Background Upper airway obstruction (UAO) is a significant clinical concern due to its potential to lead to serious health issues, including obstructive sleep apnea (OSA) and cardiovascular diseases. Traditional diagnostic methods, such as spirometry, are often invasive and complex. This study aims to validate a portable ventilatory airway screening (PVAS) device as a non-invasive, cost-effective alternative for measuring upper airway breathing pressure and respiratory flow. Objectives To validate the accuracy of the PVAS device in measuring upper airway breathing pressure and respiratory flow by comparing its readings with those obtained from standard spirometry tests. Methods This cross-sectional analytical study involved 40 growing individuals aged 10-14 years, divided into two groups based on cephalometric analysis: Skeletal Class I (20 patients) and Skeletal Class II with retrognathic mandible (20 patients). Breathing pressure, volume, and velocity measurements were recorded using both the PVAS device and spirometry, and their accuracy was compared. Results The PVAS device showed high concordance with spirometry results, demonstrating significant accuracy in measuring breathing pressure, volume, and velocity. Skeletal Class II individuals exhibited significantly higher breathing pressure and reduced respiratory flow compared to Class I individuals, as measured by the PVAS device. Conclusion The PVAS device is a valid and accurate tool for non-invasive measurement of upper airway breathing pressure and respiratory flow. Its ease of use and reliability make it a valuable tool for clinical practice, particularly in the early diagnosis and management of airway obstructions.

BACKGROUND: In this study, we sought to quantify the influence of vertical control assisted by a temporary anchorage device (TAD) on orthodontic treatment efficacy for skeletal class II patients with a hyperdivergent facial type and probe into the critical factors of profile improvement.
METHODS: A total of 36 adult patients with skeletal class II and a hyperdivergent facial type were included in this retrospective case-control study. To exclude the effect of sagittal anchorage reinforcement, the patients were divided into two groups: a maxillary maximum anchorage (MMA) group (N = 17), in which TADs were only used to help with anterior tooth retraction, and the MMA with vertical control (MMA + VC) group (N = 19), for which TADs were also used to intrude the maxillary molars and incisors. The treatment outcome was evaluated using dental, skeletal, and soft-tissue-related parameters via a cephalometric analysis and cast superimposition.
RESULTS: A significant decrease in ANB (P < 0.05 for both groups), the retraction and uprighting of the maxillary and mandibular incisors, and the retraction of protruded upper and lower lips were observed in both groups. Moreover, a significant intrusion of the maxillary molars was observed via the cephalometric analysis (- 1.56 ± 1.52 mm, P < 0.05) and cast superimposition (- 2.25 ± 1.03 mm, P < 0.05) of the MMA + VC group but not the MMA group, which resulted in a remarkable decrease in the mandibular plane angle (- 1.82 ± 1.38°, P < 0.05). The Z angle (15.25 ± 5.30°, P < 0.05) and Chin thickness (- 0.97 ± 0.45°, P < 0.05) also improved dramatically in the MMA + VC group, indicating a better profile and a relaxed mentalis. Multivariate regression showed that the improvement in the soft tissue was closely related to the counterclockwise rotation of the mandible plane (P < 0.05).
CONCLUSIONS: TAD-assisted vertical control can achieve intrusion of approximately 2 mm for the upper first molars and induce mandibular counterclockwise rotation of approximately 1.8°. Moreover, it is especially important for patients without sufficient retraction of the upper incisors or a satisfactory chin shape.

OBJECTIVE: Currently, there is no reliable automated measurement method to study the changes in the condylar process after orthognathic surgery. Therefore, this study proposes an automated method to measure condylar changes in patients with skeletal class II malocclusion following surgical-orthodontic treatment.
METHODS: Cone-beam CT (CBCT) scans from 48 patients were segmented using the nnU-Net network for automated maxillary and mandibular delineation. Regions unaffected by orthognathic surgery were selectively cropped. Automated registration yielded condylar displacement and volume calculations, each repeated three times for precision. Logistic regression and linear regression were used to analyse the correlation between condylar position changes at different time points.
RESULTS: The Dice score for the automated segmentation of the condyle was 0.971. The intraclass correlation coefficients (ICCs) for all repeated measurements ranged from 0.93 to 1.00. The results of the automated measurement showed that 83.33% of patients exhibited condylar resorption occurring six months or more after surgery. Logistic regression and linear regression indicated a positive correlation between counterclockwise rotation in the pitch plane and condylar resorption (P < .01). And a positive correlation between the rotational angles in both three planes and changes in the condylar volume at six months after surgery (P ≤ .04).
CONCLUSIONS: This study\'s automated method for measuring condylar changes shows excellent repeatability. Skeletal class II malocclusion patients may experience condylar resorption after bimaxillary orthognathic surgery, and this is correlated with counterclockwise rotation in the sagittal plane.
CONCLUSIONS: This study proposes an innovative multi-step registration method based on CBCT, and establishes an automated approach for quantitatively measuring condyle changes post-orthognathic surgery. This method opens up new possibilities for studying condylar morphology.

BACKGROUND: The relation between orthodontic treatment and temporomandibular disorders (TMDs) is under debate; the management of TMD during orthodontic treatment has always been a challenge. If TMD symptoms occur during orthodontic treatment, an immediate pause of orthodontic adjustments is recommended; the treatment can resume when the symptoms are managed and stabilized.
METHODS: This case report presents a patient (26-year-old, female) with angle class I, skeletal class II and TMDs. The treatment was a hybrid of clear aligners, fixed appliances and temporary anchorage devices (TADs). After 3 mo resting and treatment on her TMD, the patient\'s TMD symptom alleviated, but her anterior occlusion displayed deep overbite. Therefore, the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves. After the levelling, the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion. After careful examination of temporomandibular joints (TMJ) position, the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion. Eventually, the improved facial appearance and relatively stable occlusion were achieved. The 1-year follow-up records showed there was no obvious change in TMJ morphology, and her occlusion was stable.
CONCLUSIONS: TMD screening and monitoring is of great clinical importance in the TMD susceptible patients. Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.

OBJECTIVE: A randomized controlled trial was undertaken to investigate the orthopaedic effect of functional appliances on the pharyngeal airway space and nocturnal breathing of children with skeletal class II due to mandibular retrusion.
METHODS: Forty patients were randomized into a 1:1 ratio study (Twin block) group and a control (fixed appliance) group. Each group included equal numbers of boys and girls. Diagnosis with sleep-disordered breathing was not an inclusion criterion. The duration of the trial was 12 months (T0 - T12). Eligibility criteria included skeletal Class II division 1 malocclusion with mandibular retrognathism, SNA ≥82, SNB ≤78, ANB ≥4, overjet ≥6 mm, and patients in circumpubertal stage CVM2 and CVM3. The main outcomes were pharyngeal airway volume, oxygen desaturation index (ODI), and maximum expiratory pressure (MEP), while the secondary outcomes were skeletal and dental changes of the maxilla and mandible. Randomization was accomplished with random blocks of 20 patients with allocation concealed in sequentially numbered, opaque, and sealed envelopes. Blinding was only applicable for data analysis of radiographic measurements and data extracted from the pulse oximeter.
RESULTS: The mean age of the patients was 10 ± 1.5 and 10 ± 1.2 at (T0) for the Twin Block and the control groups, respectively. The changes in the oropharyngeal (2.66 cc and 0.056; P = .03) and nasopharyngeal (1.3 cc and 0.84; P = .053) airway volumes for the Twin block and control groups, respectively, were significantly different for the oropharynx. There was a significant decrease in ODI by [median -3.55 (-5.05 to 0.50); P ≤ .001] and a significant increase [median 45 (0.0-110); P ≤ .001] in MEP for the Twin block group. A significant inverse correlation (r = -.589; P = .006) could be found between the total volume of the oropharynx and ODI. No serious harm was observed.
CONCLUSIONS: The Twin block group showed significant change in oropharyngeal airway volume and improvement of nocturnal breathing.
BACKGROUND: This trial was registered at https://www.
RESULTS: gov, registration number NCT04255511.

BACKGROUND: Treatment for deep overbite cases can be difficult. This case report presents some techniques with improved super-elastic Ti-Ni alloy wire (ISW) for deep overbite correction.
METHODS: A 21-year-old woman had a chief complaint of flaring maxillary teeth. Orthodontic evaluation revealed a skeletal class II malocclusion and a convex profile appearance. A deep overbite with palatal impingement and large overjet were also noted. Bilateral maxillary first premolars were extracted, and spaces were closed using a closed-coil spring and elastic chain. The deep overbite was corrected by applying the ISW curve and ISW intrusion arch. Intermaxillary elastics was used to adjust the intermaxillary relationship. Active treatment took approximately 3 years, and the appearance and dentition alignment noticeably improved.
CONCLUSIONS: The use of the ISW technique in a case of skeletal class II malocclusion with deep overbite achieved a desirable result, and the patient was satisfied with the treatment outcome.

OBJECTIVE: To study the difference in mandibular asymmetry between patients with skeletal Class I and skeletal Class II malocclusions and analyze the correlation between mandibular asymmetry and different facial skeletal sagittal patterns based on CBCT measurements.
METHODS: One hundred and twenty patients were selected according to the inclusion and exclusion criteria. Patients were divided into two groups (60 in the skeletal Class I group and 60 in the skeletal Class II group) based on ANB angles and Wits values. Patients\' CBCT data were collected. Dolphin Imaging 11.0 was used to determine the mandibular anatomic landmarks and calculate the linear distance in patients in the two groups.
RESULTS: Intragroup comparison: in skeletal Class I group, measurements of the most posterior point of the condyle (Cdpost), the outer lateral point of the condyle (Cdlat), sigmoid notch point (Sn)), coronoid process point (Cop), gonion point (GO) and antimony notch point (Ag), right>left (P<0.05); in skeletal Class II group, measurements of Cdpost and Cop, right>left (P<0.05). Intergroup comparison: for measurements of GO and Ag, skeletal Class I group>skeletal Class II group (P<0.05). The asymmetry of the Ag and GO points was negatively correlated with the ANB angle (p<0.05).
CONCLUSIONS: Mandibular asymmetry was significantly different between patients with skeletal Class I and skeletal Class II malocclusions. The asymmetry of the mandible angle region in the former group was greater than that in the latter group, and the asymmetry of the mandibular angle was negatively correlated with the ANB angle.

OBJECTIVE: Anterior segmental osteotomy (ASO) following the surgery-first approach is a long-established treatment modality to resolve lip protrusion in patients with skeletal class II patterns. However, the indications and effectiveness of ASO still remain uncertain. The objective of this study is to investigate the effectiveness of ASO in Asian skeletal class II patients by evaluating the skeletal and soft tissue changes and analyzing pre-treatment variables that determine successful outcomes in occlusal as well as esthetic aspects.
METHODS: The lateral cephalograms of 44 skeletal class II patients who underwent ASO and orthodontic treatment for resolving lip protrusion were retrospectively collected. Hard and soft tissue variables of two groups, normalized (NG) and unnormalized (UNG) ANB after treatment were compared and analyzed. The rotational effect of the anterior segment on the hard and soft tissue was also investigated.
RESULTS: ASO was successful in correcting the skeletal class II relationship and lip protrusion (ΔANB - 2.3°, 4-5 mm lips retraction) in most cases. However, for patients with severely camouflaged skeletal class II incisors involving a large ANB and SNA, a large ANB still remained post-treatment. The study also found that rotation of the upper and lower anterior segments further augmented the amount of lip retraction.
CONCLUSIONS: ASO was found to successfully correct ANB of skeletal class II patients under the following conditions (ANB 5.3° ± 1.5°, SNB 77.3° ± 4.5°, U1 to FH 115° ± 7.5, L1 to FH 48.0° ± 4.6). However, patients with larger ANB and SNA values may require bi-maxillary surgery. In addition, ASO has limitations in correcting gummy smile in cases of extreme maxillary excess. For patients requiring a large amount of lip retraction, rotation of the anterior segment may be beneficial in conjunction with bi-maxillary surgery.

OBJECTIVE:  This study was conducted to assess the effects of applying a gel of combined glucosamine sulfate and chondroitin sulfate on the temporomandibular joint (TMJ) area in patients with skeletal Class II malocclusion treated by removable functional appliances in terms of TMJ internal proportions, levels of pain, and tension.
METHODS: The study included 36 patients aged 10-13 years with skeletal Class II malocclusion due to retrusion of the mandible characterized by: 4-8 degrees of the sagittal skeletal discrepancy (ANB) angle, 4-7 mm of overjet, 72-76 degrees of the sagittal mandibular positioning (SNB) angle, and a bone maturity stage located at pubertal growth spurt. Patients were distributed to the experimental group (Twin-Block appliance + Jointance® gel) or the control group (conventional treatment with the Twin-Block appliance). An allocation ratio of 1:1 was employed. Pre- and post-treatment digital lateral cephalometric radiograms were taken, and the TMJ joint spaces were measured using the Viewbox software (dHAL Software, Kifissia, Greece). The pain and discomfort levels were evaluated using a questionnaire with a four-point Likert scale at three assessment times.
RESULTS:  The anterior and posterior glenoid and anterior condylar distances to the pterygoid vertical (PTV) reference plane significantly decreased after treatment (p<.001), and the anterior joint space decreased significantly (p<.001). In contrast, the superior distance of the condyle to the Frankfort horizontal reference plane increased significantly after treatment, and the same results were found for the posterior and superior joint spaces (p<.05). There were no significant differences between the two groups in the evaluated linear variables. No significant differences were found when comparing pain and tension levels between the two groups at each assessment time. A gradual decrease in pain and tension levels was observed between the three evaluation times in both groups.
CONCLUSIONS:  A combination of glucosamine sulfate and chondroitin sulfate did not affect the temporomandibular joint spaces, pain, and tension levels in patients with skeletal Class II malocclusions treated by removable functional appliances.

This case report describes the treatment of an adolescent patient with an Angle Class II malocclusion, severe open bite and overjet, proclined incisors, skeletal Class II anteroposterior dysplasia, high mandibular plane angle and convex profile. The importance of stopping of a prolonged thumb sucking habit, which was a major causative factor of the open bite is discussed. A combination of a high-pull headgear and a modified transpalatal arch with a loop embedded with resin, at a distance from the palate, were used along with an Edgewise appliance. Treatment timing, favourable growth and good patient response led to an optimal outcome with excellent stability of the treatment results five years and five months post-treatment.