Comparision of orofacial airway dimensions in subject with different breathing pattern

Effect of SEC III protocol on upper airway dimensions in growing class III patients: a retrospective study

BACKGROUND

The primary objective of the study was to evaluate the effects of SEC III (Splints, Class III Elastics, and Chin cup) protocol on the upper airway dimensions using lateral cephalometric radiographs. The secondary objectives were to evaluate the skeletal and dental effects of the SEC III protocol using lateral cephalometric radiographs.

METHODS

The pre- and post-treatment lateral cephalometric radiographs of 24 patients treated using the SEC III protocol were used to address the aim of the study. Children in the pre-pubertal (CS-1 or CS-2) or circumpubertal (CS-3 or CS-4) skeletal maturation stage and having class III dentoskeletal malocclusion were included in the study. Patients with a history of previous orthodontic treatment, maxillofacial surgery or trauma, tonsillectomy, adenoidectomy, or craniofacial malformations were excluded. The pre-treatment and post-treatment lateral cephalometric radiographs were traced, then airway measurements, skeletal measurements, and dental measurements were performed. The results were analysed using paired samples t-test or Wilcoxon signed rank test according to the data normality.

RESULTS

Data of 6 males and 18 females were analysed (Mean age = 11.21 ± 1.02 years). Duration of active treatment was 5.75 ± 1.03 months. Treatment using SEC III protocol resulted in a significant increase in ANB angle (2.92 ± 1.50 degrees, p < 0.001) and Wits appraisal (3.31 ± 1.99 mm) (p < 0.001). The increase in the mandibular plane angle (0.75 ± 1.42 degrees, p = 0.02) and the maxillary length (2.29 ± 2.69 mm, p < 0.001) was statistically significant. Contrarily, the mandibular length did not change significantly (p = 0.10). The maxillary incisors were significantly proclined (4.38 ± 4.28 degrees; p < 0.001), while the mandibular incisors were significantly retroclined (-5.79 ± 6.21 degrees; p < 0.001) following treatment. The change in the nasopharyngeal airway and the retropalatal airway was not statistically significant. The middle and inferior pharyngeal space (retroglossal airway) significantly decreased by 1.33 ± 1.97 mm (p = 0.003) and 1.96 ± 2.48 mm (p = 0.001), respectively.

CONCLUSIONS

Early class III correction using SEC III protocol reduced the retroglossal airway dimensions but did not affect the nasopharyngeal and retropalatal airway dimensions. Correction of the class III dentoskeletal relationship was obtained through both skeletal and dental changes.

Association between the Obstructive Sleep Apnea and Cephalometric Parameters in Teenagers

BACKGROUND

OSA is a common problem in children and adolescents. Angle class II malocclusion, a tendency toward the vertical type of growth, causes a decrease in the volume of the oral air space, increasing the risk of OSAS. The aim of this study was to evaluate the relationship between cephalometric and OSA parameters, to develop collaborative approaches between orthodontists and somnologists in the treatment of adolescents with OSA.

METHODS

We analyzed data from 41 adolescents with OSA. Their mean age was 15.8 ± 1.08 years. Orthodontic and polysomnographic examinations of patients were conducted. Statistical analysis was performed in SPSS 19.0.0.

RESULTS

Most often in patients with distal occlusion, a violation of the harmony in the development of the dental system was observed. The sagittal incisive fissure, characteristic of a distal occlusion, was absent due to the palatal inclination of the upper incisors in 25 (60.98%) patients. The SNB was 79.4 ± 3.1°, indicating a distal position of the mandible relative to the anterior cranial base. The SNA exceeded the normal value, which is one of the prerequisites for mandibular retrognathia. The ANB angle was 4.3 ± 1.9°. Tonsillar hypertrophy affected 6 patients, 21 had adenoid hypertrophy, and 3 had both of them. Movements of the masticatory muscles during sleep were recorded in 22.0% of patients.

CONCLUSION

To improve the quality of diagnosis and treatment of OSA, a multidisciplinary approach is needed that will correct the processes of child growth and development.

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.

A New Method for Anterior Boundary Demarcation of the Nasopharynx in Three-Dimensional Analysis

ABSTRACT

Three-dimensional (3D) measurements of the upper airway have been extensively applied and researched, but the division of the airway is carried out in various ways, especially when demarcating the anterior boundary of the nasopharynx. The present study was to propose a new method based on the anatomical definition for the anterior boundary demarcation of the nasopharynx used in three-dimensional analysis. Twenty computed tomography scans (age 9.5 ± 2.5 years, 11 males, and 9 females) of head and neck were randomly selected and transferred to Materialism's interactive medical image control system 19.0 for segmentation of the nasopharynx. Precise localization of the reference points that determining the nasopharyngeal anterior and inferior boundaries was managed by recording their coordinates in the interface of the software. The area of the anterior and the inferior boundaries, and the volume of the nasopharynx were measured and repeated with a 2-week interval for the consistency test. Both the interobserver reliability as well as the intra-observer reliability were very high (intraclass correlation coefficients, 0.985-0.997). Paired t test showed no significant difference between the first and the second examinations. This new simple method proposed for demarcation of the nasopharyngeal anterior boundary was based on the innate anatomical boundary, which was statistically reliable, technically convenient, and clinically reasonable.

Differences of Craniofacial Characteristics in Oral Breathing and Pediatric Obstructive Sleep Apnea

BACKGROUND

Oral breathing (OB) was considered associated with specific craniofacial structures and same for pediatric obstructive sleep apnea (OSA). This study aimed to investigate the differences of craniofacial structures between OB and OSA.

METHODS

In this retrospective study, 317 children under age 18 years were recruited and divided into OB group, OSA group, and control group. OSA group (15 boys, 4 girls) were referred from qualified sleep center and diagnosed as pediatric OSA with full-night polysomnography. OB group (10 boys, 10 girls) were mostly referral from pediatric or ENT department, some of whom undertook polysomnography and were not OSA. Control group consisted of orthodontic patients within the same period. Lateral cephalograms were obtained in all groups and their parameters were compared with Chinese normal values and each other.

RESULTS

R-PNS of OB group (18.04 ± 2.49 mm) was greater than OSA group (14.27 ± 4.36 mm) and even control group (16.22 ± 3.91 mm) (P < 0.01). U1-NA was also the greatest in OB group (7.15 ± 2.92 mm), followed by OSA group (4.88 ± 2.66 mm), while control group was the smallest (5.71 ± 2.94 mm) (P < 0.05). In addition, OB group presented the smallest adenoids and tonsils among three groups. Bony nasopharynx development, mandibular length and growth direction of mandible of OB group were all better than OSA group.

CONCLUSION

Despite of oral breathing, anatomical morphology (well-developed dentoalveolar structures; mild adenotonsillar hypertrophy) might protect children from developing OSA.

A new segmentation algorithm for measuring CBCT images of nasal airway: a pilot study

Background

Three-dimensional (3D) modeling of the nasal airway space is becoming increasingly important for assessment in breathing disorders. Processing cone beam computed tomography (CBCT) scans of this region is complicated, however, by the intricate anatomy of the sinuses compared to the simpler nasopharynx. A gold standard for these measures also is lacking. Previous work has shown that software programs can vary in accuracy and reproducibility outcomes of these measurements. This study reports the reproducibility and accuracy of an algorithm, airway segmentor (AS), designed for nasal airway space analysis using a 3D printed anthropomorphic nasal airway model.

Methods

To test reproducibility, two examiners independently used AS to edit and segment 10 nasal airway CBCT scans. The intra- and inter-examiner reproducibility of the nasal airway volume was evaluated using paired t-tests and intraclass correlation coefficients. For accuracy testing, the CBCT data for pairs of nasal cavities were 3D printed to form hollow shell models. The water-equivalent method was used to calculate the inner volume as the gold standard, and the models were then embedded into a dry human skull as a phantom and subjected to CBCT. AS, along with the software programs MIMICS 19.0 and INVIVO 5, was applied to calculate the inner volume of the models from the CBCT scan of the phantom. The accuracy was reported as a percentage of the gold standard.

Results

The intra-examiner reproducibility was high, and the inter-examiner reproducibility was clinically acceptable. AS and MIMICS presented accurate volume calculations, while INVIVO 5 significantly overestimated the mockup of the nasal airway volume.

Conclusion

With the aid of a 3D printing technique, the new algorithm AS was found to be a clinically reliable and accurate tool for the segmentation and reconstruction of the nasal airway space.

A new methodology for automatic detection of reference points in 3D cephalometry: A pilot study

OBJECTIVE

The aim of this study was to develop a new method for an automatic detection of reference points in 3D cephalometry to overcome the limits of 2D cephalometric analyses.

MATERIALS AND METHODS

A specific application was designed using the C++ language for automatic and manual identification of 21 (reference) points on the craniofacial structures. Our algorithm is based on the implementation of an anatomical and geometrical network adapted to the craniofacial structure. This network was constructed based on the anatomical knowledge of the 3D cephalometric (reference) points.

RESULTS

The proposed algorithm was tested on five CBCT images. The proposed approach for the automatic 3D cephalometric identification was able to detect 21 points with a mean error of 2.32mm.

DISCUSSION

In this pilot study, we propose an automated methodology for the identification of the 3D cephalometric (reference) points. A larger sample will be implemented in the future to assess the method validity and reliability.

The 3D Tele Motion Tracking for the Orthodontic Facial Analysis

Aim. This study aimed to evaluate the reliability of 3D-TMT, previously used only for dynamic testing, in a static cephalometric evaluation. Material and Method. A group of 40 patients (20 males and 20 females; mean age 14.2 ± 1.2 years; 12–18 years old) was included in the study. The measurements obtained by the 3D-TMT cephalometric analysis with a conventional frontal cephalometric analysis were compared for each subject. Nine passive markers reflectors were positioned on the face skin for the detection of the profile of the patient. Through the acquisition of these points, corresponding plans for three-dimensional posterior-anterior cephalometric analysis were found. Results. The cephalometric results carried out with 3D-TMT and with traditional posterior-anterior cephalometric analysis showed the 3D-TMT system values are slightly higher than the values measured on radiographs but statistically significant; nevertheless their correlation is very high. Conclusion. The recorded values obtained using the 3D-TMT analysis were correlated to cephalometric analysis, with small but statistically significant differences. The Dahlberg errors resulted to be always lower than the mean difference between the 2D and 3D measurements. A clinician should use, during the clinical monitoring of a patient, always the same method, to avoid comparing different millimeter magnitudes.

A retrospective cephalometric study on pharyngeal airway space changes after rapid palatal expansion and Herbst appliance with or without skeletal anchorage

Background

The aim of this study is to investigate the pharyngeal airway space changes in patients treated with rapid palatal expansion (RPE) and Herbst appliance with or without skeletal anchorage.

Methods

A 40-patient study group treated with the Herbst RME combination was included; moreover, a comparison between two subgroups based on whether miniscrews were used was evaluated. A subgroup 1 included 20 patients who were treated with RPE and an acrylic splint Herbst with miniscrews, and subgroup 2 included 20 patients who were treated with RPE and an acrylic splint Herbst. A cephalometric analysis was performed before (T1) and after (T2) treatment. The skeletal parameters of the sagittal occlusion analysis of Pancherz were utilized together with some extra measurements to evaluate the airways.

Results

An increased nasopharyngeal airway space was observed in group 1 (p < 0.05) from T1 to T2. Furthermore, the increase in nasopharyngeal airway space was significantly higher in subgroup 1 (p < 0.05) in comparison to the subgroup 2. Oropharyngeal (OA) and laryngopharyngeal (LA) dimensions were significantly increased in the subgroup 1 at the end of the treatment. In the subgroup 1, a significant decrease in SNA, a significant increase in SNB, and a significant decrease in ANB were observed from T1 to T2. In the subgroup 2, the treatment resulted in a significant decrease in ANB. In both groups, Pogonion increased significantly from T1 to T2.

Conclusions

The results suggest that the RPE and the Herbst appliance allow a slight improvement of the sagittal dimensions of the airways. The oropharyngeal dimension increased significantly more in the skeletal anchorage group.

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.

Dentofacial characteristics of oral breathers in different ages: a retrospective case-control study

BACKGROUND

This study aimed to investigate the dental and skeletal variables associated with disturbances of craniofacial development in oral-breathing (OB) individuals and the probability that these variables are related to this condition.

METHODS

This is an observational retrospective case-control study of 1596 patients divided into three groups of age n1 5-12, n2 13-18, and n3 19-57 years. Radiographic, clinical, and models data were analyzed. The control group was consisted of nasal breathing (NB) individuals. Statistical analyses of the qualitative data were performed with x (2) test to identify associations, and odds ratio (OR) tests were performed for the variables that the chi-square test (x (2)) identified an association.

RESULTS

In the descriptive analysis of the data, we observed that the class II malocclusion was the most frequent in the total sample, but when divided by age group and mode of breathing, there is a random division of these variables. In n1 group, class II, (OR = 2.02) short and retruded mandible (SM and RM) (OR = 1.65 and1.89) were associated with OB and it was considered a risk factor. In n2 group, class II (OR = 1.73), SM (OR = 1.87) and increased lower anterior height (ILAFH) (OR = 1.84) seemed to be associated and to be risk factors for OB. In the n1 group, decreased lower anterior facial height (DLAFH) and brachycephalic facial pattern (BP) seemed to be associated with NB and a protective factor against oral breathing.

CONCLUSIONS

This study showed that dental and skeletal factors are associated with OB in children, and it seems that it becomes more severe until adolescence. But adults showed no associations between OB and skeletal factors, only in dental variables, indicating that there is no cause-effect relationship between the dental and skeletal factors and OB. The treatment of nose breathing patient should be multidisciplinary, since OB remains even when dental and skeletal factors slow down.

Relationships between Malocclusion, Body Posture, and Nasopharyngeal Pathology in Pre-Orthodontic Children

BACKGROUND

Malocclusion, body posture, and breathing pattern may be correlated, but this issue is still controversial. The aim of the study was to examine the relationship between the type of malocclusion, body posture, and nasopharyngeal obstruction in children aged 7-14 years.

MATERIAL AND METHODS

The study group comprised 94 patients aged 7-14 years (mean±SD: 11.9±2.1 years); 44 (46.8%) males and 50 (53.2%) females. All patients passed an examination performed by the same orthodontist (study model and cephalometric radiograph analysis), orthopedic surgeon (body posture examined from the front, side, and back), and otorhinolaryngologist (anterior and posterior rhinoscopy and pharyngoscopy) in a blind manner.

RESULTS

Postural disorders were observed in 72 (76.6%) patients. Hypertrophy of the adenoids was diagnosed in 54 (57.4%) patients, hypertrophy of the tonsils in 85 (90.3%), nasal septum deviation in 51 (54.3%), and allergic rhinitis in 19 (20.2%) patients. There was a statistically significant correlation between presence of kyphotic posture and a reduction in the SNB angle, representing sagittal position of the mandible. Also, there was a statistically significant association between kyphotic posture and nasopharyngeal obstruction (54.1% of patients with nasopharyngeal obstruction were kyphotic, compared with 25% of patients with no nasopharyngeal obstruction; p=0.02). Kyphotic posture and reduced SNB angle were more common among males.

CONCLUSIONS

We concluded that: 1) there was a significant association between the sagittal position of the mandible (SNB angle) and a kyphotic posture; 2) kyphotic posture was significantly more common among patients with nasopharyngeal obstruction.