Three-dimensional diagnosis and management of Class II malocclusion in the mixed dentition

Predictors of patient compliance during Class II division 1 malocclusion functional orthodontic treatment

OBJECTIVES

To determine factors that could predict Class II/1 malocclusion patient compliance during functional treatment.

MATERIALS AND METHODS

The sample consisted of 77 subjects (aged 11-13 years; 47% girls) presenting with Class II/1 malocclusion. Inclusion criteria were distal molar relationship, overjet greater than 5 mm, and confirmed pubertal growth spurt. Removable functional appliances (62% Twin Block [TB], 38% Sander Bite Jumping [BJ]) with built-in maxillary expansion screws were used. Follow-up period was 1 year. Patients and parents independently filled out the Child Perception Questionnaire, Parental/Caregiver Perception Questionnaire, and Family Impact Scale to assess emotional and social well-being, oral symptoms, functional limitations, parental emotions, family activities, conflicts, and financial burden as possible predictors of compliance during treatment. Sex, overjet, and appliance type were also analyzed.

RESULTS

There were more noncompliant than compliant patients (55% vs 45%). Parental perception of altered emotional well-being of their children was the strongest predictor, increasing compliance odds 3.4 times (95% confidence interval [CI], 1.2-9.4; P = .017). Patients were 3.2 times (95% CI, 1.1-9.3; P = .033) more likely to cooperate with TB compared with BJ appliance. OJ ≥ 8 mm increased compliance odds 3.1 times (95% CI, 1.0-9.4; P = .044).

CONCLUSIONS

Parental perception of child's emotional well-being alteration, severity of malocclusion, and type of appliance are major predictors of compliance. Psychosocial issues and oral function limitations reported by children and family impact are of negligible influence.

Effects of surgical mandibular advancement on the upper airways of adult class II patients: A systematic review with meta-analysis

AIM

To systematically review the effects of surgical mandibular advancement (SMA) regarding changes of the upper airways in adult patients with skeletal Class II malocclusion.

MATERIALS AND METHODS

Five electronic databases were searched up to April 2020. Human studies focusing on the morphology and dimension of the upper airways after SMA were included. 'Quality assessment for Before-After (Pre-Post) Studies' was used to assess the risk of bias of the individual studies. Standard mean differences (SMD) with 95% confidence intervals (CI) were calculated for random effect model meta-analysis. The certainty of evidence was assessed using the GRADE tool.

RESULTS

Twenty cohort studies of only treated patients without control group were eligible for qualitative synthesis, of which 17 were used for quantitative synthesis. Very low certainty of evidence indicated that SMA resulted in significant increase of the volume and of the smallest cross-sectional area (SMC) of the nasopharynx (volume SMD: 1.43, CI: 0.62, 2.24, P = .001, I²  = 87.8%; SMC SMD: 1.53, CI: 0.59, 2.47, P = .001, I²  = 90.5%) and oropharynx (volume SMD: 1.36, CI: 0.37,2.35, P = .007, I²  = 92.1%; SMC SMD: 1.21, CI: 0.11,2.32, P = .032, I²  = 93.1%). Significant augmentation of the distances between the posterior pharynx wall and the uvala (SMD: 0.73, CI: 0.46,0.98, P < .001, I²  = 72.7%), the posterior border of the tongue (SMD: 0.52, CI: 0.21,0.84, P = .001; I² : 60.5%), the gonion (SMD: 1.24, CI: 0.56,1.91, P < .001; I²  = 88.8%) and the epiglottis (SMD: 0.40, CI: 0.06,0.74, P = .033; I²  = 84.8%) were observed.

CONCLUSIONS

Weak evidence suggests enlargement of the upper airways of adult Class II subjects following SMA, with major increases in the oropharynx.

Complications encountered during Forsus Fatigue Resistant Device therapy

Introduction:

Fixed functional appliances are non-compliant solutions to Class II malocclusion treatment. The clinician, however, should be careful of unexpected complications during the therapy.

Methods:

58 female adolescents who presented with Class II malocclusion due to deficient mandible were treated with Forsus Fatigue Resistant Device (FFRD) therapy until an overcorrection to an edge to edge incisor relationship was achieved.

Results:

Incisor relationship and overjet were corrected successfully in all the subjects. Twenty-two patients had a complications-free treatment, while several complications were encountered with the remaining 36 subjects. In particular, mandibular canine rotation and development of posterior crossbites were the most common complications, with percentages of 51.7% and 25.9% respectively. Other complications included the breakage and shearing of the extraoral tubes of the first molar bands, and excessive intrusion of the upper first molars.

Conclusions:

FFRD is an efficient appliance for treatment of Class II malocclusion; however, different complications were encountered during the appliance therapy. A focus on taking precautions and applying preventive measures can help to avoid such problems, reducing the number of emergency appointments and enhancing the treatment experience with the appliance.

Dentoskeletal modifications in Class II deep bite malocclusion treatment with anterior bite plane functional appliance

Background

A treatment modality for Class II division 1 malocclusion is discussed. Orthodontic treatment of patients with deep bite and Class II malocclusion is an important challenge in clinical practice. The aim of this work is to compare the efficacy of anterior bite plane functional appliance (ABPFA) by assessing the changes in different times with untreated patients by literature.

Material and Methods

The study group comprised 22 subjects with Class II division 1 malocclusion and hypo-divergent. Eligibility criteria for this study were: dental Class II division 1 malocclusion, hypo-divergent skeletal pattern, late mixed or permanent dentition. We analyzed with the use of stable bone structure (ASCB) at two different times: pre-treatment (T0) and post-treatment (T1) after 24 months. Inter-group differences were evaluated with paired samples t-test at the P<0.05 level.

Results

No statistical significant differences were found in cephalometric skeletal measurements, whereas dental parameters showed a significant different overjet, which was significantly reduced (6 mm at T0 vs. 5 mm at T1) in our series.

Conclusions

In ABPFA group, the treatment effects were reduce mainly Class II malocclusion, overjet and overbite alteration. This appliance seems to suggest a significant beneficial effect in mandible displacement by reducing the counter clockwise rotation of the mandible, which is further confirmed by the almost absence of modifications of ArGoMe and SNGoMe angles. The ABPFA is particularly suitable to reduce the non-desirable dental effects represented by lower incisors pro inclination, and upper incisors retro-inclination.

Key words:Orthodontics, Functional orthodontics, Class II malocclusion, Anterior bite plane functional appliance.

Skeletal effects in Angle Class II/1 patients treated with the functional regulator type II : Cephalometric and tensor analysis

OBJECTIVES

The purpose of this work was to employ both cephalometric and tensor analysis in characterizing the skeletal changes experienced by patients with Angle Class II/1 malocclusion during functional orthodontic treatment with the functional regulator type II.

METHODS

A total of 23 patients with Class II/1 malocclusion based on lateral cephalograms obtained before and after treatment with the functional regulator type II were analyzed. Another 23 patients with Angle Class II/1 malocclusion who had not undergone treatment were included as controls.

RESULTS

Our cephalometric data attest to significant therapeutic effects of the functional regulator type II on the skeletal mandibular system, including significant advancement of the mandible, increases in effective mandibular length with enhancement of the chin profile, and reduction of growth-related bite deepening. No treatment-related effects were observed at the cranial-base and midface levels. In addition, tensor analysis revealed significant stimulation of mandibular growth in sagittal directions, without indications of growth effects on the maxilla. Its growth-pattern findings differed from those of cephalometric analysis by indicating that the appliance did promote horizontal development, which supports the functional orthodontic treatment effect in Angle Class II/1 cases.

CONCLUSIONS

Tensor analysis yielded additional insights into sagittal and vertical growth changes not identifiable by strictly cephalometric means. The functional regulator type II was an effective treatment modality for Angle Class II/1 malocclusion and influenced the skeletal development of these patients in favorable ways.

Therapeutic approach to Class II, Division 1 malocclusion with maxillary functional orthopedics

INTRODUCTION:

Interceptive treatment of Class II, Division 1 malocclusion is a challenge orthodontists commonly face due to the different growth patterns they come across and the different treatment strategies they have available.

OBJECTIVE:

To report five cases of interceptive orthodontics performed with the aid of Klammt's elastic open activator (KEOA) to treat Class II, Division 1 malocclusion.

METHODS:

Treatment comprehends one or two phases; and the use of functional orthopedic appliances, whenever properly recommended, is able to minimize dentoskeletal discrepancies with consequent improvement in facial esthetics during the first stage of mixed dentition. The triad of diagnosis, correct appliance manufacture and patient's compliance is imperative to allow KEOA to contribute to Class II malocclusion treatment.

RESULTS:

Cases reported herein showed significant improvement in skeletal, dental and profile aspects, as evinced by cephalometric analysis and clinical photographs taken before, during and after interceptive orthodontics.

Dentoskeletal effects of the Bite-Jumping Appliance and the Twin-Block Appliance in the treatment of skeletal Class II malocclusion: a randomized controlled trial

OBJECTIVES

The current parallel group, randomized controlled trial aimed to compare the dentoalveolar and skeletal changes resulting from treatment using two popular functional appliances: the Bite-Jumping Appliance (BJA) and the Twin-Block Appliance (TBA).

STUDY DESIGN

This study is designed as a parallel-group, randomized controlled trial.

MATERIALS AND METHODS

Patients were screened from the patients who were seeking treatment at the Department of Orthodontics, Al-Baath University. Eligibility criteria included skeletal Class II division 1 malocclusion resulting from the retrusion of the mandible. A computer-generated randomization list was used to randomly divide the patients into two equal groups to be treated with either the BJA or the TBA. Blinding was applicable for outcome assessment only. Forty-four patients (22 male and 22 female) aged 10.2-13.5 years were randomized in a 1:1 ratio to either the BJA or the TBA groups, and four patients were lost to follow-up (two from each group). Lateral cephalometric radiographs were obtained before treatment and after 12 months of active appliance therapy. Inter-group differences were evaluated with two-sample t-tests, and intra-group differences were assessed with paired-sample t-tests at the P <0.05 level.

RESULTS

Forty patients (20 in each group) were available for the statistical analysis. Baseline characteristics were similar between groups. Similar changes were observed in the sagittal plane, including a significant increase in the SNB angle. No significant changes were observed in the maxilla. The lower incisors were significantly proclined, and the upper incisors significantly retruded. In the vertical plane, BJA induced mandibular clockwise rotation, and the SN:MP angle increased by 2.14 ± 2.97° (P = 0.002). Conversely, no significant changes took place in this angle in the TBA group 0.75 ± 2.37° (P = 0.096). Similarly, Jarabak ratio decreased significantly in the BJA group by -1.78 ± 0.85% (P = 0.002) and increased significantly in the TBA group by 1.26 ± 0.76% (P = 0.032), with significant differences between the two groups (P ≤ 0.001). No serious harm was observed.

LIMITATIONS

A limitation of this research is a lack of an untreated control group. However, the resulting differences between the two groups can be attributed to the appliance differences, which fulfil the aim of the current research.

CONCLUSIONS

Each of the two appliances is recommended for the functional treatment of skeletal Class II malocclusion resulting from the retrusion of the mandible. The BJA is recommended when clockwise rotation is desired, whereas the TBA is recommended to inhibit vertical development.

REGISTRATION

This trial was registered at the Department of Orthodontics, Al-Baath University, Number 16, on 6/25/2012.

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

No funding or conflict of interest to be declared.

Evaluation of the soft tissue treatment simulation module of a computerized cephalometric program

Objective:

The purpose of this study is to compare the accuracy of the treatment simulation module of Quick Ceph Studio (QCS) program to the actual treatment results in Class II Division 1 patients.

Design:

Retrospective study.

Materials and Methods:

Twenty-six skeletal Class II patients treated with functional appliances were included. T0 and T1 lateral cephalograms were digitized using QCS. Before applying treatment simulation to the digitized cephalograms, the actual T0-T1 difference was calculated for the SNA, SNB, ANB angles, maxillary incisor inclination, and protrusion and mandibular incisor inclination and protrusion values. Next, using the treatment simulation module, the aforementioned values for the T0 cephalograms were manually entered to match the actual T1 values taking into account the T0-T1 differences. Paired sample t-test were applied to determine the difference between actual and treatment simulation measurements.

Results:

No significant differences were found for the anteroposterior location of the landmarks. Upper lip, soft tissue A point, soft tissue pogonion, and soft tissue B point measurements showed statistically significant difference between actual and treatment simulation in the vertical plane.

Conclusion:

Quick Ceph program was reliable in terms of reflecting the sagittal changes that would probably occur with treatment and growth. However, vertical positions of the upper lip, soft tissue pogonion, soft tissue A point, and soft tissue B point were statistically different from actual results.

Evaluation of Cervical Spine Posture After Functional Therapy with FR-2: A Longitudinal Study

The authors compared postural changes produced in 20 Caucasian female children treated with the Frankel Functional Regulator appliance (FR-2) (Frankel Industries, Morangis Cedex, France) using cephalometric tracings and comparing the tracings to 20 untreated Class II controls from the University of Chieti. Each patient in the study group was treated for exactly two years by the same operator using the FR-2 appliance and a standardized design and clinical technique, including prefunctional orthodontics where indicated. The average starting age was 8.4 yrs. (SD+/-2.1). At the end of the therapy, the average age was 10.3 yrs. (SD+/-2.4). Two teleradiographs were made of each patient: the first one at the beginning of treatment and the second one after six months. The radiographs were taken with the subjects standing in the ortho-position with no ear rods in the cephalostat; mirror position was carried out. In order to detect errors due to landmark identification, duplicate measurements were made using ten radiographs, and the error variance was calculated using Dahlberg's formula. Thirty-seven variables were studied. The cervical lordosis angle (CVT/EVT) was significantly higher in the study group as compared to the control group (p<0.05) at the end of treatment, probably due to a significant backward inclination of the upper segment of the cervical column (OPTNer and CVTNer) in the treated group (p<0.001 and p<0.01) from pre- to posttreatment. There was no significant change in the lower segment of the cervical column inclination (EVT/Ver). The changes resulted in a weak association in the multiple regression model to an increasing of maxillary base length and mandibular protrusion (R2=0.272; p<0.05). Other variables in the multiple regression were not significant.

Management of a growing Skeletal Class II Patient: A Case Report

Sagittal and transverse discrepancies often coexist in skeletal class II malocclusions. Orthopedic growth modification can work well in such cases, provided that the remaining pubertal growth is adequate and that the clinician can provide timely treatment to coincide with the peak growth period. The transverse discrepancy is generally corrected first, establishing a proper base for the sagittal correction to follow. For example, in a skeletal class II case with a narrow maxillary arch and retrusive mandible, maxillary expansion is performed initially to facilitate functional mandibular advancement. The present article illustrates an exception to this rule, in a case where sagittal correction was undertaken before transverse correction to make optimal use of the patient's pubertal growth spurt in first phase followed by a second phase of fixed appliance therapy during adolescence to achieve optimal results. How to cite this article: Sharma NS. Management of a growing Skeletal Class II Patient: A Case Report. Int J Clin Pediatr Dent 2013;6(1):48-54.

Changes in stress distribution of orthodontic miniscrews and surrounding bone evaluated by 3-dimensional finite element analysis

INTRODUCTION

Miniscrews can be used to provide absolute anchorage during orthodontic treatment. If we could obtain the optimum design or shape of the miniscrew, we might be able to reduce its size and lessen the chance of root contact. In addition, miniscrews are placed at several angles, and orthodontic forces are applied in various directions for clinical requirements. In this study, we used finite element analysis to investigate changes in stress distribution at the supporting bone and miniscrew by changing the angle and the shape of the miniscrew and the direction of force.

METHODS

Three types of miniscrews (cylindrical pin, helical thread, and nonhelical thread) were designed and placed in 2 types of supporting bone (cancellous and cortical). The miniscrews were inclined at 30°, 40°, 45°, 50°, 60°, 70°, 80°, and 90° to the surface of the supporting bone. A force of 2N was applied in 3 directions.

RESULTS

Significantly lower maximum stress was observed in the cancellous bone compared with the cortical bone. By changing the implantation angle, the ranges of the maximum stress distribution at the supporting bone were 9.46 to 14.8 MPa in the pin type, and 17.8 to 75.2 MPa in the helical thread type. On the other hand, the ranges of the maximum stress distribution at the titanium element were 26.8 to 92.8 MPa in the pin type, and 121 to 382 MPa in the helical thread type. According to the migration length of the threads in the nonhelical type, the maximum stresses were 19.9 to 113 MPa at the bone, and 151 to 313 MPa at the titanium element. By changing the angle of rotation in the helical thread type, the maximum stress distributions were 25.4 to 125 MPa at the bone, and 149 to 426 MPa at the titanium element. Furthermore, the maximum stress varied at each angle according to the direction of the applied load.

CONCLUSIONS

From our results, the maximum stresses observed in all analyzed types and shapes of miniscrews were under the yield stress of pure titanium and cortical bone. This indicates that the miniscrews in this study have enough strength to resist most orthodontic loads.

Meta-analysis of skeletal mandibular changes during Frankel appliance treatment

The purpose of this study was to perform a meta-analysis of articles to verify the mandibular changes produced by the Fränkel-2 (FR-2) appliance during the treatment of growing patients with Class II malocclusions when compared with untreated growing Class II subjects. The literature published from January 1966 to January 2009 was reviewed with search engines. A quality analysis was performed. The effects on primary end points were calculated with random-effect models. Heterogeneity was assessed using Q statistic and investigated using study-level meta-regression. A total of nine articles were identified. The quality of the studies ranged from low to medium. Meta-analysis showed that the FR-2 was associated with enhancement of mandibular body length [0.4 mm/year 95 per cent confidence interval (CI) 0.182-0.618], total mandibular length (1.069 mm/year, 95 per cent CI 0.683-1.455), and mandibular ramus height (0.654 mm/year, 95 per cent CI 0.244-1.064). A consistent heterogeneity among studies was found for all the considered linear measurements. The FR-2 appliance had a statistically significant effect on mandibular growth. Nevertheless, the heterogeneity of the FR-2 effects, the quality of studies, the differences in age, skeletal age, treatment duration, and the inconsistent initial diagnosis seem to overstate the benefits of the FR-2 appliance. An evidence-based approach to the orthodontic outcomes of FR-2 appliance is needed, by selecting and comparing groups of children with the same cephalometric characteristics with and without treatment.

Transverse skeletal base adaptations with Bionator therapy: a pilot implant study

The purpose of this randomized, controlled trial was to evaluate transverse skeletal base adaptations to Bionator therapy. The sample included 25 patients (15 male, 10 female) aged 6.9 to 11.2 years with Class II Division 1 malocclusion. The patients were randomly allocated to either a control (n = 11) or treatment (n = 14) group and followed longitudinally for approximately 12 months. Treatment consisted of a Bionator only, constructed to remain approximately 2 mm from the buccal dentition. Transverse maxillary and mandibular changes were evaluated cephalometrically according to 4 bilateral maxillary and 2 bilateral mandibular implants. Untreated Class II controls exhibited significant increases between posterior maxillary implants but no significant changes between the anterior maxillary or mandibular implants. There were no significant width differences between the control and treated groups before treatment. Posterior maxillary implant widths increased significantly (P < .05) in both groups, but the treated group showed significantly greater width increases than the control group. The treated group also showed greater increases between mandibular implants, but the differences were not statistically significant. These results suggest that transverse skeletal base adaptations occur as a result of Bionator therapy.

The overbite and intraoral mandibular distraction osteogenesis

PURPOSE

The purpose of this study was to quantify the overbite reduction in skeletal Angle Class II malocclusions and discuss the management of the overbite during and after intraoral distraction of the mandible, and during orthodontic treatment with fixed appliances.

MATERIAL AND METHODS

Cephalograms of 26 patients with an Angle Class II malocclusion and orthodontic appliances and distraction osteogenesis of the horizontal part of the mandible before (T0) and at least 1 year after treatment (T1) were evaluated. Mean age of the patients at the time of distraction was 14.6 years (range 12.8-15.9 years) and at the final registration 17.3 years (range 14.6-20.4 years).

RESULTS

The overbite decreased significantly and the SpP/MP value increased significantly. The increase in the value of the Y-axis and the MP/SN angle before and after treatment was statistically insignificant.

CONCLUSION

Opening of the bite during distraction of the mandible can be expected. The use of the 'floating bone' technique did not correct the overbite permanently. The patients in whom an open bite has already been treated are not ideal for mandibular lengthening by means of distraction osteogenesis.

An assessment of skeletal and dental responses to the functional magnetic system (FMS)

Correction of a skeletal Class II malocclusion with functional appliances has been accepted as a viable treatment modality. However, its mechanism of action is still disputed. This retrospective study compared 20 Class II patients treated with the functional magnetic system (FMS) with Class I and Class II groups (the control groups) of 20 untreated subjects each. Dental and skeletal changes were compared using serial lateral cephalograms. The FMS group differed significantly from the control groups in 15 of 24 parameters. The great increase in articulare-gnathion distance (3.07 mm) attributed to the attractive magnetic component of the FMS dictates a prolonged propulsion of the mandible. The skeletal:dental response ratio was 1:2 for the anterior region and 1:1 for the posterior region. The dental and skeletal parameters demonstrated a synergistic response in the maxilla and a competitive response in the mandible. This means that greater maxillary molar distal movement and incisor retroclination resulted in a more significant restraint of point A. In contrast, increasing the mandibular molar mesial movement and the incisor proclination accompanied less advancement of the pogonion. Although the skeletal contribution to the resolution of the malocclusion was less than the dental contribution (anteriorly, one third), the functional correction response was found to be regulated by skeletal factors.

Current concepts on functional appliances and mandibular growth stimulation

The mode of action of functional appliances, particularly in relation to stimulating mandibular growth, is a controversial subject. Many of the reports concerning growth effects of functional appliances have been characterized by poor methodology. In assessing functional appliances, results from prospective randomized clinical trials should be given prominence. On the basis of available evidence, it cannot be concluded that functional appliances are effective in stimulating and increasing mandibular growth in the long term. Although favourable growth changes have been reported following phase 1 therapy, they are generally not substantial and long term stability appears to be poor.

Three-dimensional Bolton-Brush Growth Study landmark data: ontogeny and sexual dimorphism of the Bolton standards cohort

OBJECTIVE

The treatment of craniofacial reconstructive surgery patients may benefit from comparison to average referent three-dimensional landmark data. These data may be useful for diagnosis, treatment planning, prosthetic design, or outcomes assessment. With regard to subadult patients, we hypothesize that the pattern of ontogenetic shape change of same sex, same ethnicity, referent populations will show gross uniformity. We present a preliminary shape analysis of 50 three-dimensional landmarks derived from 317 Bolton-Brush Growth Study biorthogonal image pairs. We determine which landmarks can be collected from scanned radiographs reliably by four operators for the precisely locatable points, ontogenetic trends in landmark configuration shape change, and patterns of sexual dimorphism.

PARTICIPANTS

Participants were Bolton standards individuals (16 male and 16 female) who contributed biplane cephalograms seven or more times with annual or greater spacing between ages 3 and 18 years.

DESIGN

After removing outliers, we searched for ontogenetic heterogeneity, including sexual dimorphism and within sex-specific Procrustes coordinate shape spaces.

RESULTS

A cut-off of 4.3-mm interoperator error left 32 landmarks in our analysis. Three different approaches (principal component analysis, age-trend analysis, and principal components of age residuals) all found no patterns of individual variation around sex-specific average trends of shape change. Male shape change peaks at age 15, a correlate of the growth spurt.

CONCLUSIONS

Simultaneous frontal and lateral anatomic landmark identification improves three-dimensional localization reliability. Three-dimensional craniodental shape change from ages 8 to 18 within the Bolton standards presents little heterogeneity. Considerations of ethnicity aside, these may be initial grounds for use of these data as a normative referent.