized as follows: Secular change (n = 16), Diet (n = 33), Breastfeeding/NNSH (n = 28), Nasal obstruction/Mouth breathing (n = 57), and Masticatory muscle function (n = 35). 93% of included studies reported a significant association between craniofacial morphology and environmental factors. The majority of studies were characterized as low LoE studies with 90% of studies being LoE 4 or 5.

CONCLUSIONS

The studies in this review suggest that environmental factors are associated with changes in craniofacial development. However, most studies were heterogeneous and low-level studies, making strong conclusions about these relationships difficult. Future rigorous studies are needed to further our understanding of environmental influences on craniofacial development and OSA risk.

Assessing the effect of adenoidectomy on nasal resistance and airflow. A systematic review and meta-analysis

OBJECTIVE

Clinical guidelines suggest adenoidectomy when enlarged adenoids are associated with nasal obstruction and other symptoms. Given that nasal obstruction is the leading symptom of adenoid hypertrophy, it should be thoroughly explored. However, there is no consensus regarding what could be the best approach. This systematic review is designed with the objective of exploring the extent to which adenoidectomy can decrease nasal resistance through rhinomanometry.

REVIEW METHODS

3 authors members of the YO-IFOS rhinology study group independently analyzed the data sources (Pubmed, the Cochrane Library, EMBASE, SciELO) for papers assessing the change in nasal resistance and/or nasal airflow in rhinomanometry after adenoidectomy in pediatric patients.

RESULTS

A total of 9 studies with a total population of 423 participants (323 patients excluding healthy controls) met the inclusion criteria. All of them found decreased nasal resistance after adenoidectomy. 5 studies could be combined in a metanalysis, which revealed a statistically significant difference of 0.52 Pa in basal conditions, and 0.64 Pa in rhinomanometry under nasal decongestion. 4 authors explored changes in nasal airflow. All of them found a statistically significant increase in nasal airflow after adenoidectomy. However, their results could not be merged in a meta-analysis.

CONCLUSION

This systematic review and meta-analysis demonstrated the existence of a systematic decrease in nasal resistance and increase in nasal airflow with and without nasal decongestant after adenoidectomy. The available evidence suggests that rhinomanometry with nasal decongestant could help in intermediate cases of adenoid hypertrophy, in order to identify the presence of nasal obstruction and, when present, the possibility of other causes for it rather than enlarged adenoids, mainly turbinate hypertrophy.

Effect of treatment of transverse maxillary deficiency using rapid palatal expansion on oral health-related quality of life in children: A randomized controlled trial

INTRODUCTION

This trial aimed to longitudinally evaluate the effect of the treatment of transverse maxillary deficiency using rapid palatal expansion (RPE) on self-perceived oral health-related quality of life (OHRQOL) in children.

METHODS

Eighty participants aged 8-10 years with transverse maxillary deficiency and bilateral posterior crossbite were randomly assigned to 2 groups (n = 40 each): a group treated with RPE using hyrax-type appliances and a nontreated control group. OHRQOL was assessed by using the Child Perceptions Questionnaire for 8-10-year-olds at 4 times: before RPE, during RPE (T₁), at the end of RPE (T₂), and 1 month after the appliance removal (T₃). Generalized mixed models were used for data analysis (α = 0.05).

RESULTS

Both groups exhibited similar demographic characteristics and OHRQOL scores at baseline. All participants completed the study. RPE had a time-dependent effect on OHRQOL. At T₁ and T₂, this therapy is expected to increase the overall OHRQOL scores by 1.17 times (ie, ∼17% increase; T₁ 95% confidence interval [CI], 1.08-1.26; T₂ 95% CI, 1.09-1.27; P = 0.001). In contrast, the overall OHRQOL scores at T₃ are expected to be 0.28 times the baseline scores (ie, ∼72% reduction; T₃ 95% CI, 0.26-0.31; P = 0.001). All individual domains of the OHRQOL evidenced a positive impact of treatment at T₃ (P = 0.001). Only the oral symptoms and social well-being domains showed a significantly negative impact of the treatment at T₁ and T₂.

CONCLUSIONS

Correction of the transverse maxillary deficiency by RPE in children aged 8-10 years improves OHRQOL. There is a temporary worsening of OHRQOL during the treatment of this condition using RPE.

REGISTRATION

This trial was not registered.

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

This study was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil, Financing Code 001.

Exploring palatal and dental shape variation with 3D shape analysis and geometric deep learning

OBJECTIVES

Palatal shape contains a lot of information that is of clinical interest. Moreover, palatal shape analysis can be used to guide or evaluate orthodontic treatments. A statistical shape model (SSM) is a tool that, by means of dimensionality reduction, aims at compactly modeling the variance of complex shapes for efficient analysis. In this report, we evaluate several competing approaches to constructing SSMs for the human palate.

SETTING AND SAMPLE POPULATION

This study used a sample comprising digitized 3D maxillary dental casts from 1,324 individuals.

MATERIALS AND METHODS

Principal component analysis (PCA) and autoencoders (AE) are popular approaches to construct SSMs. PCA is a dimension reduction technique that provides a compact description of shapes by uncorrelated variables. AEs are situated in the field of deep learning and provide a non-linear framework for dimension reduction. This work introduces the singular autoencoder (SAE), a hybrid approach that combines the most important properties of PCA and AEs. We assess the performance of the SAE using standard evaluation tools for SSMs, including accuracy, generalization, and specificity.

RESULTS

We found that the SAE obtains equivalent results to PCA and AEs for all evaluation metrics. SAE scores were found to be uncorrelated and provided an optimally compact representation of the shapes.

CONCLUSION

We conclude that the SAE is a promising tool for 3D palatal shape analysis, which effectively combines the power of PCA with the flexibility of deep learning. This opens future AI driven applications of shape analysis in orthodontics and other related clinical disciplines.

Automated landmarking for palatal shape analysis using geometric deep learning

OBJECTIVES

To develop and evaluate a geometric deep-learning network to automatically place seven palatal landmarks on digitized maxillary dental casts.

SETTINGS AND SAMPLE POPULATION

The sample comprised individuals with permanent dentition of various ethnicities. The network was trained from manual landmark annotations on 732 dental casts and evaluated on 104 dental casts.

MATERIALS AND METHODS

A geometric deep-learning network was developed to hierarchically learn features from point-clouds representing the 3D surface of each cast. These features predict the locations of seven palatal landmarks.

RESULTS

Repeat-measurement reliability was <0.3 mm for all landmarks on all casts. Accuracy is promising. The proportion of test subjects with errors less than 2 mm was between 0.93 and 0.68, depending on the landmark. Unusually shaped and large palates generate the highest errors. There was no evidence for a difference in mean palatal shape estimated from manual compared to the automatic landmarking. The automatic landmarking reduces sample variation around the mean and reduces measurements of palatal size.

CONCLUSIONS

The automatic landmarking method shows excellent repeatability and promising accuracy, which can streamline patient assessment and research studies. However, landmark indications should be subject to visual quality control.

Relationship between olfaction and maxillofacial morphology in children with malocclusion

OBJECTIVES

Functional problems, including nasal flow problems, are associated with specific skeletal and dental features. Further, maxillary expansion has been associated with nasal airway resistance alterations. This study aimed to investigate whether there is a correlation between skeletal features and nasal airflow- and olfaction-related problems.

MATERIALS AND METHODS

This prospective study included 68 patients (30 boys, 38 girls; mean age 9 ± 2 years) examined at the Ohu University Hospital. We classified patients into three skeletal Classes (Class I, II, and III) based on the ANB angle. Olfactory disorder history was collected from the guardians. Maxillofacial measurements, nasal airflow assessments, and olfactory tests were performed using cephalometric analysis, rhinomanometry, and T&T olfactometer, respectively.

RESULTS

Malocclusion, resulting from skeletal mandibular protrusion and smaller maxilla, was associated with reduced olfaction in children. The detection and recognition thresholds of skeletal Class III were significantly higher than those of Classes I (p = .01) and II (p = .01). Significant correlations were observed between SNA and the detection threshold (r = -.50) as well as between nasion perpendicular-point A and the recognition threshold (r = -.53). The detection and recognition thresholds were significantly higher in Class III than in Classes I (r = .3) and II (r = -.1).

CONCLUSIONS

Maxillary growth and development may be associated with olfaction in children. Changing the maxillofacial morphology may improve olfactory function. In the future, we will investigate how malocclusion treatment affects olfactory function.

The role of pediatric maxillary expansion on nasal breathing. A systematic review and metanalysis

OBJECTIVE

A reduced transversal dimension of the maxilla leads to narrower nasal cavities, which may reduce airflow to the lungs. Maxillary expansion widens nasal floor. However, there is huge controversy regarding whether this increase does actually lead to increased airflow. In this systematic review and meta-analysis we aim to resolve this question by evaluating studies that have undertaken rhinomanometric measurements.

REVIEW METHODS

Pubmed (Medline), the Cochrane Library, EMBASE and Trip Database were checked by two authors. Two authors extracted the data. Main outcome was expressed as the difference between resistance before and after treatment and the 95% confidence interval.

RESULTS

30 studies were selected for full text reading. A total of 12 studies (301 patients) met the inclusion criteria. All selected articles found reduced resistance after palatal expansion. The data pooled in the meta-analysis reveals a statistically significant difference of 0.12 Pa s/cm³ mean reduction after palatal expansion (CI 95% 0.06, 0.18) for nine uncontrolled studies. Regarding nasal airflow, the pooled data show a statistically significant difference of 29.9 cm³/s increase after palatal expansion (CI 95% 9.17, 50.64).

CONCLUSION

According to the available evidence, palatal expansion in pediatric patients decreases nasal resistance and increases nasal flow.

Preliminary comparison of three-dimensional reconstructed palatal morphology in subjects with different sagittal and vertical patterns

Background

The aim of this study was to assess the difference of palatal morphology in different vertical patterns between skeletal Class I subjects and skeletal Class II subjects with retrusive mandible.

Methods

Seventy-six skeletal Class II subjects with retrusive mandible (38 females, 38 males) and 85 skeletal Class I subjects (45 females, 40 males) were collected retrospectively and divided into hyperdivergent, normodivergent and hypodivergent groups. CBCT images of these subjects were reoriented by Dolphin 3D Imaging software. Three-dimensional (3D) maxilla was segmented by ProPlan software before using Geomagic Studio software to reconstruct 3D palatal morphology. Deviation patterns on 3D colored map analysis was performed to compare the difference of 3D palatal morphology between different groups.

Results

3D colored map analysis showed that male’s palate was higher and wider than that of female in the posterior part, regardless of different sagittal and vertical patterns. In skeletal Class II subjects with retrusive mandible, males with hyperdivergent and normodivergent showed higher and narrower in the posterior part of palate, while females with hyperdivergent and normodivergent had a higher but no obviously narrow palate compared with the hypodivergent subjects. Skeletal Class II subjects with retrusive mandible showed flatter and narrower in the posterior part of palate than that of skeletal Class I subjects.

Conclusions

Sagittal and vertical patterns have great influence on the palatal morphology and as the vertical dimension increased, the palate tended to be higher and narrower.

[Three-dimensional morphological analysis of the palate of mouth-breathing children in mixed dentition]

OBJECTIVE

To study the effects of mouth-breathing on maxillary arch development by comparing the palatal morphology of mouth- and nose-breathing children in mixed dentition.

METHODS

Children in mixed dentition were enrolled and categorized into mouth-breathing (test group) and nose-breathing groups (control group) according to their breathing patterns. Children's plaster models were scanned with 3D laser scanner, and the 3D data were reconstructed and measured using Minics 15.0 and Geomagic 12.0 software. Measurement data (inter-molar width, palatal height, palatal volume, and palatal surface area) of the two groups were compared, and the correlation among the four measurement items was analyzed.

RESULTS

The participants were 73 children (37 in test group and 36 in control group) with a mean age of (8.63±0.78) years old. The test group had significantly smaller inter-molar width, palatal volume, and palatal surface area but significantly higher palatal height than the control group (P<0.05). Inter-molar width and palatal volume were positively correlated with the palatal surface area in the test group (P<0.05). Inter-molar width and palatal height were positively correlated with the palatal surface area in the control group (P<0.01).

CONCLUSIONS

Mouth-breathing children have significantly reduced inter-molar width, palatal volume, and surface, and substantially increased palatal height, leading to different developmental patterns of the palatal morphology.

Palatal morphology in unilateral cleft lip and palate patients: Association with infant cleft dimensions and timing of hard palate repair

OBJECTIVES

To assess the impact of cleft severity and timing of hard palate repair on palatal dimensions in unilateral cleft lip and palate (UCLP) children.

SETTING AND SAMPLE POPULATION

Single-centre analysis within a multicenter RCT of primary surgery; 122 UCLP randomized to early hard palate closure (EHPC) at 12 months or delayed hard palate closure (DHPC) at 36 months; 28 frequency-matched controls.

METHODS

Linear measurements of palatal height, width and length were performed on 116 digital models of UCLP subjects (8.21 years, SD = 0.53) and 28 models of non-cleft individuals (8.44 years SD = 0.72). Cleft dimensions at infancy (mean 1.8 months) were considered. In a pilot study, shell-to-shell distances between the 3D cleft palate objects and a reference mesh were calculated and differences between the groups assessed. Morphological differences were visualized using colour mapping.

RESULTS

Compared to controls, UCLP subjects presented a higher palate at the level of the anterior scar (P = 0.002), but generally a lower palate in the middle region (P < 0.001). Comparing UCLP subgroups, the DHPC subjects showed a flatter palate posteriorly (P = 0.048) and the EHPC group exhibited more transversal constriction (P = 0.003 at M1 level). 3D analysis revealed a shallower palate in the DHPC group both in the middle (P = 0.002) and the posterior part (P = 0.008). Anterior cleft severity correlated negatively with palatal height (P = 0.01).

CONCLUSIONS

Unilateral cleft lip and palate palates differ from controls in width and height. DHPC may represent an advantage for the transversal dimension, but a disadvantage for palatal height. Infant cleft dimensions partially explain differences in palatal height.

Deviations in palatal region between indirect and direct digital models: an in vivo study

Background

Studies focusing on accuracy of intraoral digital models in the palatal region are scarce. The present study aimed to investigate the influence of different scanning sequences on palatal trueness and to assess deviation and distribution character of trueness in palate.

Methods

Overall, 35 participants accepted three types of procedures to acquire upper digital models. Indirect models digitalised from plaster models were considered as the reference. Two direct digital models were acquired using TRIOS 3 POD intraoral scanners, namely Groups Tr1 and Tr2, wherein intraoral scanning differed in terms of palatal scanning sequences. Based on a modified dental-level superimposition method, 3D measurements of trueness in palate and palatal vault region (PVR) for palatal stable regional superimposition in Groups Tr1 and Tr2, respectively, were performed. Absolute deviations were measured for trueness, while signed deviations were analysed for shape distortion. Colour-coded maps were used for quantitative analysis of deviation distribution pattern. Paired t test was used to analyse differences in palatal trueness between different scanning sequences. One-way repeated-measures analysis of variance and Bonferroni test were used to compare trueness measurements among different superimposition methods. Intraclass correlation coefficient (ICC) was used to verify reproducibility of the proposed method.

Results

Palatal trueness in Group Tr1 (118.59 ± 37.67 μm) was slightly less accurate than that (108.25 ± 33.83 μm) in Group Tr2 (p = 0.012 < 0.05). Trueness of PVR in Groups Tr1 (127.35 ± 54.11 μm) and Tr2 (118.17 ± 49.52 μm) did not differ significantly (p = 0.149). Moreover, no significant difference was noted in distortion of the palatal region and PVR in Groups Tr1 and Tr2 (p = 0.582 and 0.615, respectively). A similar pattern of palatal trueness was noted in a majority of participants (22/35). For 3D palatal trueness measurement, there were different applications for different superimposition methods. ICC for the proposed method was > 0.90.

Conclusions

Scanning sequences can affect palatal trueness. Palatal scanning should be initiated at the palatal side of the posterior teeth where the initial scan begins. For 3D PVR superimposition, distal boundary of the selected region should be adjusted mesially whilst referring to intraoral digital models.

Trial registration

The trial has been registered (registration No: R000039467, Trial ID: UMIN000034617, date of registration: 2018/10/24‘retrospectively registered’).

Effects of maxillary expansion on the upper airways: Evidence from systematic reviews and meta-analyses

BACKGROUND

Constricted maxilla is frequently associated with reduced nasal airway dimensions. Wheatear skeletal maxillary expansion (ME) is effective on the dimension of the upper airways is still a debated issue.

OBJECTIVES

This overview aimed to report the evidence provided by systematic reviews (SRs) on the effect of ME on the upper airways and to assess the methodological quality of the included SRs.

METHODS

Six electronic databases have been explored up to November 2017. After title and abstract screening, SRs addressing the effects of fixed palatal expanders on the dimension and function of the nasal airways were included. The methodological quality of the included SRs was assessed using the updated version of A Measurement Tool to Assess Systematic Review (AMSTAR-2).

RESULTS

Eight SRs were included. The methodological quality of most of the included SRs ranged between low and critically low. One SR was rated of high quality. A significant increase in nasal linear dimensions was reported both in the short and long term, but supported by low-/critically low-quality SRs. The significant increase in nasal cavity volume was the only outcome supported by a high-quality SR Controversial results were found with regards to nasal function.

CONCLUSION

Whenever a constricted maxilla is present general dentists, paediatricians and ENTs should be familiar with the potential improvement provided by ME. However, due to the low/critically low quality of SRs supporting these results, ME cannot be indicated only for upper airways enhancement, but should be supported by an orthodontic indication.

Analysis of the relationship between the morphology of the palate and facial skeletal patterns in Class III malocclusion using structural equation modelling

INTRODUCTION

The present study investigated the relationship between facial skeletal patterns and morphology of the palate in adult patients with Class III malocclusion using structural equation modelling (SEM).

SETTING AND SAMPLE POPULATION

One hundred cone beam computed tomography images of Class III adults were evaluated for skeletal measurements.

MATERIALS AND METHODS

The skeletal measurements were classified into the vertical, anteroposterior and transverse group based on factor analysis. 3D scanning model of the maxilla was analysed by Generalized procrustes analysis (GPA) and principal component analysis (PCA). Structural equation modelling was used to analyse relationship among the skeletal and morphometric factors.

RESULTS

According to the factor analysis, latent variables were extracted by each skeletal variable. First principal component (PC1) and PC2 of palatal morphology were used to analyse relationship with skeletal variables. As results of the structural equation model, the transverse latent variable had the most influence on PC1, followed by vertical and anteroposterior variables. This result means that as the facial width increases, the palate becomes narrower, deeper and longer.

CONCLUSIONS

The relationship between the skeletal pattern with Class III malocclusion and palatal morphology was analysed through SEM. The transverse facial skeletal pattern showed the highest correlation with PC1 of palatal morphology.

Volumetric measurement of dentoalveolar defects by means of intraoral 3D scanner and gravimetric model

The aim of this study was to evaluate the accuracy in volumetric measurements obtained on an experimental model using an intraoral scanner and a gravimetric method. Three identical partial dentate maxillary acrylic models with three fabricated alveolar defects, in anterior and posterior regions, were scanned using an intraoral scanner (20 scans/defects). The defects differed in terms of size and distance of neighbouring teeth. As references, replicas of each defect were created using a dimensional stable silicone impression material. After measuring the mass of each replica, the volume was calculated by dividing the mass of each replica by the density of the impression material. The defects had a volume, according to the gravimetric method, ranging from 40.5 to 143.7 mm³. The scans were imported to metrology software for analyses. Accuracy was determined in terms of trueness and precision. The mean trueness for all defect types was 0.168 mm³ (SD 0.691, range 2.82). There was no statistical significant difference between the mean trueness for all defects measured (p = 0.910). The mean precision for all defect types was 0.147 mm³ (SD 0.524, range 2.86). There were no statistical significant differences between the dental models in regard to mean precision (p = 0.401), however, there were statistical significant differences between defects in position 1 and 2 (p = 0.002) and 1 and 3 (p = 0.001). Based on the findings of this study, the intraoral scanner utilized in the current study presented an acceptable level of accuracy when measuring volume of defects.

Morphometric covariation between palatal shape and skeletal pattern in children and adolescents: a cross-sectional study

Objective

To assess shape covariation of the palate and craniofacial complex (CFC) in children and adolescents.

Methods

Pre-treatment lateral cephalometric radiographs and corresponding maxillary casts of 100 children (8-10 years) and 100 adolescents (15-20 years) were digitized. Exclusion criteria were previous orthodontic treatment, craniofacial syndromes, mouth breathing, finger sucking, crossbite, tooth agenesis, and tooth impaction. Palatal shape was described with 239 surface and curve semilandmarks and craniofacial shape with 10 fixed landmarks and 117 curve semilandmarks. Procrustes superimposition and principal component analysis were applied for evaluation of shape variability. Shape covariation between palate and CFC was assessed with partial least squares analysis.

Results

The first five principal components explained 77 per cent (palate) and 60 per cent (CFC) of total shape variability. The palate varied mainly in height (adolescent group) and width-length (both groups), whereas the CFC varied mainly in the vertical dimension. Significant covariation was found between the craniofacial and palatal components (RV coefficient: 0.27, children; RV: 0.23, adolescents). Variation of the CFC in the vertical and anteroposterior direction was mainly related to variation in the height-width and the width-length ratio of the palate, respectively.

Limitations

The use of lateral cephalometric radiographs eliminated the transverse dimension from the craniofacial shape analysis. The study was cross-sectional, so the observed intergroup differences should be interpreted with caution.

Conclusions

Covariation strength and pattern were similar in children and adolescents. The closer a subject was to the high-angle end of the variability spectrum, the higher and narrower was the palate, and conversely.

Obstructive sleep apnea in children with Marfan syndrome: Relationships between three-dimensional palatal morphology and apnea-hypopnea index

OBJECTIVE

To evaluate the relationship between the severity degree of OSA (apnea/hypopnea index AHI>1) and palatal area and volume, measured by 3D analysis of digital casts in Marfan children.

METHODS

Twenty children with a clinical diagnosis of MS were recruited from a tertiary medical center. All the subjects underwent standard nocturnal polygraphy testing. Sixteen Marfan patients (7F,9 M; mean age 8.8yy ± 1.5yy) with AHI>1 were enrolled. Marfan Group (MG) was compared with a control group (CG) of 17 children without Marfan syndrome (9F,8 M; mean age 8.5yy ± 1.7yy) presenting with nose-breathing pattern. For each subject maxillary digital casts were taken and palatal area and volume were measured. Unpaired t-test was used to test significant differences between MG and CG for area and volume measurements. Pearson correlation coefficient (PCC) was used to measure the linear correlation between the degree of OSA (AHI index) and palatal volume and palatal area.

RESULTS

80% of Marfan children presented an AHI>1 and a diagnosis of OSA. MG presented statistically significant lower values of palatal surface area (662.68 mm²; P < 0.0001) and palatal volume (2578.1 mm³; P < 0.0001) with respect to CG (923.0 mm² and 3756.6 mm³, respectively). Correlation analysis showed that AHI index had no linear correlation with palatal area (r = - 0,07) and with palatal volume (r = - 0,11).

CONCLUSION

OSA is highly prevalent in children with Marfan's syndrome (80%). Marfan children present a reduction of palatal area and volume when compared to healthy subjects. OSA in Marfan children is not linear correlated to the palatal morphology and it shows a multifactorial aetiology.

Three-dimensional morphological evaluation of the hard palate in Korean adults with mild-to-moderate obstructive sleep apnea

Objective

The purpose of this study was to evaluate differences in three-dimensional (3D) morphology of the hard palate between Korean adults with and without mild-to-moderate obstructive sleep apnea (OSA) using cone-beam computed tomographic (CBCT) data.

Methods

The protocol for the two-dimensional (2D) and 3D mathematical modeling was established by analyzing CBCT images of 30 adults with OSA and 30 matched controls without OSA, using MIMICS software. The linear and angular measurements were also determined using this software. The measurements were repeated for 30 palates, by the same operator, to assess reliability.

Results

The palates of OSA patients were higher in the posterior part and narrower in the anterior-superior part than those of the control group (p < 0.05). The nasal cavities of patients with OSA were narrower (p < 0.05) than those of controls. The increasing angle of the first molar palatal root is a compensation of the upper dental arch to improve occlusion. However, for most palatal measurements, there were no significant differences between the OSA and control groups (p > 0.05). The results of 2D and 3D mathematical models were consistent for linear and angular measurements, indicating that 2D and 3D mathematical modeling of the palate is a reliable methodology.

Conclusions

OSA is a multifactorial disease; the palates of adults with mild-to-moderate OSA do not have specific morphological features distinct from those of healthy controls.

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.

Palatal volume and area assessment on digital casts generated from cone-beam computed tomography scans

OBJECTIVES

The objective of this study was to develop a reproducible method to measure the change of palatal volume and area through superimposition using maxillary expansion digital cast models.

MATERIALS AND METHODS

A total of 10 pre- and 10 postexpansion dental cast models were scanned by the same cone-beam computed tomography machine. Superimposition was performed using a fully automated surface-best fit of the palatal surfaces on the digital cast models. A gingival plane, identified only once on superimposed casts, and a distal plane with the lateral closing border and the palatal surface were used to localize this selection of air. Area and volume were calculated for pre- and postexpansion records. Pre- and postexpansion palatal volume and area were measured by the main investigator and three different observers for inter- and intra-observer reproducibility assessment.

RESULTS

The level of intra- and inter-observer agreement was very strong (intraclass correlation coefficients ≥ 0.953; P value < .0001) for all measurements.

CONCLUSIONS

Palatal volume and area measurements based on the proposed superimposition are reproducible and can be used reliably.

Non-surgical treatment of transverse deficiency in adults using Microimplant-assisted Rapid Palatal Expansion (MARPE)

INTRODUCTION

Maxillary transverse deficiency is a highly prevalent malocclusion present in all age groups, from primary to permanent dentition. If not treated on time, it can aggravate and evolve to a more complex malocclusion, hindering facial growth and development. Aside from the occlusal consequences, the deficiency can bring about serious respiratory problems as well, due to the consequent nasal constriction usually associated. In growing patients, this condition can be easily handled with a conventional rapid palatal expansion. However, mature patients are frequently subjected to a more invasive procedure, the surgically-assisted rapid palatal expansion (SARPE). More recently, researches have demonstrated that it is possible to expand the maxilla in grown patients without performing osteotomies, but using microimplants anchorage instead. This novel technique is called microimplant-assisted rapid palatal expansion (MARPE).

OBJECTIVE

The aim of the present article was to demonstrate and discuss a MARPE technique developed by Dr. Won Moon and colleagues at University of California - Los Angeles (UCLA).

METHODS

All laboratory and clinical steps needed for its correct execution are thoroughly described. For better comprehension, a mature patient case is reported, detailing all the treatment progress and results obtained.

CONCLUSION

It was concluded that the demonstrated technique could be an interesting alternative to SARPE in the majority of non-growing patients with maxillary transverse deficiency. The present patient showed important occlusal and respiratory benefits following the procedure, without requiring any surgical intervention.

Measuring 3D shape in orthodontics through geometric morphometrics

Background

Geometric morphometrics (GMM) has been traditionally applied to the field of biology to study developmental differentiations between species. Orthodontics deals with the shape and size of the face and its components. While several tools have been used to measure size, proportions, and relations between anatomical components, shape has been mainly described by esthetic criteria. The purpose of this paper is to present methods to measure shape of 3D orthodontic data, beyond the conventional tools that have been traditionally used in cephalometrics and in facial and dental cast analysis.

Findings

The authors showcase an example of applying geometric morphometrics to measure palates from scanned dental casts. GMM can be used as a useful tool to describe the three-dimensional shape of surfaces of orthodontic interest. A general introduction to the theoretical principles of how to apply GMM is provided.

Conclusions

Variability can be measured through the Principal Component Analysis (PCA) and can lead to the identification of shape patterns and sources of variability of the shape, independently from changes in size.

Correlation between acoustic rhinometry, computed rhinomanometry and cone-beam computed tomography in mouth breathers with transverse maxillary deficiency

INTRODUCTION

To provide clinical information and diagnosis in mouth breathers with transverse maxillary deficiency with posterior crossbite, numerous exams can be performed; however, the correlation among these exams remains unclear.

OBJECTIVE

To evaluate the correlation between acoustic rhinometry, computed rhinomanometry, and cone-beam computed tomography in mouth breathers with transverse maxillary deficiency.

METHODS

A cross-sectional study was conducted in 30 mouth breathers with transverse maxillary deficiency (7-13 y.o.) patients with posterior crossbite. The examinations assessed: (i) acoustic rhinometry: nasal volumes (0-5cm and 2-5cm) and minimum cross-sectional areas 1 and 2 of nasal cavity; (ii) computed rhinomanometry: flow and average inspiratory and expiratory resistance; (iii) cone-beam computed tomography: coronal section on the head of inferior turbinate (Widths 1 and 2), middle turbinate (Widths 3 and 4) and maxilla levels (Width 5). Acoustic rhinometry and computed rhinomanometry were evaluated before and after administration of vasoconstrictor. Results were compared by Spearman's correlation and Mann-Whitney tests (α=0.05).

RESULTS

Positive correlations were observed between: (i) flow evaluated before administration of vasoconstrictor and Width 4 (Rho=0.380) and Width 5 (Rho=0.371); (ii) Width 2 and minimum cross-sectional areas 1 evaluated before administration of vasoconstrictor (Rho=0.380); (iii) flow evaluated before administration of vasoconstrictor and nasal volumes of 0-5cm (Rho=0.421), nasal volumes of 2-5cm (Rho=0.393) and minimum cross-sectional areas 1 (Rho=0.375); (iv) Width 4 and nasal volumes of 0-5cm evaluated before administration of vasoconstrictor (Rho=0.376), nasal volumes of 2-5cm evaluated before administration of vasoconstrictor (Rho=0.376), minimum cross-sectional areas 1 evaluated before administration of vasoconstrictor (Rho=0.410) and minimum cross-sectional areas 1 after administration of vasoconstrictor (Rho=0.426); (v) Width 5 and Width 1 (Rho=0.542), Width 2 (Rho=0.411), and Width 4 (Rho=0.429). Negative correlations were observed between: (i) Width 4 and average inspiratory resistance (Rho=-0.385); (ii) average inspiratory resistance evaluated before administration of vasoconstrictor and nasal volumes of 0-5cm (Rho=-0.382), and average expiratory resistance evaluated before administration of vasoconstrictor and minimum cross-sectional areas 1 (Rho=-0.362).

CONCLUSION

There were correlations between acoustic rhinometry, computed rhinomanometry, and cone-beam computed tomography in mouth breathers with transverse maxillary deficiency.

Three-dimensional analyses of palatal morphology and its relation to upper airway area in obstructive sleep apnea

OBJECTIVE

To evaluate the relationship between palatal morphology and pharyngeal airway morphology in patients who have obstructive sleep apnea (OSA) and compare with a nonsnoring and nonapneic control group.

MATERIALS AND METHODS

Three-dimensional maxillary dental cast measurements from 25 OSA patients (6 women, 19 men) with a mean age of 41.5 (4.8) years, and 25 control group participants (14 women, 11 men) without any symptom of OSA with a mean age of 38.3 (3.7) were correlated with an analysis of pharyngeal area evaluated with lateral cephalograms. Intermolar and intercanine widths and palatal volumes were calculated on the dental casts, and the upper airway area measurements were performed on lateral cephalograms.

RESULTS

OSA patients had smaller oropharyngeal volume and upper airway when compared with controls (P < .001). Palatal area measurements were significantly smaller in OSA (P < .001). OSA patients had significantly narrower maxilla with smaller intermolar and intercanine widths (P < .001). A positive correlation was found between the palatal morphology and pharyngeal dimensions.

CONCLUSIONS

A significant correlation exists between palatal morphology and pharyngeal airway.

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.

The role of rapid maxillary expansion in the promotion of oral and general health

Rapid maxillary expansion (RME) is an effective orthopedic procedure that can be used to address problems concerned with the growth of the midface. This procedure also may produce positive side effects on the general health of the patient. The aim of the present consensus paper was to identify and evaluate studies on the changes in airway dimensions and muscular function produced by RME in growing patients. A total of 331 references were retrieved from a database search (PubMed). The widening of the nasal cavity base after midpalatal suture opening in growing patients allows the reduction in nasal airway resistance with an improvement of the respiratory pattern. The effects of RME on the upper airway, however, have been described as limited and local, and these effects become diminished farther down the airway, possibly as a result of soft-tissue adaptation. Moreover, limited information is available about the long-term stability of the airway changes produced by RME. Several studies have shown that maxillary constriction may play a role in the etiology of more severe breathing disorders such as obstructive sleep apnea (OSA) in growing subjects. Early orthodontic treatment with RME is able to reduce the symptoms of OSA and improve polysomnographic variables. Finally, early orthopedic treatment with RME also is beneficial to avoid the development of facial skeletal asymmetry resulting from functional crossbites that otherwise may lead to functional and structural disorders of the stomatognathic system later in life.