Sagittal Patterns Research Articles

Intradiscal vacuum phenomenon matches lumbar spine degeneration patterns in an ageing population

PurposeIntra-Discal Vacuum phenomenon (IDVP) is well-recognised, yet poorly visualised and poorly understood radiological finding in disc degeneration, particularly with regard to its role in spinal alignment. CT analysis of the lumbar spine in an aging population aims to identify patterns associated with IDVP including lumbopelvic morphology and associated spinal diagnoses.MethodsAn analysis was performed of an over-60s population sample of 2020 unrelated abdominal CT scans, without acute spinal presentations. Spinal analysis included sagittal lumbopelvic reconstructions to assess for IDVP and pelvic incidence (PI). Subjects with degenerative pathologies, including previous vertebral fractures, auto-fusion, transitional vertebrae, and listhesis, were also selected out and analysed separately.ResultsThe prevalence of lumbar spine IDVP was 50.3% (955/1898) and increased with age (125 exclusions). This increased in severity towards the lumbosacral junction (L1L2 8.3%, L2L3 10.9%, L3L4 11.5%, L4L5 23.9%, and L5S1 46.3%). A lower PI yielded a higher incidence of IDVP, particularly at L5S1 (p < 0.01). A total of 292 patients had IDVP with additional degenerative pathologies, which were more likely to occur at the level of isthmic spondylolisthesis, adjacent to a previous fracture or suprajacent to a lumbosacral transitional vertebra (p < 0.05).ConclusionsThis study identified the prevalence and severity of IDVP in an aging population. Sagittal patterns that influence the pattern of IVDP, such as pelvic incidence and degenerative pathologies, provide novel insights into the function of aging spines.

Three-dimensional quantification of mandibular asymmetries in Caucasian adult patients with different sagittal and vertical skeletal patterns. A cone beam study using 3D segmentation and mirroring procedures

IntroductionAn accurate identification of mandibular asymmetries is required by modern orthodontics and orthognathic surgery to improve diagnosis and treatment planning of such deformities. Although craniofacial deformities are very frequent pathologies, some types of asymmetries can be very difficult to assess without the proper diagnostic tools. The purpose of this study was to implement the usage of three-dimensional (3D) segmentation procedures to identify asymmetries at the mandibular level in adult patients with different vertical and sagittal patterns where the asymmetries could go unnoticed at the observational level.MethodsThe study sample comprised 60 adult patients (33 women and 27 men, aged between 18 and 60 years). Subjects were divided into 3 sagittal and vertical skeletal groups. CBCT images were segmented, mirrored and voxel-based registered with reference landmarks using ITK-SNAP® and 3DSlicer® software’s. 3D surface models were constructed to evaluate the degree of asymmetry at different anatomical levels.ResultsThere was a degree of asymmetry, with the left hemimandible tending to contain the right one (0.123 ± 0.270 mm (CI95% 0.036–0.222; p < 0.001). Although the subjects under study did not present significant differences between mandibular asymmetries and their sagittal or vertical skeletal pattern (p = 0.809 and p = 0.453, respectively), a statistically significant difference has been found depending on the anatomical region (p < 0.001; CI95%=1.020–1.021), being higher in the condyle, followed by the ramus and the corpus.ConclusionsAlthough mandibular asymmetries cannot be correlated with vertical and sagittal skeletal patterns in symmetric patients, knowledge about 3D segmentation procedures and color maps can provide valuable information to identify mandibular asymmetries.

In vivo structural and functional imaging of human nailbed microvasculature using photoacoustic microscopy.

Monitoring microvascular structure and function is of great significance for the diagnosis of many diseases. In this study, we demonstrate the feasibility of OR-PAM to nailbed microcirculation detection as a new, to the best of our knowledge, application scenario in humans. We propose a dual-wavelength optical-resolution photoacoustic microscopy (OR-PAM) with improved local-flexible coupling to image human nailbed microvasculature. Microchip lasers with 532 nm wavelength are employed as the pump sources. The 558 nm laser is generated from the 532 nm laser through the stimulated Raman scattering effect. The flowing water, circulated by a peristaltic pump, maintains the acoustic coupling between the ultrasonic transducer and the sample. These designs improve the sensitivity, practicality, and stability of the OR-PAM system for human in vivo experiments. The imaging of the mouse ear demonstrates the ability of our system to acquire structural and functional information. Then, the system is applied to image human nailbed microvasculature. The imaging results reveal that the superficial capillaries are arranged in a straight sagittal pattern, approximately parallel to the long axis of the finger. The arterial and venular limbs are distinguished according to their oxygen saturation differences. Additionally, the images successfully discover the capillary loops with single or multiple twists, the oxygen release at the end of the capillary loop, and the changes when the nailbed is abnormal.

Orthodontic craniofacial pattern diagnosis: cephalometric geometry and machine learning.

Efficient and reliable diagnosis of craniofacial patterns is critical to orthodontic treatment. Although machine learning (ML) is time-saving and high-precision, prior knowledge should validate its reliability. This study proposed a craniofacial ML diagnostic workflow base on a cephalometric geometric model through clinical verification. A cephalometric geometric model was established to determine the landmark location by analyzing 408 X-ray lateral cephalograms. Through geometric information and feature engineering, nine supervised ML algorithms were conducted for sagittal and vertical skeleton patterns. After dimension reduction, plane decision boundary and landmark contribution contours were depicted to demonstrate the diagnostic consistency and the consistency with clinical norms. As a result, multi-layer perceptron achieved 97.56% accuracy for sagittal, while linear support vector machine reached 90.24% for the vertical. Sagittal diagnoses showed average superiority (91.60 ± 5.43)% over the vertical (82.25 ± 6.37)%, where discriminative algorithms exhibited more steady performance (93.20 ± 3.29)% than the generative (85.98 ± 9.48)%. Further, the Kruskal-Wallis H test was carried out to explore statistical differences in diagnoses. Though sagittal patterns had no statistical difference in diagnostic accuracy, the vertical showed significance. All aspects of the tests indicated that the proposed craniofacial ML workflow was highly consistent with clinical norms and could supplement practical diagnosis.

Association of the Vertical and Sagittal Growth Patterns of Jaws with the type of Third Molar Impactions: A Radiological Analysis

Objective: To evaluate if the jaw growth patterns are associated with third molar impactions.&#x0D; Design: Cross-sectional study.&#x0D; Study setting: Orthodontics Department, Islamic International Dental College &amp; Hospital Islamabad, Jan to Jun 2018.&#x0D; Methods: We analysed the records of 300 mandibular and maxillary third molars with specific criteria. Orthopantomogram Xrays were used to identify impactions and were classified by Pell and Gregory (P&amp;G) and Winter lines. In addition, lateral cephalograms were assessed for sagittal classes and vertical growth patterns.&#x0D; Results: Angles of impaction (Winter lines) of mandibular M3s were significantly associated with sagittal growth patterns(p=0.021), with most mesioangular impactions found in Classes I and II. High-angle subjects resulted in the highest impactions in the vertical growth patterns. High angle was followed by low angle and normal angle in mandibular M3s and normal angle and low angle in maxillary M3s. Levels of maxillary M3s (P&amp;G) and vertical patterns showed a significant association (p=0.016), with the highest M3s at level C. The maximum number of impacted M3 coexisted with P&amp;G Class- II and level B for both jaws.Conclusion: Significant associations were found between mandibular M3 angles, sagittal patterns, and levels of maxillary M3s and vertical patterns. Results conclude that facial growth patterns and M3 impactions are not completely independent and may help predict impaction status in adolescence and aid in orthodontic treatment.

Evaluation of cuspid cortical anchorage with different sagittal patterns using cone-beam computed tomography: a retrospective study

BackgroundNo studies have focused on cortical anchorage resistance in cuspids, this study aimed to characterize the cortical anchorage according to sagittal skeletal classes using cone-beam computed tomography (CBCT).MethodsCBCT images of 104 men and 104 women were divided into skeletal class I, II, and III malocclusion groups. Skeletal and dental evaluations were performed on the sagittal and axial cross-sections. One-way analysis of variance followed by least significant difference post-hoc tests was used for group differences. Multiple linear regression was performed to evaluate the relationship between influential factors and cuspid cortical anchorage.ResultsAll cuspids were close to the labial bone cortex in different sagittal skeletal patterns and had different inclinations. There was a significant difference in the apical root position of cuspids in the alveolar bone; however, no significant difference in the middle or cervical portions of the root was found between different sagittal facial patterns. The middle of the cuspid root was embedded to the greatest extent in the labial bone cortex, with no significant difference between the sagittal patterns. For all sagittal patterns, 6.03 ± 4.41° (men) and 6.08 ± 4.45° (women) may be appropriate root control angles to keep maxillary cuspids’ roots detached from the labial bone cortex.ConclusionsComparison of skeletal class I, II, and III malocclusion patients showed that dental compensation alleviated sagittal skeletal discrepancies in the cuspid positions of all patients, regardless of the malocclusion class. Detailed treatment procedures and clear treatment boundaries of cuspids with different skeletal patterns can improve the treatment time, periodontal bone remodeling, and post-treatment long-term stability. Future studies on cuspids with different dentofacial patterns and considering cuspid morphology and periodontal condition may provide more evidence for clinical treatment.

Clinical-statistical study on the use of articulators in orthodontic practice

Dental-maxillary anomalies are accompanied by changes in the interbasal maxillary ratio in all reference planes, with influences on the functionality of articular structures. These joint changes not detected in time and not included in the treatment plan may worsen while wearing fixed appliances, as orthodontic treatment changes the cranio-mandibular position and causes cranio-mandibular reshaping. The articulator is an instrument that reproduces more or less all mandible movements. TMJ characteristics of skeletal dento-maxillary anomalies, especially class II sagittal pattern mainly reflected in condylar position rather than morphology. TMJ of different vertical patterns differed more in joint spaces, position of condyle and glenoid fossa than in morphologic measurements. Vertical position of glenoid fossa and proportion of posterior condyle increased gradually from hypodivergent to hyperdivergent. Highest glenoid fossa position, maximum ratio of posterior positioned condyle, smallest joint spaces, shallowest glenoid fossa depth, and narrowest condylar long axis diameter were found in skeletal class. The patients with high angle have considerable joint instable factors, and we should especially pay attention when orthodontic treatment is carried out on them. The condyle-fossa position and morphology differ with various vertical facial patterns in individuals with skeletal Class II mandibular retrognathism. These differences could be considered during temporo-mandibular diagnosis and orthodontic treatment

Mandibular asymmetry in patients with skeletal class I and skeletal class II Malocclusions: A cone-beam computed tomography study

ObjectiveTo 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. MethodsOne 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. ResultsIntragroup 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). ConclusionMandibular 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.

Craniofacial Morphology of Temporomandibular Disorder Patients with Different Disc Positions: Stratifying Features Based on Sex and Sagittal Skeletal Pattern.

Disc displacement (DD) appears in the majority of temporomandibular disorder (TMD) patients. The correlation between craniofacial morphology and different disc positions has been underlined, while the craniofacial morphological differences based on sex and sagittal skeletal pattern stratification have been insufficiently studied. In this study, 304 patients with TMD complaints were included and classified into normal position, disc displacement with reduction (DDwR) and disc displacement without reduction (DDwoR) groups according to magnetic resonance imaging. A total of 24 cephalometric measurements, covering the cranial base, vertical relationship, sagittal relationship, mandible position and morphology, and dental relationship, were assessed using lateral cephalograms. A stratified analysis was performed based on the sex and sagittal skeletal pattern. Overall, DD patients had distinctive craniofacial morphological features. The posterior cranial base length and mandibular arc angle were statistically different only in females, while the Y-axis angle, occlusal plane angle and sella nasion point A angle (SNA) might be unique features in males. Skeletal class II had the most statistically different measurements compared to the others. Differences in the Frankfort mandibular incisor angle (FMIA) and saddle angle were especially displayed in skeletal class III patients. The sex and skeletal sagittal pattern could affect the morphological differences in TMD patients with different disc positions.

Knee Kinematic Patterns and Early Cartilage Lesion Characteristics in Patients with Anterior Cruciate Ligament Reconstruction.

Specific knee kinematic alterations have been theorized to correlate with the progression of cartilage degeneration, and therefore, post-traumatic osteoarthritis in patients with anterior cruciate ligament reconstruction (ACLR). However, how specific knee kinematic alterations contribute to knee joint cartilage degenerations remains to be unclear. To solve this problem, we hypothesized that there are specific cartilage-degenerating kinematic gait patterns that could be supported by the specific areas of cartilage lesions in ACLR knees. Thirty patients with unilateral ACLR knees and 30 healthy controls were recruited for the study. The kinematic differences between the ACLR knees and the healthy control knees during the stance phase were calculated to identify the kinematic patterns. Cartilage lesion distribution characteristics were acquired for patients with ACLR knees to validate the kinematic patterns using magnetic resonance images. Two kinematic patterns were modeled, i.e., sagittal (increased flexion angle and posterior tibial translation) and coronal (increased lateral tibial translation and abduction angle) kinematic patterns. For the sagittal pattern, the cartilage lesion distributions showed that there were more cartilage lesions (CLs) in the superoposterior regions than the posterior regions in the femoral condyles (p = 0.001), and more CLs in the posterior regions than the middle regions in the tibial plateau (p < 0.001). For the coronal pattern, the cartilage lesion distributions showed that there were more CLs in the lateral compartments near the tibial spine than the medial compartments near the tibial spine (tibial sides, p = 0.005 and femoral sides, p = 0.290). To conclude, the cartilage degeneration distribution evidence largely supports that the two kinematic patterns may contribute to cartilage degeneration in ACLR knees. These findings may provide a potential strategy of delaying early cartilage degeneration in ACLR knees by using motion (kinematic) pattern modification or training. However, investigations should be conducted on the actual effects of this potential strategy.

The association between Roussouly sagittal alignment type and risk for adjacent segment degeneration following short-segment lumbar interbody fusion: a retrospective cohort study

BackgroundTo date, the influence of Roussouly type on development of adjacent segment degeneration (ASD) after lumber fusion is still not fully explored, and the current study is aimed to evaluate the effect of Roussouly type on development of radiological ASD after single-level lumber fusion, and to compare the Roussouly types and spinopelvic parameters among those with different degenerative patterns of ASDs on sagittal plane.MethodsA retrospective review of 288 patients underwent L4/5 or L5/S1 single-level posterior interbody fusions between January 2016 and December 2018 with a minimum 2-year follow up was performed. Radiological ASDs were identified and divided into 3 groups according to different degenerative patterns of the cephalad adjacent level on sagittal plane, including the types of retrolisthesis (Group A), anterolisthesis (Group B), and axial disc space narrowing (Group C). Roussouly types and radiological measurements were compared among three groups and potential risk factors for ASD were evaluated.ResultsRadiological ASD was found in 59 (20.5%) cases, in which patients with Roussouly type-2 was the most common. While, on subgroup analysis among three ASD groups, Roussouly type-1 occupied the highest proportion in Group A, differ in Group B and Group C, both with Type-2 as the most common. Moreover, Group A had significantly lower pelvic tilt (PT), larger sacral slope (SS), and larger segmental angle (SA) than Group B and Group C, which showed a more anteverted pelvic in Group A. Multivariate regression analysis noted Roussouly type, preoperative PT, and ∆PI-LL as the independent risk factors for radiological ASD.ConclusionRoussouly type was significantly associated with the development of radiological ASD; however, the Roussouly types and spinal pelvic parameters were varied among different sagittal degenerative patterns of ASD, which was important in restoring optimal lumbar sagittal alignments in initial surgery.

The "Wind Surf" Deformity-Correcting Fixed Flexion Deformity and Hyperextension in Bilateral CAS TKA.

Severe knee arthritis can result in complex coronal and sagittal angular deformities. Windswept deformity is used to describe a varus deformity and contralateral valgus deformity. We recognized a new sagittal pattern at the time of computer-assisted surgery (CAS) in total knee arthroplasty (TKA) in which one knee has a fixed flexion deformity (FFD), while the contralateral knee has a hyperextension deformity. We propose to define it as "wind surf" deformity mimicking the opposite pull of the wind and a surfer. The incidence of "wind surf" deformity in this series was 0.96% among a cohort of 2,291 bilateral TKAs performed between 2013 and 2018. Twenty-two patients were identified with an FFD of 5° to 20° on one knee and recurvatum of -5° to -20° on the contralateral knee. Additional bone resection and soft-tissue releases were performed for the FFD with a goal to maintain residual 1° to 3° of flexion. Minimal bone resection and soft-tissue disruption were performed on the knee with hyperextension with a goal to maintain 5° to 7° of flexion. These opposite strategies applied with the help of CAS prevented recurrence resulting in satisfactory clinical results at 2-year follow-up. The "wind surf" deformity variant should be identified in patients presenting with severe knee arthritis to guide surgical treatment, prevent recurrence, and obtain favorable clinical patient outcomes.

A preliminary study of buccal and lingual alveolar bone thickness of posterior teeth in patients with skeletal Class III malocclusion and mandibular asymmetry

The purposes of this retrospective study were to investigate the buccal and lingual alveolar bone thickness values of the posterior teeth in patients with asymmetrical skeletal Class III malocclusion and compare them with patients with symmetrical skeletal Class III and Class I malocclusion. Seventy-eight cone-beam computed tomography scans were classified into 3 groups according to the sagittal pattern and menton deviation: asymmetrical Class III (n= 26), symmetrical Class III (n= 26), and symmetrical Class I (n= 26). The buccal and lingual alveolar bone thickness of the first molar and premolars in the maxilla and mandible were measured at 3, 6, and 8 mm apical to the cementoenamel junction and the apical and middle levels of the root. Measurements were compared among the 3 groups. In the asymmetrical Class III group, the buccal alveolar bone along the distobuccal root of the maxillary first molar on the deviated side was thinner by 1.07 to 1.10 mm than that in the symmetrical Class I group at 6-mm, 8-mm, and middle-level planes (P<0.001, P<0.01, and P<0.001). The buccal alveolar bone thickness along the distal and mesial roots of the mandibular first molar on the deviated side was thinner by 1.28 to 1.85 mm, and by 0.72 to 1.21 mm, respectively (P <0.001 and P <0.01), than that in the symmetrical Class I group at 6-mm, 8-mm, apical and middle-level planes. In this preliminary study, patients with skeletal Class III malocclusion showed thinner buccal and lingual alveolar bone in the posterior teeth than subjects with Class I malocclusion. Particular attention should be paid to buccal alveolar bone thickness along the distobuccal root of the maxillary and distal root of the mandibular first molar to prevent periodontal complications in decompensation. Future studies should involve larger sample sizes, more repeatable and comprehensive measuring and statistical methods.

The Correlation Between Morphologic Characteristics of Condyle and Glenoid Fossa with Different Sagittal Patterns of Jaw Assessed by Cone-Beam Computed Tomography.

This study aimed to determine the relationship between the morphologic characteristics of condyle and glenoid fossa in different sagittal skeletal patterns using cone-beam computed tomography. In this cross-sectional study, the lateral cephalometric and cone-beam computed tomography images of 90 patients were evaluated. The patients were categorized into three equal groups of sagittal skeletal patterns, according to the ANB angle. The greatest anteroposterior and mediolateral diameters of the mandibular condyles, as well as the angle between the long axis of the mandibular condyles and the midsagittal plane, were measured on the axial view of cone-beam computed tomography images. The anterior joint space, superior joint space, posterior joint space, articular eminence inclination, depth of the glenoid fossa, and width of the glenoid fossa were also measured on the central sagittal slices. One-way analysis of variance (ANOVA), Tukey's post hoc test and chi-square test were performed. Patients with the skeletal Class III had a significantly higher articular eminence inclination, while Class II patients had a lower articular eminence inclination (P = .001). In Class III patients, the depth of the glenoid fossa was greater, and the width of the glenoid fossa was smaller than in the other groups (P < .01). The anterior and posterior joint space did not show any significant differences between the 3 groups. There were significant differences in some morphological characteristics of the condyle and glenoid fossa in patients with different sagittal skeletal patterns; therefore, this relationship should be considered in the treatment of these patients.

PADRÕES FRONTAIS E SAGITAIS DAS DEFORMIDADES NEUROMUSCULARES DA COLUNA VERTEBRAL, SEGUNDO O PERFIL NOSOLÓGICO

ABSTRACT Objective: Reveal frontal and sagittal patterns of spinal deformity depending on neuromuscular nosology for surgery and outcome planning. The characteristics of spinal deformity vary according to the pathology. In cerebral palsy, muscular dystrophies, and spinal muscular atrophy, specific features of deformities are poorly written, especially in the sagittal profile. Methods: The evaluation criteria were age, gender of the patients, the volume of blood loss, duration of hospitalization, measurement of the deformity curve, thoracic and lumbar kyphosis (Cobb angle), pelvic obliquity concerning the horizontal line, the percentage of curve correction. Cobb angle was measured preoperatively before hospital discharge (up to 21 days postoperatively) and one year after surgery. Results: The cohort of 71 patients with spinal deformities due to neuromuscular diseases included four groups: muscular dystrophy (MD), spinal muscular atrophy (SMA), Duchenne muscular dystrophy (DMD), and cerebral palsy (CP). The most characteristic deformity in the frontal plane was C-shaped thoracolumbar scoliosis with rotation of the pelvis; rotation of the vertebrae increased according to the magnitude of scoliosis. Lumbar hyperlordosis was common in patients with PD, whereas decreased thoracic kyphosis or even thoracic lordosis occurs more frequently in patients with DMD. Moderate correction of scoliosis was observed in all groups. There was no significant improvement in functional status, according to the FIM. Conclusion: The findings showed that rigid hyperlordosis is the main problem of spinal deformities in neuromuscular patients. Scoliosis and pelvic obliquity can be well corrected in NMS by pedicle screw construction with standard maneuvers and pelvic screw fixation. Level of Evidence IV; Lesser quality prospective study.

Update on the parameters influencing the adjustment of the sagittal and transversal condylar inclination of dental articulators.

The literature review aimed to compile and summarize the results of research relating to the recordings of condylar displacements obtained with extraoral devices, to guide clinicians to set dental (virtual) articulator parameters. The meta-analysis was undertaken to assess the sagittal condylar inclination (SCI) and transversal condylar inclination (TCI, also known as Bennett angle) values according to horizontal reference planes, movement studied, and patient characteristics: dental status, interocclusal relationship, skeletal pattern, and signs and symptoms of temporomandibular disorders (TMD). A bibliographic search was conducted in the three following electronic databases: MEDLINE, EMBASE, and Cochrane Library and Best Evidence. The review was restricted to trials involving participants meeting the following criteria: (1) adult, (2) no previous surgery in the temporomandibular region, and (3) no serious comorbidity conditions. Descriptive statistics were calculated for all study groups and were compared by applying a one-way ANOVA. All 20 articles selected corresponded to a total of 933 subjects evaluated. The recording devices and horizontal reference planes had a significant impact on the SCI values. Age, dental status, and the presence of symptoms and signs of TMD in subjects had no influence on SCI values, unlike Angle class II, division 2, the class II sagittal pattern, or the increased vertical skeletal pattern SCI parameters (P < .05). The mean TCI value was 8 degrees and was independent of individual patient characteristics and the extraoral recording device used. For accurate kinematic simulation, the patient's personal plane of reference must be transferred to the system.

Prevalence of mandibular asymmetry in different skeletal sagittal patterns.

To analyze the prevalence of mandibular asymmetry in skeletal sagittal malocclusions. PubMed/MEDLINE, EMBASE, LILACS, Web of Science, Scopus, LIVIVO and gray literature (OpenGrey, ProQuest, and Google Scholar) were electronically searched. Two independent investigators selected the eligible studies, and assessed risk of bias and certainty of evidence (GRADE). One reviewer independently extracted the data and the second reviewer checked this information. Any disagreement between the reviewers in each phase was resolved by discussion between them and/or involved a third reviewer for final decision. Electronic search identified 5,132 studies, and 5 observational studies were included. Risk of bias was low in two studies, moderate in one, and high in two. The studies showed high heterogeneity. Mandibular asymmetry ranged from 17.43% to 72.95% in overall samples. Horizontal chin deviation showed a prevalence of 17.66% to 55.6% asymmetry in Class I malocclusions, and 68.98% in vertical asymmetry index. In Class II patients, prevalence of mandibular asymmetry varied from 10% to 25.5% in horizontal chin deviation, and 71.7% in vertical asymmetry index. The Class III sample showed a prevalence of mandibular asymmetry ranging from 22.93% to 78% in horizontal chin deviation and 80.4% in vertical asymmetry index. Patients seeking orthodontic or orthognathic surgery treatment showed greater prevalence of mandibular asymmetry. Skeletal Class III malocclusion showed the greatest prevalence of mandibular asymmetry. Mandibular vertical asymmetry showed a marked prevalence in all malocclusions. However, conclusions should be interpreted with caution due to use of convenience samples and low-quality study outcomes.

Comparison of mandibular cross-sectional morphology between Class I and Class II subjects with different vertical patterns: based on CBCT images and statistical shape analysis

BackgroundThis study is aimed to (1) investigate the influence of sagittal and vertical patterns on mandibular cross-sectional morphology and to (2) provide visualized mandibular cross-sectional morphology in different groups with General Procrustes Analysis (GPA), canonical variance analysis (CVA) and discriminant function analysis (DFA).Methods324 cone-beam computed tomography (CBCT) images were collected to analyze mandibular cross-sectional morphology and were categorized into 12 groups according to sagittal and vertical pattern and gender. One-way analysis of variance (ANOVA) was used to compare the difference among the groups. Thirty equidistant points were marked along the contour of mandibular cross-section and GPA, CVA and DFA were applied.Results(1) Mandibular height in hyperdivergent groups was significantly higher than that in normodivergent and hypodivergent groups (P < 0.05). (2) Hypodivergent groups showed significantly wider upper third of mandibular width from symphysis to molar region than that in hyperdivergent group (P < 0.05), except for the premolar and molar regions in male groups (P > 0.05). (3) Class II hyperdivergent group showed narrowest lower third width in the molar region, with the mean value of 12.03 mm in females and 11.98 mm in males. (4) For males and females, the ratio between height and lower third width at symphysis was significantly higher in Class II hyperdivergent group than that in Class I hyperdivergent group (P < 0.05).Conclusions(1) The influence of vertical facial patterns on mandibular cross-sectional morphology is more obvious than that of sagittal skeletal pattern. (2) Subjects with increased vertical dimension presented with a remarkable “slimer” mandibular cross-sectional morphology at symphysis. (3) A deeper curve along the anterior contour of symphysis in Class II hyperdivergent group was noted with GPA.

Specific sagittal alignment patterns are already present in mild adolescent idiopathic scoliosis

PurposeThe complex three-dimensional spinal deformity in AIS consists of rotated, lordotic apical areas and neutral junctional zones that modify the spine’s sagittal profile. Recently, three specific patterns of thoracic sagittal ‘malalignment’ were described for severe AIS. The aim of this study is to define whether specific patterns of pathological sagittal alignment are already present in mild AIS.MethodsLateral spinal radiographs of 192 mild (10°–20°) and 253 severe (> 45°) AIS patients and 156 controls were derived from an international consortium. Kyphosis characteristics (T4–T12 thoracic kyphosis, T10–L2 angle, C7 slope, location of the apex of kyphosis and of the inflection point) and sagittal curve types according to Abelin-Genevois were systematically compared between the three cohorts.ResultsEven in mild thoracic AIS, already 49% of the curves presented sagittal malalignment, mostly thoracic hypokyphosis, whereas only 13% of the (thoraco) lumbar curves and 6% of the nonscoliosis adolescents were hypokyphotic. In severe AIS, 63% had a sagittal malalignment. Hypokyphosis + thoracolumbar kyphosis occurred more frequently in high-PI and primary lumbar curves, whereas cervicothoracic kyphosis occurred more in double thoracic curves.ConclusionsPathological sagittal patterns are often already present in curves 10°–20°, whereas those are rare in non-scoliotic adolescents. This suggests that sagittal ‘malalignment’ patterns are an integral part of the early pathogenesis of AIS.

Velopharyngeal closure pattern and speech characteristics of patients congenital velopharyngeal insufficiency

To analyze velopharyngeal closure patterns and speech characteristics of patients with congenital velopharyngeal insufficiency. Patients visiting the Department of Cleft Lip and Palate Surgery, West China Hospital of Stomatology, Sichuan University between 2009 and 2017 were reviewed. Outcomes of subjective speech evaluation, including resonance, consonant articulation, and correction rate, were analyzed. Furthermore, the mobility of soft palate and pharyngeal walls under nasopharyngeal fiberscope were analyzed retrospectively. A total of 47 cases were retrieved and subjected to nasopharyngeal fiberscopic examination. Among them, 29 (61.7%) demonstrated a circular closure pattern, 16 (34.0%) showed a coronal pattern, and 2 (4.3%) had a sagittal pattern. Furthermore, 25 (53.2%) presented medium soft-palate mobility, 22 (46.8%) had weak lateral pharyngeal wall mobility, and 41 (87.2%) had no posterior pharyngeal wall mobility. Among all of the patients, 23 (48.9%) presented medium hypernasality, accounting for the highest proportion. Consonant misarticulation occurred in 89.4% of the cases. The articulation manners with the highest correction rate were in the following order: nasal, lateral, fricatives, stops, and affricates. The articulation places with the highest correction rate were in the following order: bilabial, alveolar, velar, and linguadental. Circular closure was the most prevalent velopharyngeal closure pattern among patients with congenital velopharyngeal insufficiency, and consonant omission was the most common articulation abnormality.