Correlation between the three-dimensional hyoid bone parameters and pharyngeal airway dimensions in different sagittal and vertical malocclusions.

OBJECTIVE: This study aimed to explore the relationship between three-dimensional (3D) measurements of the hyoid bone (HB) and pharyngeal airway space (PAS) in relation to sagittal and vertical malocclusion. METHODS: A total of 368 cone-beam computed tomography (CBCT) scans were classified into three skeletal groups (Class I, II, and III) and subdivided by vertical growth patterns (hypodivergent, normodivergent, and hyperdivergent). PAS dimensions, including nasopharyngeal, oropharyngeal, hypopharyngeal, and total airway spaces, were measured in surface area, volume, minimum constricted area (MCA), length, and width, HB position and dimension were analyzed in 3D using InVivo 6.0.3 and Dolphin 11.8 software. Data were analyzed using two-way ANOVA, and Bonferroni post-hoc tests, with P ≤ 0.05 considered significant. RESULTS: The study found that patients with skeletal Class III and hypodivergent growth pattern had the highest sagittal position of the hyoid bone, while those with skeletal Class II and hyperdivergent pattern had the lowest hyoid length. Nasopharyngeal airway space width was significantly lower in skeletal Class III patients, while volume and area were lower in hyperdivergent patients. Oropharyngeal and hypopharyngeal dimensions were also affected by skeletal class and growth pattern, with hyperdivergent patients having the lowest values. Total pharyngeal volume, area, and minimum constricted area were also affected, with hyperdivergent patients having the lowest values and skeletal Class II patients having the lowest minimum constricted area. CONCLUSION: Pharyngeal airway dimensions and hyoid bone parameters vary with malocclusions. The hyoid bone's position influences the airway, identifying patients at risk for airway obstruction and sleep-disordered breathing.

Oral appliance therapy vs. positional therapy for managing positional obstructive sleep apnea; a systematic review and meta-analysis of randomized control trials.

AIM: To assess the efficacy of positional therapy and oral appliance therapy for the management of positional obstructive sleep apnea. METHODS: We searched PubMed, Web of Science, Cochrane, and SCOPUS for relevant clinical trials. Quality assessment of the included trials was evaluated according to Cochrane's risk of bias tool. We included the following outcomes: The apnea-hypopnea index (AHI), AHI non-supine, AHI supine, sleep efficiency, percentage of supine sleep, Adherence (≥ 4 h/night, ≥ 5 days/week), Oxygen desaturation Index, Arousal Index, Epworth Sleepiness Scale score (ESS), Mean SpO2, and Functional Outcomes of Sleep Questionnaire. RESULTS: The AHI non-supine and the ESS scores were significantly lower in the OAT cohort than in the PT cohort. The PT cohort was associated with a significantly decreased percentage of supine sleep than the OAT cohort (MD= -26.07 [-33.15, -19.00], P = 0.0001). There was no significant variation between PT cohort and OAT cohort regarding total AHI, AHI supine, ODI, sleep efficiency, arousal index, FOSQ, adherence, and mean SpO2. CONCLUSION: Both Positional Therapy and Oral Appliance Therapy effectively addressed Obstructive Sleep Apnea. However, Oral Appliance Therapy exhibited higher efficiency, leading to increased supine sleep percentage and more significant reductions in the Apnea Hypopnea Index during non-supine positions, as well as lower scores on the Epworth Sleepiness Scale.

Evaluation of maxillary sinus changes following molar distalization using clear aligners: A three-dimensional study.

OBJECTIVE: To evaluate the impact of molar distalization with clear aligners (CAs) on maxillary sinus parameters and its proximity to the root apices of maxillary molars using Cone Beam Computed Tomography (CBCT). METHODS: The study involved pre- and post-treatment CBCT images of 27 adult patients. MIMICS 21.0 software was used to measure maxillary sinus volume and surface area, while Invivo Dental 6.0 program was used to measure the sinus diameters and proximity of the maxillary molar root apices to the sinus floor. RESULTS: Post-treatment, there was a marked increase in the average volume and surface area of the maxillary sinus on both sides; however, changes in dimensions were not statistically significant. Sinus proximity to the root apices of the maxillary molars showed statistically significant differences, particularly on the left side for all roots. Gender and age impacted the outcomes, with males and younger individuals showing more pronounced changes. No significant differences were observed between the left and right sinuses in all parameters. CONCLUSION: Molar distalization with CAs increases maxillary sinus parameters, more notably in younger and male patients. All molar teeth roots moved toward the sinus, particularly the mesiobuccal root of the maxillary second molar protruded to the sinus.

Impact of molar teeth distalization by clear aligners on maxillary alveolar bone thickness and root resorption: a three­dimensional study.

OBJECTIVE: This study aimed to evaluate the impact of molar teeth distalization movement by clear aligners on changes in the alveolar bone thickness and orthodontically induced inflammatory root resorption (OIIRR) in maxillary molars using conebeam computed tomography (CBCT). MATERIALS AND METHODS: Three-dimensional CBCT scans of 35 adult patients (one hundred forty maxillary molars) with pre-designed selection criteria and a mean age of 24.4 ± 7.1 years were included. The measured parameters, including alveolar bone thickness for maxillary molars and root resorption (OIIRR), were analyzed using pre-and post-treatment CBCT (T0 and T1, respectively) with Invivo 6.0 software. RESULT: Post-treatment, relevant statistically significant changes included deposition of bone in the average palatal surface of the 1st molars. The reduction of bone was seen in the average buccal surface of the first molars and both surfaces of the second molars. Regarding root length after treatment, the average maxillary 1st molar roots showed significant OIIRR (p < 0.001). CONCLUSION: Clear aligner treatment could effectively reduce the incidence of alveolar bone thickness reduction and OIIRR in treating Class II malocclusions compared to conventional braces, as shown in previous studies. This research will aid in fully grasping the benefits of clear aligners.

Alveolar bone changes following bi-maxillary vertical molars' movements using clear aligners.

OBJECTIVE: This study aimed to assess the alveolar bone changes following maxillary and mandibular molars' intrusion and extrusion movements using Clear Aligners using Cone-Beam Computed Tomography (CBCT). MATERIALS AND METHODS: This is a retrospective clinical study in which 24 adult patients with pre-designed selection criteria and a mean age of 31.1 + 9.9 years were enrolled. The alveolar bone changes around one hundred thirty-three maxillary and mandibular molars intruded or extruded by Clear Aligners therapy were analyzed from CBCT using Invivo 6.0 software. Intra- and inter-examiner reliability analysis was performed using the intra-class correlation coefficient (ICC) and Cronbach's Alpha statistics. The paired t-test was used to analyze significant differences before and after treatment (T0-T1). The significance level was considered at P < 0.05. RESULT: The patients were divided into two groups: extrusion (48.9%, n = 65 molars' root) and intrusion (51.1%, n = 68 molars' root) group. There was a significant decrease in the alveolar bone changes in the buccal surface of the mandibular right and left 1st molars in the extrusion group (-1.05 ± 0.97, -0.76 ± 1.12 mm, respectively) and the maxillary left 2nd molars in intrusion group (-0.42 ± 0.77 mm), and the lingual surface of intrusion of the mandibular left 1st molar (-0.64 ± 0.76 mm). Comparing the mean maxillary and mandibular changes (T0-T1) of both studied groups showed that the buccal alveolar bone changes for the left 1st and right 2nd molars showed a significant difference in extrusion and intrusion groups, respectively. CONCLUSIONS: The buccal alveolar bone changes is considered the most affected surface following maxillary and mandibular molars' intrusion and extrusion movements using clear aligners, with mandibular molars being more affected than the maxillary ones.