Skeletal class-II Malocclusion Research Articles

Cephalometric Assessment of Skeletal Class II Malocclusion in a Sample of Kurdish Population in Sulaimani City (Retrospective Study)

Objective: This retrospective comparative cephalometric study aims to identify the cephalometric features of skeletal class IImalocclusion in a sample of the Kurdish population, the result of this study willl be useful in diagnosing and treating orthodontic andjaw surgery.
 Methods: A total of 85 pre-treatment lateral cephalometric radiographs with skeletal class II malocclusion (ANB>=4) and 81 withskeletal class I malocclusion (1=<ANB<4) were obtained from the pre-orthodontic patient records in a private orthodontic clinic inSulaimani city. The patients were between 18 and 35 years old. The lateral cephalometric radiographs were analyzed digitally usingFACAD cephalometric software. Twenty-two variables were measured from each cephalometric radiograph. The correlation betweenClass I and II was analyzed using the Mann-Whitney Test.
 Results: The result showed that the values of SNA, ANB, Y-axis, Convexity angle, Gonial angle, Intermaxillary angle, facial angleand FMA, posterior cranial base, effective maxillary length, LAFH were higher in skeletal Class II than in Class I cases, which indicatesthat skeletal class II Kurdish population have more vertical mandibular growth and prognathic maxilla, retrognathic mandible, andlonger face than class I. Meanwhile, SNB, Mandibular length, TFH, UAFH, Maxillary length, UI-Palatal plane angle, IMPA, andeffective mandibular length values were lower and the difference was statistically significant in the majority of cases.This illustratesthat the incisors are more proclined in class I than skeletal class II, whereas the mandible is shorter in skeletal class II patients. Theseresults summarize the characteristic features of skeletal class II patients in a sample of the Kurdish population in Sulaimani City, whichare caused by etiological factors (genetic, congenital). This information is useful for enabling orthodontists and maxillofacial surgeonsto attain a diagnosis and treatment plan for skeletal class II patients in a shorter period.
 Conclusions: Skeletal class II malocclusion in the Kurdish population is characterized by a prognathic but short maxilla, retrognathic,short, backward, and downward rotated mandible, and a prominent chin.

Ortho-Surgical Management of Skeletal Class Iii Malocclusion With Severe Tooth Size Arch Length Discrepancy

Ortho-Surgical Management of Skeletal Class Iii Malocclusion With Severe Tooth Size Arch Length Discrepancy

Orthosurgical synergism in the management of severe skeletal Class-III malocclusion- A case report

: What is now known as a Class-III malocclusion was initially recognized by Pierre Fauchard. True Class-III malocclusion is a genetically based condition that manifests in childhood. As the youngster reaches the teenage growth spurt, it becomes more obvious. Typically, we will discover a parent or grandparent who is dealing with the same issue. Class-III malocclusion, however, is not a disease. The abnormality itself is a compensatory mechanism to make up for variation that has happened at some point during the course of the individual's development.The case presented here demonstrates the importance of presurgical decompensation, surgical planning, including cephalometric predictions, and mock surgery in the management of severe skeletal Class-III malocclusion. The treatment included comprehensive orthodontic and surgical workup that included bilateral sagittal split osteotomy for mandibular setback of 3mm and LeFort-I osteotomy for maxillary advancement of 3mm. Class-I jaw relationships with a pleasing profile and correctly aligned arches were attained after 2 years of detailed treatment. This led to an aesthetic improvement and a significant increase in the patient's confidence. Class-III skeletal malocclusions can be corrected surgically or through camouflage. However, an ortho-surgical approach may be necessary if the issue cannot be resolved with orthodontics alone. When done correctly, bi-jaw surgery has repeatedly been shown to be quite successful.

Skeletal Class II Malocclusion: From Clinical Treatment Strategies to the Roadmap in Identifying the Genetic Bases of Development in Humans with the Support of the Collaborative Cross Mouse Population.

Depending on how severe it is, malocclusion, which may involve misaligned teeth, jaws, or a combination of the two, can hurt a person's overall facial aesthetics. The maxillary molar develops before the mandibular molar in class II malocclusion, which affects 15% of the population in the United States. With a retrusive mandible, patients typically have a convex profile. The goal of this study is to classify the skeletal and dental variability present in class II malocclusion, to reduce heterogeneity, present the current clinical treatment strategies, to summarize the previously published findings of genetic analysis, discuss these findings and their constraints, and finally, propose a comprehensive roadmap to facilitate investigations aimed at determining the genetic bases of malocclusion development using a variety of genomic approaches. To further comprehend the hereditary components involved in the onset and progression of class II malocclusion, a novel animal model for class II malocclusion should be developed while considering the variety of the human population. To overcome the constraints of the previous studies, here, we propose to conduct novel research on humans with the support of mouse models to produce contentious findings. We believe that carrying out a genome-wide association study (GWAS) on a large human cohort to search for significant genes and their modifiers; an epigenetics-wide association study (EWAS); RNA-seq analysis; integrating GWAS and the expression of quantitative trait loci (eQTL); and the testing of microRNAs, small RNAs, and long noncoding RNAs in tissues related to the skeletal class II malocclusion (SCIIMO) phenotype, such as mandibular bone, gum, and jaw in humans and the collaborative cross (CC) mouse model, will identify novel genes and genetic factors affecting this phenotype. We anticipate discovering novel genetic elements to advance our knowledge of how this malocclusion phenotype develops and open the venue for the early identification of patients carrying the susceptible genetic factors so that we can offer early prevention treatment strategies.

Effect of maxillary expansion combined with orofacial myofunctional therapy on the position of the tongue of children with mouth breathing

Objective:This study aimed to investigate the change of the position of the tongue before and after combined treatment of maxillary expansion and orofacial myofunctional therapy in children with mouth-breathing and skeletal class Ⅱmalocclusion. Methods:A total of 30 children with skeletal class Ⅱ malocclusion and unobstructed upper airway were selected. The 30 children were divided into mouth-breathing group（n=15） and nasal-breathing group（n=15） and CBCT was taken. The images were measured by Invivo5 software. The measurement results of the tongue position of the two groups were analyzed by independent samples t-test. 15 mouth-breathing children with skeletal class Ⅱ malocclusion were selected for maxillary expansion and orofacial myofunctional therapy. CBCT was taken before and after treatment, the measurements were analyzed by paired sample t test with SPSS 27.0 software package. Results:The measurement of the tongue position of the mouth-breathing and nasal-breathing groups were compared, the differences were statistically significant（P<0.05）. The measurement of the tongue position showed significant difference after the combined treatment of maxillary expansion and orofacial myofunctional therapy in children with mouth-breathing and skeletal class Ⅱmalocclusion（P<0.05）. Conclusion:Skeletal class Ⅱ malocclusion children with mouth-breathing have low tongue posture. The combined treatment of maxillary expansion and orofacial myofunctional therapy can change the position of the tongue.

Mandibular advancement with clear aligners and functional appliances in the treatment of skeletal ClassⅡmalocclusion: a systematic review and meta-analysis.

This study aimed to conduct a meta-analysis of the efficacy of mandibular advance clear alig-ners with traditional functional appliances as the control group. PubMed, Web of Science, Embase, Cochrane Library, China Biomedical Abstracts Database, China Knowledge Network Database, Wanfang Database, and Weipu Database were used in this study. The two groups of researchers screened the literature and extracted data based on the inclusion and exclusion criteria established by PICOS entries, and used the ROBINS-I scale for quality evaluation. Revman 5.4 and Stata 17.0 software were used for meta-analysis. Nine clinical controlled trials were included in this study with a total sample size of 283 cases. No significant difference was found in SNA, SNB, ANB, Go-Pog, U1-SN, Overjet, and other aspects between the invisible group and the traditional group in the treatment of skeletal class Ⅱ ma-locclusion patients; there was a 0.90° difference in mandibular plane angle between the two groups; the growth of the mandibular ramus (Co-Go) in the traditional group was 1.10 mm more than that in the invisible group; the lip inclination of the lower teeth in the invisible group was better controlled, 1.94° less than that in the control group. The invisible group can better control the lip inclination of the mandibular anterior teeth when guiding the mandible. Furthermore, the mandibular plane angle (MP-SN) can remain unchanged, but the growth of the mandibular ramus is not as good as the traditional group, and auxiliary measures should be taken to improve it in clinical practice.

Retrospective study on the relationship between alveolar-bone morphology at the mandibular incisors and their inclination in adults with low-angle, skeletal class III malocclusion

Background and Aim: The orthodontic tooth movements should be such that the tooth moves safely within the alveolar bone. The alveolar bone around the mandibular central incisors of patients with skeletal class I and II malocclusion is thicker in comparison to those with skeletal class III malocclusion. The present study aimed to investigate an association between low angle inclination skeletal class-III malocclusion and the alveolar bone morphology around it. Materials and Methods: A retrospective study was carried out on 75 malocclusion patients in the Orthodontics Department of a Tertiary Care Hospital of Islamabad, Pakistan from January 2020 to December 2022. The malocclusions were confirmed in the patients via cone beam computed tomography (CBCT) imaging. The low angle, skeletal class III malocclusions were categorized into three different groups: Group-I (lingual-inclination), Group-II (upright), and Group-III (labial-inclination). Outcomes such as height of alveolar bone and area of cortical as well as cancellous thickness were determined independently on each side. Results: The labial cancellous bone thickness, thickness of labial cortical bone, alveolar bone total thickness, labial alveolar bone total area, and labial alveolar bone height were highest in group-III (labial-inclination). There was a positive correlation between mandibular central incisors and other aforementioned variables.

EVALUATION OF DENTOALVEOLAR COMPENSATION IN DIFFERENT SKELETAL MALOCCLUSIONS IN BENGALEE POPULATION- A CEPHALOMETRIC STUDY

Introduction: Humans have been aware of facial esthetics from prehistoric times. An 'esthetically pleasing face' is described as one in which various facial features are well proportioned and balanced from both 'frontal and prole' view. Evaluating the face in prole is an integral part of a complete orthodontic diagnosis. The labiolingual inclination and anteroposterior (AP) position of maxillary incisors have a crucial effect on the appearance of the smiling prole. Aims: To evaluate and compare dentoalveolar compensations in various skeletal malocclusions. The Cross sectional study Materials and methods: , this Study was conducted from January 2018 to June 2019 at Guru Nanak Institute of Dental Sciences and Research, panihati, Kolkata- 7 00114. 120 patients were taken in our study. Result: In the present study mandibular central incisor to SN shows statistically signicant difference in mean value when intergroup comparison were made between control group with group-II, and group-III, between group- Mandibular incisors are proclined labially in skeletal class- II malocclusion, while mandibular incisors were found upright or retroclined in skeletal class-III malocclusion. In Group-II (skeletal Conclusion: Class- II malocclusion) upper incisors are proclined in the upper jaw, and lower incisor proclined in lower jaw.

Treatment of skeletal classIII malocclusion using acombined clear aligner and surgery-early approach : Assessment based on the American Board of Orthodontics Objective Grading System.

To evaluate whether clear aligner therapy (CAT) combined with asurgery-early approach can achieve good therapeutic effects in patients with skeletal classIII malocclusion. Thirty consecutive skeletal classIII malocclusion cases treated with clear aligners combined with early surgery were selected. Treatment time, lateral cephalograms and American Board of Orthodontics Objective Grading System (ABO-OGS) scores of the treatment models were measured to evaluate the treatment efficiency, facial profile, and occlusion. The results showed that early surgery was achieved after 7.71months of presurgical orthodontics, on average. ANB decreased by 5.57° (P < 0.001), and STissueN Vert to Pog' decreased by 7.29 mm (P = 0.001), both reaching normal values. The posttreatment ABO-OGS scores were 26.600 on average, meeting its standards. With the assistance of CAT, early surgery can be accomplished in patients with skeletal classIII malocclusion, improving their facial profile and achieving functional occlusion.

The Lower Lip Profile Change During Total Distalization of the Mandibular Dentition

Objectives: This study aimed to determine the factors influencing the lower lip profile during Class III lower total arch distalization camouflage treatment. Methods: The cohort included 45 patients diagnosed with skeletal class III malocclusion. These patients underwent camouflage orthodontic treatment with lower arch total distalization. Lateral cephalograms were taken at the pretreatment and posttreatment stages. Cephalometric measurements were analyzed to unravel the influencing factors of the lower lip profile. This study defined new variables, i.e., CK and CKA, for detailed soft tissue analysis. Results: Novel soft tissue measurements presented in this study showed statistically significant changes after treatment. The CK angle and L1 to A Pog, L1 to NB, and IMPA were statistically correlated. Simple regression analysis was performed between variables. The formula was ΔCKA = 0.79(Δ L1 to NB) -1.6, and multiple regression resulted in ΔCKA = 0.5(Δ L1 to NB) – 0.42 (‘LL to Eline’, before treatment). Conclusion: The present study provided evidence that the lower lip evaluations, including the novel CKA and CKHA, were significantly related to the mandibular incisor position during total distalization of the mandibular dentition. The results demonstrated that clinically significant lip retraction could be obtained. Therefore, non-extraction with distalization must be suggested as the first treatment option in mild skeletal class III malocclusion patients.

COMPARATIVE ANALYSIS OF THREE MACHINE LEARNING MODELS FOR EARLY PREDICTION OF SKELETAL CLASS-III MALOCCLUSION FROM PROFILE PHOTOS

The pre-adolescent growth period is the best time for the skeletal Class-III malocclusion treatment. Diagnosis and treatment during this period continue to be a complex orthodontic problem. Class-III malocclusion is complicated to treat with braces frequently requiring surgical intervention after a pubertal growth spurt. In addition, delayed recognition of the problem will yield significant functional, aesthetic, and psychological concerns. This study presents the first fully automated machine learning method to accurately diagnose Class-III malocclusion applied across mobile images, to the best of our knowledge. For this purpose, we comparatively evaluated three machine learning approaches: a deep learning algorithm, a machine learning algorithm, and a rule-based algorithm. We collected a novel profile image data set for this analysis along with their formal diagnosis from 435 orthodontics patients. The most successful method among the three was the machine learning method, with an accuracy of %76.

Comparison of the short-term effects of facemask therapy preceded by conventional rapid maxillary expansion or by an alternate rapid maxillary expansions and constrictions protocol : Aretrospective study.

We aimed to compare the short-term effects of alternate rapid maxillary expansion and constriction (Alt-RAMEC) with conventional rapid maxillary expansion (RME) followed by facemask (FM) therapy. A total of 30patients who had received facemask therapy after RME or Alt-RAMEC protocols were included in the study. The Alt-RAMEC/FM and RME/FM groups were created to be well-matched regarding cervical vertebral maturation stage and sex. In the Alt-RAMEC group (10males and 5females, 10.99 ± 1.80years), expansion screws were activated for aweek (two turns/day), then deactivated in the following week (two turns/day). The activation-deactivation protocol continued for 6 or 7weeks. In the RME/FM group (10males and 5females, 11.61 ± 1.20years), screw activation was performed according to the patients' requirements. Lateral cephalograms which had been taken at the beginning of treatment and at the end of the facemask therapy were analyzed. Intragroup and intergroup differences were statistically analyzed. Both groups showed asignificant sagittal advancement of the maxilla. However, the Alt-RAMEC/FM group showed statistically greater improvements than the RME/FM group for SNA (3.11 ± 1.79 vs. 1.45 ± 1.34, p = 0.008), ANB (4.29 ± 1.80 vs. 2.95 ± 1.19, p = 0.023), convexity (8.91 ± 4.29 vs. 5.61 ± 2.51, p = 0.016), and overjet (5.86 ± 2.29 vs. 4.61 ± 2.10, p < 0.001). The sagittal mandibular, vertical skeletal, dental, and soft tissue changes were similar between the groups (p > 0.05). The Alt-RAMEC protocol was found to be more effective in the correction of skeletal classIII malocclusion in the short term.

Comparative Evaluation of the Forces Produced by Tongue on Circummaxillary Sutures in Skeletal Class-III Malocclusion with Maxillary Hypoplasia Using Tongue Crib with that of Facemask Therapy: A FEM Study

Introduction: The tongue exerts its force during swallowing, while it rests behind the crib. Magnitude of forces tongue exerts through tongue crib at various sutures, its implication in various grades of maxillary hypoplasia in Class III malocclusion is not provided in literature. The rationale of this study is to investigate stress distributions in the sutures of craniofacial region produced by forces applied by tongue through tongue crib in comparison with facemask therapy in Class III malocclusion with maxillary hypoplasia in maxillary protraction.&#x0D; Objectives: The rationale of this study was to compare forces generated by tongue through tongue crib and facemask therapy in Class III malocclusion with maxillary hypoplasia in child of pubertal age group.&#x0D; Methodology: Finite element model of skull would be generated and simulation of tongue crib and facemask therapy would be done and stresses would be studied at various sutures. Quantitative analysis is done by elucidating values of finite element analysis.&#x0D; Expected Results: The forces produced by tongue on circummaxillary sutures in skeletal Class III malocclusion with maxillary hypoplasia using tongue crib with that of facemask therapy would be substantial.&#x0D; Conclusion: Stress distribution produced by protraction forces exerted by tongue through tongue crib in comparison with facemask therapy in Class III malocclusion with maxillary hypoplasia would be studied through finite element analysis to promote growth in maxilla.

Comparative Analysis of Dentoskeletal Changes of the Twin Block Appliance and the AdvanSync2 Appliance in Treatment of Skeletal Class-II Malocclusion in Pakistani Population: A Randomized Clinical Trial.

Objective This study aimed to compare dentoskeletal changes in skeletal class-II malocclusion with removable twin block appliance and fixed AdvanSync2 appliance. Materials and Methods A prospective randomized clinical trial was conducted over a span of 1 year at AFID at Rawalpindi. Thirty patients with skeletal class-II malocclusion, 16 males (53.3%) and 14 females (46.6%), were randomly selected and divided in two equal groups (15 each) to be treated with either fixed functional appliances (FFAs) or with removable functional appliances (RFAs). Out of 30 patients, 15 between cervical vertebral maturation (CVM) stages of 2 and 3 were treated with RFA (twin block appliances) and remaining 15 between CVM stages of 4 and 5 were treated with FFA (AdvanSync2 appliances). Pretreatment (T 1 ) and posttreatment (T 2 ), angular variable, and linear variable were measured to compare the dentoskeletal effects between the two groups. Statitical Analysis Paired sample t-test was used to assess significant difference between variables at T1 (Pre-treatment) and T2 (Post-treatment) stage for both RFA and FFA group. Comparison among the RFA and FFA group was made using non-parametric Mann-Whitney U Test. IBM SPSS version 25.0 was used for evaluation. Results No significant difference was found in angular variables between the RFA and FFA groups ( p > 0.05) with the exception of linear variables. Sella-posterior nasal spine (S-PNS) length significantly increased and Jarabak's ratio significantly decreased for FFA group ( p = 0.010 and 0.045, respectively), when compared with RFA group. Conclusion Both the appliances, twin block (RFA) and AdvanSync2 (FFA), are effective for correction of skeletal class-II malocclusion. Both the appliances produced similar effects in the sagittal plane but for better vertical control twin block should be the appliance of choice. AdvanSync2 appliance could be preferred over twin block appliance when dentoalveolar and slight retrusive effect on the maxilla is desired especially for individuals in postpubertal growth spurt.

Orthosurgical management of skeletal class-II malocclusion with vertical growth pattern- A case report

Edward H Angle first gave the classification for malocclusions into Classes I, II and III. Amongst these, Class II is the most prevalent and commonly treated at orthodontic clinics. Treatment of Class II malocclusion with mandibular deficiency in adult patients is usually managed with ortho-surgical treatment modality. In this article a case of Skeletal Class II malocclusion with vertical growth pattern is represented which was treated with BSSRO and mandibular advancement was carried out.

Evaluation of Changes in Condylar Cartilage Thickness Using MRI and Ultrasound Imaging in Patients Treated by Mandibular Advancement With Myofunctional Appliance: An In-Vivo Pilot Study.

IntroductionThe changes occurring due to growth modulation of the condylar cartilage act as an important mechanism for mandibular advancement using myofunctional appliance therapy. So this study aims to evaluate the condylar cartilage thickness by using MRI and USG in patients undergoing myofunctional appliance therapy for mandibular advancement with the null hypothesis being that there are no changes seen in the thickness of condylar cartilage in growing children.Materials and methodsA prospective evaluation of samples having skeletal Class-II malocclusion ranging between cervical vertebral maturation index (CVMI) stage II and III, requiring twin block functional therapy was performed. Ten patients were selected randomly who underwent MRI and USG in the open and close positions for the evaluation of condylar cartilage thickness and the dimensional changes in the width of the right and left condyle in mm at T0 and T1.ResultThere was no statistically significant difference between the values interpreted by MRI or USG imaging when compared at T0 and T1 and in the open and closed mouth on the left and right sides. At T0, the mean thickness noted was 0.49 mm and 0.48 mm during opening and closing on the left side and 0.52 mm in both positions on the right side. At T1, the mean thickness noted was 0.8 and 0.79mm during opening and closing on the left side, whereas it was 0.81 mm in both positions on the right side.ConclusionThe condylar cartilage thickness increases significantly after twin block therapy suggestive of mandibular growth in skeletal class II malocclusion. It can be inferred that both MRI and USG carry equal diagnostic interpretation, as there was no statistically significant difference between the two imaging modalities.

Analysis of MYO1H Gene Polymorphism in Skeletal Class-III Malocclusion Due to Mandibular Prognathism.

Background Mandibular prognathism (MP) is a craniofacial deformity resulting from the combined effects of environmental and genetic factors. Although various linkage and genome-wide association studies for mandibular prognathism have identified multiple strongly associated regions and genes, the causal genes and variants responsible for the deformity remained ambiguous. Aim This research work was aimed to study the association between polymorphism rs10850110 of the MYO1H gene and skeletal class-III malocclusion in our local population. Materials and Methods Thirty patients with skeletal class III due to mandibular prognathism in the study group and 30 patients with skeletal class I in the control group were selected for this study. These patients were from both sexes and above age 10 years. Based on the cephalometric values, patients were categorized into study and control groups. SNB (angle between sella, nasion and point B at nasion) greater than 82 degrees with an ANB (angle between point A, nasion and point B at nasion) of less than 0 degrees in the study group and ANB (angle between point A, nasion and point B at nasion) of 2 to 4 degrees in the control group were categorized. The polymorphism (rs10850110) of the MYO1H gene was genotyped using polymerase chain reaction and restriction fragment length polymorphism. Associations were tested with SNP exact test using SNPstats software. Results The single-nucleotide polymorphism rs10850110 showed a statistically significant association with mandibular prognathism. The G allele of marker rs10850110 (5′ of myosin1H - MYO1H ) was overrepresented when compared with the “A” allele in mandibular prognathism cases ( p < 0.0001), and this was very significant. Conclusion These results suggest that the rs10850110 polymorphism of the MYO1H gene is associated with an increased risk for mandibular prognathism.

Management of Skeletal Class-II Malocclusion Using Advansync 2: A Case Series

Angle’s class II division 1 malocclusion, being the most commonly occuring type of malocclusion, ischallenging to treat especially when there is an underlying skeletal discrepancy. Various fixed functionalappliances have been developed over the years by different authors for correction of skeletal class IImalocclusion due to retrognathic mandible. Among the fixed functional appliances available for class IIcorrection, Advansync2 (Ormco Co, Glendora, Calif) also known as molar to molar appliance has been usedeffectively in the recent past. It is a fixed tooth-born functional appliance with an advantage of allowingconcurrent use of fixed orthodontic therapy. This facilitates reduction of the overall treatment duration. Twocase reports of patients treated using the Advansync2 class II corrector has been presented along with theskeletal and dentoalveolar changes observed during the treatment. The effects observed were similar to mostfixed functional appliances however the treatment duration was considerably reduced in all the cases.

Role of the SDF-1/CXCR4 signaling pathway in cartilage and subchondral bone in temporomandibular joint osteoarthritis induced by overloaded functional orthopedics in rats

ObjectivesTo (i) use a mandibular advancement appliance in rats to investigate the role of the stromal cell-derived factor/CXC receptor 4 (SDF-1/CXCR4) signaling pathway in temporomandibular joint osteoarthritis (TMJ OA) induced by overloaded functional orthopedics (OFO) and (ii) provide a cellular and molecular basis for efficacious treatment of skeletal class-II malocclusion and avoidance of TMJ OA.MethodMale Sprague-Dawley rats (6 weeks) were divided randomly into control + normal saline (NS), EXP + ADM3100 (SDF-1 antagonist), EXP + NS, and control + ADM3100 groups. Changes in articular cartilage and subchondral bone after TMJ OA in these four groups were observed by hematoxylin and eosin (H&E), immunofluorescence double staining (IDS), Safranin-O staining, immunohistochemical (IHC) staining, real-time polymerase chain reaction, and micro-computed tomography at 2, 4, and 8 weeks.ResultsOFO led to increased expression of SDF-1, CXCR4, and matrix metalloproteinase (MMP) 13 and decreased expression of collagen II. The thickness of the hypertrophic cartilage layer was reduced at 4 weeks in the EXP + NS group, and damage to subchondral bone was observed at 2 weeks. Using ADM3100 to inhibit SDF-1 signaling could attenuate expression of MMP13, cartilage damage, and osteoblast differentiation. IDS showed that the areas of expression of SDF-1 and OSX in subchondral bone overlapped.ConclusionsOverloaded functional orthopedics (OFO) induced TMJ OA. The destruction of subchondral bone in TMJ OA caused by OFO occurred before damage to cartilage. SDF-1/CXCR4 may induce the osteogenic differentiation and cause cartilage degradation in TMJ OA caused by OFO.

Three-dimensional skeletal and pharyngeal airway changes following therapy with functional appliances in growing skeletal ClassII malocclusion patients : Acontrolled clinical trial.

To three-dimensionally analyze the skeletal and pharyngeal airway changes induced by Twin Block (TWB) and Forsus Fatigue Resistance Device (FFRD) in skeletal ClassII female patients compared with untreated controls. The study comprised 62growing female patients with skeletal ClassII malocclusion due to mandibular retrusion treated with either TWB (n = 23) or FFRD (n = 21), or neither (n = 18; controls). Pre- and posttreatment/observational cone beam computed tomography images were used to evaluate the treatment changes. TWB induced more obvious mandibular skeletal changes and caused significant retrusive effects on the maxilla. Similarly, the sagittal and vertical jaw relationships were affected more obviously with TWB (P<0.001) compared to FFRD. Changes in oropharyngeal volume and minimal axial area were more obvious with TWB. The TWB functional appliance induced significant skeletal and pharyngeal airway changes. These changes were more obvious relative to the slight changes induced by FFRD or by natural growth.