Increase In Mandibular Length Research Articles

Craniofacial Effects of Zoledronic Acid on the Osteogenesis Imperfecta Mouse (−/−) Model of Severe Osteogenesis Imperfecta

Background: Osteogenesis imperfecta (OI) is a rare genetic disorder affecting mainly type I collagen, which leads to bone fragility and deformities. OI patients also present craniofacial abnormalities such as macrocephaly and malocclusion. Recently, craniofacial dysmorphism was highlighted in the osteogenesis imperfecta mouse (oim), a validated model of the most severe form of OI. This study explores the impact of zoledronic acid (ZA), commonly administered to OI patients to increase bone mass and mechanical strength, on oim craniofacial structure. Methods: Fifteen oim received a single intravenous ZA injection (100 µg/kg) at 5 weeks (ZA group), while fifteen remained untreated (control). Before euthanasia at 14 weeks, in vivo computed tomography provided craniometric data. Post-euthanasia, heads underwent peripheral Quantitative Computed Tomography (pQCT); coronal decalcified sections through temporomandibular joints were analyzed (n = 6/mouse) after Masson’s trichrome staining (3 sections) or under polarized light to study collagen birefringence (3 sections). Results: In vivo craniometry highlighted the positive effect on vertical growth in ZA oim models as compared to untreated ones, with significant increases in mandibular length and incisor height and without any change in transversal dimensions. The pQCT scans showed the significantly higher total mineral density and cortical mineral density of the mandibular ramus in the ZA than the untreated group. Via microscopic analysis, the cranial vault was thicker and the collagen birefringence was higher in the ZA group than in the untreated group, but differences were not significant. Conclusion: To conclude, ZA had some beneficial effects on craniofacial vertical height and ramus density and, to a lower extent, on vault thickness, while transversal dimensions did not seem to be influenced by ZA intake. These data emphasize the need to consider the whole skeleton when treating OI patients.

Morphologic predictors of mandibular changes induced by Sander's Bite Jumping Appliance.

This study aimed to identify pretreatment cephalometric variables as possible predictors of the mandibular length increase in Class II patients with mandibular retrusion, treated by means of the Bite Jumping Appliance (BJA). Forty-three subjects (22 males and 21 females) with Class II malocclusion, treated with a BJA, were selected on the basis of the following inclusion criteria: full Class II molar relationship, Overjet (OVJ) ≥ 6 mm and a skeletal Class II malocclusion with mandibular retrusion at the start of the treatment (T0); cervical vertebral maturation stage 2 or 3 at time 0 (T0). The following mandibular structural features were measured on lateral cephalograms at time 0 and time 1 (15 months of treatment): the width and height of the mandibular symphysis and its width/height ratio, the width and height of the mandibular ramus and its width/height ratio, the antegonial notch depth and the Condilion-Gonion-Menton (Co-Go-Me) angle. Post-treatment changes were assessed by Pancherz's cephalometric analysis, evaluating the increases in mandibular length. A regression statistical model was used to test the association between morphologic variables and mandibular length changes. At T1, a significant increase in mandibular length (7.1 + 3.4 mm, p < .001) was measured. A significant negative association between the pretreatment Co-Go-Me angle and mandibular length change was found (p < .05). IMPA angle was negatively associated with mandibular length change. All the others morphological feature were not statistically related to mandibular length change. Co-Go-Me angle and IMPA angle at T0 can be used as predictors for mandibular response to the treatment with BJA.

Craniofacial morphology in patients with impacted canine: a case control-study.

The objective of this study was to evaluate the risk of maxillary canine impaction through cephalometric evaluation. One hundred and eighty-two Caucasian patients (80 males and 102 females) with a mean age of 12.4±0.5 were retrospectively enrolled in the present study. Ninety patients with impacted canines were compared with ninety-two patients with physiologically erupted canines. The following cephalometric variables were analyzed: SNA, ANB, SN-GOME, GO-ME, SP-CL, SELLA TURCICA DEPHT, A-Pt LINE, B-Pt LINE, A-Pt LINE°, B-Pt LINE°, A1s-Pt, A1i-Pt, A1s-Pt°, A1i-PT°, A-SN, B-SN and SN-U1. When applicable, a paired sample t-test was performed to investigate the difference in means between the two sample groups, while the Mann-Whitney Test was used as a non-parametric test in the case of a non-normal distribution of data. Statistical significance was set at P<0.05. The group with impacted canines showed an increase in Go-Me distance, SNA angle and A1s-Pt angle compared with the control group. In addition, the same group showed a decrease in A-SN and SP-Cl distance compared with the control group. An increase in mandibular length (GO-ME) and SNA angle associated with a reduction in A-Sn distance and interclinoid distance (SP-Cl) were observed in patients with impacted canines.

Long-term mandibular growth in patients with airway obstruction treated with mandibular distraction

Congenital craniofacial malformations play an important role in upper airway obstruction. One of the main causes is mandibular hypoplasia which is present in the pierre robin sequence. Mandibular distraction osteogenesis (MDO) is one of the most commonly used treatments for the resolution of upper airway obstruction in patients that do not respond to a conservative treatment. We performed a long term follow up of syndromic and non-syndromic patients with pierre robin sequence where the lateral xrays were studied before surgery (T1), after MDO (T2) and long-term follow-up (T3, at least 5 years). Possible complications of the surgery were also studied through panoramic x-rays and clinical controls. The results evidenced an increase of mandibular length comparing T1-T2 and a good stability during the long-term follow-up. The Sd patients presented smaller mandible dimensions. We had not found any complications during the follow-up. The scars outcomes are modest, but none of the patients requested a surgical correction. Mandibular distraction osteogenesis is a treatment to be considered in patients with upper airway obstruction that do not respond to conservative treatments. The results of the surgery are stable and the complications in experienced hands are low.

A Three-Dimensional Evaluation of Skeletal and Dentoalveolar Changes in Growing Class II Patients after Functional Appliance Therapy: A Retrospective Case-Control Study.

Background: The aim was to assess three-dimensionally mandibular and maxillary changes in growing Class II patients treated with removable functional appliances followed by fixed appliances. Methods: Twenty-four Class II patients (age range: 9 to 14, mean: 12.1 ± 1.1 years) treated with removable functional appliances followed by fixed appliances (functional appliance group-FAG) were retrospectively selected and compared to an age-matched control group (CG) treated with fixed appliances only. To be included in the study, pre- and post-treatment CBCT scans had to be available. The CBCTs were used to analyze, in 3D, the changes following treatment and growth. Results: Before treatment, overjet (FAG: 9 mm ± 2.8 (mean ± standard deviation); CG: 4 mm ± 1.7), ANB (FAG: 5.7° ± 2.0; CG: 3.2° ± 1.4), and effective mandibular length (FAG: 113.0 mm ± 4.1; CG: 116.6 mm ± 5.9) were statistically significantly different between the two groups. After treatment, overjet (FAG: -6.8 mm ± 2.8; CG: -1.8 mm ± 1.8) and effective mandibular length (FAG: 6.3 mm ± 2.6; CG: 3.9 mm ± 2.6) statistically significantly changed. There was a significant difference in the treatment effect between the FAG and the CG in overjet, ANB, and effective mandibular length. Conclusions: The results indicate that functional appliances are effective in correcting Class II malocclusions. The growth modification in the FAG resulted in an increase in mandibular length. Yet, the final length of the mandible in the FAG was smaller when compared to the CG.

Effectiveness of Functional Mandibular Advancer in Patients with Class II Malocclusion: A Systematic Review and Meta-analysis.

We aimed to evaluate the effectiveness of functional mandibular advancer (FMA) in treating growing patients with Class II malocclusion. Electronic searches were conducted in MEDLINE (via PubMed), Cochrane Library, Web of Science, Scopus, Embase, and Lilacs from 1945 to 30th November 2021. Studies were selected based on the following inclusion criteria: human studies, Class II growing patient treated with FMA, untreated control group or a comparable group treated with another fixed functional appliance, pre- and post-treatment lateral cephalograms/magnetic resonance imaging/cone-beam computed tomography, randomized clinical trials, prospective studies, and retrospective studies. Data extraction of the included articles was independently performed independently by two authors. The risk of bias was assessed using the ROBINS-I tool. Meta-analysis was performed using the inverse generic model. Seven articles met the criteria and were included in the systematic review and three articles were included in the meta-analysis. Three studies had at low risk of bias and four studies had a moderate risk of bias. All articles reported anterior positioning of the mandible along with an increase in mandibular length. The meta-analysis results indicated a negligible difference between FMA and other functional appliances for the parameters SNA [0.11, 95% confidence interval (CI) of -1.07 and 1.29] and ANB (-1.00, 95% CI of -1.34 and -0.65). The evidence was limited for soft tissue changes. Class II correction with FMA involved a combination of skeletal and dentoalveolar changes and was similar to other fixed functional appliances.

Evaluation of Skeletal and Dentoalveolar Changes in Patients With Class II Div 1 Malocclusion Treated With Twin Block Appliance.

Objective The study was focused on evaluating the change in mandibular morphology following the Twin Block appliance therapy and recording its effect on the maxilla and maxillary dentoalveolar complex. Also, the results of the Twin Block appliance between males and females were compared. Material and methods In this two-armed retrospective cephalometric study, 30 patients (mean age 12 years) treated with Twin Block appliance for the period of 8-12 months were chosen, and their records were obtained to analyze. These results were compared with 15 control subjects of the same age group chosen from the American Association of Orthodontics Foundation (AAOF) growth legacy collection: Michigan Growth Study Class II subjects. Cephalometric tracing was done, and data was processed for descriptive statistical analysis. Results Paired sample t-test and ANOVA test were performed to evaluate the differences in the pre-treatment (T1) and post-functional (T2) values. ∠ANB showed a mean difference of -4.71°±1.55° for males and 6.22°±6.78° for females, which is significant. The mandibular length (Co-Gn), for male subjects, the mean difference was 5.14±1.74 mm, and for female subjects, it was 6±2mm, which is highly significant; 49.88% of skeletal changes and 50.12% of dentoalveolar changes were reported to bring about Class II correction with Twin Block. Conclusion A successful increase in mandibular length was achieved using a Twin Block as a functional appliance. Also, the significant maxillary restraining effect was recorded. More skeletal changes were observed in males than females.

Evaluation of Hard Tissue, Soft Tissue and Airway Changes Post Twin Block Therapy: An In-vitro Study

Introduction: Aesthetic improvement happens to be one of the main reasons for seeking orthodontic treatment in patients with Angle’s Class II malocclusion. Prognathic maxilla, retrognathic mandible or a combination of both are the main aetiological factors for this malocclusion. Growth modification treatment with different methods can be performed in order to correct skeletal class II malocclusion. Appliance therapy to correct similar malocclusions should immaculately be directed towards addressing the dentoskeletal discord, in order to gain a favourable facial aesthetic result. Aim: To assess the effects of twin block on mandibular length, soft tissue profile and Oropharyngeal Airway (OAW) dimensions in skeletal class II malocclusion patients. Materials and Methods: An in-vitro study was carried out in the Department of Paedodontics at Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Lucknow from June 2018 to March 2021. Study was done on lateral cephalograms of 15 growing children with Angle’s Class II Division 1 malocclusion in the age group of 9-12 years, who had undergone functional appliance therapy with twin block appliance. Standardised lateral cephalograms were evaluated at pretreatment (0 month) and postactive phase of twin-block therapy (9-12 months). Selected hard tissue, soft tissue and airway landmarks were marked and traced to evaluate hard tissue, soft tissue and airway changes. The data was analysed using statistical package for social sciences (SPSS) version 21. Results: There was a statistically significant increase in effective mandibular length (Condyle-Gnathion) and mandibular base length Gonion-Pogonion (Go-Pog) values (p&lt;0.001). Significant decrease in the facial convexity Glabella- Soft tissue Nasion (G-Sn) Soft tissue Nasion- Soft tissue Pogonion (Sn-Pog) was observed and airway dimensions showed significant increase after twin block therapy. Conclusion: Correction of Class II malocclusion by twin block appliance resulted in significant cephalometric changes in the hard tissue profile (increase in mandibular length), together with clinically favourable soft tissue changes and OAW dimensions.

Efficiency of Skeletal Class II Malocclusion Treatment Using Herbst Appliance (Type II)

Purpose: The aim of this study was to assess the skeletal and dentoalveolar treatment outcomes using Herbst type II appliance with multibracket system in treatment of skeletal Class II malocclusion. Subject and Methods: The present study was applied on ten female patients with age ranges 12-13 years old, with skeletal Class II Division 1 malocclusion (deficient mandible). The line of treatment was to use nonextraction fixed functional appliance (Herbst) type II with multibracket system. Pre and post-treatment lateral cephalometric radiograph were obtained, cephalometric analysis and superimposition was performed to assess changes in skeletal and dentoalveolar structure. Results: Class II correction was obtained mainly by dentoalveolar effects, which include statistically significant lingual inclination of the upper incisors and labial inclination of the lower incisors with mesializiation of the lower molars. There was relative mandibular length increase with maxillary restriction. P ≤ 0.05. Conclusions: Skeletal Class II Divison 1 in adolescent patients can be effectively treated by Herbst type II with multibracket system. Both skeletal and soft tissue profile convexities are reduced as a result of dentoalveolar changes with mandible growth and forward movement.

How does changing the vector of transport disc distraction affect the outcomes of surgery in patients of temporomandibular joint ankylosis with obstructive sleep apnea?

Temporomandibular joint ankylosis (TMJA) in children is associated with retrognathia, reduction in pharyngeal airway volume (PAV), and obstructive sleep apnea (OSA). Distraction-osteogenesis (DO) is the proven method in the management of OSA. There is paucity in literature about the effect of distraction vector on PAV. It can be expected that an oblique vector would improve PAV and relieve OSA. Thus, the study was designed to explore the feasibility, advantages, and disadvantages of this modified technique for managing TMJA and OSA simultaneously. The investigators designed a prospective study on patients of TMJA with retrognathia. Ethical approval was obtained (IECPG-547/14.11.2018). In all patients, simultaneous ankylosis release and mandibular distraction were performed. Primary outcome variables were improvement in 3-dimensional (3D) PAV and maximal interincisal opening (MIO). Secondary outcome variables were changed mandibular length, distraction relapse, and re-ankylosis. Paired t-test and multivariate ANOVA were used to assess all the parameters. The study included 13 joints in 8 patients of TMJA with retrognathia (2 unilateral and 6 bilateral ankylosis) with mean age of 14.25 ± 7.37years. Mean distraction performed was 19 ± 4.0mm. There was a statistically significant improvement of PAV by 225% (p = 0.002), a reduction in Epworth's scale (p = 0.017), an increase in MIO (p = 0.001), and an increase in mandibular length. Three patients had re-ankylosis at the 25-month follow-up. The results of the present study conclude that modification of distraction vector improves 3D PAV and MIO in TMJA patients, with the added advantage of a reduction in overall treatment time and improved patient compliance.

Dental and Skeletal Effects of Herbst Appliance, Forsus Fatigue Resistance Device, and Class II Elastics-A Systematic Review and Meta-Analysis.

Background: Our study aimed to systematically summarize the dentoskeletal effects of Herbst appliance; Forsus fatigue resistance device; and Class II elastics in adolescent Class II malocclusion. Methods: Five databases; unpublished literature; and reference lists were last searched in August 2022. Randomized clinical trials and observational studies of at least 10 Class II growing patients that assessed dentoskeletal effects through cephalometric/CBCT superimpositions were eligible. The included studies quality was assessed with the RoB 2 and ROBINS-I tools. A random-effects model meta-analysis was performed. Heterogeneity was explored with subgroup and sensitivity analyses. Results: Among nine studies (298 patients); two-to-three studies were included in each meta-analysis. Less post-treatment upper incisor retroclination (<2) and no overbite; overjet; SNA; SNB; and lower incisor inclination differences were found between Herbst/Forsus and Class II elastics. No differences in maxilla; condyle; glenoid fossa; and most mandibular changes were found between Herbst and Class II elastics; except for a greater 1.5 mm increase in mandibular length and right mandibular ramus height (1.6 mm) with Herbst. Conclusions: Herbst and Class II elastics corrected the molar relationship; but Herbst moved the lower molars more mesially. Apart from an additional mandibular length increase; no other dental and anteroposterior skeletal difference was found. Forsus was more effective in molar correction; overjet reduction; and upper incisor control than Class II elastics. Trial registration number OSF: 10.17605/OSF.IO/8TK3R.

Successful balance of occlusal plane using functional orthopedics appliance

In this article, the treatment of two clinical cases is presented, in which the two patients showed distocclusion, severe overbite, required correction of the occlusal plane and movements of the mandible. Both were treated with functional orthopedic appliances In the first case. the patient was 4 years and 5 months old, and in second, 10 years 10 months old. Both had a significant pathological occlusal plane with a large difference in the height between the right and left sides. The lateral movements of the mandible showed completely different Functional Masticatory Angle Planes. The protrusion and opening movements of the mandible also showed deviation. The Functional Orthopedic appliance would advance the position of the mandible forward and would produce better responses if it were able to touch the incisors in the specific area. The forward mandibular position would activate the Ihh (Indian Hedgehog) and produce replication of the mesenchymal cells in the condyle and glenoid fossa. Moreover, it could produce an increase of mandibular length, and regulate the factors of mandibular condylar growth. The space produced between the occlusion as a result of the change to the forward mandible position must stimulate tooth eruption to correct the curve of the occlusal plane. Both cases showed balance of the occlusal plane and same functional masticatory angle Planes. Furthermore, the protrusion and opening movement of the mandible were corrected and no longer showed deviations. Note in both cases that the stability of the mandibular advancement occurred due to maintenance of twice as long to achieve incisor contact.

Three-dimensional cone-beam computed technology evaluation of skeletal and dental changes in growing patients with Class II malocclusion treated with the cervical pull face-bow headgear appliance

This study aimed to 3-dimensionally quantify and compare the outcomes of growing patients with Class II malocclusion treated with the cervical pull face-bow headgear appliance in combination with full fixed orthodontic appliances. The study sample consisted of 22 patients with Class II malocclusion with the following inclusion criteria: ANB>4.75°, Class II molar relationship, and SN-GoGn<37°. The mean age of patients was 12.5 ± 1.1 years at baseline. The average treatment time was 27.7 ± 7.3 months. Cone-beam computed tomography scans were superimposed in the cranial base, maxillary regional, and mandibular regional to evaluate growth, treatment displacements, and bone remodeling. Relevant statistically and clinically significant skeletal changes included average decreases in ANB (2.1 ± 1.1°) and SNA (1.8 ± 1.1°); posterior (1.3 ± 1.4 mm) and inferior (4.6 ± 2.2 mm) displacement of A-point; inferior displacements of B-point (5.4 ± 2.8 mm) and Pogonion (5.8 ± 2.6 mm); superior displacement of Condylion (6.9 ± 2.4 mm); increase in mandibular length (5.4 ± 2.0 mm); and clockwise rotation of palatal plane (1.9 ± 1.9°). Significant proclination of the maxillary incisors (9.8 ± 11.1°) and nonsignificant proclination of the mandibular incisors (4.7 ± 9.6°) were also noted. Class II skeletal correction was primarily achieved by posterior, inferior displacement of the sagittal position of the maxilla. Change in the sagittal position of the mandible/chin (B-point, Pogonion) was not significant; rather, mandibular displacement was significant in an inferior vertical direction without backward rotation, as seen from marked condylar and ramus growth.

Ortho-surgical treatment in Class II skeletal patients with mandibular retrognathism: a concise systematic review

Introduction: In the setting of class II malocclusion corrections, the union of orthodontic and surgical procedures was developed. Bilateral sagittal split osteotomy is standard protocol for correcting mandibular retrognathism. Class II dental malocclusion with deep bite needs to be treated early by orthodontics. Thus, the commonly used technique combines BSSO for mandibular advancement and recoil genioplasty to correct the resulting chin protrusion. Objective: To carry out a systematic review of the main considerations of ortho-surgical treatments in class II patients with mandibular retrognathism. Methods: Experimental and clinical studies (case reports, retrospective, prospective and randomized) with qualitative and/or quantitative analysis were included, following the rules of the systematic review-PRISMA. Results and Conclusion: A total of 128 articles was found involving class II malocclusion and ortho-surgical treatments. After, a total of 64 articles were fully evaluated and 24 were included and discussed in this study. A meta-analysis study evaluated the best functional appliance improving mandibular length in individuals with retrognathism. Sander Bite Jumping reported the greatest increase in mandibular length, with 3.40 mm. Another meta-analysis study compared dental, skeletal, and aesthetic outcomes between orthodontic camouflage and orthodontic-surgical treatment in patients with Class II skeletal malocclusion and retrognathic mandible with anterior growth. The difference between treatments was not statistically significant regarding SNA angle, linear measure of the lower lip to the Ricketts aesthetic line, convexity of the skeletal profile or soft tissue profile excluding the nose. In contrast, orthodontic-surgical treatment was more effective to the ANB, SNB and ML/NSL angles and the soft tissue profile including the nose.

Dentoskeletal effects of Twin Block appliance in patients with Class II malocclusion.

Background and aimClass II malocclusions are most commonly seen in orthodontic practice and in the recent times Twin Block appliance has been the most popular and widely used among removable functional appliances for the correction of Class II malocclusion in growing patients. The aim of this retrospective study was to evaluate the dentoskeletal effects produced by the Twin Block appliance for the correction of Class II division 1 malocclusion with retrognathic mandible.MethodsPre-treatment (T1) and post-treatment (T2) lateral cephalograms of 30 patients treated with Twin Block appliance (mean age = 10.8 ± 1.2 years) for the correction of class II division 1 malocclusion were compared with the 30 untreated class II control patients (mean age 11.2 ± 0.8 years) who did not undergo any treatment during this period. Both the groups were evaluated for the dentoskeletal changes using 24 angular and linear cephalometric measurements. The differences between the pre and post-treatment were calculated using a paired t-test.ResultsThe cephalometric analysis revealed that the Twin Block appliance stimulated mandibular growth and statistically significant differences were found between the two groups. Twin Block patients showed a statistically very high significant (p<0.001) increase in mandibular length (6.02 mm) compared with the control group (0.3 mm). “Headgear effect” on the maxilla, increase in lower anterior facial height, significant reduction of overjet, overbite and Class I molar relationship were achieved in the Twin Block group. However, no significant changes appeared in the control group.ConclusionThe results of the present study conclude that the Twin Block appliance is effective in the treatment of Class II malocclusion and this is due to a combination of skeletal and dentoalveolar changes in both the arches.

Treatment of Class II Malocclusion With Removable Functional Appliances: A Narrative Review

AbstractAround half of all malocclusions that need orthodontic treatment are Class II in nature. Patients with Class II malocclusion primarily seek treatment for aesthetic improvement. Most of the skeletal class II malocclusions are because of mandibular deficiency, and can be best treated during the growing phase of development by removable functional appliances. The objective of this review is to evaluate and compare skeletal and dentoalveolar effects of various removable functional appliances in the treatment of class II malocclusion. Manual and electronic databases were searched, and out of 5,711 articles, 221 abstracts were shortlisted and reviewed. A total of 19 articles that fulfilled the selection criteria was then retrieved and analyzed. A significant increase in mandibular length and dentoalveolar effects with an increase in vertical dimension in a short time was observed with Twin-Block appliance treatment, followed by Bionator appliance treatment. The long-term stability of results achieved with Twin-Block appliance treatment is still questionable. In addition, Frankel appliance treatment effects are more skeletal in nature, with better control in the vertical dimension. However, it takes a more extended treatment duration to produce similar effects. Based on available evidence, we are convinced that removable functional appliances are valuable tools for correction of the Class II malocclusion at a growing age with a horizontal growth pattern.

Retrospective comparison of dental and skeletal effects in the treatment of Class II malocclusion between Herbst and Xbow appliances

The purpose of this research was to compare dentoskeletal changes produced by Herbst and Xbow appliances in late mixed/early permanent dentition patients with Class II Division 1 malocclusion to an untreated control group. The retrospective cohort consisted of 41 patients treated with the Herbst appliance on average for 14months (mean age of 11.3years), 41 patients treated with Xbow appliance on average for 14months (mean age of 11.11years), and an untreated control sample of 25 patients followed on average for 21months (mean age of 11.9years). All patients had Class II Division 1 malocclusion characteristics. Lateral cephalometric radiographs were taken before and after phase 1 treatment/follow-up. Data were analyzed by an analysis of variance followed by Tukey post-hoc tests. Although there was a high equivalence among the groups in the pretreatment cephalometric values, 4 variables showed differences (U6-FHp, L6-FHp, LAFH, and PP-U1). When comparing the mean changes (before and after phase 1 treatment/follow-up), incisormandibular plane angle (IMPA), Wits appraisal, L6-FHp, Co-Pog, and PP-U1 measurements showed statistically significant differences. In addition, more relative mesial movement of the mandibular molars (an additional 2.4mm) and a larger increase in mandibular length (an additional 3.2mm) was noted for the Herbst group. Class II correction using Herbst and Xbow occurred in both groups through improvement in the maxillomandibular relationship and labial inclination of the mandibular incisors, as well as a relatively increased mesialization of the mandibular molars. Although both appliances improve occlusal features, the portrayed changes were not always similar. Herbst seems to produce more mandibular size increase over a similar treatment period.

Comparative Evaluation of Esthetic and Structural Aspects in Class II Functional Therapy. A Case-Control Retrospective Study.

Background: To compare the skeletal, dental, and esthetic changes produced by three functional devices, Fränkel-2 appliance (FR-2), Twin Block (TB), and Occlus-o-Guide® (O-o-G®), for the treatment of Class II malocclusion. Methods: Sixty-five patients with Class II Division 1 malocclusion were divided into three groups and were analyzed through cephalometric analysis of skeletal, dental, and esthetic variables before and after treatment. The first group of 23 patients (F: 9; M: 14; mean age: 10.3 ± 1.08 years) was treated with FR-2, the second group of 18 patients (F: 8; M: 10; mean age 10.7 ± 1.05 years) was treated with TB, the third group (F: 11; M: 13; mean age: 9.05 ± 0.39 years) of 24 patients was treated with O-o-G®. The structural effects of the three devices were compared with a control group generated by the growth variations reported in the cephalometric atlas of Bhatia and Leighton. Esthetic analysis was performed comparing the results of the patients treated with a control group of 20 subjects with mandibular retrognathia and Class II Division 1 malocclusion, not subjected to therapy. Results: The three devices resulted in a significant increase in mandibular length, with higher results obtained for FR-2 and TB. A statistically significant increase in the IMPA angle was found for the O-o-G® group, and a notable reduction of both overjet and overbite was detected in all three groups of treated patients. The esthetic evaluation showed overall more significant results in the TB group, especially with regard to the reduction of facial convexity. The retrusion of the upper lip was on average more significant in the O-o-G® group, followed by that in the TB. Conclusions: All three devices have proven to be effective overall in resolving skeletal changes and improving facial esthetics.

CBCT evaluation of cephalometric variables among samples of Egyptian non-operated cleft lip and palate patients

Objectives: to evaluate the cephalometric and craniofacial measurements in unilateral and bilateral cleft lip and palate (CLP) patients and to investigate the effect of these measurements in growing and non-growing cleft patients using cone beam computed tomography (CBCT) 3D software, and to compare them to healthy individual. Setting and Sample population: Retrospective study was performed in Department of pedodontics and Orthodontics, October 6 University. The study sample comprised unilateral and bilateral 36 growing CLP (aged 6-17years), and 24 non-growing CLP (aged 18- 40 years). The control group included 60 Non-CLP subjects. Methods: Cephalometric measurements were obtained using CBCT software, all measurements were assessed by Mann-test to clarify differences between study samples. Results: There was a significant difference between (Growing Bilateral) and (Control Growing) for (MP-SN, B, A, ANB, SNB & ANS-ME) and There was a significant difference between (Growing Unilateral) and (Control Growing) for (MP-SN, B, SNA, SNB, GO-GN, GO-GN, N-ANS & ANS-ME). While there was a significant difference between (Non-Growing Bilateral) and (Control Non-Growing) for (MP-SN, B, A, SNA, SNB, GO-GN, & ANS-ME) and there was a significant difference between (Non-Growing Unilateral) and (Control Non-Growing) for (MP-SN, B, A, SNA, SNB & ANS-ME) where (Z) values were significant at (0.05). Conclusion: Our study shows that there was significant increase in mandibular length in both growing and non- growing BCLP than of UCL, in growing UCLP there was reduced upper face height and in growing BCLP there was increased lower face height

Skeletal and dental changes induced by the Flip-Lock Herbst appliance in the treatment of Angle's class II division 1 malocclusion during active growth period: A preliminary study.

Background. The Flip-Lock Herbst (TP Orthodontics Inc.) is a fixed functional appliance, a variant of the Herbst appliance, introduced by Miller. It is claimed to have better patient tolerance due to its increased freedom for the mandible’s lateral movements. There have been no studies on the flip lock Herbst till date. This study was undertaken to assess the efficiency of the Flip-Lock Herbst appliance in correcting Angle’s class II division 1 malocclusion. Methods. Eight subjects in their active growth period with class II division 1 malocclusion due to a retrognathic mandible were included in the study. Standardized lateral cephalometric radiographs were used to evaluate skeletal and dental changes with the SO analysis. Paired samples t-test was used to assess statistical significance. Results. Statistically significant increases in mandibular length (pg/OLp) and effective mandibular length (ar/OLp + pg/OLp) were observed. There was a significant maxillary restraining effect. Dental effects were significant and exhibited class II correction features except for the position of lower incisors within the mandible (ii/OLp - pg/OLp). Skeletal changes accounted for 61% and dental changes for 39% of the total treatment for molar correction. For overjet correction, skeletal changes contributed to 63% and dental changes to 37% of the total treatment. Conclusion. The Flip-Lock Herbst appliance was efficient in correcting Angle’s class II division 1 malocclusion due to a retrognathic mandible. Both skeletal and dental changes were evident, with the former predominating (60:40).