Cephalometric Variables Research Articles

Correlations between Morphology, the Functional Properties of Upper Airways, and the Severity of Sleep Apnea.

Obstructive sleep apnea (OSA) is considered the silent killer pathology of the new millennium. This is due to increased risk factors such as obesity. Healthcare systems face an increasing burden from severe cases of OSA. We performed a study on a group of 152 Romanian patients with OSA recording data obtained through polysomnography and cephalometric variables, recorded in lateral plain X-rays. The results confirmed some of the data available from previous studies worldwide, but some of the variables presented a positive statistical correlation specific to our study group. For example, the apnea-hypopnea index (AHI) correlated with the uvula length but surprisingly did not correlate with body mass index (BMI) because obesity tends to become endemic in Romania. To our knowledge, this is one of the first studies focusing on cephalometric data in Romanian OSA patients. The results obtained through this study will be further analyzed in research on larger groups of Romanian OSA patients.

Correlation of cephalometric variables with obstructive sleep apnea severity among children: a hierarchical regression analysis

ABSTRACT Objective To evaluate the correlation between cephalometric parameters and apnea–hypopnea index (AHI) after controlling gender, body mass index (BMI), and adenoid size in children with obstructive sleep apnea (OSA). Methods Sixty-four children with OSA (40 males, 24 females, 8.72 ± 0.899 years) were chosen by simple random sampling for a cross-sectional study from January 2018 to March 2022. They were diagnosed with OSA, assessed by Obstructive Sleep Apnea-18 questionnaire and home polysomnography and underwent lateral cephalograms. Results Hierarchical regression analysis indicated that cephalometric parameters (except adenoid size) were associated with OSA severity, explaining 18.1% of the AHI variance. Among cephalometric measurements, AHI was positively associated with H-RGn and N-Go-Me angle (p < 0.05) and negatively associated with NP (p < 0.05). Conclusion The sagittal diameter of the oropharynx, lower gonial angle, and hyoid position are significant AHI predictors in children with OSA, independent of demographic characteristics and adenoid size.

Disc Displacement of the Temporomandibular Joint and Facial Asymmetry in Children and Adolescents: A Systematic Review and Meta-Analysis.

Subjects with facial skeletal asymmetries have a higher incidence of anterior temporomandibular joint disc displacement. The objective of the study was to consolidate existing evidence on the connection between temporomandibular joint disc displacement and mandibular asymmetry in youngsters and adolescents. A thorough examination was undertaken in the following databases: PubMed, Scopus, EMBASE, Web of Science, and Cochrane. To judge the publications’ methodological quality Newcastle Ottawa Scale was used. From the 1011 identified records, eight were selected for the qualitative synthesis and five for the quantitative synthesis, amounting to 692 subjects. Fifteen cephalometric variables were meta-analyzed. The distance from menton (Me) to midline (lateral mandibular asymmetry) was significantly shorter [−1.75 (95% CI −2.43–−1.07), p ≤ 0.001] in subjects with disc displacement compared to those without disc displacement. The distance from articulare (Ar) to gonion (Go) was significantly longer [3.74 (95% CI 1.04–6.44), p = 0.007] in subjects with disc displacement compared to those without disc displacement. The relationship between distance from articulare (Ar) to gonion (Go) or sella (S) to gonion (Go) and disc displacement was shown to be close to statistical significance level, but not for other cephalometric data. Disc displacement was associated with several cephalometric measurement variations in children and adolescents.

Características cefalométricas en la maloclusión clase II

La Organización Mundial de la Salud, considera las maloclusiones como la tercera causa de enfermedad dental. El presente estudio describe las características cefalométricas esqueletales y dentoalveolares de 58 pacientes clínicamente diagnosticados con una maloclusión clase II de acuerdo a la clasificación de Angle. Se compararon algunas características cefalométricas de los análisis de Steiner, Jarabak, Wits y Bimler, para diagnosticar y asociar la maloclusión clase II dental con la esqueletal, de acuerdo al género y la edad de crecimiento. El estudio se realizó en 58 radiografías laterales de cráneo de pacientes que asistieron a la Facultad de Odontología UNAM, en el periodo comprendido de agosto 2003 a febrero 2004, los datos se analizaron mediante la prueba “t” Student con un nivel de significancia de 0.05 o menor, al comparar el género y diferentes grupos de edades con las variables cefalométricas, resultando el 71% con una maloclusión clase II dental y esqueletal, predominando la alteración mandibular en el género femenino y maxilar en el masculino. Se concluyó que la maloclusión clase II dental no siempre corresponde a una clase II esqueletal.

Correlation between Apnea Severity and Sagittal Cephalometric Features in a Population of Patients with Polysomnographically Diagnosed Obstructive Sleep Apnea.

Background and Objective: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder featuring a repeated closure of the upper airway during sleep. Craniofacial anatomy is a potential risk and worsening factor for OSA. This study aims to assess the relationship between cephalometric features of craniofacial morphology and OSA severity in a population of patients with OSA. Material and Methods: A sample of forty-two patients (n = 42, M = 76%, mean age = 57.8 ± 10.8) with a polysomnographically (PSG) confirmed diagnosis of OSA were recruited and underwent cephalometric evaluation of 16 cephalometric variables. In addition, the apnea–hypopnea index (AHI), oxygen desaturation (SatMin), Epworth sleepiness scale (ESS), and body mass index (BMI) were assessed. Then t-tests were performed to compare the values of all cephalometric variables between two AHI severity-based groups (mild-to-moderate = AHI ≤ 30; severe = AHI > 30). Single- and multiple-variable regression analyses were performed to assess the associations between AHI scores and cephalometric features. Results: Mean AHI, SatMin, and BMI were 31.4 ev/h, 78.7%, and 28.1, respectively. The cephalometric variables were not significantly different between the two OSA-severity groups (p > 0.05). Multiple-variable regression analyses showed that gonial angle and nasopharynx space were negatively associated with AHI, explaining 24.6% of the total variance. Conclusion: This investigation reported that severity of AHI scores in patients with OSA showed a negative correlation with gonial angle and nasopharynx space. As a general remark, although maxillofacial anatomy can be a predisposing factor for OSA, disease severity depends mainly upon other variables.

Influence of rapid maxillary expansion in the stability of anterior open bite treatment.

This study aimed to compare the stability of anterior open bite (AOB) in patients treated with and without rapid maxillary expansion (RME) before fixed palatal crib (PC) therapy in the mixed dentition. Expansion/palatal crib group (EPC) was comprised of 25 patients (10 male, 15 female, mean initial age of 7.8years) with AOB treated with RME before PC therapy. Palatal crib group (PC) included 25 patients with AOB (10 male, 15 female, mean initial age of 8.0years) treated only with PC therapy. Lateral cephalograms were analyzed at pre-treatment (T0), after PC therapy (T1), and 3years after PC removal (T2) in both groups. AOB relapse was considered when a negative overbite was observed at T2. Intergroup comparisons of interphase changes were performed using t and Mann-Whitney tests (p < 0.05). Treatment and post-treatment alterations showed similar changes in both groups for all cephalometric variables. Overall changes from T0 to T2 were similar between the groups except for the maxillary incisors that tipped lingually in PC group (1.PP = - 3.37°) and labially in EPC group (1.PP = 1.76°). The frequency of AOB relapse was 8% and 4% in the EPC and PC groups, respectively. Treatment time in the EPC group (9.7months) was shorter (p = 0.024) when compared to the PC group (11.0months). In the mixed dentition, stability of AOB treated with RME before fixed PC therapy was similar to PC therapy alone. However, treatment time with fixed PC was slightly shorter in the group treated with RME. This study aims to understand if RME performed previously to fixed palatal crib contributes to the index of stability of AOB treatment in the mixed dentition.

Age, Sex, and Maxillary Position Are Associated with Successful Microimplant-Assisted Rapid Palatal Expansion in Adults

The purpose of this study was to investigate the possible predictors of success of microimplant-assisted rapid palatal expansion (MARPE) in skeletally mature patients. Additionally, factors associated with the amount of maxillary expansion were analyzed. Factors associated with MARPE success were analyzed in 53 adult patients (27 males, 26 females, mean age 25.8 ± 8.9 years, and range 18.0 to 56.6 years) who had a maxillary transverse deficiency greater than 2 mm and a cervical vertebral maturation stage of 6. Age at pretreatment (T1), sex, sutural bone density at T1, type of appliance, mode of microimplant fixation, and lateral cephalometric variables at T1 were considered for inclusion as predictors for MARPE success. In patients who showed successful maxillary skeletal expansion, the linear distances of maxillary widths were measured on cone-beam-computed-tomography images at T1 and after MARPE (T2), and factors associated with the amount of expansion were analyzed. In total, 41 of the 53 patients showed successful maxillary expansion. Age (p = 0.019), sex (p = 0.002), and A-N perp (p = 0.015) were significantly associated with the success of MARPE. The factors associated with the amount of maxillary skeletal expansion were SN-MP and midpalatal-suture density at T1. In conclusion, there is a greater chance of failure in male patients who are older and have maxillary retrusion. A greater amount of maxillary expansion can be expected in patients with a higher mandibular-plane angle and with lower midpalatal-suture density.

Cephalometric Variables Prediction from Lateral Photographs Between Different Skeletal Patterns Using Regression Artificial Neural Networks.

This study aimed to design an artificial neural network for the prediction of cephalometric variables via a lateral photo- graph in skeletal Class I, II, and III patterns. A total of 94 patients were recruited for this prospective study, with an age range of 15-20 years (41 boys and 53 girls) seek- ing orthodontic treatment. According to cephalometric analysis, using AutoCAD 21.0, they were allocated into three groups. Thirty with skeletal Class I (14 boys and 16 girls), 34 with skeletal Class II (14 boys and 20 girls), and 30 with skeletal Class III malocclusion (13 boys and 17 girls) according to SNA, SNB, and ANB angles measured from cephalometric radiographs. The study includes (1) finding the correlation of the skeletal measurements between lateral profile photographs and cephalometric radiographs for the recruited patients and (2) designing a specific artificial neural networks for the assessment of skeletal factors via lateral photographs, these artificial neural networks are trained and tested with the total of 94 standard lateral cephalograms. This novel Network provided models of regression that can forecast the cephalometric variables through analogous photo- graphic measurements with excellent predictive power R = 0.99 and limited estimation error for each malocclusion (Class I, II, and III). This study suggests that artificial intelligence would be useful as an accurate method in orthodontics for the prediction of cephalometric variables and its performance was achieved by several factors such as proper selection of the input data, preferable generalization, and organization.

Prognostic Factors for Orthognathic Surgery in Children With Cleft Lip and/or Palate: Dentition and Palatal Morphology.

To determine dental and palatal morphology in children with cleft lip and/or palate (CL/P) and identify morphological prognostic factors for orthognathic surgery (OGS). Retrospective cohort study. Orthodontic department of a university dental hospital. This study included 80 patients with bilateral and unilateral CL/P who had lateral cephalograms at the ages of 7 (T1), 15 (T2) years, and a dental plaster model at T1. Plaster models at T1 were scanned with a three-dimensional (3D) scanner. Morphological features were extracted from 3D models with geometric morphometrics software as principal components (PCs). The combinations of the PCs and other predictive factors (ie, the No. of clefts in the lip and alveolus, the palatal repair method, sex, cephalometric variables at T1, and the No. of missing teeth) were examined by logistic regression to determine the predictability for OGS. The need for OGS and skeletal and dental discrepancies at T2 were examined as outcomes. Shrinkage of the palate, including vertical shallowing and transverse narrowing of the posterior maxilla and cleft-side asymmetry of the anterior maxilla at T1, as well as the No. of clefts in the lip and alveolus, the palatal repair method, male sex, several cephalometric variables for the sagittal and vertical dimensions, and the No. of missing teeth, were found to be predictive factors for OGS. Morphological prognostic factors for OGS in children with CL/P were determined.

Vowel sound production and its association with cephalometric characteristics in skeletal Class III subjects.

This study aimed to evaluate differences in vowel production using acoustic analysis in skeletal Class III and Class I Japanese participants and to identify the correlation between vowel sounds and cephalometric variables in skeletal Class III subjects. Japanese males with skeletal Class III (ANB < 0°) and Class I skeletal anatomy (0.62° < ANB < 5.94°) were recruited (n = 18/group). Acoustic analysis of vowel sounds and cephalometric analysis of lateral cephalograms were performed. For sound analysis, an isolated Japanese vowel (/a/,/i/,/u/,/e/,/o/) pattern was recorded. Praat software was used to extract acoustic parameters such as fundamental frequency (F0) and the first four formants (F1, F2, F3, and F4). The formant graph area was calculated. Cephalometric values were obtained using ImageJ. Correlations between acoustic and cephalometric variables in skeletal Class III subjects were then investigated. Skeletal Class III subjects exhibited significantly higher/o/F2 and lower/o/F4 values. Mandibular length, SNB, and overjet of Class III subjects were moderately negatively correlated with acoustic variables. This study did not take into account vertical skeletal patterns and tissue movements during sound production. Skeletal Class III males produced different /o/ (back and rounded vowel), possibly owing to their anatomical positions or adaptive changes. Vowel production was moderately associated with cephalometric characteristics of Class III subjects. Thus, changes in speech after orthognathic surgery may be expected. A multidisciplinary team approach that included the input of a speech pathologist would be useful.

Heritability of maxillary dental cephalometric variables among monozygotic twins, dizygotic twins and their siblings.

The purpose of this study was to investigate the heritability of dental cephalometric variables by analyzing vertical linear measurements and angular measurements of the upper incisor, canine, and first molar. Among the 553 Korean patients who participated in twin studies conducted at Samsung Medical Center, 150 patients had their lateral cephalometric radiograph data included in this study. The group was comprised of 36 monozygotic (MZ) twins (males, 16 pairs; females, 20 pairs), 13 dizygotic (DZ) twins (males, 7 pairs; females, 6 pairs), and 26 same-sex sibling pairs (males, 11 pairs; females, 15 pairs). All patients were over 20years old with a mean age of 39.75years. Lateral cephalometric diagrams and linear measurements (6 vertical factors, 6 horizontal factors) were taken. Three axial planes were measured for each tooth; intraclass correlation coefficients (ICCs) were obtained for each group and heritability was calculated using Falconer's method. ICCs of vertical linear measurements (average 0.837, P < 0.01) and the tooth axis of the central incisor and canine (average 0.679, P < 0.001) were higher in the MZ group compared to the DZ and sibling groups; thus, these variables showed high heritability. Orthodontic treatment aiming to alter the tooth axis of the maxillary central incisor or canine or other vertical factors with greater heritability can be difficult, requiring strategic treatment planning to achieve desired treatment outcome and stability. The active early treatment to gain tooth eruption space can lead to normal tooth position.

Skeletal, Dental and Soft Tissue Cephalometric Changes after Orthodontic Treatment of Dental Class II Malocclusion with Maxillary First Molar or First Premolar Extractions.

The aim of the present retrospective study was evaluating skeletal, dental and soft tissue changes of two groups of Class II patients orthodontically treated with extractions of upper first premolars (U4 group) and upper first molars (U6 group). In total, 21 patient records (9M and 12F; mean age 12.5 ± 1.2 years) were selected for the U4 group, and 38 patient records (17M and 21F; mean age 13.2 ± 1.3 years) were recruited for the U6 group. Twenty cephalometric variables were analysed on standardised lateral cephalograms at baseline (T0) and at the end of orthodontic treatment (T1). Means and standard deviations (SDs) were calculated for both groups and increments were calculated. After revealing the normal distribution of data with the Shapiro–Wilk test, Student’s t-test was used to compare variables at T0 between groups. A paired t-test was used to analyse changes between time points within each group, and Student’s t-test to compare differences between groups at T1. Both groups showed a significant increase in the distance among upper second molars and the vertical pterygoid line (PTV-maxillary second molar centroid U6 group: 6.66 ± 5.00 mm; U4 group: 3.66 ± 2.20 mm). Moreover, the distance of upper incisors to the palatal plane significantly increased (PP-maxillary incisor tip U6 group: 1.09 ± 1.52 mm; U4 group: 0.20 ± 2.00 mm; p = 0.061). Significant changes were found for overjet (U6 group: −4.86 ± 1.62 mm; U4 group: −3.27 ± 1.90 mm; p = 0.001). The distance between upper lip and esthetic plane showed a significantly reduction in both groups (ULip-E Plane U6 group: −2.98 ± 1.65 mm; U4 group: −1.93 ± 1.57 mm). No statistically significant changes were found in sagittal or vertical skeletal values. The significantly larger reduction of upper lip protrusion and overjet in the U6 group compared to the U4 group suggests preferring molar extraction treatment for severe Class II with protrusive soft tissues’ profile and increased overjet. Since no differences on vertical values were found, an increased SN^GoGn angle should not be considered a discriminating factor for choosing molar extraction treatment.

Iatrogenic retroposition of the lips sequel after bicuspid extraction-a retrospective study

AimThis study aims to explore the prevalence of Iatrogenic retroposition of the lips sequel (IRLS) after bicuspid extraction, associated dentofacial characteristics and the effectiveness of surgical treatment. Materialand methods: Patients with bicuspid extraction as part of an orthodontic treatment plan were retrospectively included. IRLS was identified by clinical evaluation and cephalometric Legan and Burstone analysis. Association of demographic and cephalometric variables were assessed. The effectiveness of combined orthodontic-orthognathic correction of the retroposition of the lips was evaluated. ResultsOut of 144 patients with extracted bicuspids, eight Class I patients, nine Class II patients and five Class III patients were seeking treatment because their lips had retruded as a consequence of compensating orthodontic treatment. Lower jaw bicuspid extraction and a decreased vertical facial height in Class II patients correlated significantly more with IRLS development. Postoperative cephalometric analysis of orthodontic-orthognathic treated patients reported improvement in lip projection and naso-labial angle. Only two Class I patients reported postoperative normalization of the lip position according to Legan and Burstone. ConclusionThe consequence of bicuspid extractions on soft tissue profile differs according to skeletal jaw relation. The impact of orthognathic surgery on IRLS is beneficial, although insufficient to completely correct the facial profile when judged on cephalometric standards.

Volumetric Analysis of the Jaws in Skeletal Class I and III Patients with Different Facial Divergence Using CBCT Imaging.

Aim The main objective was to evaluate any possible maxillary or mandibular volumetric difference between hyperdivergent skeletal Class III (CIII), normodivergent skeletal CIII, hypodivergent skeletal CIII, and normodivergent skeletal Class I (CI) patients using cone-beam computed tomography (CBCT) images. Also, the secondary objective was to investigate any possible correlation between CBCT-derived lateral cephalometric variables and the mandibular and maxillary volumes (MdV and MxV, respectively). Materials and Methods 80 CBCT images of patients between 18 and 32 years of age were taken with one CBCT imaging device (Scanora 3D®, Soredex, Tuusula, Finland). The sample consisted of four groups: 20 hypodivergent skeletal CIII (11 males and 9 females), 20 normodivergent skeletal CIII (7 males and 13 females), 20 hyperdivergent skeletal CIII (8 males and 12 females), and 20 normodivergent skeletal CI (5 males and 15 females). The volumes of both jaws and the ratio of MxV/MdV were obtained using Mimics™ 19 software (Materialise, NV, Belgium), and 2D variables were obtained from CBCT-derived lateral cephalogram using AudaxCeph™ software (Orthodontic software suite, Ljubljana, Slovenia). One-way ANOVA test and Kruskal–Wallis analysis were employed to detect any possible significant difference between the volumetric variables, whereas Pearson's and Spearman's correlation coefficients were calculated to detect any possible relationship between the 2D variables and the volumetric measurements. Results There were no statistically significant differences in the maxillary volume or maxillary/mandibular ratio between the four groups (p=0.081 and 0.432, respectively). There was a significant difference in MdV between CIII hypodivergent (higher mean) and CIII hyperdivergent (p=0.039). There were some correlations between the MdV and 2D variables in the four studied groups especially in the posterior facial height (S-Go) and the facial depth (N-Go). There were some weaker correlations between the MxV and some 2D variables in the CIII hypodivergent and hyperdivergent groups. Conclusions The mandibular volume of the Class III hypodivergent patient was significantly greater than that of the Class III hyperdivergent patients. Correlations between the maxillary or mandibular volumes were found with some of the 2D variables. The volume of both jaws increased when the maxillofacial complex moved toward a horizontal growth pattern.

Effect of Twin-block Appliance on Pharyngeal Airway, Sleep Patterns, and Lung Volume in Children with Class II Malocclusion

In this study, we sought to evaluate the effect of the twin-block appliance on pharyngeal airway dimensions, sleep patterns, and lung volumes in growing children with class II malocclusion with a retrognathic mandible. Twenty children aged 9-12 years with class II malocclusion with a retrognathic mandible participated in the study. A validated sleep questionnaire assessed the sleep patterns and the sleep problems of the children. The pre-treatment cephalometric variables and the pharyngeal airway passage (PAP) dimensions were analyzed. Spirometry tests were performed to evaluate lung volumes. A custom-made twin-block appliance was fabricated, and children were instructed to wear it for a minimum of 10 months. All variables including sleep problems, cephalometric variables, and pharyngeal airway measurements were evaluated post-treatment. Spirometry tests were re-evaluated at the end of the twin-block treatment. All data were statistically analyzed. Post-twin-block appliance treatment, there was a definite decrease in snoring, noisy breathing, and sleeping with mouth open. The sella-nasion to B point angle (SNB), mandibular length, the depths of oropharynx, nasopharynx, and hypopharynx as well as the height of nasopharynx (HNP) were significantly increased post-treatment (p <0.001). The length and thickness of soft palate (SPI) increased significantly (p <0.001), while its inclination decreased significantly (p <0.001). We found improvements in forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV1); however, the changes were statistically not significant (p = 0.88 and p = 0.78). Twin-block appliance significantly increased the pharyngeal airway dimensions and improved the length and thickness of the soft palate in children with class II malocclusion. Post-twin-block treatment showed a considerable reduction in the sleep problems of the children. The lung volume measurements showed improvement; however, it was not statistically significant. Twin block may be used not only to correct the facial disharmony of children with a retrognathic mandible but also to improve the airway dimensions and lung volume as well as to reduce the sleep-disordered symptoms.

Dental, skeletal, and soft-tissue changes in adult orthodontic patients treated with premolar extraction and nonextraction: A cross-sectional study

Various treatment modalities exist to improve and correct Class I malocclusion. This study evaluated the dental, skeletal, and soft-tissue changes in patients treated by premolar extraction (PME) and nonextraction. A cross-sectional study was conducted, including subjects ideally planned for PME. Pretreatment and posttreatment lateral cephalograms were compared among the 2 groups. The American Board of Orthodontics Objective Grading System (ABO-OGS) was used to score the posttreatment casts, and soft-tissue profile silhouettes were judged by a panel of orthodontists to evaluate the improvement among the 2 groups. Comparisons between the 2 groups were performed using the Mann-Whitney U test.Spearman correlation was used to study the correlation between the assessment methodologies. Highly significant differences were observed between the 2 groups for ABO-OGS scores (P≤0.001) and profile silhouette assessment (P≤0.001). Compared with posttreatment cephalometric readings, highly significant differences were seen for the dental variables: SN-U1, IMPA, and interincisal angle (P≤0.001). Statistically significant differences were seen for all soft-tissue cephalometric variables. Highly significant moderate to negative correlation (r= -0.410, P≤0.001) was seen between profile silhouettes and ABO-OGS alignment scores. Highly significant strong negative correlation (r= -0.642, P≤0.001) was seen between profile silhouettes and the lower lip. Dental and soft-tissue changes were highly significant and were found to be in the ideal range when treated with PME. However, PME and nonextraction treatment modalities did not significantly affect the skeletal parameters as seen on the lateral cephalogram.

Current Trends in Skeletal Borderline Patients: Surgical versus Orthodontic Treatment Decisions—What Is the Evidence?

Background: The aim is to assess the current evidence-based knowledge about treatment decisions for skeletal malocclusion in adult borderline patients. Methods: A literature search was conducted through three databases. Inclusion criteria were restricted to systematic reviews, prospective, retrospective, and control studies. Only articles comparing orthodontic camouflage and orthognathic surgical treatment for Class II and Class III malocclusions in adult patients were selected to be reviewed. Results: Seven articles concerning Class II and nine concerning Class III met the inclusion criteria. Scientific evidence was poor due to low methodological quality. Conclusions: Surgical treatment was found to better improve skeletal and soft-tissue cephalometric values, whereas camouflage treatment mainly involved dentoalveolar movements. Aesthetic changes, as perceived by the patient, were not significantly different in the two groups. Recently improved surgical techniques, differing from those described in the analyzed articles, may provide similar or more stable outcomes compared with orthodontic-only treatment. Although some cephalometric variables can be helpful, the most important parameters for treatment selection are the patient’s presenting complaint and their self-image perception. Further studies with larger sample sizes and similar pretreatment conditions, and considering patient self-evaluation of esthetics and function, should be undertaken.

A retrospective study of factors contributing to anchorage loss in upper premolar extraction cases.

Anchorage control is one of the components in the treatment of extraction cases. However, what determines more or less anchorage loss is still an unanswered question. Aim: The purpose of this study was to investigate the most important factors contributing to the anchorage loss of maxillary first molars in premolar extraction cases. The study included 726 upper premolar extraction cases, including 214 male patients and 512 female patients, and the mean age was 14.4 ± 4.5 years old (range: 9-45). Factors including physiological characteristics, treatment mechanics, and cephalometric variables were collected and their influences on the angulation changes of maxillary first molars were analyzed. The mean angulation change of maxillary first molar after treatment was 2.81°(mesial tipping). The change of UM/PP showed a statistically significant difference in different sex (male 3.84° ± 5.26° vs female 2.38° ± 5.10°), age (adult -0.05° ± 4.73° vs teenager 3.46° ± 5.07°), and molar relationship (Class II 3.28° ± 5.15° vs Class I 2.36° ± 5.19°). There are six variables accounted in the regression analysis (R = 0.608, R2 = 37.0%). Among them, the pre-treatment molar tipping (Standardized Coefficients: -0.65) and the pre-treatment incisor/molar height ratio (Standardized Coefficients: -0.27) were the most important factors influencing anchorage loss during treatment. Compared with treatment-related factors, the patient's physiological characteristics play a more important role in anchorage loss. The pre-treatment angulation of the maxillary first molar is the most influential factor in changes to maxillary molar angulation, which are often predisposing anchorage loss.

Orthodontic space management in first molar missing or unusual extraction patients

This article aimed to describe the various clinical considerations when opening or closing first molar spaces caused by missing or extracted first molars. Orthodontic patients sometimes need unusual first molar extraction or have some missing first molars. Orthodontic treatment can manage those spaces in one of two ways: prosthetic treatment preceded by regaining orthodontic space by uprighting the adjacent teeth or orthodontic space closure without additional prostheses. To determine whether to close or open the first molar missing or extracted spaces, various factors, including adjacent periodontal status, maxillary sinus pneumatization, gingival invagination, different malocclusions, and cephalometric variables and facial treatment objectives, should be considered. The first molar missing or unusual extraction spaces should be managed with careful consideration and proper orthodontic mechanics to maximize the benefits of treatment and minimize potential risks. The chances of extraction of problematic molar vs sound premolar and molar extraction space closure with missing spaces, rather than opening spaces, increase with the development of orthodontic mechanics. Therefore, it is essential to understand the factors that determine the prognosis.

Functional orthopedic treatment for anterior open bite in children. Asystematic review of randomized clinical trials.

This systematic review aimed to assess the effects of orthopedic functional appliances for anterior open bite (AOB) in primary or mixed dentition children. A search for randomized controlled trials (RCT) was conducted in November 2020 in electronic databases with no data or language restrictions. Primary outcomes were skeletal cephalometric variables and adverse events. We used the Cochrane risk-of-bias tool to assess methodological quality and the GRADE approach to assess the certainty of the evidence. We identified five RCTs (220 participants). Very low certainty evidence showed an improvement in overbite (mean difference [MD] 3.60; 95% confidence interval [CI] 2.63-4.57) and in the angulation of the upper incisors to the palatal plane (MD 3.70; 95% CI 0.85-6.55) with Frankel's functional regulator, compared to no treatment. There was no difference in the measured cephalometric variables when comparing removable palatal crib to fixed palatal crib, bonded spurs, and chin cup. When comparing removable versus magnetic bite blocks, abeneficial effect was observed in overbite, overjet, skeletal anteroposterior angular measurements, and skeletal vertical linear measures in the magnetic group. No adverse events were reported. There was insufficient evidence to infer the effects of these treatments for AOB, and high-quality RCTs are needed to increase the estimated effects. CRD42020175634, prospectively registered (05July 2020).