Global distribution of malocclusion traits: A systematic review

Novel concept for posterior crossbite correction : Preliminary results

PURPOSE

The efficiency of dentoalveolar compensation involving both jaws for posterior crossbite correction using computer-aided design/computer-aided manufacturing (CAD/CAM) expansion and compression archwires was evaluated. Treatment outcome was tested against the null hypothesis that the transverse correction achieved would be significantly smaller than planned.

METHODS

This retrospective study included 64 patients (mean age 23.5 years, median 17.0, minimum/maximum: 9.0/63.0, standard deviation 13.7) with uni- or bilateral posterior crossbite. In all consecutively debonded patients, expansion and/or compression archwires were used for dentoalveolar correction involving both jaws. Plaster casts prior to (T1) and following treatment (T2) with completely customized lingual appliances (CCLA) were compared with the treatment plan represented by an individual target set-up. The statistical analysis was carried out using the Schuirmann TOST (two one-sided t‑tests) equivalence test on the basis of a one-sample t‑test with α = 0.025 to one side. The non-inferiority margin was set at δ = 0.5 mm.

RESULTS

All posterior crossbites could be corrected by dentoalveolar compensation involving both jaws. The mean total correction achieved was 6.9 mm (mean maxillary expansion: 4.3 mm/mean mandibular compression: 2.6 mm) with a maximum of 12.8 mm. The transverse corrections achieved in both arches at T2 were equivalent to the planned corrections in the set-up (p < 0.001).

CONCLUSION

The results of this study indicate that CAD/CAM expansion and compression archwires can be an efficient tool to achieve the desired correction in patients with a posterior crossbite even in more severe cases.

A Fully Integrated Orthodontic Aligner With Force Sensing Ability for Machine Learning-Assisted Diagnosis

Currently, the diagnosis of malocclusion is a highly demanding process involving complicated examinations of the dental occlusion, which increases the demand for innovative tools for occlusal data monitoring. Nevertheless, continuous wireless monitoring within the oral cavity is challenging due to limitations in sampling and device size. In this study, by embedding high-performance piezoelectric sensors into the occlusal surfaces using flexible printed circuits, a fully integrated, flexible, and self-contained transparent aligner is developed. This aligner exhibits excellent sensitivity for occlusal force detection, with a broad detection threshold and continuous pressure monitoring ability at eight distinct sites. Integrated with machine learning algorithm, this fully integrated aligner can also identify and track adverse oral habits that can cause/exacerbate malocclusion, such as lip biting, thumb sucking, and teeth grinding. This system achieved 95% accuracy in determining malocclusion types by analyzing occlusal data from over 1400 malocclusion models. This fully-integrated sensing system, with wireless monitoring and machine learning processing, marks a significant advancement in the development of intraoral wearable sensors. Moreover, it can also facilitate remote orthodontic monitoring and evaluation, offering a new avenue for effective orthodontic care.

Detection of Lip, Tongue, Masseter, and Temporalis Muscle Contractions with Electromyography Tools as an Early Diagnostic Medium for Dentoalveolar Malocclusion

OBJECTIVES

 This study aims to detect early class I, II, and III malocclusions through the muscle strength of the lips, tongue, masseter, and temporalis.

MATERIALS AND METHODS

 The study subjects were 30 pediatric patients with predetermined criteria. The subjects were divided into class I, II, and III malocclusions where each classification of malocclusion amounted to 10 people. Subjects were differentiated according to gender and age. Tongue pressure during swallowing was recorded by a palatal measurement sensor system. The strength of the activity was assessed when the lip muscles resisted as hard as possible the traction plate placed between the teeth and the lips, then the force was connected to an electromyograph (EMG) to be measured. Temporal and masseter muscle contractions were assessed when the muscles performed swallowing, chewing, mouth opening, resting, mouth closing, and biting movements.

STATISTICAL ANALYSIS

 Data analysis using the SPSS application was performed with the ANOVA test if the data distribution was normal, and if the data distribution was not normal, then the Kruskal-Wallis test was used. Significant data were evaluated by post-hoc tests using least significant difference if the data distribution was normal or the Mann-Whitney test if the data distribution was not normal.

RESULTS

 It was found that there was a significant difference in the left masseter muscle and left temporalis muscle.

CONCLUSION

 EMG can be considered as a tool to detect class I, II, and III malocclusions through muscle contraction. Biting and chewing positions have satisfactory EMG examination results for malocclusion detection. Age and gender of the child may affect the results of EMG examination in certain conditions.

A 3-dimensional comparative assessment of the dentoskeletal effects of clear aligners vs temporary skeletal anchorage device-assisted posterior intrusion in adolescents with anterior open bite: A single-center, retrospective, cohort study

INTRODUCTION

The dentoskeletal effects of clear aligner treatment (CAT) with Invisalign vs temporary skeletal anchorage device-anchored Sydney intrusion spring (SIS) were compared in consecutively treated growing patients with anterior open bite using cone-beam computed tomography scans.

METHODS

Fifteen adolescents treated exclusively with Invisalign, and 14 with SIS (first-phase treatment) were assessed retrospectively. Rigid-wise, voxel-based registration of pretreatment and posttreatment cone-beam computed tomography scans were performed using the anterior cranial base, maxillary plane, and mandibular body as reference regions. Treatment outcomes were compared between groups using median regression modeling.

RESULTS

Molar intrusion and incisor extrusion (millimeters), as well as buccolingual inclination changes (°), were not expressed as prescribed in the ClinChecks for Invisalign. Both treatment modalities resulted in similar improvement of anterior open bite; however, via different mechanics. Compared with CAT, SIS demonstrated significantly greater intrusion of the maxillary first molars when measured from the mesiobuccal (16: 2.09 mm [95% confidence interval {CI}, 1.05-3.12]; 26: 2.98 mm [95% CI, 2.00-3.96]) and palatal cusps (16: 2.08 mm [95% CI, 1.15-3.01], 26: 2.83 mm [95% CI, 1.92-3.74]) and less extrusion of the maxillary incisors (12: -1.30 mm [95% CI, -2.13 to -0.47], 11: -1.30 mm [95% CI, -2.40 to -0.20], 21: -0.92 mm [95% CI, -1.73 to -0.12], 22: -0.85 mm [95% CI, -1.71 to -0.00]). There was weak evidence of association with less extrusion of the mandibular incisors using SIS. Maxillary and mandibular incisors tipped lingually in both groups with no statistical difference across groups.

CONCLUSIONS

SIS demonstrated greater maxillary molar intrusion, whereas CAT was associated with incisor extrusion.

Possible link between the preferential unilateral chewing side and eruptive guidance of the maxillary canine germ : Cross-sectional study on panoramic radiographs

AIM

To determine whether unilateral preferent chewing (UPC) affects the position and angulation of the permanent maxillary canine germ on the preferred side.

MATERIALS AND METHODS

In a retrospective cross-sectional study, medical records from children 7.91(± 0.8) years old with unilateral preferred chewing side and unilateral posterior crossbite were selected. The position of the maxillary canines was analysed by measuring the following angles and distances: the angles formed between the canine axis and the midline (PS; potential impact range > 15°), and that between the canine axis and the bicondylar line (W; potential impact range < 75°). In addition, the canine's position with respect to the lateral incisor (EK; potential impact range > II) and the distance between the canine cusp and the occlusal plane (CCOP potential impact range > 10 mm) were measured.

RESULTS

The final sample consisted of 106 radiographs; thus, a total of 212 maxillary canines were analysed. Tooth angulation on the preferred chewing side was higher for the angle PS with an average angle of 13.88° (± 7.56) and its position was more frequently found in sector II (49.1%), according to the EK analysis, compared to its contralateral that had an average of 11.75° (± 10.13) for the PS angle and a frequency of 67% in the sector I (p < 0.05 in both analyses). The data obtained for the angle W resulted in an average of 76.12° (± 9.09), while on the contralateral side it was 77.16° (± 12.56; p = 0.012). Lastly, according to the CCOP analysis, the preferred chewing side measured on average 15.3 mm (± 2.4), while on the nonpreferred side it was 15.19 mm (± 2.43; p = 0.143).

CONCLUSIONS

Based on this research, UPC seems to have a certain unfavourable influence on canine position and angulation. Thus, this is another factor to consider in decision-making regarding early treatment of this development disorder.

Dentoskeletal effects of miniscrew-anchored maxillary protraction: Evaluating the role of mandibular anchorage bar and night facemask

INTRODUCTION

This study evaluated the dentoskeletal effects of miniscrew-anchored maxillary protraction, which included a mandibular anchorage bar and a night facemask in adolescents.

METHODS

A total of 20 growing patients with Class III malocclusion and maxillary deficiency were treated with a hybrid hyrax expander with 2 miniscrews in the maxilla and a mandibular anchor bar supported in 2 miniscrews in the anterior region of the mandible. Class III elastics were used from the maxillary first molars to the mandibular anchorage bar, joining the mandibular miniscrews installed between permanent incisors and canines. The variables that met the presuppositions of a parametric analysis were analyzed using the paired t test, and the remaining variables were analyzed using the nonparametric Wilcoxon paired test.

RESULTS

The final sample included 17 subjects (4 females and 13 males; initial age, 12.3 ± 1.2 years). The results demonstrated a significant increase in Wits appraisal (mm), ANB (°), SNA (°), N perp-A (mm), Co-A (mm), Co-Gn (mm), AFAI (mm), molar relationship (mm), overjet (mm), U6-vertical Pt (mm), L1-NB (mm) and U1-L1 (°) (P <0.05).

CONCLUSIONS

The study showed that miniscrew-anchored maxillary protraction associated with facemasks and mandibular anchorage bars produces positive skeletal effects in adolescents while also favoring the control of dental effects.

Evaluation of Facial Aesthetic Changes in Growing Class II Patients Treated with Herbst or Elastodontics: A Retrospective Study

Objective: The objective of this study was to evaluate the facial profile changes of patients treated for class II skeletal malocclusions with an elastodontic appliance compared to those treated with the Herbst appliance and a control group. Methods: Forty class II patients were treated using an elastodontic appliance (Group EA) and were compared to 40 patients treated with the Herbst appliance (Group H) and to 40 untreated class II children (Group C). Aesthetic profile variables were analysed using Arnett's analysis. Cephalograms were compared pre-treatment (T0) and post-treatment (T1). The Wilcoxon signed-rank test or paired-samples t-test was used for pairwise comparison of cephalometric measurements taken at T0 and T1. One-way ANOVA and Tukey's post hoc test were performed to assess differences between the groups. Results: In the elastodontic group, the inclination of the upper incisors increased by 4.05°. In addition, the Pog-TVL and B-TVL distances decreased by 2.84 mm and 1.79 mm, respectively. In patients treated with an elastodontic appliance, the inclination of the upper incisors increased by 4.05°. In addition, the Pog-TVL and B-TVL distances decreased by 2.84 mm and 1.79 mm, respectively. In patients treated with the Herbst appliance, the inclination of the lower incisors increased by 6.11°. Furthermore, the treatment resulted in reductions in the Pog-TVL distance (2.58 mm), the B-TVL distance (2.26 mm), and the LL-TVL distance (2.31 mm). Conclusions: The profile changes achieved by both devices are favourable for correcting class II skeletal malocclusion.

Three-dimensional assessment of mandibular asymmetry in patients with unilateral cleft lip and palate at different growth stages: a cross-sectional study

INTRODUCTION

The early diagnosis of mandibular asymmetry (MA) in patients with unilateral cleft lip and palate (UCLP) can contribute to its treatment.

OBJECTIVE

The aim of this study was to evaluate the occurrence and the extent of MA in UCLP patients at different growth stages.

METHODS

Cone-beam computed tomography (CBCT) of 47 UCLP patients were included, and divided into two groups (prepubertal stage and pubertal stage). The mandibular ramus height (Co-Go), mandibular body length (Go-Me), total mandibular length (Co-Me), gonial angle (CoGoMe), the volume of the mandibular condyles, and lateral chin deviation were evaluated. The cleft side (CS) and noncleft side (NCS) were compared using the paired t-test for dependent samples. Chin deviation and its possible association with specific sides were evaluated using the Mann-Whitney and Fisher's Exact tests, respectively. The significance level was set at 5%.

RESULTS

Comparison of CS and NCS revealed that in prepubertal stage, Co-Me was shorter (105.5 ± 5.7 mm; p = 0.036) in the CS, and that in pubertal stage, Co-Go was lower (46 ± 6 mm; p= 0.004) and Go-Me was greater (78.5 ± 5.8 mm; p = 0.026) in the CS. In both growth stages, a significant association (p< 0.05) was observed between the side to which the chin has deviated and the CS.

CONCLUSIONS

Although patients with UCLP in the prepubertal and pubertal stages presented significant measurements revealing MA, only Co-Go in the pubertal stage showed a clinically relevant difference. This specific result indicates that MA must be monitored during patients' growth.

Investigation of oral health findings and genotype correlations in osteogenesis imperfecta

Osteogenesis imperfecta, a common genetic connective tissue disorder affecting bone with multisystemic implications, is caused by genomic alterations at various levels that disrupt the biosynthesis stages of collagen Type I. This study evaluated the intraoral and clinical findings of 43 OI cases in relation to genetic variants, aiming to contribute new insights into the roles of collagen and non-collagen genes in the oral-dental pathology of OI. Significant associations were found between OI variants and dental anomalies such as dentinogenesis imperfecta, enamel hypoplasia, taurodontism, and hypodontia. COL1A1/2-truncated variants were linked to atypical intercanine width, and midface hypoplasia correlated with reduced overjet and overbite. Bisphosphonate treatment, especially when initiated before age two, was associated with enamel hypoplasia. Oral hygiene habits, including brushing frequency and use of additional products, were linked to lower DMFT. In the OI group, significant associations were noted between Angle Class III malocclusion and reduced brushing frequency, as well as between deep palatal vault and increased DMFT. A correlation was also observed between maximum mouth opening and joint hypermobility. These findings, along with new dental observations related to non-collagen variants, shed light on the oral health challenges in OI patients. Our study underscores the importance of multidisciplinary collaboration between dentistry and medical genetics in understanding complex conditions like OI. The comprehensive analysis of oral and dental findings in OI cases is expected to inform future research and enhance clinical approaches to managing the dental challenges associated with this disorder.

Prevalence and Symmetry of Positional Anomalies in Second Permanent Molars: Study of Romanian Patients

BACKGROUND/OBJECTIVES

This study aimed to investigate the prevalence and characteristics of positional anomalies in second permanent molars among Romanian patients. These molars play a crucial role in occlusion but can exhibit positional issues such as tilting, rotation, infraocclusion, and impaction.

METHODS

This retrospective study examined the digital models of 103 patients aged 12-40, which were obtained by using the Medit i500 intraoral scanner. Positional anomalies were categorized by tilting, rotation, infraocclusion, and impaction.

RESULTS

The results showed a high prevalence of anomalies, particularly infraocclusion and buccal tilting in upper molars and oral tilting and mesio-buccal rotations in lower molars. The significant symmetry of anomalies within the same dental arch was noted. Gender and malocclusion type did not significantly influence anomaly frequency.

CONCLUSIONS

The findings emphasize the need for the vigilant monitoring of second permanent molars to maintain functional occlusion and suggest potential common etiological factors within dental arches. Despite this study's limitations, including sample size and retrospective design, this study underscores the clinical importance of the early detection and management of molar anomalies. Future research should expand on these findings, considering genetic and environmental influences on dental development.

Masseter muscle thickness before and after the correction of unilateral functional posterior crossbite in growing individuals: a prospective controlled clinical trial

OBJECTIVES

To evaluate whether unilateral functional posterior crossbite in growing children creates an asymmetry in masseter muscle thickness and whether this asymmetry is normalized after crossbite correction.

MATERIALS AND METHODS

Two groups of growing individuals were studied prospectively: (i) a treatment group: children with unilateral functional posterior crossbite, undergoing crossbite correction with maxillary expansion; and (ii) a control group: children without transversal malocclusions and orthodontic treatment. The thickness of the masseter muscles was measured bilaterally using ultrasonographic recordings at three time points: pre-treatment (T0); 9 months after (T1); and 30 months after posterior crossbite correction (T2); and at equivalent time points in the control group. Differences within and between the groups were evaluated using paired and unpaired t-tests respectively.

RESULTS

It was found that the thickness of the masseter muscles in patients with unilateral functional posterior crossbite was significantly thinner on the crossbite side (P = .013) by 0.5 mm. At T1, the masseter muscle of the treated crossbite side was thicker than that of the previous normal side (0.3 mm difference; P = .046) while this difference disappeared at T2 (P > .05).

LIMITATIONS

The lack of the inclusion of an untreated posterior crossbite group, and the heterogeneity in appliances used are the principal limitations of this study.

CONCLUSIONS

The masseter muscles in untreated individuals with unilateral functional posterior crossbite are thinner in the crossbite side than in the contralateral non-crossbite side. This muscular asymmetry however is eliminated some time after successful treatment of this malocclusion, possibly due to the bilateral symmetrization of the activity of the elevator masticatory muscles.

Characteristics of dental malocclusion in a 18th/19th century population from Radom (Poland)

OBJECTIVE

The aim of the study was to assess the diachronicity of factors that produce malocclusion from the 18th century to the present.

MATERIALS

A total of 74 adult individuals Radom (Poland) of both sexes were examined (males: 46, females: 28).

METHODS

The skulls were grouped according to the type of malocclusion found: i) anterio-posterior (skeletal Class I/II/III), ii) transverse (cross bite/scissor bite), and iii) vertical (open bite/deep bite).

RESULTS

Normal bites were recorded in 14 % (10/74) of the study group. Malocclusion was observed in the remaining cases (64/74, 86 %). Class I was diagnosed most often (53 %), and Class III (8 %) was the least common in the study group.

CONCLUSIONS

The observed order of frequency of Angle's Classes (I > II > III) in the population from Radom indicates malocclusion was similar to that of the contemporary population. In the population from Radom, similar to other contemporary European populations, Class II defects were found at a higher frequency than Class III defects.

SIGNIFICANCE

The research demonstrates the diachronic nature of the factors that produce different types of malocclusion in Polish populations over the past four centuries, even if these factors cannot be identified.

LIMITATION

The main limitation of this research is the relatively small sample size.

SUGGESTIONS FOR FURTHER RESEARCH

Future studies should evaluate malocclusion in older populations from Radom and other areas of Poland and Europe.

Biomechanical simulation of segmented intrusion of a mandibular canine using Robot Orthodontic Measurement & Simulation System (ROSS)

OBJECTIVE

Aim of this study was to investigate the forces and moments during segmented intrusion of a mandibular canine using Cantilever-Intrusion-Springs (CIS).

METHODS

Three different CIS modifications were investigated using a robotic biomechanical simulation system: unmodified CIS (#1, control), CIS with a lingual directed 6° toe-in bend (#2), and CIS with an additional 20° twist bend (#3). Tooth movement was simulated by the apparative robotic stand, controlled by a force-control algorithm, recording the acting forces and moments with a force-torque sensor. Statistical analysis was performed using Shapiro-Wilk, Kolmogorov-Smirnov, Kruskal-Wallis ANOVA and post hoc tests with Bonferroni correction (α = 0.05).

RESULTS

The initial intrusive force, which was uniformly generated by a 35° Tip-Back bend, decreased significantly (p < 0.05) from 0.31 N in group (#1) to 0.28 N in group (#3). Vestibular crown tipping reduced significantly (p < 0.05) from 2.11° in group (#1) and 1.72° in group (#2) to 0.05° in group (#3). Matching to that the direction of orovestibular force significantly (p < 0.05) shifted from 0.15 N to vestibular in group (#1) to 0.51 N to oral in group (#3) and the orovestibular tipping moment decreased also significantly (p < 0.05) from 4.63 Nmm to vestibular in group (#1) to 3.56 Nmm in group (#2) and reversed to 1.20 Nmm to oral in group (#3). Apart from that the orovestibular displacement changed significantly (p < 0.05) from 0.66 mm in buccal direction in group (#1) to 0.29 mm orally in group (#2) and 1.49 mm in oral direction as well in group (#3).

SIGNIFICANCE

None of the modifications studied achieved pure mandibular canine intrusion without collateral effects. The significant lingual displacement caused by modification (#3) is, not least from an aesthetic perspective, considered much more severe than a slight tipping of the canine. Consequently, modification (#2) can be recommended for clinical application based on the biomechanical findings.

Application of bilateral condylectomy as an alternative surgical treatment for Class III malocclusion with posterior vertical excess, a technical note

The Posterior vertical excess (PVE) associates a symmetric ramus and condyle elongation to an Angle Class III malocclusion. This dento-skeletal discrepancy can be isolated or associated to a condyle hyperplasia or a transverse overgrowth of the mandible due to macroglossia. We present the technique and the postoperative results of bilateral condylectomy applied for the surgical correction of PVE. Bilateral condylectomy represents an alternative to the bimaxillary surgery and adds to the therapeutic arsenal for the correction of Angle Class III malocclusion.

Genetic factors underlying Mandibular prognathism: insights from recent human and animal studies

This review aims to provide an updated overview of the genetic etiology of mandibular prognathism (MP), focusing on recent research efforts, to summarize the findings from human studies utilizing genome-wide association studies (GWAS), candidate gene analyses, whole exome sequencing (WES) and single-nucleotide polymorphisms (SNPs) in relation to MP. Additionally, insights from animal studies are incorporated to understand the molecular mechanisms underlying mandibular development and the pathogenesis of MP. A comprehensive literature search was conducted to identify relevant studies on the genetic basis of MP. Human studies employing GWAS, candidate gene analyses, and SNPs investigations were reviewed. Animal studies, including European seabass, zebrafish, transgenic mouse and miniature horse were also examined to provide additional insights into mandibular development and MP's pathogenesis using GWAS, WES, transgenic techniques, morpholino antisense oligos and homozygote. Human studies have identified multiple loci and genes potentially associated with MP through GWAS, candidate gene analyses, and SNP investigations. Animal models have contributed valuable information about the molecular mechanisms involved in mandibular development and the development of MP. Recent research efforts have enhanced our understanding of the genetic etiology of MP. Integration of genetic studies with functional analyses has shed light on key signaling pathways and gene regulatory networks implicated in MP.

Effect of maxillary molars distalization using clear aligners and fixed orthodontic appliances on the positional and dimensional temporomandibular joint parameters: a three-dimensional comparative study

OBJECTIVE

The use of clear aligners (CAs) for orthodontic treatment has substantially increased in recent decades. However, limited empirical evidence exists regarding their potential effects on the temporomandibular joint (TMJ). The aim of this study was to assess the effect of maxillary molar distalization on the positional and dimensional TMJ parameters between CAs and conventional fixed orthodontic appliances (FAs) in skeletal class II malocclusion.

METHODS

This is a retrospective cohort study examined 70 adult patients with skeletal class II malocclusion with similar baseline characteristics based on American Board of Orthodontics (ABO) discrepancy index scores. The patients were treated by maxillary distalization movement by CAs or FAs, of which there were two equal groups of 35 patients were included in each group. CBCTs on TMJs were performed before and after treatment through Anatomage Invivo Dental 6.0. The measured parameters included inclination, position, condyle and articular fossa dimensions, and the volumetric joint spaces.

RESULTS

In both groups, linear measurements of the maxillary molar position revealed significant improvement after treatment (P < 0.001). Regarding TMJ parameters, intra-group comparisons revealed significant changes in FA group in the anterioposterior condylar inclination and condylar position across the three planes. Additionally, the pretreatment-centric condylar position in the glenoid fossa was 45.7% and 40% in the CA and FA groups, respectively. After treatment, these percentages changed to 51.4% and 31.4%, respectively. In inter-group comparisons, significant changes were noted in the mediolateral condylar position, which was more inward in the FA group than the CA group.

CONCLUSION

The FA group had more significant dimensional and positional changes in the mandibular condyle than the CA group; nevertheless, the changes are considered clinically negligible.

Biomechanical effects of different mandibular movements and torque compensations during mandibular advancement with clear aligners: a finite element analysis

Introduction

This study aimed to evaluate the biomechanical effects of different mandibular movements and torque compensations during mandibular advancement with clear aligners using finite element analysis.

Methods

Models were constructed to include the mandible, teeth, periodontal ligament (PDL), and clear aligners with buccal wings. Five oral muscles (superficial masseter, deep masseter, medial temporalis, posterior temporalis, and medial pterygoid) were represented as springs. Muscle values were measured and applied during different mandibular movements, including advancement distances (1-7 mm) and occlusal opening distances (2-4 mm). Different torque compensation angles (0°, 1°, 2°, and 3°) were applied to the mandibular central incisor.

Results

When the mandibular advancement was equal to or slightly excessed the occlusal opening distance, stress on the posterior PDL decreased and became more evenly distributed. Increasing the occlusal opening distance significantly raised stress on the posterior PDL and caused grater labial inclination of the mandibular anterior teeth. As the torque compensation increased, the labial inclination of the mandibular central incisor decreased, but stress on the PDL increased. Nearly complete bodily movement of the lower central incisor was achieved with torque compensation angles of approximately 15°, 19°, and 20° in models M1-2, M2-3, and M3-4, respectively.

Conclusion

To maintain periodontal health during mandibular advancement, it is recommended that the mandibular advancement distance be equal to or slightly excessed the occlusal opening distance. Excessive occlusal opening distance increases stress on the posterior PDL and the labial inclination of mandibular anterior teeth, requiring careful control. Additionally, proper torque control of the mandibular interior teeth is crucial for optimal outcomes.

Dental Abnormalities in Osteogenesis Imperfecta: A Systematic Review

Osteogenesis imperfecta (OI) is a rare genetic disorder characterized by fragile bones and skeletal deformities. Individuals with OI may have dental abnormalities such as dentinogenesis imperfecta (DI) type I, malocclusions, and unerupted or missing teeth. This review comprehensively examines these dental abnormalities to assess their prevalence among the OI population and explore potential differences across different clinical types of OI and pathogenic variants. In accordance with the PRISMA guidelines, a systematic literature search in PubMed, Embase, and Web of Science was conducted that included articles up to June 2024. Out of 672 articles screened, 34 were included. The included studies confirmed that dental abnormalities are prevalent in OI, with DI prevalence ranging from approximately 20 to 48%. Those with a more severe skeletal phenotype (OI type III/IV) exhibited more dental abnormalities than those with a milder skeletal phenotype (OI type I). Notably, OI type V individuals generally do not have DI, although a few isolated cases have been reported. The prevalence of occlusion types varied: Class I occlusion ranged from 14.8 to 50% and Class II malocclusion ranged from 0 to 37.5%, while Class III malocclusion from 4.1 to 84%. This differs from the general population, where Class III malocclusion is typically the least common. Open bites, cross-bites, and unerupted and missing teeth are also commonly reported, particularly in OI types III and IV. This review emphasizes the need for comprehensive dental examinations in OI due to the high prevalence of dental abnormalities. Additionally, the review draws attention to the lack of clear guidelines for diagnosing DI.

Evaluation of the effect of orthodontic treatment on the reliability of facial recognition by using three-dimensional model superimposition technique

3D-3D registration of facial models, has great advantages in personal individual identification in forensic medicine. However, orthodontic treatment has brought changes in facial soft and hard tissues, which has a potential effect in personal identification. The aim of the study was to explore whether orthodontic treatment affects 3D-3D facial recognition. A total of 68 patients aged between 18 and 38 were selected (30 subjects with tooth extraction, 38 subjects with non-tooth extraction) and a control group consisting of 30 volunteers without orthodontic treatment was selected from a database of 3dMD facial models. 3dMD facial model acquisition was performed twice for each subject. For both extraction and non-extraction groups, T0 was acquired before treatment, and T1 was acquired at the end of treatment. The time span of 2 times 3dMD facial model acquisition in the control group was about 2 years. 3dMD facial models were then registered onto other 3dMD models belonging to the same and different individuals according to the minimum point-to-point distance, getting a cohort of matches and mismatches. Root mean square (RMS) value of the minimum point-to-point distance between two models was then calculated. The intra- and inter-observer repeatability coefficients were 0.986 (P<0.001) and 0.982 (P<0.001). The absolute technical error of measurement (TEM) value was 0.05 mm and 0.04 mm, and relative technical error of measurement (rTEM) value was 4.91 % and 3.60 %, respectively. Possible significant differences between groups were assessed through independent samples t-test or Mann-Whitney U test (p<0.001). The average RMS value was 1.03±0.33 mm in matches of orthodontic group, 0.67±0.22 mm in matches of control group, and 2.66±0.51 mm in mismatches. An RMS value range of 1.70-1.77 mm could distinguish matches from mismatches in 100 % of cases in the present study. This study showed that orthodontic treatment would not affect 3D-3D facial recognition in adults for the purpose of individual identification in forensic medicine.

Influence of the force magnitude of fixed functional appliances for class II subdivision 1 treatment-a cephalometric study

PURPOSE

To investigate the skeletal and dental effects of a hybrid fixed functional appliance (FFA) used with different force magnitudes for class II subdivision 1 treatment.

METHODS

Treatment records from 70 patients were evaluated: 35 patients were treated with a FFA with standard activation (SUS group) and 35 with a FFA with an additional force-generating spring (TSUS group). Two control groups were matched from the American Association of Orthodontists Foundation (AAOF) Craniofacial Growth Legacy Collection for comparison with the two treatment groups to determine skeletal and dental treatment effects. The cephalometric parameters at T0 (before treatment) and T1 (before debonding) were assessed using the Munich standard cephalometric analysis and by the sagittal occlusal analysis (SO) according to Pancherz. Data were analyzed statistically using SPSS.

RESULTS

No statistically significant difference for any cephalometric parameter was observed between the SUS and TSUS groups concerning the measurements at T0 and T1. Both treatment groups exhibited an effective class II therapy mainly due to a significant reduction in SNA, and ANB and an increase in SNB. In contrast to the control group, as the result of treatment a skeletal class I was achieved.

CONCLUSION

No significant statistical differences were observed between the patient group treated with the FFA with standard activation (SUS) and those treated with an additional spring (TSUS) regarding the cephalometric parameters investigated. Both variants were equally effective in treating class II division 1 malocclusions.

Research Trends in Class II Malocclusion Treatment in Growing Individuals: A Bibliometric Study

INTRODUCTION AND AIMS

This study aims to perform a bibliometric analysis of the literature on correction of Class II malocclusion in growing individuals by evaluating the evolution and current state of treatment and to predict future research hot spots and trends.

METHODS

Keyword queries were used to search for articles in the Web of Science Core Collection at the electronic library of University of Catania. The resulting literature data were imported into CiteSpace 6.3.R1 and VOSviewer software to analyse authorship, countries, institutions, and keywords and to perform cluster analysis.

RESULTS

A total of 843 articles were analysed. Research in this field has shown a consistent and ongoing publication trend on the addressed topic, with a significant increase in the last decade, attributed to growing interest in skeletal anchorage. The institutions in the United States, Italy, and Brazil contributed predominantly to the investigated subject area.

CONCLUSIONS

Class II correction in growing individuals using functional appliances or headgears has gained widespread attention and popularity due to the potential to counteract unfavourable maxillary and/or mandibular growth patterns, improving skeletal disharmony and facial attractiveness. A specific geographic publication trend was found for functional appliances and headgears that may represent an ethical and racial bias . Both of the latter approaches are effective in reducing the overjet. However, the primary rationale for early intervention is reducing the risk of incisal trauma and bullying episodes at childhood.

Assessment of Thermal Influence on an Orthodontic System by Means of the Finite Element Method

The development of the finite element method (FEM) combined block polynomial interpolation with the concepts of finite difference formats and the variation principle. Because of this combination, the FEM overcomes the shortcomings of traditional variation methods while maintaining the benefits of current variation methods and the flexibility of the finite difference method. As a result, the FEM is an advancement above the traditional variation methods. The purpose of this study is to experimentally highlight the thermal behavior of two stomatognathic systems, one a control and the other presenting orthodontic treatment by means of a fixed metallic orthodontic appliance, both being subjected to several thermal regimes. In order to sustain this experimental research, we examined the case of a female subject, who was diagnosed with Angle class I malocclusion. The patient underwent a bimaxillary CBCT investigation before initiating the orthodontic treatment. A three-dimensional model with fully closed surfaces was obtained by using the InVesalius and Geomagic programs. Like the tissues examined in the patient, bracket and tube-type elements as well as orthodontic wires can be included to the virtual models. Once it is finished and geometrically accurate, the model is exported to an FEM-using program, such as Ansys Workbench. The intention was to study the behavior of two stomatognathic systems (with and without a fixed metallic orthodontic appliance) subjected to very hot food (70 °C) and very cold food (-18 °C). From the analysis of the obtained data, it was concluded that, following the simulations carried out in the presence of the fixed metallic orthodontic appliance, significantly higher temperatures were generated in the dental pulp.

Biomechanical effects of mandibular deviation on the temporomandibular joint in patients with mandibular prognathism under incisal occlusion

PURPOSE

The aim of this study was to investigate the biomechanical effects of mandibular deviation on the TMJ in patients with mandibular prognathism before and after orthognathic surgery using three-dimensional finite element analysis.

METHODS

Eight patients with mandibular prognathism without deviation, eight patients with mandibular prognathism with deviation and sixteen normal subjects were recruited. Three-dimensional models of the maxillofacial were reconstructed using MIMICS. Nine muscle forces were used to simulate incisal occlusion and contact was used to simulate fossa-disc-condyle interactions.

RESULTS

Before surgery, the stress in the TMJ was generally greater in the Pre-MD&MP group than in the Pre-MD group; it was much greater in both groups than in the control group, ranging from about 2 to 12 times as great in the Pre-MD group and from about 5 to 64 times as great in the Pre-MD&MP group. After orthognathic surgeries, the stresses in the Post-MP&MD were significantly reduced by approximately 21.7 % to 93.4 %. And in the Post-MP group, the stresses were reduced by approximately 1.4 % to 51.1 %.

CONCLUSION

Mandibular deviation exacerbated the abnormal stress distribution in the TMJ of patients with mandibular prognathism. Orthognathic surgeries could improve the stress distribution in patients with mandibular prognathism (with and without deviation). TMD was closely related to the stress levels of the TMJ.

Effect of condylar rotation on the stress environment of the temporomandibular joint in patients with mandibular protrusion

PURPOSE

The study aims to analyse the effects of condylar rotation on the biomechanical environment of the TMJ after bilateral sagittal split ramus osteotomy (BSSRO) through the finite element method (FEM).

METHODS

Thirteen patients with mandibular prognathism and twenty-three normal subjects were recruited. The three-dimensional (3D) models were reconstructed. 13 representative morphological parameters were measured for comparison. A patient was selected to perform virtual BSSRO surgery by rotating the condyles in MIMICS. The preoperative and postoperative 3D models of the patient were subsequently imported into ABAQUS for finite element analysis. The preoperative and postoperative stresses and joint spaces in the TMJs were investigated.

RESULTS

The maxillofacial morphologies of the patients with mandibular protrusion was significantly different from those of the asymptomatic subjects (P<.05). Stresses in the postoperative group were lower than those in the preoperative group. The rotation of the condyle could cause the variations in stress levels and joint spaces within the TMJs. Inward and upward rotation of the condyle was associated with higher stress in the TMJ, whereas the lowest stress was observed when the condyle remained stationary following surgical intervention.

SIGNIFICANCE

Lateral, medial and superior joint spaces were more related to the stresses in the TMJs. The condyle should be kept in place as much as possible to avoid disrupting the balance of the TMJ in patients with mandibular protrusion.

Orthognathic-Like Orthodontics: Management of Skeletal Class II Malocclusion in an Adult Patient

Advances in orthodontic treatment, particularly with the use of temporary anchorage devices (TADs), have significantly improved outcomes for adult patients with skeletal Class II malocclusion. Traditionally reliant on orthognathic surgery, these malocclusions can now benefit from non-surgical options like maxillary molar distalization. Bone screws offer superior anchorage compared to conventional methods, enabling precise tooth movement without undesirable side effects. This case report explores the efficacy of TAD-assisted maxillary molar distalization in an adult patient while focusing on a 50-year-old female who sought orthodontic treatment for Class II malocclusion, characterized by deep bite and increased overjet. Treatment involved the use of an infra-zygomatic crest (IZC) bone screw for maxillary molar distalization as a camouflage strategy to achieve optimal dento-skeletal and soft tissue profile improvements. The case also discusses the key considerations and benefits of utilizing bone screws in adult orthodontic treatment, particularly in minimizing reciprocal effects and reducing dependence on patient compliance.

Current Trends in Pediatric Orthodontics: A Comprehensive Review

Pediatric orthodontics is a critical field focusing on the diagnosis, prevention, and treatment of dental and facial irregularities in children. This comprehensive review explores current trends and methodologies in pediatric orthodontics and discusses the multifactorial etiology of malocclusions, including genetic, environmental, and disease-related factors. The importance of proper diagnosis is highlighted, and the extraoral, intraoral, and functional evaluations essential for effective treatment planning are detailed. Various orthodontic conditions such as Class III and Class II malocclusions, abnormal oral habits, arch length discrepancies, anterior and posterior crossbites, open bites, and deep bites are examined in depth. The review also addresses the role of temporomandibular joint disorders (TMDs) and obstructive sleep apnea (OSA) in pediatric patients, emphasizing the need for early and accurate diagnosis to facilitate appropriate intervention. The use of clear aligners in early orthodontic intervention is evaluated given their efficacy and improved patient satisfaction compared to traditional appliances. Additionally, the article discusses the non-advisability of early interception for certain self-correcting malocclusions and the limitations of pediatric orthodontic treatment, including compliance-related issues and the unique anatomical considerations of deciduous dentition. This review aims to provide a detailed understanding of contemporary practices and challenges in pediatric orthodontics, offering insights for clinicians to enhance treatment outcomes and patient care.

Artificial Intelligence for Predicting the Aesthetic Component of the Index of Orthodontic Treatment Need

The aesthetic component (AC) of the Index of Orthodontic Treatment Need (IOTN) is internationally recognized as a reliable and valid method for assessing aesthetic treatment need. The objective of this study is to use artificial intelligence (AI) to automate the AC assessment. A total of 1009 pre-treatment frontal intraoral photos with overjet values were collected. Each photo was graded by an experienced calibration clinician. The AI was trained using the intraoral images, overjet, and two other approaches. For Scheme 1, the training data were AC 1-10. For Scheme 2, the training data were either the two groups AC 1-5 and AC 6-10 or the three groups AC 1-4, AC 5-7, and AC 8-10. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were measured for all approaches. The performance was tested without overjet values as input. The intra-rater reliability for the grader, using kappa, was 0.84 (95% CI 0.76-0.93). Scheme 1 had 77% sensitivity, 88% specificity, 82% accuracy, 89% PPV, and 75% NPV in predicting the binary groups. All other schemes offered poor tradeoffs. Findings after omitting overjet and dataset supplementation results were mixed, depending upon perspective. We have developed deep learning-based algorithms that can predict treatment need based on IOTN-AC reference standards; this provides an adjunct to clinical assessment of dental aesthetics.

Well-Being of Orthodontic Patients Wearing Orthodontic Appliances

Background and Objectives: Orthodontic appliances may cause discomfort for patients. This could influence the person's psychological well-being. The aim of this study was to examine the psychological health of patients wearing orthodontic appliances. It is important to analyze the well-being of patients during orthodontic treatment because it is started in a young age and it may affect one's psychological health. Therefore, for doctors and patients, it is important to understand and take every aspect of the treatment into consideration when deciding when to start the treatment and what appliance to choose. Materials and Methods: A total of 339 patients filled out an anonymous questionnaire. They were divided into four groups according to their age and type of appliance. The main reasons to seek treatment were crooked teeth and a bad bite. There was a statistically significant difference between women and men as women sought treatment because of crooked teeth; meanwhile, men indicated bad bite as their main reason for seeking treatment. Results: A total of 48.7% of subjects noted that they were feeling good during treatment; however, 4% of all patients noted that they were feeling bad. A total of 45% of subjects stated that they felt unhappy at least sometimes. A total of 43% of subjects felt stress. Conclusions: Even though patients indicated various negative aspects on their well-being during treatment, for the majority of the subjects, the end results significantly increased their psychological well-being.

Designing an artificial intelligence system for dental occlusion classification using intraoral photographs: A comparative analysis between artificial intelligence-based and clinical diagnoses

INTRODUCTION

This study aimed to design an artificial intelligence (AI) system for dental occlusion classification using intraoral photographs. Moreover, the performance of this system was compared with that of an expert clinician.

METHODS

This study included 948 adult patients with permanent dentition who presented to the Department of Orthodontics, School of Dentistry, Mashhad University of Medical Sciences, during 2022-2023. The intraoral photographs taken from the patients in left, right, and frontal views (3 photographs for each patient) were collected and underwent augmentation, and about 7500 final photographs were obtained. Moreover, the patients were clinically examined by an expert orthodontist for malocclusion, overjet, and overbite and were classified into 6 groups: Class I, Class II, half-cusp Class II, Super Class I, Class III, and unclassifiable. In addition, a multistage neural network system was created and trained using the photographs of 700 patients. Then, it was used to classify the remaining 248 patients using their intraoral photographs. Finally, its performance was compared with that of the expert clinician. All statistical analyses were performed using the Stata software (version 17; Stata Corp, College Station, Tex).

RESULTS

The accuracy, precision, recall, and F1 score of the AI system in the malocclusion classification of molars were calculated to be 93.1%, 88.6%, 91.2%, and 89.7%, respectively, whereas the AI system had an accuracy, precision, recall, and F1 score of 89.1%, 88.8%, 91.42%, and 89.8% for malocclusion classification of canines, respectively. Moreover, the mean absolute error of the AI system accuracy was 1.98 ± 2.11 for overjet and 1.28 ± 1.60 for overbite classifications.

CONCLUSIONS

AI exhibited remarkable performance in detecting all classes of malocclusion, which was higher than that of orthodontists, especially in predicting angle classification. However, its performance was not acceptable in overjet and overbite measurement compared with expert orthodontists.

New Solution in the Treatment of Children with Class II Malocclusion: Biblock Appliance

BACKGROUND

A new design, the Biblock appliance, was developed for the functional treatment of Class II malocclusions.

AIM

To compare the effects of Biblock appliance (BA) and Activator appliance (AA) on the skeleton, dentoalveolar, and soft tissue in Class II malocclusions.

METHODS

Thirty-five patients with mandibular retrognathia caused by skeletal Class II malocclusion and normodivergent growth pattern were included in this study. After selecting the BA group (n = 17, 8 boys and 9 girls, mean age = 12.08 ± 0.37 years), we selected the active control group treated with AA (n = 18, 9 boys and 9 girls, mean age = 12.3 ± 0.27 years), which matched the BA group's development and gender. All patients were between PP2 = DP3u periods according to hand-wrist maturation. Cephalometric variables related to the skeletal, dentoalveolar, and soft tissue were measured.

RESULTS

Treatment duration was 18.17 ± 1.45 months with BA and 16.92 ± 1.09 months with AA. Skeletal Class II malocclusion improved significantly in both groups. In the compared groups, the increase in ANS-Me was significantly higher in the AA group (P < 0.05). The Cd⊥SN and S-Cd increase in the compared groups was significantly higher in the BA group (P < 0.05). There was no significant difference in measurements between the groups in skeletal, dentoalveolar, and soft tissue measurements (P > 0.05).

CONCLUSION

The effects of AA, an appliance accepted by the orthodontic community, and BA, a new design, on the skeletal, dentoalveolar, and soft tissue were similar.

Mapping the evolving trend of research on Class III malocclusion: a bibliometric analysis

OBJECTIVES

This study aimed to provide visualized knowledge maps to show the evolving trends and key focal points of Class III malocclusion research through a comprehensive bibliometric analysis.

MATERIALS AND METHODS

Class III malocclusion research published between 2000 and 2023 was retrieved from the Web of Science Core Collection. VOSviewer was utilized to count the citation and publication number of authors, institutions, countries and journals. Co-occurrence, co-citation, and cluster analyses and burst detection were conducted using CiteSpace.

RESULTS

A total of 3,682 publications on Class III malocclusion were included in the bibliometric analysis. During 2000-2023, both the annual publication count and citation frequency exhibited a gradual upward trajectory, with a noticeable surge in recent years. In terms of production and citation counts of Class III malocclusion research, the core journal is the American Journal of Orthodontics and Dentofacial Orthopedics. Furthermore, apart from the primary keyword 'Class III malocclusion', 'orthognathic surgery' was identified as keyword with the most frequency. The cluster analysis of cited references reveals that the research focal points have shifted to 'skeletal anchorage' and 'surgery-first approach'. Furthermore, the burst detection identified 'quality of life' as a potential research hotspot since it has recently gained increasing scholarly attention.

CONCLUSIONS

The current study provides scholars with the knowledge maps of evolving trends and prominent topics of Class III malocclusion research and a summary of research progress on various priorities during different periods. These findings are expected to provide a valuable guidance to facilitate the future research on Class III malocclusion.

Prevalence of Malocclusion Traits in Primary Dentition, 2010-2024: A Systematic Review

The present review was aimed to describe the prevalence and the regional distribution of malocclusion among preschool children worldwide. Two independent reviewers performed a systematic literature search to identify English publications from January 2010 to May 2024 using PubMed, ISI Web of Science and Embase. Search MeSH key words were "malocclusion", "primary dentition" and "child, preschool". The reporting quality was assessed by the modified Newcastle-Ottawa Quality Assessment Scale. We identified 2599 publications and recruited 47 articles. Fourteen of the included studies were conducted in Asia, four in Europe, twenty-eight in South America and one in Africa. The prevalence of malocclusion ranged from 28.4% to 83.9%, and half of the reported prevalences were higher than 50%. The highest percentage was in Asia (61.81%), followed by Europe (61.50%), South America (52.69%) and Africa (32.50%). Statistically significant differences existed in deep overbite, anterior open bite, posterior crossbite, edge-to-edge incisor relationship and distal step between continents (p < 0.05). Europe showed the highest prevalence (33.08%) of deep overbite. Africa showed the highest prevalence (18.60%) of anterior open bite. Europe showed the highest prevalence (15.38%) of posterior crossbite. The most common malocclusion traits were increased overjet and deep overbite. To conclude, malocclusion remained prevalent in the primary dentition and varied between countries.

Genetic Insights into Skeletal Malocclusion: The Role of the FBN3 rs7351083 SNP in the Romanian Population

Background and Objectives: irregularities in the growth and development of the jawbones can lead to misalignments of maxillary and mandibular structures, a complex condition known as skeletal malocclusion, one of the most common oral health problems. Skeletal malocclusions, particularly Class II and Class III, can significantly affect facial appearance, chewing efficiency, speech, and overall oral health, often requiring orthodontic treatment or surgery to correct. These dentofacial anomalies are influenced by genetic and environmental factors and exhibit diverse phenotypic expressions. Materials and Methods: in this study, we investigated the correlation between the rs7351083 SNP of the FBN3 gene that encodes a member of the fibrillin protein family and malocclusion risk in a group of 57 patients from Romania. Results: the results shed light on the relationship between the selected genetic marker and the investigated dentofacial disorder, revealing a positive association between the reference allele (A) and Class II and that the alternate allele (G) is associated with Class III. Conclusions: cephalometric analysis revealed no significant differences among genotypes, suggesting that while genetic factors are implicated in malocclusion, they may not directly affect cephalometric parameters or that the sample size was too small to detect these differences. The discovery of an A > T transversion in one individual with a Class II deformity underscores the genetic diversity within the population and the necessity of comprehensive genotyping to uncover rare genetic variants that might influence craniofacial development and the risk of malocclusion. This study highlights the need for larger studies to confirm these preliminary associations.

Class III malocclusion treated with a 3D-printed hybrid hyrax distalizer combined with mentoplate using Alt-RAMEC protocol: A case report

INTRODUCTION

The aim of this report was to assess the skeletal, dental and soft tissue changes in a juvenile patient with a severe class III malocclusion. This case report describes a novel method of class III treatment using skeletal anchorage for maxillary protraction and Alt-RAMEC protocol.

PATIENT CONCERNS

The patient did not have any subjective complaints before treatment and there was no family history of class III malocclusion.

CLINICAL FINDINGS AND PRIMARY DIAGNOSES

Extra-orally, the patient had a concave profile with a retrusive mid-face and prominent lower lip. The intra-oral examination revealed angle class III malocclusion with a -3-mm overjet. There was no anterior displacement on closure when the patient was assessed clinically. According to the cephalometric analysis, the sagittal jaw relation and Wits appraisal were reduced due to a retrognathic maxilla and prognathic mandible.

INTERVENTIONS

The treatment plan involved maxillary protraction, Alt-RAMEC protocol for 10 weeks and upper molar distalisation with a hybrid hyrax distalizer in combination with a mentoplate. The active treatment time was estimated to 18 months followed by 6 months retention with the appliance.

OUTCOMES

The sagittal jaw relationship was increased by approximately 9°, mainly due to maxillary advancement of 8 mm and a positional change of the mandible anteroposteriorly. Natural decompensation of the lower incisors was also observed. In addition, both the facial profile and the smile became more harmonious after treatment. The treatment analysis revealed that the changes achieved were mainly skeletal and it was possible to avoid adverse effects on the dentition.

CONCLUSION

In conclusion, treatment with a hybrid hyrax distalizer combined with mentoplate using the Alt-RAMEC protocol is effective in correcting the anteroposterior discrepancy in a juvenile class III patient and it is possible to achieve maxillary advancement of 8 mm.

Evaluation of Sella Turcica Variations in Lateral Cephalometric Radiographs and its Association with Malocclusion

Objectives

Understanding the shape and size of the sella turcica may help predict future orthodontic treatment needs related to skeletal malocclusion. This study aims to assess different morphological types of the sella turcica in lateral cephalometric radiographs and its correlation with malocclusion, as well as the relationship between gender and linear measurements of sella turcica.

Materials and Methods

The lateral cephalometric radiographs of 410 volunteers (111 men and 299 women) aged 8 to 30 years were evaluated. The patients were divided into three groups based on their skeletal growth patterns (cl I, II, and III). Then the anatomical shape and linear dimensions of sella turcica were assessed. Measurements were made using Adobe Photoshop Version: 20.0.0 software, and data analysis was performed by IBM SPSS Statistics version 25.

Results

The following morphologies were observed: normal (37.8%), oblique anterior wall (9.3%), double contour of the floor (21.5%), sella turcica bridge (8.8%), irregularity (notching) in the posterior part of sella turcica (16.6%), and pyramidal shape of the dorsum sellae (6.1%). No statistically significant relationship was found between sella turcica variations and skeletal malocclusion. The correlation between female sex with the diameter (p=0.027) and depth values (p=0.035) of sella turcica was statistically significant. There was no statistically significant difference (p>0.05) in length based on gender.

Conclusion

The most morphological type reported was normal sella turcica (37.8%). Anatomical variations of sella turcica had no association with malocclusion. The most considerable depth and diameter of sella turcica were found in women.

Is There Variation in the Morphology of the Frontal Sinus in Individuals with Different Craniofacial Patterns? A Systematic Review with Meta-Analysis

To evaluate differences in the morphology of the frontal sinus in adolescents and adults with different craniofacial patterns, searches up to April 2024 were conducted in six databases and other information sources to identify observational studies. Study selection, data extraction, and quality assessment using the NOS scale were performed independently by two reviewers. Random effects meta-analyses were conducted to estimate the difference in frontal sinus measurements between different craniofacial skeletal patterns (α = 0.05). The certainty of the evidence was evaluated according to GRADE. Fourteen studies were included in the review. All studies had methodological limitations that affected their quality. The syntheses showed that skeletal Class II subjects presented a significantly smaller width of the frontal sinus than skeletal Class I subjects (MD = 0.56; 95% CI: 0.38, 0.74; p < 0.0001; I2 = 3%). Skeletal Class III subjects showed a frontal sinus width (MD = -0.91; 95% CI: -1.35, -0.47; p < 0.0001; I2 = 36%) and area (MD = -28.13; 95% CI: -49.03, -7.23; p = 0.0084; I2 = 66%) significantly larger than those of the skeletal Class I subjects. The available evidence suggests a positive relationship between mandibular and frontal sinus size. There is limited evidence to make reliable estimates of the association of other craniofacial patterns and frontal sinus characteristics. These reported results are not conclusive and should be evaluated carefully due to the very low certainty of the evidence. The current evidence is scarce and consists of studies with methodological limitations; the results of the studies are often inconsistent, and the pooled estimates are imprecise. New high-quality research is still necessary.

Aucubin produces anti-osteoporotic effects under mechanical stretch stress and orthodontic tooth movement

Aucubin (AU), an iridoid glycoside extracted from Eucommia ulmoides, exerts anti-osteoporotic effects by promoting osteogenesis, as reported in previous studies. Here, we investigated the effects of AU under mechanical stretch stress. MC3T3-E1 cells were treated with dexamethasone (DEX) in vitro and subjected to mechanical stretch stress to establish an osteoporotic orthodontic force cell model. AU treatment increased the mRNA and protein expressions of BMP2, OPN, RUNX2, COL-1 and other osteogenic differentiation factors in MC3T3-E1 cells. Furthermore, we established an in vivo orthodontic tooth movement (OTM) model of osteoporosis. Serum parameter detection of ALP concentration, radiography of the femur, hematoxylin-eosin (HE) staining, and micro-CT of the maxilla confirmed that AU could partially reverse the damage induced by DEX. Immunohistochemical (IHC) analysis showed that AU increased the expression of COL-1, OCN, and OPN on the tension side of the periodontium. In conclusion, AU treatment promotes osteogenic differentiation under mechanical stretch stress and positively affects bone remodeling during OTM in DEX-induced osteoporosis.

Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children

BACKGROUND

Prominent lower front teeth (Class III malocclusion) may be due to jaw or tooth position or both. The upper jaw (maxilla) can be too far back or the lower jaw (mandible) too far forward; the upper front teeth (incisors) may be tipped back or the lower front teeth tipped forwards. Orthodontic treatment uses different types of braces (appliances) fitted inside or outside the mouth (or both) and fixed to the teeth. A facemask is the most commonly reported non-surgical intervention used to correct Class III malocclusion. The facemask rests on the forehead and chin, and is connected to the upper teeth via an expansion appliance (known as 'rapid maxillary expansion' (RME)). Using elastic bands placed by the wearer, a force is applied to the top teeth and jaw to pull them forwards and downward. Some orthodontic interventions involve a surgical component; these go through the gum into the bone (e.g. miniplates). In severe cases, or if orthodontic treatment is unsuccessful, people may need jaw (orthognathic) surgery as adults. This review updates one published in 2013.

OBJECTIVES

To assess the effects of orthodontic treatment for prominent lower front teeth in children and adolescents.

SEARCH METHODS

An information specialist searched four bibliographic databases and two trial registries up to 16 January 2023. Review authors screened reference lists.

SELECTION CRITERIA

We looked for randomised controlled trials (RCTs) involving children and adolescents (16 years of age or under) randomised to receive orthodontic treatment to correct prominent lower front teeth (Class III malocclusion), or no (or delayed) treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcome was overjet (i.e. prominence of the lower front teeth); our secondary outcomes included ANB (A point, nasion, B point) angle (which measures the relative position of the maxilla to the mandible).

MAIN RESULTS

We identified 29 RCTs that randomised 1169 children (1102 analysed). The children were five to 13 years old at the start of treatment. Most studies measured outcomes directly after treatment; only one study provided long-term follow-up. All studies were at high risk of bias as participant and personnel blinding was not possible. Non-surgical orthodontic treatment versus untreated control We found moderate-certainty evidence that non-surgical orthodontic treatments provided a substantial improvement in overjet (mean difference (MD) 5.03 mm, 95% confidence interval (CI) 3.81 to 6.25; 4 studies, 184 participants) and ANB (MD 3.05°, 95% CI 2.40 to 3.71; 8 studies, 345 participants), compared to an untreated control group, when measured immediately after treatment. There was high heterogeneity in the analyses, but the effects were consistently in favour of the orthodontic treatment groups rather than the untreated control groups (studies tested facemask (with or without RME), chin cup, orthodontic removable traction appliance, tandem traction bow appliance, reverse Twin Block with lip pads and RME, Reverse Forsus and mandibular headgear). Longer-term outcomes were measured in only one study, which evaluated facemask. It presented low-certainty evidence that improvements in overjet and ANB were smaller at 3-year follow-up than just after treatment (overjet MD 2.5 mm, 95% CI 1.21 to 3.79; ANB MD 1.4°, 95% CI 0.43 to 2.37; 63 participants), and were not found at 6-year follow-up (overjet MD 1.30 mm, 95% CI -0.16 to 2.76; ANB MD 0.7°, 95% CI -0.74 to 2.14; 65 participants). In the same study, at the 6-year follow-up, clinicians made an assessment of whether surgical correction of participants' jaw position was likely to be needed in the future. A perceived need for surgical correction was observed more often in participants who had not received facemask treatment (odds ratio (OR) 3.34, 95% CI 1.21 to 9.24; 65 participants; low-certainty evidence). Surgical orthodontic treatment versus untreated control One study of 30 participants evaluated surgical miniplates, with facemask or Class III elastics, against no treatment, and found a substantial improvement in overjet (MD 7.96 mm, 95% CI 6.99 to 8.40) and ANB (MD 5.20°, 95% CI 4.48 to 5.92; 30 participants). However, the evidence was of low certainty, and there was no follow-up beyond the end of treatment. Facemask versus another non-surgical orthodontic treatment Eight studies compared facemask or modified facemask (with or without RME) to another non-surgical orthodontic treatment. Meta-analysis did not suggest that other treatments were superior; however, there was high heterogeneity, with mixed, uncertain findings (very low-certainty evidence). Facemask versus surgically-anchored appliance There may be no advantage of adding surgical anchorage to facemasks for ANB (MD -0.35, 95% CI -0.78 to 0.07; 4 studies, 143 participants; low-certainty evidence). The evidence for overjet was of very low certainty (MD -0.40 mm, 95% CI -1.30 to 0.50; 1 study, 43 participants). Facemask variations Adding RME to facemask treatment may have no additional benefit for ANB (MD -0.15°, 95% CI -0.94 to 0.64; 2 studies, 60 participants; low-certainty evidence). The evidence for overjet was of low certainty (MD 1.86 mm, 95% CI 0.39 to 3.33; 1 study, 31 participants). There may be no benefit in terms of effect on ANB of alternating rapid maxillary expansion and constriction compared to using expansion alone (MD -0.46°, 95% CI -1.03 to 0.10; 4 studies, 131 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

Moderate-certainty evidence showed that non-surgical orthodontic treatments (which included facemask, reverse Twin Block, orthodontic removable traction appliance, chin cup, tandem traction bow appliance and mandibular headgear) improved the bite and jaw relationship immediately post-treatment. Low-certainty evidence showed surgical orthodontic treatments were also effective. One study measured longer-term outcomes and found that the benefit from facemask was reduced three years after treatment, and appeared to be lost by six years. However, participants receiving facemask treatment were judged by clinicians to be less likely to need jaw surgery in adulthood. We have low confidence in these findings and more studies are required to reach reliable conclusions. Orthodontic treatment for Class III malocclusion can be invasive, expensive and time-consuming, so future trials should include measurement of adverse effects and patient satisfaction, and should last long enough to evaluate whether orthodontic treatment in childhood avoids the need for jaw surgery in adulthood.

Digital setup accuracy for moderate crowding correction with fixed orthodontic appliances: a prospective study

OBJECTIVES

To evaluate the accuracy of a semi-automatic 3D digital setup process in predicting the orthodontic treatment outcome achieved by labial fixed appliances.

SUBJECTS AND METHODS

Twenty-five adult patients (18 to 24 years old) with class I malocclusion and moderate crowding were prospectively enrolled and received treatment on both jaws through the straight-wire technique. Prior to treatment commencement, a semi-automatic digital setup simulating the predicted treatment outcome was performed for each patient through Orthoanalyzer software (3Shape®, Copenhagen, Denmark) to obtain the prediction model. This was compared to the final outcome model through 3D superimposition methods. Metric variables and inspection of color-coded distance maps were used to detect how accurately the digital setup predicts the actual treatment outcome.

RESULTS

The mean absolute distances (MAD) between the superimposed dental arches of the predicted and the final models were: 0.77 ± 0.13 mm following superimposition on the palate, 0.52 ± 0.06 mm following superimposition on the maxillary dental arch, and 0.55 ± 0.15 mm following superimposition on the mandibular dental arch. The MAD at the palatal reference area was 0.09 ± 0.04 mm. Visualization of color-coded distance maps indicated that the digital setup accurately predicted the final teeth position in a few cases. Almost half of the cases had posteriorly wider upper and lower dental arches and palatally/lingually positioned or inclined anterior teeth, whereas the rest still showed errors within 2-3 mm, distributed over the entire dental arches with no distinct pattern.

CONCLUSIONS

The accuracy of semi-automatic prediction of the labial fixed appliance treatment outcome in Class I cases with moderate crowding is not yet sufficient. While average measures showed deviations less than 1 mm, examination of individual color-coded distance maps revealed significant disparities between the simulated and the actual results.

Language bias in orthodontic systematic reviews: A meta-epidemiological study

BACKGROUND

Orthodontic systematic reviews (SRs) include studies published mostly in English than non-English languages. Including only English studies in SRs may result in a language bias. This meta-epidemiological study aimed to evaluate the language bias impact on orthodontic SRs.

DATA SOURCE

SRs published in high-impact orthodontic journals between 2017 and 2021 were retrieved through an electronic search of PubMed in June 2022. Additionally, Cochrane oral health group was searched for orthodontic systematic reviews published in the same period.

DATA COLLECTION AND ANALYSIS

Study selection and data extraction were performed by two authors. Multivariable logistic regression was implemented to explore the association of including non-English studies with the SRs characteristics. For the meta-epidemiological analysis, one meta-analysis from each SRs with at least three trials, including one non-English trial was extracted. The average difference in SMD was obtained using a random-effects meta-analysis.

RESULTS

174 SRs were included in this study. Almost one-quarter (n = 45/174, 26%) of these SRs included at least one non-English study. The association between SRs characteristics and including non-English studies was not statistically significant except for the restriction on language: the odds of including non-English studies reduced by 89% in SRs with a language restriction (OR: 0.11, 95%CI: 0.01 0.55, P< 0.01). Out of the sample, only fourteen meta-analyses were included in the meta-epidemiological analysis. The meta-epidemiological analysis revealed that non-English studies tended to overestimate the summary SMD by approximately 0.30, but this was not statistically significant when random-effects model was employed due to substantial statistical heterogeneity (ΔSMD = -0.29, 95%CI: -0.63 to 0.05, P = 0.37). As such, the overestimation of meta-analysis results by including non-English studies was statistically non-significant.

CONCLUSION

Language bias has non-negligible impact on the results of orthodontic SRs. Orthodontic systematic reviews should abstain from language restrictions and use sensitivity analysis to assess the impact of language on the conclusions, as non-English studies may have a lower quality.

Prevalence of Malocclusions among Schoolchildren from Southwestern Romania

Malocclusions have a continuously increasing prevalence from one generation to another as a result of climate change, soil, atmosphere, and water pollution. All of these aspects have unfavorable consequences for the nutritional scheme. Thus, nutrition, together with other etiopathogenic factors, contributes to complex alterations in the somatic development of the entire organism and, implicitly, of the cephalic extremity. The study group included 4147 children from randomly selected schools from Vâlcea County, Romania. The aim of this study is to determine the prevalence of malocclusions in schoolchildren in Vâlcea County, Romania, according to the three main classes of malocclusions (according to Angle's classification), age groups (from 6 to 10 years old and from 11 to 14 years old), gender (male and female), and place of origin (rural and urban). For Angle class I malocclusions, we recorded the highest prevalence (48.78% of the total number of schoolchildren with malocclusions), followed by Angle class II malocclusions (45.85% of the total number of schoolchildren with malocclusions), and for Angle class III malocclusions we found the lowest prevalence (5.37% of the total number of schoolchildren with malocclusions). According to gender, we found the highest prevalence in the female gender (29.90% of the total number of female subjects), while in the male gender, we recorded a prevalence of 27.70% of the total number of male subjects. Regarding the place of origin, there is a higher prevalence of malocclusions in urban areas (29.16%). The study subgroup included 140 children randomly selected from the total number of subjects in the study group. They were included in a more advanced study. The aim is to find potential associations between the presence of malocclusions and various oral variables. Categorical variables were expressed as numerical values and percentages, and their association was evaluated with either the Chi-square test of association or homogeneity, or the Fisher Exact test. The acquired data were incorporated into a binomial logistic regression model to assess the likelihood of developing malocclusions in relation to the following variables: defective phonation, bruxism, frequency of teeth brushing, onychophagia, oral respiration, infantile deglutition, placing objects between the maxillaries, thumb sucking, and salivary aspects. It is also aimed at comparing the results obtained with similar ones from the specialized literature.

Craniocervical posture in patients with skeletal malocclusion and its correlation with craniofacial morphology during different growth periods

The association between craniocervical posture and craniofacial structures in the various sagittal skeletal malocclusion during different growth stages has been the focus of intense interest in fields of orthodontics, but it has not been conclusively demonstrated. Thus, this study aimed to investigate the association between craniofacial morphology and craniocervical posture in patients with sagittal skeletal malocclusion during different growth periods. A total of 150 from a large pool of cephalograms qualified for the inclusion and exclusion were evaluated and classified into three groups according to the Cervical Vertebral Maturation (CVM) by examining the morphological modifications of the second through fourth cervical vertebrae, each group consisted of 50 cephalograms. In each growth period, for the comparison of head and cervical posture differences among various skeletal classes, the radiographs were further subdivided into skeletal Class I (0° < ANB < 5°, n = 16), skeletal Class II (ANB ≥ 5°, n = 18), and skeletal Class III (0° ≤ ANB, n = 16) on the basis of their ANB angle. There was no significant difference in gender (P > 0.05). Some variables were found to be significant during pubertal growth and later in patients with sagittal skeletal malocclusion (P < 0.05). Most indicators describing craniocervical posture were largest in skeletal Class II and smallest in skeletal Class III during the peak growth periods and later. Cervical inclination variables were greater in skeletal Class III than in skeletal Class II. Variables of craniofacial morphology and craniocervical posture are more correlated during the pubertal growth period and later in patients with sagittal skeletal malocclusion. A tendency is an indication of the close interrelationship that a more extended head was in skeletal Class II while a flexed head was in skeletal Class III. Nevertheless, with the considerations of some limitations involved in this study, further longitudinal studies with large samples are required to elucidate the relationship clearly.

Evaluation of the anterior dentoalveolar relationship in skeletal Class III malocclusion patients with different vertical facial patterns using cone-beam computed tomography

OBJECTIVES

To measure and compare labiolingual inclinations of the teeth and alveolar bone and the anterior dentoalveolar inclination in patients with skeletal Class III malocclusions with different vertical facial patterns using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Based on the inclusion and exclusion criteria, 84 CBCT images of patients with untreated skeletal Class III malocclusion were selected. There were 28 patients each in the hypo-, normo-, and hyperdivergent groups. The labiolingual inclinations of the teeth, the corresponding alveolar bone, and the anterior dentoalveolar inclinations were measured and analyzed statistically.

RESULTS

The inclinations of the mandibular canine and corresponding alveolar bone were smaller in the hypodivergent group than in the hyperdivergent group. The inclination of the alveolar bone and the maxillary dentoalveolar inclination were smaller in the hyperdivergent group than in the hypodivergent group.

CONCLUSIONS

There were differences in the inclination of the teeth, corresponding alveolar bone, and dentoalveolar inclinations at different positions among skeletal Class III patients with different vertical facial patterns. The roots were generally located on the labial side of the alveolar bone.

Morphological Changes of the Mandibular Angle After Orthognathic Surgery with Class III Deformity in East Asia

The aims of this study were to analyze the morphological changes of the mandibular angle after orthognathic surgery for mandibular setback and investigate related factors. This retrospective study included patients from January 2017 to December 2021 diagnosed with skeletal class III deformity who underwent BSSRO (Group I) or bimaxillary surgery (Group II). Preoperative (T0), within 1 month postoperatively (T1), and 6 months postoperatively (T2) CT scans were collected from 61 patients to three-dimensionally analyze the proximal segment displacement, the linear and angular changes of the mandibular angle. The gonion points moved posteriorly and laterally (P < 0.001), while the inferior movement was not significant (P = 1.000, P = 0.274). The intergonial width increased by 3.32 ± 1.87 mm and 2.34 ± 1.77 mm as revealed by T2 CTs, respectively, in Group I and Group II. Mandibular angle decreased in both groups and by 1.41 ± 2.95° in Group I and 1.37 ± 3.41° in Group II. The increase in intergonial width between T1 and T0 was negatively correlated with the preoperative mandibular angle (P = 0.003) and positively correlated with the transverse outward movement of the proximal segment (P < 0.001). After surgery, the intergonial width increased and the inferior and posterior border of the proximal segment flared outward. The changes in intergonial width and mandibular angle were mainly related to the rotation of the proximal segment, which has a certain impact on the aesthetics of the lower face. Therefore, controlling the position of the proximal segment is of vital importance to lessen the changes in the mandibular angle area.Level of Evidence III. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Optimal Treatment Timing in Orthodontics: A Scoping Review

The appropriate timing for orthodontic intervention has been a subject of debate for a long time, concerning not only the immediate effects but also the long-term benefits of such treatment. This review aimed to find the appropriate treatment timing for the intervention of various orthodontic problems. A literature search was performed in all major databases, including PubMed and Cochrane Library, until February 20, 2023. All observational and experimental studies published in English that compared early versus late orthodontic treatment in different types of orthodontic problems were included. Data selection and charting were undertaken by a single investigator. A total of 32 studies were identified that discussed various aspects of interventions, including Class II and Class III malocclusion, pseudo-Class III malocclusion, anterior and posterior crossbite, extractions, and long-term benefits. Overall, early intervention was not found to be superior in terms of effectiveness, overall duration of appliances, and cost-benefit ratio. Early intervention should be reserved for specific conditions or localized malocclusions that have psycho-social benefits, or to significantly reduce the severity of problems to be dealt with in comprehensive treatment in the permanent dentition.

Malocclusion: Prevalence and Determinants among Adolescents of Karachi, Pakistan

OBJECTIVES

 The aim of this study was to determine the prevalence of malocclusion and its associated demographic and clinical factors in young adolescents (13-15 years) of Karachi, Pakistan.

MATERIALS AND METHODS

 An epidemiological survey included 500 young adolescents of registered schools, madrassas (Islamic education system), and shop workers of Gulshan-e-Iqbal Town. It was a cross-sectional analytical study design. Multistage random sampling technique was used to enroll participants. The pattern of occlusion was recorded with other related features using Angle's classification. Health status was recorded through World Health Organization-guided indices (decayed, missing, and filled permanent teeth [DMFT], community periodontal index of treatment needs [CPITN], and body mass index [BMI]). The information, thus, obtained was analyzed through SPSS using the chi-squared test and regression models.

RESULTS

 Forty four percent of the participants were female, while overall estimated prevalence of malocclusion in young adolescents of Karachi was 57.4%. After adjustments, participants going to any kind of education system had less malocclusion in comparison to those who were not going to any education system (adjusted odds ratio [aOR] = 0.305, 95% confidence interval [CI] = 0.12-0.73); mother's education especially higher level (aOR = 2.02, 95% CI = 1.08-3.75) and presence of periodontal disease (aOR = 1.57, 95% CI = 1.06-2.33) were significantly associated with malocclusion.

CONCLUSION

 This study showed that the class I malocclusion is prevalent in the local community. Demographic factors like gender, age, self-reported ethnicity, and BMI did not show any significant role. Education or knowledge of parents and young adolescents does play an influential role in decreasing malocclusion. Young adolescents, who are more prone to oral health problems at an early age, would have more chances to develop occlusal discrepancies.

Long-term stability of posterior crossbite correction, treated in the mixed or permanent dentition of growing children: A systematic review and meta-analysis

When treating posterior crossbite, the primary goal is to achieve long-term crossbite correction. The majority of studies however focus on relapse of the increase in the transverse dimension, but not relapse of the crossbite itself, which is an essential outcome. The aim of the present study was to determine long-term stability (2 years minimum post-treatment) of posterior crossbite correction, treated in mixed or early permanent dentitions of growing children. Following registration in PROSPERO (CRD42022348858), an electronic literature search including PubMed, Embase, Web of Science, the Cochrane Library, and a manual search were conducted up to January 2023, to identify longitudinal studies looking into the long-term stability of crossbite correction in growing children. Data extraction and risk of bias assessment were carried out, and subsequently, a random-effects meta-analyses models were used to calculate estimates for relapse of the crossbite and relapse at the transverse level. Twenty-two studies were included, of varying designs and quality, representing 1076 treated patients, with different expansion appliances and protocols. Meta-analysis results showed that 19.5% (95% CI: 15%; 25%) of patients present with relapse of posterior crossbite at long-term follow-up. At the transverse level, 19.3% of the total expansion (including overexpansion) relapsed (95% CI: 13%; 27%) regardless of whether there a was relapse of the crossbite itself. Data from existing studies, with a moderate level of evidence, indicate that the long-term stability of posterior crossbite correction in growing children is unfavourable in roughly 1 in 5 growing children, with crossbite relapse long-term. On average, 19% of the maxillary expansion performed (including overexpansion) relapses long-term, which may occur in cases with or without relapse of the crossbite.

Orthodontics in the oral health care network of the Unified Health System (SUS)

This observational study aimed to describe and analyze data from two external evaluations of the National Program for Improving Access to and Quality of Dental Specialty Centers (PMAQ CEO), held in 2014 and 2018 in Brazil, which evaluated Dental Specialty Centers (CEO) using a national and census approach. We selected questions through a search in the microdata of the first and second evaluations. The groups were analyzed independently. To compare the groups, nonparametric tests were performed (Mann Whitney U). The formulated hypotheses were: there would be no differences between the data of these groups (h0) and there would be differences between the data of these groups (h1). For qualitative nominal variables, frequency distribution was verified and association tests were performed (chi-square test). The significance level for this study was set at 5%. We observed that orthodontic treatments were found in about 13% of the CEO. Regarding human resources, most professionals were specialists or had MSc or PhD degrees; were civil servants; had been hired by direct administration; or had been hired via public tender. Regarding the work process and inclusion of the CEO in the health care network, we observed a greater number of services that use single and electronic medical records, greater presence of services monitoring and analyzing goals, greater knowledge about monthly average of absenteeism (for 2018); and larger number of services with referrals from primary health care centers (for 2014). Expanding the view on orthodontics and including preventive, interceptive, and corrective treatments at different points in health care networks are essential strategies for achieving comprehensive care in universal health systems.

Assessment of dental, skeletal, and soft tissue changes following mandibular advancement with Invisalign in skeletal Class II

Objective

This study evaluated the dentoskeletal and soft tissue changes for Class II malocclusion patients treated with Invisalign clear aligners with mandibular wings (IAMW).

Methods

This retrospective study included 50 skeletal Class II patients treated with Invisalign clear aligner with mandibular wings. Records of 20 subjects were collected from the AAOF Legacy Collection (The Case Western Bolton Brush Growth Study) and were used as a control. The dental, skeletal, and facial soft tissue changes were assessed by digitizing and analyzing lateral cephalograms using Dolphin Imaging software (version 11.95 Premium; Dolphin Imaging & Management Solutions, Chatsworth, Calif). Paired t-tests and independent t-tests were used to assess the changes before and after and to compare between the IAMW and control groups.

Results

The different measurements of the maxilla have shown that IAMW effect on the maxilla included minimal, non-significant retraction compared to the control group. The SNB and mandibular base position increased by 1.17° (±2.63) and 3.79 (±8.13), respectively. The mandible advanced significantly in the treatment group compared to the control group. Dentally, the lower incisors tipped slightly buccally, but the change was not significant (p > 0.05). The facial convexity angle decreased by 1.16° (±4.36).

Conclusion

Invisalign clear aligner with mandibular advancer wings was able to correct the Class II malocclusion. This correction was mainly skeletal with some dental changes. This device can be used to address the growth modification problem in Class II malocclusion at the same time as addressing the other occlusal problems.