Transverse skeletal and dental asymmetry in adults with unilateral lingual posterior crossbite

Novel concept for posterior crossbite correction : Preliminary results

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Fluctuating arch symmetry: a comparison of two methods of assessment - applicability and efficiency

INTRODUCTION

Symmetry is balance, some correspondence in the size, form, and arrangements of parts on opposite sides of a plane, line, or point. The opposite of this concept is asymmetry, or imbalance.

OBJECTIVE

This retrospective study compared two methods for assessing arch symmetry with linear measurements based on triangles, to determine their applicability and efficiency.

METHODS

Two groups were enrolled: children (n=20) and adults (n=20), and the arch symmetry was assessed from linear measurements. Method 1: the incisor-canine (INC), canine-molar (CM), and incisor-molar (INM) distances (paired t-test and Pearson correlation). Method 2: a mathematical equation between the cusps measurements of the canines and the distobuccal of the first molars leading to result 1 (t-test for one sample and bootstrapping analysis). Dental casts were digitized and analyzed using a software program. The Bland-Altman test compared the methods (α=0.05).

RESULTS

The Bland-Altman test revealed concordance between the methods; however, separately the results were different: In method 1, the mandibular arch did not demonstrate correlation (children, INC r=0.33; CM r=0.45; INM r=0.51; adults, CM r=0.46; INM r=0.35), however, the maxilla revealed a strong correlation in children and a strong/moderate correlation in adults. In method 2, both arches were symmetrical (p>0.05).

CONCLUSION

Method 1 may be appropriate during orthodontic treatment, and method 2 may be indicated for final treatment. These methods are useful; however, only method 1 identified the side of asymmetry. The methods can contribute to future studies in syndromic and non-syndromic patients, before and after orthognathic surgeries and orthodontic treatment, comparing results.

Positional, morphologic, and volumetric differences in TMJ in unilateral posterior crossbites and controls: A retrospective CBCT study

OBJECTIVES

The objective of this study was to evaluate if there are any morphologic, positional, and volumetric differences in the temporomandibular joint (TMJ) of patients with unilateral posterior crossbite (UPC) compared to controls. Another objective was to analyse the discrepancy in the TMJ between the crossbite versus non-crossbite side in UPC versus right and left sides in controls. Additionally, this study aimed to evaluate the differences in the bone density at the masseteric insertion site at the angle of mandible in the UPC group and control group.

MATERIAL AND METHODS

One hundred and thirty-two CBCTs were analysed with 66 patients in UPC group and 66 patients in control group (non-crossbite). Temporomandibular joint spaces - Anterior joint space (AJS), Superior joint space (SJS), Posterior joint space (PJS), Medial joint space (MJS), Middle joint space (MiJS), and Lateral joint space (LJS) were measured. Additionally, bone density at angle of mandible and volume of mandibular condyle were evaluated. The measurements were compared between the groups as well as between the crossbite and non-crossbite sides within the UPC group and between right and left sides within the control group. Furthermore, the associations between UPC and changes in TMJ regarding joint space availability, bone density, condylar head volume, and the effects of sex and age were evaluated using regression analysis.

RESULTS

It was observed that UPC group showed a greater condylar volume, than the control group. Additionally, a larger mean discrepancy was observed between the crossbite side and non-crossbite side within the UPC group concerning condylar volume than controls. Concerning age, condylar volume was observed to be larger in adults than children. Adults showed significantly greater bone density and condylar volume than adolescents. Concerning sex, it was observed that males showed a larger SJS (right), MiJS, LJS, and bone density at the mandibular angle than females.

CONCLUSION

There is a difference in the TMJ parameters particularly condylar volume in patients with UPC compared to controls.

A Correlation Analysis between Arch Width and Molar Inclination Using Cone-Beam Computed Tomography Transverse Measurements: A Cross-Sectional Study

A new era in 3-dimensional analysis has begun with the use of cone-beam computed tomography (CBCT) in orthodontics, which promises to provide a more thorough understanding of the craniofacial skeletal architecture. This study aimed to investigate the correlation between the transverse basal arches discrepancy and dental compensation by utilizing CBCT width analysis. An observational study was conducted to retrospectively review 88 CBCT scans of patients presented to dental clinics from 2014 to 2020 obtained from the Planmeca Romexis x-ray system at three centers. Dental compensation data across normal and narrow maxillae were analyzed and a Pearson correlation was used to find the relationship between molar inclination and width difference. Significant maxillary molar compensation differences were observed between the normal maxilla and narrow maxilla group, where the amount of dental compensation (164.73 ± 10.15) was higher in the narrow maxilla group. A significant negative correlation (r = -0.37) was observed between width difference and maxillary molar inclination. Maxillary molars were tipped buccally to compensate for the reduced maxillary arch width. These findings are important to determine the amount of needed maxillary expansion taking into account the buccal inclination while treating cases.

In silico approach towards neuro-occlusal rehabilitation for the early correction of asymmetrical development in a unilateral crossbite patient

Neuro-occlusal rehabilitation (N.O.R.) is a discipline of the stomatognathic medicine that defends early treatments of functional malocclusions, such as unilateral crossbite, for the correction of craniofacial development, avoiding surgical procedures later in life. Nevertheless, N.O.R.'s advances have not been proved analytically yet due to the difficulties of evaluate the mechanical response after the treatment. This study aims to evaluate computationally the effect of N.O.R.'s treatments during childhood. Therefore, bilateral chewing and maximum intercuspation occlusion were modelled through a detailed finite element model of a paediatric craniofacial complex, before and after different selective grinding-alternatives. This model was subjected to the muscular forces derived from a musculoskeletal model and was validated by the occlusal contacts recorded experimentally. This approach yielded errors below 2% and reproduced successfully the occlusal, muscular, functional and mechanical imbalance before the therapies. Treatment strategies balanced the occlusal plane and reduced the periodontal overpressure (>4.7 kPa) and the mandibular over deformation (>0.002 ε) on the crossed side. Based on the principles of the mechanostat theory of bone remodelling and the pressure-tension theory of tooth movement, these findings could also demonstrate how N.O.R.'s treatments correct the malocclusion and the asymmetrical development of the craniofacial complex. Besides, N.O.R.'s treatments slightly modified the stress state and functions of the temporomandibular joints, facilitating the chewing by the unaccustomed side. These findings provide important biomechanical insights into the use of N.O.R.'s treatments for the correction of unilateral crossbite, but also encourage the application of computing methods in biomedical research and clinical practise.

Three-dimensional quantitative analysis of dental and skeletal characteristics of skeletal Class I unilateral posterior crossbite in adults

BACKGROUND

To study the dentoskeletal characteristics and the degree of compensations in skeletal Class I adults with unilateral posterior crossbite (UPCB).

METHODS

A sample of 40 adults was chosen for this cross-sectional study. 20 skeletal Class I adults with UPCB (mean age: 22.20 ± 2.88 years), were compared to 20 skeletal Class I adults with normal occlusion (mean age: 27.56 ± 5.76 years). The respective dentoskeletal measurements were made on cross-sectional images from cone-beam computed tomography scans.

RESULTS

Skeletally, both groups showed significant differences (P < 0.05) in mandibular corpus length and menton deviation with the UPCB group showing the greatest displacement. Maxillomandibular vertical asymmetry and condylar positional asymmetry were not significant in both groups (P > 0.05). For dental variables on the second premolar and first molar, the UPCB group showed greater linear and angular differences when compared to the control group (P < 0.05). On the crossbite side, maxillary posterior teeth were more buccally inclined, and mandibular posterior teeth were more lingually inclined. However, on the non-crossbite side, both maxillary and mandibular posterior teeth were lingually inclined.

CONCLUSION

Adults with UPCB showed distinct transverse dentoskeletal asymmetry. No asymmetry was found in the condylar position and the mandibular height in UPCB adults.

Biomechanical evaluation of the unilateral crossbite on the asymmetrical development of the craniofacial complex. A mechano-morphological approach

BACKGROUND AND OBJECTIVE

The occlusion effect on the craniofacial development is a controversial topic that has attracted the interest of many researchers but that remains unclear, mainly due to the difficulties on measure its mechanical response experimentally. This mechano-morphological relationship of the craniofacial growth is often explained by the periosteal and capsular matrices of the functional matrix hypothesis (FMH); however, its outcomes have not been analytically demonstrated yet. This computational study aims, therefore, to analytically demonstrate the mechano-morphological relationship in the craniofacial development of children with unilateral crossbite (UXB) using the finite element (FE) method.

METHODS

The craniofacial complex asymmetry of ten children, five of whom exhibit UXB, was 3D-analysed and compared with the biomechanical response computed from a FE analysis of each patient's occlusion. Due to the complexity of the geometry and the multitude of contacts involved, the inherent limitations of the model were evaluated by comparing computed occlusal patterns with those recorded by an occlusal analysis on 3D printed copies.

RESULTS

Comparison's outcomes proved the reliability of our models with just a deviation error below 6% between both approaches. Out of validation process, computational results showed that the significant elongation of mandibular branch in the contralateral side could be related to the mandibular shift and increase of thickness on the crossed side, and particularly of the posterior region. These morphological changes could be associated with periodontal overpressure (>4.7 kPa) and mandibular over deformation (0.002 ε) in that side, in agreement with the periosteal matrix's principles. Furthermore, the maxilla's transversal narrowing and the elevation of the maxillary and zygomatic regions on the crossed side were statistically demonstrated and seem to be related with their respective micro displacements at occlusion, as accounted by their specific capsule matrices. Our results were consistent with those reported clinically and demonstrated analytically the mechano-morphological relationship of children's craniofacial development based on the FMH's functional matrices.

CONCLUSIONS

This study is a first step in the understanding of the occlusion's effect on the craniofacial development by computational methods. Our approach could help future engineers, researchers and clinicians to understand better the aetiology of some dental malocclusions and functional disorders improve the diagnosis or even predict the craniofacial development.

The Vectra M3 3-dimensional digital stereophotogrammetry system: A reliable technique for detecting chin asymmetry

Purpose

The aim of this study was to evaluate the reliability of the Vectra M3 (3D Imaging System; Canfield Scientific, Parsippany, NJ, USA) in detecting chin asymmetry, and to assess whether the automatic markerless tracking function is reliable compared to manually plotting landmarks.

Materials and Methods

Twenty subjects (18 females and 2 males) with a mean age of 42.5±10.5 years were included. Three-dimensional image acquisition was carried out on all subjects with simulated chin deviation in 4 stages (1-4 mm). The images were analyzed by 2 independent observers through manually plotting landmarks and by Vectra software auto-tracking mode. Repeated-measures analysis of variance and the Tukey post-hoc test were performed to evaluate the differences in mean measurements between the 2 operators and the software for measuring chin deviation in 4 stages. The intraclass correlation coefficient (ICC) was calculated to estimate the intra- and inter-examiner reliability.

Results

No significant difference was found between the accuracy of manually plotting landmarks between observers 1 and 2 and the auto-tracking mode (P=0.783 and P=0.999, respectively). The mean difference in detecting the degree of deviation according to the stage was <0.5 mm for all landmarks.

Conclusion

The auto-tracking mode could be considered as reliable as manually plotted landmarks in detecting small chin deviations with the Vectra® M3. The effect on the soft tissue when constructing a known dental movement yielded a small overestimation of the soft tissue movement compared to the dental movement (mean value<0.5 mm), which can be considered clinically non-significant.

Evaluation of mandibular changes after rapid maxillary expansion: a CBCT study in youngsters with unilateral posterior crossbite using a surface-to-surface matching technique

OBJECTIVES

The purpose of this study was to evaluate mandibular asymmetry in youngsters with posterior unilateral crossbite (PUXB), through cone-beam computed tomography and reverse engineering technique, before and after rapid maxillary expansion (RME) treatment.

MATERIALS AND METHODS

Forty cone-beam computed tomography (CBCT) images were obtained from all patients at two time points, namely T0 acquired before the placement of a Hyrax expander and T1 after appliance removal. The CBCT scans were segmented and volume rendered into a surface there-dimensional (3D) mesh model. Thereafter, mandibular models were digitally registered by using a "best-fit" algorithm. Surface and volumetric changes, between T0 and T1, were compared by using Student's t tests.

RESULTS

A slight increase of 0.45 cm3 of the total mandibular volume was found at T1 when compared with T0 (p < 0.001). The mandibular hemi-volume on the crossbite side (CB) was slightly smaller than the non-crossbite side both at T0 and T1. However, the mean differences of hemi-volume from the CB (crossbite) and non-CB side between T0 and T1 show a decrease of 0.26 cm3 (p < 0.001). Findings for the surface-to-surface deviation analysis demonstrated a fine percentage of matching at T0 which slightly improved at T1 (p < 0.001).

CONCLUSIONS

Youngsters affected by PUXB showed a very slight and not statistically significant volumetric and morphological asymmetry between CB side and non-CB side at T0. However, the change in mean differences of 0.26 cm cannot be considered clinically relevant.

CLINICAL RELEVANCE

Mandibles in young PUXB patients exhibit only a very mild mandibular asymmetry. Although the statistically significant mean change found right after RME removal cannot be considered clinically relevant, a more consistent sample and a longer follow-up could be of interest in explaining the short-term findings.

Evaluation of mandibular symmetry and morphology in adult patients with unilateral posterior crossbite: a CBCT study using a surface-to-surface matching technique

OBJECTIVES

To investigate mandibular morphology in adults affected by posterior unilateral crossbite (PUXB) and to evaluate the hemi mandibular volumes from the crossbite (CB) and non-CB sides of the same patients.

METHODS

Thirty-eight cone beam computed tomography (CBCT) images were consecutively recruited and the Digital Imaging and Communications in Medicine (DICOM)-formatted scans were volume rendered into a surface three-dimensional (3D) mesh model and volumes to obtain the 3D model of the mandibular bone. To achieve the surface point-to-point analysis of the mandibular models, a reverse engineering software was used. The same procedure was performed for an age-matched control group (19 CBCT images).

RESULTS

Total mandibular volume showed a difference of 2.46 cm3 between patients and controls, which was not statistically significant. A mean difference of 1.53 cm3 was found comparing the hemi mandibular volumes from the CB and non-CB sides of PUXB patients, this difference was statistically significant (P ≤ 0.01). Findings for the surface-to-surface deviation analysis, demonstrated a higher percentage of mismatch in patients PUXB, over 10% at 0.5 mm tolerance level.

LIMITATIONS

Limitations are related to the intrinsic surfaces matching methodology, that make difficult to evaluate discrepancies among different mandibular anatomical units.

CONCLUSION

Adult patients affected by PUXB show a greater mandibular structural asymmetry compared to controls because of a lower matching percentage obtained from the surface-to-surface matching technique.

IMPLICATIONS

Treatment of adult patients affected by PUXB should take into consideration the possibility of a mild mandibular asymmetry mainly localized at the condyle and gonial angle levels.

Three-dimensional assessment of mandibular asymmetry in skeletal Class I and unilateral crossbite malocclusion in 3 different age groups

INTRODUCTION

This study aimed to evaluate the morphologic and positional features of the mandible in children, adolescents, and adults with skeletal Class I and unilateral posterior crossbite.

METHODS

The sample included cone-beam computerized tomography images of 76 subjects, divided in 3 groups: (1) children (aged 6.77 ± 1.5 years; n = 25), (2) adolescents (aged 14.3 ± 1.7 years; n = 26), and (3) adults (aged 32.66 ± 13.4 years; n = 25) with unilateral posterior crossbite. Condylar and mandibular linear distances and angles were performed using a mirrored 3-dimensional overlapped model. Intragroup asymmetries were determined by a comparison between crossbite and no crossbite sides. The differences between both sides of all measurements were compared among groups and correlated to mandibular horizontal rotation (yaw) and age.

RESULTS

The crossbite side showed shorter distances in the condyle and mandibular regions. Asymmetries were slightly but significantly greater in adults, as expressed by the lateromedial condylar distance, total ramus height, and mandibular length with an average 0.7 mm, 2.0 mm, and 1.5 mm, respectively. The mandibular yaw rotation was not correlated to age but moderately associated (r = 0.467) to asymmetry in mandibular length and total ramus height.

CONCLUSIONS

Patients with skeletal Class I and unilateral crossbite showed small mandibular asymmetries and these conditions were slightly greater in adults, specifically in lateromedial condylar distances and mandibular body and length.

Evaluation of structural skeletal asymmetry of the glenoid fossa in adult patients with unilateral posterior crossbite using surface-to-surface matching on CBCT images

OBJECTIVES

To compare, using surface-to-surface (StS) matching, any shape differences between the crossbite and noncrossbite side of the glenoid fossa and articular eminence in adult patients affected by posterior unilateral crossbite (PUXB) and compare them with unaffected controls.

MATERIALS AND METHODS

32 cone beam computed tomography (CBCT) scans of patients (mean age: 23.72 ± 3.74 years) undergoing surgical maxillary expansion were analyzed to obtain three-dimensional models of the left and right glenoid fossae that were superimposed using stable anatomical reference points and then compared using StS matching to evaluate the presence of any shape differences. These findings were compared with those obtained from 16 CBCT scans of unaffected controls (mean age: 23.72 ± 3.73 years).

RESULTS

A mean difference of >11% was found between the study group and controls when comparing the matching percentages of the two sides of the glenoid fossa and articular eminence at all three levels of tolerance selected for this study. These differences were found to be highly statistically significant (P ≤ .0001).

CONCLUSIONS

According to the shape analysis findings, adult PUXB patients exhibit a higher degree of glenoid fossa and articular eminence shape differences compared to unaffected controls.

Correlations between Malocclusion and Postural Anomalies in Children with Mixed Dentition

The aim of this study was to investigate the possible relationship between malocclusion and body posture anomalies. The original sample involved 127 children (45 males and 82 females) with mixed dentition. Clinical examination of oral cavity was performed by an orthodontist, who recorded molar and canine relationship, cross-bite, lower middle-line deviation, and centric relation (CR) considering mono or bilateral contacts in CR. Orthopedic examination of the body posture was clinically carried out by an orthopedist who detected anomalies such as scoliosis, false scoliosis or paramorphism, kyphosis and lordosis. Of the 127 subjects of the sample, 18 children were orthopedically normal, 80 patients had false scoliosis, 22 scoliosis and 7 showed kyphosis. In our study, we don't consider the 7 patients with kyphosis for the exiguity of the sample; so, our analysis was performed on 120 children (42 males and 78 females). The results obtained revealed that the cross-bite was more frequent when scoliosis became worse. We also found that the relationship between left cross-bite and contralateral side of deviation of the curve of the spine in subjects with scoliosis is statistically significant (p = 0.002). Furthermore, the relationship between lower midline and contralateral side of deviation of the curve of the spine in patients with false scoliosis is statistically significant (p = 0.003). In conclusion, it seems that posture anomalies are correlated to cross-bite and mandible abnormal position.

Three-dimensional assessment of back symmetry in subjects with unilateral functional crossbite during the pre-pubertal growth phase: a controlled study

BACKGROUND/OBJECTIVES

Since a high prevalence of back anomalies has been reported among subjects with crossbite, the aim was to assess the degree of back symmetry among subjects with (crossbite) and without (control) unilateral functional crossbite during the pre-pubertal growth phase.

METHODS

A group of 70 subjects (36 boys, 34 girls; 6.8 ± 1.2 years) in the primary or mixed dentition phase were included. Clinical assessment of head posture, shoulder, scapula and hip height were performed with the subject standing, and differences between the left and right side greater than 5 mm recorded. Asymmetry of the scapula and trunk prominence greater than 8 mm was recorded along with the prominence of thoracic and lumbar paravertebral musculature during the forward-bending test. Back symmetry was assessed qualitatively and quantitatively on colour deviation maps of superimposed mirrored three-dimensional back scans at a tolerance level of 2 mm.

RESULTS

No significant differences were observed between the groups regarding the frequency of clinically assessed back anomalies. The percentage of back symmetry was slightly lower in the crossbite than that in the control group (71.4 ± 13.3% and 79.2 ± 12.1%, respectively). A significant association (P < 0.05) was seen between scapula plane inclination (OR = 3.41) and scapula prominence inequalities (OR = 3.29) and unilateral functional crossbite, while hip height inequalities (OR = 0.94) were more frequent in the control group. No associations were detected between the side of crossbite and side of prominence of back parameters.

LIMITATIONS

The use of different thresholds for clinical (5-8 mm) and three-dimensional (2 mm) symmetry assessment.

CONCLUSIONS

Although some degree of back asymmetry was detected in the crossbite group during the pre-pubertal growth phase, this asymmetry does not appear to be clinically relevant.

Three-dimensional analysis of mandibular functional units in adult patients with unilateral posterior crossbite: A cone beam study with the use of mirroring and surface-to-surface matching techniques

OBJECTIVES

To use three-dimensional (3D) mirroring and surface-to-surface techniques to determine any differences in mandibular functional unit shape and morphology between the crossbite side and non-crossbite side in adult patients with posterior unilateral crossbite who had not received any corrective treatment for malocclusion.

MATERIALS AND METHODS

Cone-beam computed tomography (CBCT) records from 24 consecutive adult white patients (mean age, 27.5 years; range 22.6-39.7 years; 14 women and 10 men) seeking treatment for maxillary transverse deficiency were assessed in this study. The control group comprised CBCT scans from age- and sex-matched patients. Segmentation masks were generated to obtain 3D surface mesh models of the mandibles and analyze the six skeletal functional units, which were further analyzed with reverse engineering software.

RESULTS

Statistically significant differences in the mean surface distance when comparing the study sample and the control sample were found at the condylar process, mandibular ramus, angular process (P ≤ .0001), and alveolar process (P ≤ .01); no statistically significant differences were found for the coronoid process, the chin, and the mandibular body (P ≥ .5).

CONCLUSIONS

The condylar, angular, and alveolar processes plus the mandibular ramus appear to play a more dominant role than did the body, the coronoid, and the chin units in the asymmetry of the mandible in patients with unilateral crossbite.

Surgically assisted rapid maxillary expansion in lingual orthodontics - optimizing of coupling and timing : Best oral presentation from the 21st Meeting of German Society of Lingual Orthodontics

Background

Surgically assisted rapid maxillary expansion (SARME) is primarily used in adult orthodontics. In many cases it is followed by further surgery to address further anteroposterior and/or vertical discrepancies. Treatment times in such cases are often long with adult patients usually requesting invisible appliances. Lingual appliances can provide the mechanical control required as well as fulfil the aesthetic demands in such cases. However lingual appliances are usually custom made and indirectly bonded. Due to tooth movement following surgery there is usually a long delay before impressions can be made for customized lingual appliances. This results in a long delay before alignement and leveling can be commenced post-surgery.

Case presentations

Three cases are presented here demonstrating the simultaneous placement of bone anchored expansion devices for surgically assisted rapid maxillary expansion with customized lingual appliances.

Conclusions

The combination of the two procedures allows the alignement and leveling to commence very soon after surgery significantly reducing treatment times. The design of the appliances and the clinical procedures are described and discussed.

Three-dimensional evaluation of craniofacial characteristics related to mandibular asymmetries in skeletal Class I patients

INTRODUCTION

Our objective was to analyze the characteristics that affect skeletal Class I adults with mandibular asymmetries using cone-beam computerized tomography.

METHODS

The sample included cone-beam computerized tomography images of 120 subjects. Asymmetry was determined by the deviation of gnathion from the midsagittal plane and classified as relative symmetry, moderate asymmetry, or severe asymmetry. Maxillary and mandibular measurements were made, and the differences between the contralateral side and the deviated side were evaluated, as well as the differences between the categories of asymmetry.

RESULTS

For patients with moderate asymmetry, there were significant differences between the contralateral and deviated sides for some measuments in the transverse and vertical planes. For those with severe asymmetry, statistically significant differences were found between the sides for all measurements, except for the measuments that evaluated the position of the mandibular condyle in the transverse and sagittal directions. Furthermore, a strong correlation was found in patients with severe asymmetry, between the deviation of the mandibular dental midline and the lateral displacement of gnathion.

CONCLUSIONS

Patients with relative symmetry had a bilateral balance, whereas those with moderate and severe asymmetries showed several skeletal imbalances. A great deviation of the mandibular dental midline may indicate severe skeletal asymmetry in Class I adults.

Relationship between molar occlusion and masticatory movement in lateral deviation of the mandible

INTRODUCTION

The relationship between molar occlusion and chewing patterns was examined in subjects with laterally deviated mandibles.

METHODS

Twenty-three patients with mandibular deviation from the midline (4 mm or more) and skeletal Class I (0° ≤ANB ≤4°) were divided into 2 groups: normal bite and crossbite. The chewing pattern was classified as normal, reversed, or crossover.

RESULTS

The normal bite group had a normal chewing pattern on the affected side 100% of the time and a reversed chewing pattern on the affected and unaffected sides 0% and 7.2% of the time, respectively. Additionally, the normal bite group showed no evidence of a crossover chewing pattern and also had significantly less axial inclination of the mandibular teeth on the affected side compared with the crossbite group; lingual inclination was also evident. The crossbite group had a normal chewing pattern on the affected and unaffected sides 0% and 55.6% of the time, respectively, and reversed and crossover chewing patterns on the affected side 55.6% and 44.4% of the time, respectively.

CONCLUSIONS

A normal chewing pattern tends to result in lingual axial inclination of the mandibular molars on the affected side, as well as a more consistent chewing pattern.

The electrical activity of the temporal and masseter muscles in patients with TMD and unilateral posterior crossbite

The aim of this study was to assess the influence of unilateral posterior crossbite on the electrical activity of the temporal and masseter muscles in patients with subjective symptoms of temporomandibular dysfunctions (TMD). The sample consisted of 50 patients (22 female and 28 male) aged 18.4 to 26.3 years (mean 20.84, SD 1.14) with subjective symptoms of TMD and unilateral posterior crossbite malocclusion and 100 patients without subjective symptoms of TMD and malocclusion (54 female and 46 male) aged between 18.4 and 28.7 years (mean 21.42, SD 1.06). The anamnestic interviews were conducted according to a three-point anamnestic index of temporomandibular dysfunction (Ai). Electromyographical (EMG) recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany). Recordings were carried out in the mandibular rest position and during maximum voluntary contraction (MVC). Analysis of the results of the EMG recordings confirmed the influence of unilateral posterior crossbite on variations in spontaneous muscle activity in the mandibular rest position and maximum voluntary contraction. In addition, there was a significant increase in the Asymmetry Index (As) and Torque Coefficient (Tc), responsible for a laterodeviating effect on the mandible caused by unbalanced right and left masseter and temporal muscles.

Mandibular kinematic changes after unilateral cross-bite with lateral shift correction

The aim of this randomised prospective study was to evaluate the effects of slow maxillary expansion with expansion plates and Hyrax expanders on the kinematics of the mandible after cross-bite correction. Thirty children (15 boys and 15 girls), aged 7·1-11·8, with unilateral cross-bite and functional shift were divided into two groups: expansion plate (n = 15) and Hyrax expander (n = 15). Thirty children with normal occlusion (14 boys and 16 girls, aged 7·3-11·6) served as control group. The maximum vertical opening, lateral mandibular shift (from maximum vertical opening to maximum intercuspation, from rest position to maximum intercuspation and from maximum vertical opening to rest position) and lateral excursions were recorded before and 4 months after treatment. After treatment, the expansion plate group showed a greater lateral shift from rest position to maximum intercuspation than did the control group. The expansion plate patients also presented greater left/contralateral excursion than did the control group. Comparisons of changes after treatment in the cross-bite groups showed significant decreases in the lateral shift from the maximum vertical opening to maximum intercuspation and from the maximum vertical opening to rest position, a significant increase in the homolateral excursion and a significant decrease in the contralateral excursion in the Hyrax expander group, whereas no significant differences were found in the expansion plate group. In conclusion, the Hyrax expander showed better results than did the expansion plate. The Hyrax expander with acrylic occlusal covering significantly improved the mandibular lateral shift and normalised the range of lateral excursion.

Establishing better biological models to understand occlusion. I: TM joint anatomic relationships

Belief in and rejection of a relationship of occlusion and temporomandibular joint (TMJ) condyle-fossa position with normal and abnormal function are still contentious issues. Clinical opinions can be strong, but support in most published data (mostly univariate) is problematic. Distribution overlap, low sensitivity and specificity are a common basis to reject any useful prediction value. Notwithstanding, a relationship of form with function is a basic tenet of biology. These are multifactor problems, but the questions mostly have not been analysed as such. This review moves the question forward by focusing on TM joint anatomic organisation as the multifactor system it is expected to be in a closed system like a synovial joint. Multifactor analysis allows the data to speak for itself and reduces bias. Classification tree analysis revealed useful prediction values and usable clinical models which are illustrated, backed up by stepwise logistic regression. Explained variance, R(2), predicting normals from pooled TMJ patients was 32·6%, sensitivity 67·9%, specificity 85·7%; 37% versus disc displacement with reduction; and 28·8% versus disc displacement without reduction. Significant osseous organisational differences between TM joints with clicking and locking suggest that this is not necessarily a single disease continuum. However, a subset of joints with clicking contained characteristics of joints with locking that might contribute to symptom progression versus resistance. Moderately strong models confirm there is a relationship between TMJ osseous organisation and function, but it should not be overstated. More than one model of normals and of TM derangement organisation is revealed. The implications to clinical decision-making are discussed.

Mandibular lateral shift induces the increased expression of TGF-β, VEGF, and Col-II in the condyle of rat temporomandibular joints

OBJECTIVE

The present study evaluates histologic changes to and expression of angiogenic factors in rats with mandibular functional shift (MFS).

STUDY DESIGN

After 1, 2, and 4 weeks of MFS, rats in the experimental and control groups were killed. Histologic micrographs of the ipsilateral condyle cartilage were obtained. The localization and expression of vascular endothelial growth factor (VEGF), transforming growth factor beta (TGF-β), and type-II collagen (Col-II) in temporomandibular joints (TMJs) were evaluated through immunohistochemical staining.

RESULTS

The results showed that structural changes in the condyle cartilage could be observed 2 weeks after MFS. TGF-β expression reached its peak 2 weeks post-MFS, whereas VEGF and Col-II reached their peaks 4 weeks posttreatment.

CONCLUSIONS

Compressive forces applied to the TMJ could enhance the expressions of VEGF, TGF-β, and Col-II, and activate angiogenesis. The proteins appear to play important roles in the remodeling of the TMJ.

Scoliosis and dental occlusion: a review of the literature

BACKGROUND

Idiopathic scoliosis is a deformity without clear etiology. It is unclear wether there is an association between malocclusion and scoliosis. Several types of occlusion were described in subjects with scoliosis, mostly case-reports.

OBJECTIVES

The aim of this review was to evaluate the type of occluslins more prevalent in subjects with scoliosis

SEARCH STRATEGY

All randomised and controlled clinical trials identified from the Cochrane Oral Health Group Trials Register, a MEDLINE search using the Mesh term scoliosis, malocclusion, and relevant free text words, and the bibliographies of papers and review articles which reported the outcome of orthodontic treatment in subjects with scoliosis that were published as abstracts or papers between 1970 and 2010.

SELECTION CRITERIA

All randomised and controlled clinical trials published as full papers or abstracts which reported quantitative data on the outcomes malocclusion in subjects with scoliosis.

DATA COLLECTION AND ANALYSIS

Data were extracted without blinding to the authors, age of patients or type of occlusion.

MAIN RESULTS

Using the search strategy eleven observational longitudinal studies were identified. No randomized clinical trials were recorded. Twenty-three cross-sectional studies were recorderd, and the others studies were reviews, editorials, case-reports, or opinions. The clinical trials were often not controlled and were about the cephalometric evaluation after treatment with the modified Milwuakee brace, followed by the orthodontic treatment of the class II relationship with a functional appliance. Clinical trials also included the study of the associations between scoliosis and unilateral crossbite, in children with asymmetry of the upper cervical spine. This association was also investigated in rats, pigs and rabbits in clinical trials. The other associations between scoliosis and occlusion seems to be based only on cross-sectional studies, case-reports, opinions.

AUTHORS' CONCLUSIONS

Based on selected studies, this review concludes that there is plausible evidence for an increased prevalence of unilateral Angle Class II malocclusions associated with scoliosis, and an increased risk of lateral crossbite, midline deviation in children affected by scoliosis. Also, documentation of associations between reduced range of lateral movements and scoliosis seem convincing. Data are also mentioned about the association between plagiocephaly and scoliosis.

A preliminary anatomical study on the association of condylar and occlusal asymmetry

The aim of this study was to test the hypothesis that condylar and occlusion asymmetry are not associated. For each of 22 skulls, the asymmetry of condyles was graded by one examiner and the asymmetry of occlusion by another examiner, both blinded to each other's evaluation, as 0 = symmetrical, 1 = mild asymmetrical and 2 = severe asymmetrical. There were 18 condyles graded the same as to their occlusion, but in four, the grades differed by one degree. Nine were graded symmetrical, seven were mild, and six were graded severely asymmetrical condyles. The corresponding figures for occlusion were: 10 were graded symmetrical, seven were graded mildly asymmetrical, and five were graded severely asymmetrical occlusion. The relation between occlusion and condylar asymmetry was tested using Goodman-Kruskal's gamma and was found to be 0.970 (p < 0.001). The null hypothesis was not supported. The results indicate that asymmetry of occlusion and condyles are associated, which indicates the need for further studies on larger samples, and in vivo studies.

Three-dimensional ultrasound diagnostics of tongue posture in children with unilateral posterior crossbite

INTRODUCTION

Incorrect tongue posture on the mouth floor is considered an important factor in the etiology of unilateral posterior crossbite. The aim of this study was to objectively assess tongue posture in children with unilateral posterior crossbite and those with normal deciduous dentition by using 3-dimensional (3D) ultrasonography.

METHODS

First, referential 3D ultrasound images for differently postured tongues were acquired and reconstructed in 10 adults. Second, 27 children with unilateral posterior crossbite (mean age, 5.4 ± 1 years) and 23 children with normal deciduous dentition (mean age, 6.2 ± 0.4 years) were examined by using the 3D ultrasound technique. The referential 3D ultrasound reconstructions were used for the assessment of tongue posture in each child.

RESULTS

The characteristic 3D reconstruction of the tongue postured on the palate displays distinctive convexity of the tongue dorsum, whereas, in the 3D reconstruction with the tongue postured on the mouth floor, the dorsum is characterized by a central groove and expressed concavity. Posture on the mouth floor was demonstrated by 81.5% of the children with unilateral posterior crossbite and by only 34.8% of those with normal deciduous dentition. The difference was statistically significant (Fisher exact test: P = 0.0012).

CONCLUSIONS

Three-dimensional ultrasonography enables objective assessment of tongue posture and could become in the future an important part of functional diagnostics before, during, and after orthodontic treatment.

Analysis of facial skeletal characteristics in patients with chin deviation

BACKGROUND

This study was undertaken to investigate the facial skeletal features associated with chin deviation.

METHODS

Twenty-five patients (14 males and 11 females) diagnosed with chin deviations of more than 2 mm were recruited. Fifteen skeletal landmarks, including median and lateral points, were located on posteroanterior cephalograms. The CG-ANS (crista-galli of the ethmoid-anterior nasal spine) line and the perpendicular line through the CG were used as references. The differences between the distances from paired lateral points to reference lines were examined with intraclass correlation coefficients to analyze the symmetry of facial skeletal tissue. The factors associated with the amount or direction of chin deviation were analyzed by multiple regression analysis or by logistic regression analysis.

RESULTS

Seventeen subjects (68%) showed chin deviation to the left side and 8 subjects (32%) to the right side. Sixty-eight percent of subjects presented with Angle Class III malocclusion. Horizontal distances of all paired lateral points to the y-axis, in mandibular body length and effective length, showed a low grade of symmetry. Only vertical distances of paired zygomaticofrontal sutures and zygonion points to the x-axis were asymmetric. However, there were no significant asymmetries of the gonial angle, ramus height, and vertical distances from other paired lateral points to the x-axis. The amount of chin deviation was associated with the absolute differences of the left and right antegonion to the y-axis and zygomaticofrontal suture to the x-axis. The direction of chin deviation was significantly associated with the difference in the effective length of bilateral mandibular halves.

CONCLUSION

Facial skeletal asymmetry exists in patients with chin deviation. This should be considered when planning treatment for both the nonsurgical and surgico-orthodontic cases with chin deviation.

Muscular and condylar response to rapid maxillary expansion. Part 2: magnetic resonance imaging study of the temporomandibular joint

INTRODUCTION

In this prospective clinical study, we used bilateral temporomandibular joint (TMJ) magnetic resonance images (MRIs) to investigate the condylar response to rapid maxillary expansion (RME).

METHODS

Bilaterial MRIs of the TMJs of 18 subjects (11 girls, 7 boys; mean age, 12.54 years; range, 9.75-14.8 years) were assessed. All subjects had unilateral or bilateral posterior crossbites involving 3 or more posterior teeth. There was no control group because of the short observation period. The MRI protocol included closed-mouth parasagittal proton density weighted spin echo and fat-suppressed short T1 inversion recovery sequences. The MRIs were taken before treatment (Tx 1), and at 6 weeks (Tx 2) and at 18 weeks (Tx 3) after treatment. Alterations in the signal intensities of the TMJ region were examined visually by a radiologist who was blinded to the subjects' characteristics.

RESULTS

Increased signal intensities appeared as bright areas on the MRIs, indicating red bone marrow edema that is a sign of condylar remodeling. There were no bright areas in the condylar regions at Tx 2 in the 36 TMJs. Bright areas at the condylar region were observed both in proton density and fat-suppressed spin echo sequences at Tx 3 in 32 TMJs. Twenty-two TMJs had bright areas localized at the condylar head, and 10 TMJs had bright areas that extended through both the condyle and the mandibular ramus. No bright areas were seen at Tx 2 or Tx 3 for 4 TMJs.

CONCLUSIONS

A condylar response to RME was observed in 32 TMJs at 18 weeks after expansion. Both the extensive orthopedic and the functional occlusal forces associated with RME have roles in condylar and ramal responses.

Condylar asymmetry in unilateral posterior crossbite patients

INTRODUCTION

Posterior crossbite is defined as an abnormal buccolingual relationship between opposing posterior teeth including the canines in centric occlusion. The most common form of posterior crossbite is unilateral with a functional shift of the mandible toward the crossbite side. Lateral shift of the mandible in functional crossbite patients results in mandibular skeletal deflection to the crossbite side. Thus, the asymmetrical position of the mandible in these patients can result in asymmetrical condylar heights. The purpose of this study was to investigate condylar and ramal asymmetries in unilateral crossbite patients as compared with normocclusive subjects.

METHODS

The study groups included 81 patients with unilateral posterior crossbite and a control group of 75 patients with normal occlusion. Condylar, ramal, and condylar-plus-ramal asymmetry values were computed for all subjects on panoramic radiographs. Data were analyzed statistically with ANOVA for repeated measures and univariate ANOVA.

RESULTS

The patients with unilateral posterior crossbite had more asymmetric condyles than did the controls. In addition, condylar, ramal, and condylar-plus-ramal heights on the crossbite side were smaller than those on the noncrossbite side.

CONCLUSIONS

Subjects with functional unilateral posterior crossbite have asymmetrical condyles.

Classification of facial asymmetry by cluster analysis

INTRODUCTION

The purposes of this study were to classify patients with facial asymmetry by using the cluster analysis and to evaluate the characteristics of the resultant groups.

METHODS

One hundred consecutive orthodontic patients who had frontal cephalograms and photographs taken for the diagnosis of facial asymmetry were included in the sample. A cluster analysis was used to classify the subjects, with craniofacial measurements related to asymmetry obtained from the cephalograms and photographs.

RESULTS

The subjects were divided into 5 clusters based on only 3 variables from the frontal cephalograms: menton deviation, apical base midline discrepancy, and vertical difference of right and left antegonion. The results of the ANOVA test according to the variables showed statistically significant differences between the groups in all variables, indicating that each group can be easily identified with the variables.

CONCLUSIONS

The results suggest that patients with facial asymmetry can be classified simply based on some variables on frontal cephalograms, and this classification can be helpful in proper diagnosis and treatment planning for these patients.

Análise da mastigação em indivíduos que apresentam mordida cruzada unilateral na faixa-etária de 07 a 12 anos

OBJETIVO: analisar a função de mastigação relacionada à mordida cruzada posterior unilateral em crianças na faixa etária de sete a doze anos. MÉTODOS: dez indivíduos de ambos os sexos com mordida cruzada unilateral posterior sem intervenção ortodôntica. Na avaliação fonoaudiológica os itens considerados foram: corte do alimento, lado da mastigação, ritmo, postura labial, escape de alimentos, movimento de mandíbula, participação exagerada da musculatura perioral, acúmulo de alimento no vestíbulo da boca, posição e tamanho do bolo alimentar. RESULTADOS: dos dez indivíduos avaliados, 80% apresentaram mastigação unilateral do mesmo lado da mordida cruzada posterior unilateral e 20% mastigação bilateral. Dos oito indivíduos analisados com mastigação unilateral, os resultados encontrados foram: corte anterior, sem escape de alimentos e movimentos rotatórios 100%; ritmo lento 50% e rápido 50%; lábios fechados 75%; participação exagerada da musculatura perioral 62,5%; sem acúmulo de alimentos 87,5%; bolo alimentar centralizado 75%; tamanho do bolo pequeno 62,5%. CONCLUSÃO: dos casos avaliados, observou-se que 80% confirmam a relação entre mastigação unilateral e mordida cruzada posterior unilateral. Na mastigação, não foram evidenciadas quaisquer outras alterações que possam estar relacionadas à mordida cruzada posterior unilateral e mastigação unilateral.

Associations between orthopaedic disturbances and unilateral crossbite in children with asymmetry of the upper cervical spine

The objective of the present study was to detect possible associations between unilateral crossbite and orthopaedic disturbances in children with asymmetry of the upper cervical spine. Fifty-five children aged 3-10 years (22 girls and 33 boys) with a unilateral crossbite and 55 gender- and age-matched children with a symmetric occlusion but no crossbite, who served as the control group, were selected from an orthopaedic cohort of 240 patients. In all children, asymmetry of the upper cervical region was confirmed by radiographs and palpation. The following orthopaedic aspects were investigated: oblique shoulder and pelvis, scoliosis, functional leg length difference, and laxity of ligaments of the foot. The differences between the groups were analysed by means of an unpaired t-test. An increased occurrence of orthopaedic parameters in the frontal plane was observed in children with a unilateral malocclusion. A unilateral crossbite was not necessarily combined with a pathological orthopaedic variable, but statistically, children with a unilateral malocclusion showed more often an oblique shoulder (P = 0.004), scoliosis (P = 0.04), an oblique pelvis (P = 0.007), and a functional leg length difference (P = 0.002) than children with symmetry. The results suggest that a unilateral crossbite in children with asymmetry of the upper cervical spine is associated with orthopaedic disturbances. There is no evidence of a causal link.

Relationship Between the Masticatory Muscles and Mandibular Skeleton in Mandibular Prognathism With and Without Asymmetry

PURPOSE

The purpose of the present study was to evaluate the relationship between masticatory muscle volume and mandibular skeletal measurements in patients with and without facial asymmetry. This was done in order to determine whether asymmetric mandibular prognathism is related to masticatory muscle asymmetry.

PATIENTS AND METHODS

The study was conducted with 40 adult patients with mandibular prognathism composed of 2 groups, the asymmetry group (n = 20) and the nonasymmetry group (n = 20). Using 3-dimensional reformatted computed tomography (CT) images, the volume of masticatory muscle (masseter, temporal, medial, and lateral pterygoid muscles) and various skeletal measurements (hemimandibular volume, ramal height, body length, mandibular length, gonial angle) were evaluated and compared. The right-left difference was expressed by an asymmetry index {(right-left)/left, %}.

RESULTS

The results showed that in the asymmetry group, the longer mandibular side (contralateral side of chin deviation) exhibited longer ramal and body length, a wider gonial angle, and more hemimandibular volume with less medial pterygoid volume, whereas the nonasymmetry group did not show a statistical bilateral difference between the skeletal and muscular measurements. The correlation analysis showed that patients with facial asymmetry did not have similar patterns of muscle-bone relation as compared with the symmetrical subjects.

CONCLUSION

In patients with mandibular prognathism, the bilateral difference in muscle volume would reflect the difference in the spatial anatomy of a skeletal structure and could not predict mandibular skeletal asymmetry.

Avaliação ultra-sonográfica dos músculos mastigatórios e dimensões faciais em crianças com oclusão normale mordida cruzada posterior unilateral

OBJETIVO: avaliar a espessura dos músculos masseter e porção anterior do temporal por meio da ultra-sonografia e as dimensões faciais de crianças com oclusão normal e mordida cruzada posterior unilateral, na dentição decídua e mista inicial. MÉTODOS: foram selecionadas 49 crianças, de ambos os gêneros, divididas em quatro grupos: decídua-oclusão normal, decídua-mordida cruzada, mista-oclusão normal e mista-mordida cruzada. A espessura muscular foi comparada entre os lados direito e esquerdo (oclusão normal); e normal e cruzado (mordida cruzada) (teste "t" Student), e relacionada às dimensões faciais e variáveis corporais (teste de correlação de Pearson e Spearman). As dimensões faciais foram mensuradas sobre fotografias frontais padronizadas: altura facial anterior (AFA), distância bizigomática (DB) e intergoniana (DI) e razões AFA/DB e AFA/DI. RESULTADOS: observou-se que o músculo temporal no repouso apresentou espessura maior no lado cruzado no grupo mista-cruzada (p=0,05). O masseter não apresentou diferença significativa entre os lados em todos os grupos. As variáveis peso e altura não apresentaram correlação com a espessura muscular; já DB e DI apresentaram correlação positiva e as razões AFA/DB e AFA/DI, correlação negativa, com a espessura do masseter em todos os grupos, indicando que crianças com faces mais longas possuem menor espessura deste músculo. CONCLUSÃO: na amostra estudada, os exames da espessura dos músculos mastigatórios e das dimensões faciais demonstraram que a influência das características funcionais sobre as estruturas craniofaciais pôde ser observada já em crianças de pouca idade.

Condylar Asymmetry in Bilateral Posterior Crossbite Patients

Objective: To investigate whether patients with bilateral posterior crossbite have asymmetrically developed condyles.

Materials and Methods: The study group consisted of 75 patients with bilateral posterior crossbite, and a control group of 75 subjects with normal occlusion. Condylar, ramal, and condylar plus ramal asymmetry values were computed for all of the subjects on orthopantomograms. Data were analyzed statistically by means of paired t-test and Student's t-test.

Results: The patients with bilateral posterior crossbite had more asymmetrical condyles relative to the controls. However, there were no statistically significant differences in condylar, ramal, or condylar plus ramal heights between left and right sides in both the control and crossbite groups.

Conclusion: Patients with bilateral posterior crossbite can have asymmetrical condyles and might be at risk for the development of future skeletal mandibular asymmetries.

Evaluation of condylar position from transcranial projections in primary dentition

OBJECTIVES

To evaluate the condylar position through transcranial radiographs in children between 3 years and 6 years old and to associate it with morphological characteristics of primary dentition.

METHODS

The extraoral transcranial radiographs were taken with plain films using the Accurad-200 head holder (Denar Company, Anaheim, CA), and then they were digitized using a Hewlett Packard 6390 Scanner. The condylar position was determined according to Gelb's template, in postural rest position (RP) and maximum intercuspal position (MI), and it was associated with the characteristics: normal occlusion (n=36), open bite with or without overjet greater than 3 mm (n=27), unilateral or bilateral posterior cross bite (n=14), overbite greater than 3 mm (n=15). The chi-square and the Fisher Exact Test were used to analyse the data.

RESULTS

It was verified that when using Gelb's template, there was not a significant association between the occlusion type found and the position of the condyle in the glenoid fossa when considering the entire patient sample (P>0.05). There was a great variability in positions, and most of the children had asymmetric condyles (55.43% in MI and 51.09% in RP). Children with normal occlusion and malocclusion presented the same proportions of condylar position in both mandibular positions.

CONCLUSIONS

In conclusion, the results of this study showed that the condylar position in small children with different morphological occlusions presented great variability.