Effects of adenoid hypertrophy on nasopharyngeal airway ventilation: A computational fluid dynamics study.

Objectives: Adenoid hypertrophy causes impaired nasopharyngeal airways (NA) ventilation. However, it is difficult to evaluate the ventilatory conditions of NA. Therefore, this study aimed to analyze the nasopharyngeal airway resistance (NA) based on computational fluid dynamics simulations and the nasopharyngeal airway depth (NA) and adenoid hypertrophy grade measured on cephalometric cone-beam computed tomography images and determine the relationship between NA and grade and NA to ultimately assess using cephalometric measurements whether NA has airway obstruction defects.

Does rapid maxillary expansion improve nasal airway obstruction? A computer fluid dynamics study in patients with nasal mucosa hypertrophy and obstructive adenoids.

Introduction: Rapid maxillary expansion (RME) expands the maxillary dentition laterally and improves nasal airway obstruction. However, the incidence of nasal airway obstruction improvement after RME is approximately 60%. This study aimed to clarify the beneficial effects of RME on nasal airway obstruction in specific pathologic nasal airway diseases (nasal mucosa hypertrophy and obstructive adenoids) using computer fluid dynamics.

A three-dimensional cephalometric analysis of Japanese adults and its usefulness in orthognathic surgery: A retrospective study.

This study aimed to establish a three-dimensional (3D) cephalometric analysis of craniofacial morphology and discuss its theoretical usefulness in orthognathic patients. Cone-beam computed tomography (CBCT) images of Japanese subjects with skeletal Class I malocclusion before treatment were selected from among 1000 patients so that samples matched a historic 2D cephalometric cohort with normal occlusion using propensity score matching. In each CBCT image, 67 3D measurements were calculated based on manually identified landmarks.

Age-related changes in the effect of rapid maxillary expansion on the position of labially impacted maxillary canines: A case-control study.

Introduction: The early diagnosis and interception of potential maxillary canine impaction is the most desirable approach for correcting their path of eruption. However, there is still a lack of evidence regarding the effect of rapid maxillary expansion (RME) on labially impacted canines. This study aimed to investigate the age-related effect of RME on labially impacted maxillary canines in order to reduce the risk of their impaction in the mixed dentition and to examine the proper timing of interceptive treatment.

Upper airway in children with unilateral cleft lip and palate evaluated with computational fluid dynamics.

Introduction: Children with unilateral cleft lip and palate (UCLP) exhibit snoring and mouth breathing. They are also reported to show obstructive sleep apnea syndrome. However, their upper airway ventilation condition is not clearly understood.

Rapid maxillary expansion effects of nasal airway in children with cleft lip and palate using computational fluid dynamics.

Objectives: Rapid maxillary expansion (RME) improves nasal airway ventilation in non-cleft palate children. Children with unilateral cleft lip and palate (UCLP) may have nasal obstruction and experience an increased risk of obstructive sleep apnoea. The effect of RME in UCLP children is unclear.

Relationships among tongue volume, hyoid position, airway volume and maxillofacial form in paediatric patients with Class-I, Class-II and Class-III malocclusions.

Objectives: To clarify the associations among tongue volume, hyoid position, airway volume and maxillofacial form using cone beam computed tomography (CBCT) data for children with Class-I, Class-II and Class-III malocclusion.

Setting And Sample Population: Sixty children (mean age, 9.2 years) divided into Class-I, Class-II and Class-III malocclusion groups according to the A-nasion-B angle.

Relationships among nasal resistance, adenoids, tonsils, and tongue posture and maxillofacial form in Class II and Class III children.

Introduction: The purpose of this study was to clarify the relationships between upper airway factors (nasal resistance, adenoids, tonsils, and tongue posture) and maxillofacial forms in Class II and III children.

Methods: Sixty-four subjects (mean age, 9.3 years) with malocclusion were divided into Class II and Class III groups by ANB angles.

Herbst appliance effects on pharyngeal airway ventilation evaluated using computational fluid dynamics.

Objective: To evaluate the effect of a Herbst appliance on ventilation of the pharyngeal airway (PA) using computational fluid dynamics (CFD).

Materials And Methods: Twenty-one Class II patients (10 boys; mean age, 11.7 years) who required Herbst therapy with edgewise treatment underwent cone-beam computed tomography (CBCT) before and after treatment.

Three-dimensional cone-beam computed tomography analysis of enlargement of the pharyngeal airway by the Herbst appliance.

Introduction: Pharyngeal airway size is increasingly recognized as an important factor in obstructive sleep apnea. However, few studies have examined the changes of pharyngeal airway form after dental procedures for treating obstructive sleep apnea during growth. The purpose of this study was to evaluate the effect of the Herbst appliance on the 3-dimensional form of the pharyngeal airway using cone-beam computed tomography.

The effect of rapid maxillary expansion on pharyngeal airway pressure during inspiration evaluated using computational fluid dynamics.

Introduction: Recent evidence suggests that rapid maxillary expansion (RME) is an effective treatment of obstructive sleep apnea syndrome (OSAS) in children with maxillary constriction. Nonetheless, the effect of RME on pharyngeal airway pressure during inspiration is not clear. The purpose of this retrospective study was to evaluate changes induced by the RME in ventilation conditions using computational fluid dynamics.

CBCT of skeletal changes following rapid maxillary expansion to increase arch-length with a development-dependent bonded or banded appliance.

Objective: To assess the three-dimensional (3D) skeletal response to a standardized 5 mm of rapid maxillary expansion (RME) in growing children (6-15 years) with maxillary width deficiency and crowding.

Materials And Methods: A bonded appliance was used prior to the eruption of the maxillary first premolars (Mx4s), and a banded appliance was used thereafter. A consecutive sample of 89 patients (29 boys and 60 girls) from a large pediatric dentistry and orthodontics practice was divided into four groups: 1) 6-8 years old (n = 26), 2) 9-11 years old with unerupted Mx4s (n = 21), 3) 9-11 years with erupted Mx4s (n = 23), and 4) 12-15 years (n = 19).

Tongue posture improvement and pharyngeal airway enlargement as secondary effects of rapid maxillary expansion: a cone-beam computed tomography study.

Introduction: Rapid maxillary expansion (RME) is known to improve nasal airway ventilation. Recent evidence suggests that RME is an effective treatment for obstructive sleep apnea in children with maxillary constriction. However, the effect of RME on tongue posture and pharyngeal airway volume in children with nasal airway obstruction is not clear.

Three-dimensional analysis of the pharyngeal airway morphology in growing Japanese girls with and without cleft lip and palate.

Introduction: We evaluated the 3-dimensional craniofacial skeletal and pharyngeal airway morphology in growing patients with and without cleft lip and palate.

Methods: Our juvenile subjects consisted of 34 girls (ages, 9-12 years); 15 had cleft lip and palate, and 19 did not. The adolescent subjects consisted of 32 girls (ages, 13-17 years); 14 had cleft lip and palate, and 18 did not.

Improvement of nasal airway ventilation after rapid maxillary expansion evaluated with computational fluid dynamics.

Introduction: Rapid maxillary expansion is known to improve nasal airway ventilation. However, it is difficult to precisely evaluate this improvement with conventional methods. The purpose of this longitudinal study was to use computational fluid dynamics to estimate the effect of rapid maxillary expansion.

Evaluation of upper airway obstruction in Class II children with fluid-mechanical simulation.

Introduction: The purpose of this study was to test the null hypothesis that dolichofacial and brachyfacial children with Class II malocclusion do not differ in upper airway obstruction. Furthermore, the ability of fluid-mechanical simulation to detect airway obstruction within the limitations of simulation was examined.

Methods: Forty subjects from 7 to 11 years of age with Class II malocclusion participated and were divided into 2 groups, dolichofacial and brachyfacial, based on their Frankfort mandibular plane angles.

Pharyngeal airway in children with prognathism and normal occlusion.

Objective: To test the hypothesis that there is no difference in the pharyngeal airway width and the position of the maxillofacial skeleton between prognathic and normal children.

Materials And Methods: Twenty-five girls with prognathism (mean, 7.9 ± 0.

Oropharyngeal airway in children with Class III malocclusion evaluated by cone-beam computed tomography.

Introduction: Upper airway size is increasingly recognized as an important factor in malocclusion. However, children with Class III malocclusion are somewhat neglected compared with those with a Class II skeletal pattern. Therefore, the purpose of this study was to establish the characteristic shape of the oropharyngeal airway (OA) in children with Class III malocclusion.

Stabilization of a mobile premaxilla by cementing a bite splint with 1-stage bilateral alveolar bone grafting.

This study describes a method for stabilizing maxillary segments by performing bilateral alveolar bone grafting with an acrylic splint with a flat undersurface to reduce the occlusal pressure to the premaxilla. After premaxilla repositioning and bilateral alveolar bone grafting, the splint was attached to the maxillary teeth with glass ionomer cement. In 6 bilateral cleft cases, premaxilla repositioning and bilateral alveolar bone grafting were performed in 1-stage manner, and successful results were obtained.

Cephalometric superimposition on the occipital condyles as a longitudinal growth assessment reference: I-point and I-curve.

This retrospective study tests the hypothesis that superimposition referenced at the occipital condyles (defined as I-point, I-curve) and oriented to the anterior cranial base (ACB) will display a growth pattern that is more consistent with independent evaluations, such as the Melsen necropsy specimens and the Bjork implant studies, when compared with traditional superimpositions referenced at sella turcica. Twenty-eight sets of serial lateral cephalometric radiographs were selected from an archived growth study. The apparent facial growth was compared using polar coordinate analysis from superimposition tracings of the serial films for each subject.

Autotransplantation of 28 premolar donor teeth in 24 orthodontic patients.

Objective: To test the null hypothesis that premolar autotransplantation is not successful for orthodontic patients.

Materials And Methods: In the present study, 28 premolar transplants from 24 orthodontic patients were associated with orthodontic treatment. At a routine 3-month appointment, patients underwent a dental radiograph and a chair-side observation for periodontal problems.

Fronto-facial monobloc advancement with rigid external distraction (RED-II) system.

Fronto-facial monobloc advancement is one of the most rewarding procedures for upper and mid-face reconstruction in patients with craniosynostosis. However, it has challenging aspects. Epidural abscess and frontal bone necrosis after retrofrontal dead space is one of the major complications and has led many experienced surgeons not to continue with the procedure.