Multivariate analysis of alveolar bone dehiscence and fenestration in anterior teeth after orthodontic treatment: A retrospective study

OBJECTIVE

To compare the prevalence of fenestration and dehiscence between pre- and post-orthodontic treatment and to explore the factors related to fenestration and dehiscence in the anterior teeth after treatment.

METHODS

This study included 1000 cone-beam computed tomography (CBCT) scans of 500 patients before (T1) and after (T2) orthodontic treatment. These images were imported into Dolphin 11.9 software to detect alveolar fenestration and dehiscence in the anterior teeth area. The chi-square test and Fisher's exact test were performed to compare the prevalence of alveolar bone defects between time points T1 and T2. A total of 499 patients were selected for logistic regression analysis to examine the correlation among age, sex, crowding, sagittal facial type, extraction, miniscrew use and fenestration or dehiscence post-treatment.

RESULTS

Except for the maxillary lingual fenestration and labial fenestration of mandibular canines, a significant change in the prevalence of fenestration and dehiscence was noted between time points T1 and T2 (P < .025). Multinomial logistic regression showed that age, miniscrew use and extraction highly influenced the prevalence of anterior lingual dehiscence (P < .05). Dehiscence of the mandibular labial side (skeletal Class III vs. I, OR = 2.368, P = .000) and fenestration of the mandibular lingual side (skeletal Class II vs. I, OR = 2.344, P = .044) were strongly correlated with the sagittal facial type. Dehiscence of the maxillary labial side (moderate vs. mild, OR = 1.468, P = .017) was significantly associated with crowding.

CONCLUSIONS

Older age, maxillary moderate crowding, skeletal Class III, extraction and miniscrew potentially significantly affect the prevalence of anterior teeth dehiscence. Adult females, skeletal Class III patients on the mandibular labial side and skeletal Class II patients on the mandibular lingual side should be monitored for anterior teeth fenestration.

Cranial Base Measurements in Skeletal Malocclusion among Orthodontic Patients

BACKGROUND

Facial growth and development is necessary for proper orthodontic diagnosis and treatment planning. Growth of cranial base is linked to the overall growth of facial bones, especially the maxilla and mandible. Any change in the amount and direction of growth of the cranial base can have direct or indirect effects on the developing maxilla and mandible. Thus the aim of this study was to determine the linear and angular cranial base measurements in different skeletal malocclusion in Nepalese population.

METHODS

Pretreatment lateral cephalograms of 225 patients aged between 17-30 years were collected. Linear measurements Sella-Nasion (S-N), Sella-Articulare (S-Ar), Articulare-Gonion (Ar-Go), Gonion-Gnathion (Go-Gn) and angular measurements Saddle angle (N-S-Ar), Articular angle (S-Ar-Go) and Gonial angle (Ar-Go-Gn) were measured.

RESULTS

In angular measurements statistically significant differences were found in the saddle and gonial angles between class I, II, and III skeletal pattern. In linear measurements, anterior and posterior cranial base lengths were not significantly different among groups however, ramal height and mandibular body length were significantly different among groups with a P value < 0.05.

CONCLUSIONS

Skeletal class III has a larger gonial angle, ramal height and mandibular length. Males have larger linear measurements and females have larger angular measurements.

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

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

Three-dimensional mandibular characteristics in skeletal malocclusion : A cross-sectional study

PURPOSE

We aimed to comprehensively analyse a possible correlation between skeletal malocclusions, gender and mandibular characteristics in all three dimensions in adults and to identify mandibular characteristics that are typical for extreme skeletal patterns.

METHODS

A 3D model of the skull was calculated in 111 adult patients (mean age = 27.0 ± 10.2 years; 49 women, 62 men) from available computed tomography or cone beam computed tomography scans of their heads. Based on the 3D models, the skeletal patterns were examined in (a) the transversal dimension regarding asymmetry according to menton deviation, (b) the sagittal dimension according to the Wits appraisal and (c) the vertical dimension according to the maxillomandibular plane angle. The mandibular characteristics assessed were linear (ramus height and width, body length), angular (ramus, gonial and body angle) and volumetric (ramus/mandibular volume, body/mandibular volume) parameters.

RESULTS

No correlation between transversal skeletal asymmetry and mandibular characteristics were found, while sagittal (F(16, 174) = 3.32, p < 0.001, η2 = 0.23) and vertical (F(16, 174) = 3.18, p < 0.001, η2 = 0.23) skeletal patterns were shown to have a significant effect on the mandible. Gender correlated with mandibular characteristics independently from the skeletal pattern. Discriminant analysis revealed that class II and III patients differed in ramus and body angle with class II patients showing higher angles (ramus angle: class II = 89.8 ± 3.9° vs. class III = 84.4 ± 4.8°; body angle: class II = 87.7 ± 4.8° vs. class III = 82.1 ± 5.2°). Hypo- and hyperdivergent patients were discriminated by gonial angle, body angle and body/mandibular volume with hyperdivergent patients having a greater gonial and body angle and body/mandibular volume (gonial angle: hypodivergent = 114 ± 9.3° vs. hyperdivergent = 126.4 ± 8.6°; body angle: hypodivergent = 82.9 ± 4.4° vs. hyperdivergent = 87.7 ± 6.5°; body/mandibular volume: hypodivergent = 72.4 ± 2.7% vs. hyperdivergent = 76.2 ± 2.6%).

CONCLUSION

When analysing 3D data for treatment planning of adult patients, the orthodontist should pay attention to angular and volumetric characteristics of the mandible to identify extreme skeletal sagittal or vertical malocclusions.

Comparison of mesiodistal angulations of premolars and molars in anterior open bite subjects with different sagittal malocclusions: A retrospective study

INTRODUCTION

Mesiodistal angulation of premolars and molars can be altered by forces of open bite malocclusion. The aim of this study was to compare the mesiodistal angulations of the posterior teeth in class I, II, and III individuals with anterior open bite (AOB) versus individuals with harmonious occlusion.

METHODS

This comparative cross-sectional study used 299 lateral head radiographs of individuals with permanent dentition. There were 4 groups (harmonious occlusion [n=89], Class I open bite [OB] [n=75], Class II OB [n=66], and Class III OB [n=69]). Premolar (1UPM, 2UPM) and molar (1UM, 2UM) angulations were measured relative to the occlusal plane and the palatal or mandibular plane by a trained and calibrated evaluator. ANOVA and Scheffe tests were used for statistical analyses (P<0.05).

RESULTS

The mesial angulation of the upper premolars showed greater angulation of between approximately 2° and 5° in the OB groups compared to the harmonious occlusion group (P<0.05). Only in the Class II OB group did the first and second upper molars show distal angulation in relation to the palatal plane (1UM 81.85°±5.42°; 2UM 75.32±7.4°) (P<0.05). The Class III OB group presented the greatest distal angulations of the lower premolars and molars (between 3° to 5° of difference, P<0.05) in relation to those of the harmonious occlusion group.

CONCLUSIONS

The upper first premolars in all the AOB groups and the lower second premolars in the Class II OB group had greater mesioangulation. Additionally, the upper molars of the Class II OB group and the lower molars of the Class III OB group showed distoangulation compared with the molars in the group with harmonious occlusion.

CORRELATION BETWEEN TRANSVERSE CEPHALOMETRIC PARAMETERS AND THE SEVERITY OF SKELETAL MALOCCLUSIONS

Malocclusion prevalence varies globally, ranging from 34.9% to 93.6% for Class I, 4.4% to 44.7% for Class II, and 1.4% to 19.4% for Class III occlusions. This study aims to assess transverse cephalometric measurements related to maxillary and mandibular dimensions, intermolar and intercanine distances, and other relevant factors. The descriptive cross-sectional research included 100 individuals with malocclusion grades 1, 2, and 3. The study involved 100 participants across three age groups (15-21, 22-28, 29-35), with the majority in the 22-28 range. Gender distribution showed a significant imbalance (77% female, 23% male). Cephalometric measurements for three malocclusion types revealed distinct patterns. Notably, inter-molar width exhibited a strong positive correlation with malocclusion severity (Malocclusion 1: r=0.504 to 0.561, Malocclusion 2: r=0.560 to 0.625, Malocclusion 3: r=0.625 to 0.559), while maxillary-mandibular transverse discrepancy had a negative correlation (Malocclusion 1: r=-0.496, Malocclusion 2: r=-0.483, Malocclusion 3: r=-0.483). Age-diverse sample, gender imbalance noted. Cephalometric correlations reveal inter-molar width association with malocclusion severity, emphasizing clinical implications.

Acute dental malocclusion associated with lateral pterygoid muscle partial tear: Case Report and literature review

BACKGROUND

The article presents a rare case of acute malocclusion produced by a unilateral partial tear of the lateral pterygoid muscle and an up-to-date literature review of the pathology.

CLINICAL PRESENTATION

A 37-year-old female was examined; her chief complaints were pain on the right side of the temporomandibular joint (TMJ) area and mastication impairment associated with major occlusal modifications and anterior open bite. After magnetic resonance imaging (MRI) and cone beam computed tomography (CBCT) of the TMJ and subsequent MRI for soft tissue, the final diagnosis was a partial right lateral pterygoid muscle tear.

CONCLUSION

The case shows the value of combined imaging in temporomandibular disorders (TMD) and the importance of soft tissue evaluation in addition to articular examination, as the primary pathology might lie outside the joint. The authors' review of the current literature did not hitherto reveal a similar case.

Three-dimensional evaluation of dentopalatal changes after rapid maxillary expansion in growing children

INTRODUCTION

In growing children with transverse malocclusion problems, various types of rapid maxillary expanders (RMEs) have been effectively used in skeletal and dental expansions. We evaluated 3-dimensional dentopalatal changes in growing children who underwent maxillary expansion using RMEs and bonded RMEs.

METHODS

We investigated dentopalatal changes in 20 patients treated with bonded RMEs, 19 with RMEs, and 38 control patients. Dental plaster models before and after expansion were scanned 3-dimensionally and superimposed to evaluate transverse expansion, expansion ratio, angular expansion, and palatal expansion height ratio.

RESULTS

Using bonded RMEs, similar anterior and posterior dental expansions were achieved with an efficiency of 69%-76% (expansion ratio), and palatal soft-tissue expansion occurred more apically in the posterior area (palatal expansion height ratio, 1.00) than in the anterior area (palatal expansion height ratio, 0.64). Using RMEs, a larger posterior dental expansion was achieved, with an efficiency of 106%-117% (expansion ratio), than anterior dental expansion (55%-60%), and palatal soft-tissue expansion occurred more apically in the posterior area (palatal expansion height ratio, 0.99) than anterior area (palatal expansion height ratio, 0.23).

CONCLUSIONS

Dental expansions in the anterior and posterior areas were similar using bonded RMEs, whereas the posterior dental expansions were larger than those of the anterior area using RMEs. The entire palatal soft-tissue slope expanded in the posterior area, whereas the occlusal part expanded in the anterior area using RMEs and bonded RMEs.

Analysis of mandibular asymmetry in adolescent and adult patients with unilateral posterior crossbite on cone-beam computed tomography

INTRODUCTION

This study aimed to evaluate mandibular asymmetry in unilateral posterior crossbite (UPXB) patients and compare the asymmetry between adolescents and adults with UPXB.

METHODS

This study included and analyzed cone-beam computed tomography scans of 125 subjects. The subjects were divided into a UPXB group and a control group according to the presence or absence of UPXB, and each group included adolescent patients (aged 10-15 years) and adult patients (aged 20-40 years). Linear, angular, and volumetric measurements were obtained to evaluate the asymmetries of the mandibles.

RESULTS

Both adolescent and adult patients in the UPXB group presented asymmetries in condylar unit length, ramal height, body length, and mediolateral ramal inclination (P <0.05). Adult patients with UPXB showed greater asymmetries than adolescents. Differences with condylar unit length, condylar unit width, ramal height, condylar unit volume, and hemimandibular volume were significantly greater in adult UPXB patients than adolescent UPXB patients (P <0.05).

CONCLUSIONS

The worsening of mandibular asymmetries in UPXB adults suggests that asymmetry in UPXB patients may progress over time; therefore, early treatment should be considered for UPXB adolescent patients. Further studies are still needed to evaluate the effectiveness of early treatment.

Analysis of maxillary asymmetry before and after treatment of functional posterior cross-bite: a retrospective study using 3D imaging system and deviation analysis

BACKGROUND

Previous evidence would suggest that subjects affected by functional posterior cross-bite (FPXB) present an asymmetric morphology of the maxilla. However, no evidence is available concerning the morphology (symmetry/asymmetry) of the maxilla after treatment of FPXB. This study aimed to investigate the volumetric and morphological changes of the palate in FPXB subjects treated with maxillary expansion and to compare these data with an untreated control group. The study sample included 20 FPXB subjects (mean age 8.1 ± 0.9 years) who underwent maxillary expansion (MEG group) and 21 FPXB subjects (mean age 7.7 ± 1.2 years) as controls (CG group). Digital models were recorded at T0 (first observation) and T1 (12-18 months after first observation) and analyzed to assess palatal volume and symmetry. Deviation analysis and percentage matching calculation were also performed between original and mirrored palatal models for each patient. All data were statistically analyzed for intra-timing, inter-timing and inter-groups assessments.

RESULTS

At T0, the cross-bite side (CBS) was significantly smaller than non-cross-bite side (non-CBS) in both groups (p < 0.05). At T1, the CBS/non-CBS difference reduced significantly in the MEG group (p < 0.05) while slightly worsened in the CG, however without statistical significance (p > 0.05). The matching percentage of the palatal models improved significantly at T1 in the MEG group (T0 = 74.02% ± 9.8; T1 = 89.95% ± 7.12) (p < 0.05) while no significant differences were recorded in the CG (T0 = 76.36 ± 8.64; 72.18% ± 9.65) (p > 0.05).

LIMITATIONS

The small sample size and the retrospective design of the study represent two limitations that should be overcome with further clinical trials.

CONCLUSIONS

Subjects with FPXB present an asymmetric development of the maxillary vault that improves after reestablishment of normal occlusion following maxillary expansion.

Three-dimensional evaluation of the temporomandibular joints after unilateral surgically assisted rapid maxillary expansion in adults: A preliminary retrospective study

BACKGROUND

Unilateral surgically assisted rapid maxillary expansion (U-SARME) is a successful method for correction of true unilateral posterior crossbite (TUPC).

OBJECTIVES

This retrospective preliminary study aimed to evaluate the position and morphology of condyles in TUPC cases and the effects of U-SARME on condyle with the help of cone beam computed tomography (CBCT).

METHODS

Fifteen patients (mean age: 18.69 ± 1.59 years) who were diagnosed as TUPC and undergone U-SARME were selected. Preoperative (T0) and after 6-month retention (T1) DICOM data of CBCT images were evaluated with MIMICs version 19.0 software. Condylar morphology (medio-lateral and antero-posterior dimensions) and position (anterior, posterior, medial and lateral joint spaces, frontal/axial axis angles, the ratio of posterior to anterior joint space and the percentage of posterior to anterior joint space) were evaluated. Student's t-test was used for intergroup (crossbite, normal) comparisons. Paired-samples t-test was used for intra-group comparisons (p = .05).

RESULTS

There were no positional or dimensional asymmetry of the condyles between crossbite and normal sides initially and after expansion. Regarding T0-T1 changes, while significant increase was determined in medial (0.3 ± 0.29 mm; p = .001) and superior (0.39 ± 0.7 mm; p = .045) joint spaces on crossbite side, posterior (0.79 ± 0.99 mm; p = .008), superior (0.5 ± 0.79 mm; p = .029) and lateral joint spaces (0.31 ± 0.54 mm; p = .042) presented significant increases on normal side. However, no significant changes were found between crossbite and normal sides at T0 and T1.

CONCLUSIONS

Condyles were symmetrical in true unilateral posterior crossbite cases and the symmetry were not disrupted following U-SARME.

'Study of the maxillary yaw on cone beam computed tomography: A preliminary report and comparison between two different dento-skeletal malocclusions'

OBJECTIVES

To assess the skeletal and dental maxillary transverse compensation (yaw) on the cone beam computed tomography (CBCT) three-dimensional reconstructed image of the skull in two groups of patients, both clinically affected by a class III malocclusion with deviation of the lower midline.

MATERIALS AND METHODS

An observational retrospective study was designed to analyse differences in two groups of patients, the first one was composed by patients affected by horizontal condylar hyperplasia, the second one by patients affected by dento-skeletal asymmetric class III malocclusion. Each group was composed by 15 patients. Transverse analysis was performed by measuring five landmarks (three bilateral and two uneven) with respect to a mid-sagittal plane; sagittal analysis was performed by measuring the sagittal distance on the mid-sagittal plane between bilateral points. Means were compared through inferential analysis.

RESULTS

In the condylar hyperplasia group, all differences between the two sides were not statistically significant, nor for canines' difference (P = .0817), for molars (P = .1105) or for jugular points (.05871). In the class III group, the differences between the two sides were statistically significant for molars (P = .0019) and jugular points (P = .0031) but not for canines (P = .1158). Comparing the two groups, significant differences were found only for incisors' midline deviation (P = .0343) and canine (P = .0177).

CONCLUSION

The study of the yaw on CBCT should be integrated into three-dimensional cephalometry and could help in differentiating the various malocclusion patterns.

Comparison of nasal cavity changes between the expander with differential opening and the fan-type expander: a secondary data analysis from an RCT

INTRODUCTION

The aim of this study was to compare the nasal cavity skeletal changes between the expander with differential opening (EDO) and the fan-type expander (FE).

METHODS

This study was a secondary analysis of a previous randomized clinical trial. Forty-eight patients with posterior crossbite were randomly allocated into two study groups. Twenty-four patients (11 male, 13 female) with a mean initial age of 7.6 ± 0.9 years were treated with rapid maxillary expansion (RME) using the EDO. Twenty-four patients (10 male, 14 female) with a mean initial age of 7.8 ± 0.9 years were treated with the FE. Cone-beam computed tomography (CBCT) was performed before treatment and 1 to 6 months after the active phase of RME. Using frontal CBCT slices passing at the level of maxillary permanent first molars and maxillary deciduous canines, the width of the nasal cavity was measured in the lower, middle and upper thirds. Nasal cavity height was also evaluated in both slices. Intergroup comparisons of interphase changes were performed using t or Mann-Whitney tests (P < 0.05).

RESULTS

The two groups were similar regarding baseline data. EDO showed a greater transverse increase in the lower third of the nasal cavity in both canine (P = 0.007) and molar regions (P < 0.001). No intergroup difference was observed for changes in middle and upper widths and height of the nasal cavity.

CONCLUSIONS

Both expanders are effective in promoting an increase of the nasal cavity skeletal dimensions. The expander with differential opening produced a greater transverse increase in the lower third of the nasal cavity compared to the fan-type expander, both at the anterior and posterior regions of the maxilla.

CLINICAL RELEVANCE

EDO might be more beneficial to pediatric patients with oral breathing and obstructive sleep apnea compared to FE.

The effect of myotonic dystrophy type 1 on temporomandibular joint and dentofacial morphology: A CBCT analysis

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a neuromuscular multisystem disease. Early involvement of facial muscles may produce an extra load on the temporomandibular joint (TMJ) in DM1.

OBJECTIVES

This study aimed to investigate the morphological analyses of the bone components of temporomandibular joint (TMJ), and dentofacial morphology in myotonic dystrophy type 1 (DM1) patients by cone-beam computed tomography (CBCT).

METHODS

Sixty-six individuals (33 DM1, and 33 healthy subjects) age ranging from 20 to 69 were included in the study. Clinical examinations of the patients' TMJ regions and evaluation of dentofacial morphology (maxillary deficiency, open-bite, deep palate and cross-bite) were performed. Dental occlusion was determined based on Angle's classification. CBCT images were evaluated regarding mandibular condyle morphology (convex, angled, flat and round) and osseous changes observed in the condyle (normal, osteophyte, erosion, flattening, sclerosis). DM1-specific morphological and bony TMJ alterations were determined.

RESULTS

DM1 patients showed a high prevalence of morphological and osseous TMJ changes, and statistically significant skeletal alterations. The analysis of CBCT scans indicated the prevalent condylar shape among patients with DM1 was flat, the main osseous abnormality was flattening, there was a tendency towards skeletal Class II and a posterior cross-bite was frequently detected in DM1 patients. There was no statistically significant difference between the genders on the parameters evaluated in both groups.

CONCLUSION

Adult patients with DM1 presented a high frequency of crossbite, tendency to skeletal Class II and morphological osseous alterations of TMJ. The analysis of the morphological condylar alterations in patients with DM1 may be beneficial in the diagnosis of TMJ disorders. This study reveals DM1-specific morphological and osseous TMJ alterations to provide an appropriate orthodontic/orthognathic treatment planning to patients.

Relationship between vertical facial morphology and dental arch measurements in class II malocclusion: a retrospective study

Background

To evaluate the relationship between dental arch measurements and the vertical facial pattern determined in skeletal Class II untreated patients.

Methods

Lateral cephalograms and plaster models were obtained from 124 untreated female adults (average age: 17.6 ± 3.8 years). Class I (CI), Class II Division 1 (CII/1) and Class II Division 2 (CII/2) malocclusions were divided into three subgroups according to their vertical morphology as hypodivergent, normodivergent and hyperdivergent. The multivariate variance analysis (MANOVA) method was used in the comparison of measurement values according to vertical and sagittal morphology. The relationship between both A point-Nasion-B point (ANB) and Frankfurt-mandibular plane (FMA) angles and dental arch measurements was examined by Pearson correlation analysis. The significance level was received as p < 0.05.

Results

While vertical morphology has a statistically significant effect on mandibular arch length, sagittal morphology affects maxillary arch depth. The parameters influenced by both morphologies are maxillary and mandibular arch length, as well as maxillary intermolar width. The mandibular arch length was significantly shorter in hyperdivergent-CII-2 malocclusion (50.5 ± 7.4 mm). Larger values were obtained in both mandibular arch length and maxillary arch depth measurements in CII-1 malocclusion compared to CII-2 malocclusion. The maxillary intermolar width was significantly shorter in hypodivergent-CII-1 malocclusion (46.8 ± 3.4 mm), while it was higher in hypodivergent-CI malocclusion (51.1 ± 3.4 mm). The maxillary arch length was the lowest in hyperdivergent-CI malocclusion (63.1 ± 13.3 mm) and the highest in hypodivergent-CI malocclusion (72.8 ± 7.6 mm). Additionally, a positive but weak correlation was found between ANB and FMA angles.

Conclusion

Dental arch measurements have been found to be affected by both vertical facial morphology and skeletal sagittal relationship. A positive correlation was found between ANB and FMA angles.

Effect of rapid maxillary expansion on masticatory and swallowing functions in children with posterior crossbite

OBJECTIVE

Investigate the influence of posterior crossbite on masticatory and swallowing functions by videofluoroscopy examination and to analyze the effects of Rapid Maxillary Expansion (RME) on the same functions.

METHODS

A prospective longitudinal study was conducted on 32 children, 21 of them with posterior crossbite (10 girls and 11 boys, mean age 9.2 years, study group) and 11 children with no occlusal changes (6 girls and 5 boys, mean age 9.3 years, control group). The children were evaluated by an orthodontist for diagnosis, group characterization and occlusal treatment, by the otorhinolaryngology team for the assessment of respiratory symptoms, and by a speech therapist for videofluoroscopic evaluation of masticatory and swallowing parameters. The children with posterior crossbite were treated orthodontic ally using the Haas disjunctor for approximately six months and re-evaluated 5-months after removal of the appliance. Data were analyzed statistically by the Studentt-test for independent samples for comparison of the crossbite and control groups before and after treatment.

RESULTS

There was no significant difference in oral preparatory and oral transit times, nor in cycles and masticatory frequency, between the pre and post orthodontic treatment groups and the control group.

CONCLUSION

Rapid maxillary expansion did not influence the masticatory and swallowing variables studied by videofluoroscopy. However, the data require caution in interpretation.

A study of transverse maxillomandibular discrepancy and dental compensation in early mixed dentition with skeletal Class III malocclusion without posterior crossbite

OBJECTIVE

To evaluate transverse maxillomandibular discrepancy and dental compensation in first molar areas in 7- to 9-year-old children with skeletal Class III malocclusion without posterior crossbite using cone-beam computed tomography (CBCT).

METHODS

The sample of this retrospective study consisted of 60 children (7 to 9 years old), who were divided into the skeletal Class III malocclusion group (study group, skeletal Class III malocclusion without posterior crossbite, N = 31) and the Class I occlusion group (control group, Class I occlusion with one or two impacted teeth, N = 30). CBCT data were obtained from the database of the Department of Radiology of Hospital of Stomatology, Shandong University. For three-dimensional reconstruction of the head, the dental arch width, basal bone width, and buccolingual inclination angle were measured using MIMICS 21.0 software. Independent-sample t tests were used to compare the two groups.

RESULTS

The mean age of the children was 8.18±0.83years. The width of the maxillary basal bone was significantly smaller in the skeletal Class III malocclusion group (59.75 ± 3.14 mm) than in the Class I occlusion group (62.39 ± 3.01 mm) (P < 0.01). The mandibular basal bone width was significantly larger in the skeletal Class III malocclusion group (60.00 ± 2.56 mm) than in the Class I occlusion group (58.19 ± 2.42 mm) (P < 0.01). The difference in the width of the maxillary and mandibular bases in the skeletal Class III malocclusion group (-0.25 ± 1.73 mm) was significantly different from that in the Class I occlusion group (4.20 ± 1.25 mm) (P < 0.01). However, there was no significant difference in the upper or lower dental arch width between the two groups (P > 0.05). The buccal inclination of the maxillary molars in the skeletal Class III malocclusion group (31.4° ± 8.9°) was significantly higher than that in the Class I occlusion group (17.64° ± 7.3°) (P < 0.01), as was the lingual inclination angle of mandibular molars (45.24° ± 8.3° vs. 37.96° ± 10.18°; P < 0.01).

CONCLUSION

Transverse maxillary and mandibular discrepancies in the posterior area and transverse dental compensation were found in the early mixed dentition of patients with skeletal Class III malocclusion without posterior crossbite. This suggests that even in the absence of posterior crossbite, maxillary expansion can be attempted to correct the maxillomandibular transverse discrepancy.

Correlation between the three-dimensional maxillomandibular complex parameters and pharyngeal airway dimensions in different sagittal and vertical malocclusions

OBJECTIVES

This study aimed to determine the three-dimensional (3D) correlation between maxillomandibular complex parameters and pharyngeal airway dimensions in different sagittal and vertical malocclusions.

METHODS

This retrospective cross-sectional study included the CBCT scans of 368 patients with a mean age of 23.81 ± 3.01 years. The patients were classified into three groups (skeletal Class I, II, and III). Each class group was divided into three subgroups based on vertical growth patterns (hypo-, normo-, and hyperdivergent). The maxillomandibular complex was evaluated in the three planes using 16 skeletal measurements. Naso-, oro-, hypo-, and total pharyngeal airway spaces were assessed in terms of width, volume, surface area, and minimum constricted area (MCA). Two-way ANOVA followed by the Bonferroni post-hoc test were used.

RESULTS

The nasopharyngeal airway space was significantly lowest regarding sagittal and lateral widths in the skeletal Class III patients, the lowest volume and surface area were in hyperdivergent patients, and MCA was the highest in Class II and hypodivergent patients. The oro- and hypopharyngeal sagittal width, volume, surface area, and MCA were the lowest in the hyperdivergent patients, and oropharyngeal lateral width and hypopharyngeal sagittal width were the highest in skeletal Class III. The total pharyngeal volume, surface area, and MCA were the lowest in the hyperdivergent patients, and skeletal Class II patients had the lowest MCA.

CONCLUSIONS

The pharyngeal airway dimensions differ with various sagittal and vertical malocclusions. These differences could apply to diagnosis, treatment planning, and possible changes following orthodontic/orthopedic or surgical treatment.

Upper airway dimensions and the skeletal parameters in orthodontic patients who developed moderate-severe COVID-19 symptoms during the pandemic

BACKGROUND

Large airway dimensions are associated with a rapid decline in the lung function and a higher risk of hospitalization. Therefore, the airway dimensions of healthy subjects who tested positive for coronavirus disease 2019 (COVID-19) may be associated with the severity of COVID-19 symptoms.

OBJECTIVES

The objectives of this study were to measure the upper airway dimensions and the craniofacial skeletal parameters in patients who tested positive for COVID-19, to compare the upper airway dimensions and the craniofacial skeletal parameters between patients who developed no/mild symptoms and those with moderate-severe COVID-19 symptoms, and to assess any association of the skeletal relationships (anteroposterior (AP) and vertical) and the upper airway dimensions with the severity of COVID-19 symptoms in adult subjects.

MATERIAL AND METHODS

A total of 204 orthodontic patients who tested positive for COVID-19 were evaluated. Of these, only 137 met the inclusion criteria. The sample was further subdivided into 2 groups based on the severity of symptoms: cases (moderate-severe symptoms; n = 56); and controls (asymptomatic/ mild symptoms; n = 81). The upper airway dimensions and the skeletal parameters were measured on lateral cephalograms. The nonparametric Mann-Whitney U test was used to detect differences between the cases and the controls. Binary logistic regression analysis was used to evaluate the association between the studied variables and the severity of symptoms.

RESULTS

The cases had a reduced lower face height (LFH) and a reduced perpendicular distance from the hyoid bone to the line connecting the anteroinferior limit of the 3rd cervical vertebra (C3) and the retrognathion point (RGN) (HH1) as compared to the controls. Regression analysis revealed a significant association of LFH (p = 0.013), the vertical airway length (VAL) (p = 0.002) and HH1 (p = 0.021) with the severity of COVID-19 symptoms.

CONCLUSIONS

The types of malocclusion were similar in the cases and the controls. Patients with reduced LFH and VAL, and a superiorly positioned hyoid bone in relation to the mandible developed more severe COVID-19 symptoms.

Exploring the mylohyoid area as a reference for three-dimensional digital mandibular superimposition

INTRODUCTION

the quantification of tooth movements should be obtained at different specific times and compared at different stages for every orthodontic treatment. These movements are generally measured on teleradiographs or casts. The use of Cone Beam Computed tomography (CBCT) for maxillary superimposition is clearly established in the literature, but not well defined for mandibular superimposition. This study aims to explore and evaluate the accuracy of the mylo-hyoid area as a reference for mandibular Digital Dental Cast (DDC) three-dimensional (3D) superimposition.

MATERIALS AND METHODS

the study compared mandibular 3D overlays with profile teleradiographs in 30 patients followed at Nice Saint Roch University Hospital. The molar and incisor coordinates on the 3D superimposition based on the mylo-hyoid area were compared to the ones on the 2D lateral cephalogram. Differences between the two methods of superimposition were assessed using paired t-tests.

RESULTS

No statistically significant difference was observed between the lateral cephalogram-based and mandibular DDC superimposition methods in 3D sagittal and vertical displacements of the lower first molars and central incisors.

CONCLUSION

The study showed the mylo-hyoid area to be an accurate superimposition landmark for the 3D evaluation of mandibular orthodontic tooth displacement. This method is also applicable for patients with conventional orthodontic treatment records. Other studies should be conducted on larger populations, subgroups (malocclusions, therapeutics) and on the use of an intra-oral camera.

Morphological and dimensional variations of the frontal air sinuses in a group of adolescent Caucasians and Chinese in different skeletal malocclusions: a cross-sectional cephalometric study

OBJECTIVE

This study aimed to evaluate the morphological and dimensional variations of the frontal air sinuses in a group of adolescent Caucasians and Chinese with different skeletal malocclusions in both genders.

MATERIALS AND METHODS

This retrospective study included 290 adolescent Caucasians and Chinese patients with 145 each. Each sample included 90 females and 55 males and was categorized based on ANB angle in reference to each population norms into 65 skeletal class I, 50 skeletal class II, and 30 skeletal class III malocclusions. All linear, angular, and surface area measurements of the frontal air sinuses were evaluated using lateral cephalometric radiographs and calculated using Winceph version 8 software. The frontal air sinus parameters were compared between genders and the two ethnic groups using an independent sample t-test. ANOVA with Tukey's post hoc tests were used to compare the frontal air sinus parameters between the three skeletal malocclusions.

RESULT

The frontal air sinus width and surface area were found to be significantly greater in Caucasians when compared with Chinese patients. According to gender, the frontal air sinus length, width, and surface area, as well as the glabella convexity, were greater in males than females, while the frontal air sinus index (length/width) was significantly greater in females than males in both ethnic groups. In both ethnic groups, the frontal air sinus surface area was significantly greater in skeletal class III malocclusion when compared to skeletal class I and class II malocclusions in Caucasians (P = 0.0022) and Chinese (P = 0.0097). There was a weak-to-moderate correlation between the frontal air sinus parameters and the nasio, sella, and glabella positions (R = -0.56 to 0.62).

CONCLUSION

The frontal air sinus dimensions and surface area varied greatly in between ethnic groups, genders, and malocclusion types. The frontal air sinus parameters were correlated with nasion, sella, and glabella positions.

CLINICAL RELEVANCE

These findings could assist orthodontists, ENT specialist, and forensic medical investigators to focus on the size of frontal sinus during treatment planning, the relationship between the size of frontal air sinus and malocclusions, and age determination.

Assessment of Growth Changes in the Width of Dental Arches Caused by Removable Appliances over a Period of 10 Months in Children with Malocclusion

(1) Background: A large number of patients of orthodontic clinics are diagnosed with improper jaw relationships. Intraoral scanners have become an important part of orthodontic practice and provide an opportunity to measure the changes in the width of dental arches. The purpose of the study was to evaluate the impact of removable appliances used over a 10-month period on growth changes in children with narrowed jaw dimensions. (2) Methods: Twenty four patients were included in the study (a study group—patients, treated with removable appliances in the upper dental arch for a minimum of 10 months; a control group—patients with no craniofacial abnormalities and who did not require orthodontic treatment). A panoramic radiograph and digital intraoral scan were taken, followed by palatal width measurements in Ortho-CAD before treatment, and after a period of 10 months of treatment with removable appliances. (3) Results: After a period of 10 months of the treatment, the study group had a statistically significantly greater mean change in the anterior width of the upper dental arch than the control group. (4) Conclusions: The use of removable appliances in children with narrowed maxillary transverse dimension contributes to offsetting growth changes in comparison to children with normal occlusion.

[INDEX OF THE EVALUATION OF MALOCCLUSION EXTENT IN PATIENTS WITH SAGITTAL MALOCCLUSION FORMS]

An integrated approach to diagnosis and preparation of a treatment plan gives us the opportunity to carry out a fully correct treatment. Working with skeletal forms of occlusion anomalies, it is necessary to take into account the severity of maxillofacial changes in order to choose a treatment algorithm. For this purpose, an index has been developed to assess the severity of dental anomalies. To create the index, 120 patients with varying degrees of severity of mesial and distal occlusion were examined. The analysis of dental casts, telerentgenograms of the head in lateral projection and photometric examination were carried out. After analyzing the data, an index was created that reliably proves the severity of maxillofacial anomalies, which is the justification for choosing a method of treatment for patients. The proposed technique is a convenient express method for the diagnosis and planning of treatment of dental anomalies.

Evaluation of horizontal condylar angle in malocclusions with mandibular lateral displacement using cone-beam computed tomography

OBJECTIVES

To evaluate the horizontal condylar angle (HCA) in mandibular lateral displacement (MLD).

MATERIALS AND METHODS

HCA in MLD malocclusions were examined using cone-beam computed tomography data in subjects with MLD and control subjects.

RESULTS

HCA in joints of control patients and contralateral side joints of MLD patients were not significantly different. The mean HCA on the shifted side was larger than on the contralateral side (P < .001) in the different HCA groups. HCA was significantly larger on the shifted side than on the contralateral side in skeletal Class I, Class II, and Class III groups (P < .001).

CONCLUSIONS

(1) There was no statistically significant difference between HCA in control patients and on the contralateral side in MLD patients. (2) HCA was significantly larger on the shifted side than on the contralateral side. (3) HCA on the shifted side and the contralateral side in MLD Class I, Class II, and Class III are significantly different.

Surgical-orthodontic treatment for severe malocclusion in a patient with osteopetrosis and bilateral cleft lip and palate

Orthognathic surgery in patients with craniofacial osteopetrosis, a condition associated with osteoclast dysfunction, is usually avoided because of the risk of osteomyelitis. A 19-year-old woman presented with the chief complaint of severe malocclusion and anterior crossbite. After radiographic evaluation, craniofacial osteopetrosis was diagnosed. Surgical-orthodontic treatment was performed after meticulous history taking and verification of normal bone turnover using bone-metabolism markers for endocrine evaluation. Favorable esthetic and functional outcomes were achieved.

Digital analysis of tooth sizes among individuals with different malocclusions: A study using three-dimensional digital dental models

OBJECTIVE

It is aimed to examine the tooth sizes of digital models of patients with different malocclusions with the help of three-dimensional measurement software.

METHODS

Digital models of 252 patients aged between 13 and 25 years of age were included. According to the Angle classification, three different malocclusion groups were allocated such that there were 84 patients in each group, plaster models of patients scanned with the three-dimensional model browser 3Shape R700 3D Scanner (3Shape A/S Copenhagen, Denmark) and transferred to the digital format. 3Shape Ortho Analyzer (3Shape A/S Copenhagen, Denmark) software was used for making the necessary tooth size measurements.

RESULTS

When the measurements were evaluated, it was determined that significant changes occurred between tooth sizes of individuals with different malocclusions. Generally, higher values were observed in mesiodistal and buccolingual tooth dimensions of class II individuals compared to other groups. There was no difference between the groups in the anterior ratio values, but when the overall ratio values were evaluated among the groups, a statistically significant difference was determined. Class II malocclusion group was found to have a significantly lower overall ratio of occurrence.

CONCLUSION

Individuals with different malocclusions differ in tooth size.

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.

Effects of Invisalign (G5) with virtual bite ramps for skeletal deep overbite malocclusion correction in adults

OBJECTIVES

To investigate the skeletal and dentoalveolar effects of Invisalign's G5 protocol with virtual bite ramps in the treatment of adults with skeletal deep bites.

MATERIALS AND METHODS

This retrospective study was conducted on consecutively treated adults presenting with skeletal deep bites as defined by the Overbite Depth Indicator (ODI). Subjects were divided into 2 groups: Invisalign group (n = 24) treated with the Invisalign G5 protocol and a full fixed appliance (FFA) group (n = 24) treated with edgewise FFAs and matched to the Invisalign group by ODI, sex, type of malocclusion, and non-extraction treatment. Pretreatment (T1) and post-comprehensive treatment (T2) lateral cephalograms were obtained and analyzed.

RESULTS

Both the Invisalign and FFA groups showed significant changes from T1 to T2 in ODI and other skeletal and dentoalveolar measurements. The mean change in ODI was -1.5° (P < .001) for the Invisalign group and -2.0° (P < .001) for the FFA group. The mean decrease in overbite was 1.3 mm (P < .001) and 2.0 mm (P < .001) for the Invisalign and FFA groups, respectively. The mean increase in mandibular plane angle (Sn-GoGn) was 0.65° (P = .003) for the Invisalign group and 1.15° (P < .001) for the FFA group. When the groups were compared with each other, both ODI (P = .03) and overbite (P = .003) were significantly different in addition to other measurements.

CONCLUSIONS

Although FFA treatment had more apparent skeletal changes for deep bite adult patients when compared with Invisalign, both systems were effective in opening deep bites at dentoalveolar and skeletal levels.

[Evaluations of the morphology and position of condyle and fossa of adolescent temporomandibular joint with Class Ⅱsubdivision malocclusions]

PURPOSE

To evaluate the morphology and position of condyle and fossa and joint space of adolescent temporomandibular joint with Class Ⅱ subdivision malocclusion, in order to provide a reference for diagnosis before treatment.

METHODS

The study sample consisted of 30 adolescent patients with Class Ⅱ subdivision malocclusions(9 males, 21 females, mean age 12.5 years) as the experimental group and 30 adolescent patients with Class Ⅰ malocclusions (11 males, 19 females, mean age 12 years) as the control group treated from June 2018 to December 2019 in Suzhou Stomatological Hospital. The long axis of condyle, short axis of condyle, the distance from the outer pole of condyle to sagittal midline, horizontal angle of condyle, Joint space(medial, inner, outer, anterior, superior, posterior), vertical height of condyle, width of joint fossa, depth of joint fossa, angle of posterior wall of the articular tubercle and vertical distance of bilateral condyle to horizontal line were measured on cone-beam CT(CBCT) images and analyzed with Dolphin Imaging 11.95. SPSS 23.0 software package was used for statistical analysis of the data.

RESULTS

In Angle Class Ⅱ subdivision malocclusion patients, there were significant differences in posterior joint space, horizontal angle of condyle, vertical height of condyle, width of joint fossa, depth of joint fossa and angle of posterior wall of the articular tubercle between neutral side and distal side(P<0.01). In Angle Class Ⅰ malocclusion patients, there was no significant difference in joint fossa morphology, condyle morphology and condyle position between right side and left side (P>0.05).

CONCLUSIONS

There may be differences in condyle position, condyle shape and joint fossa shape between patients with Class Ⅱ subdivision malocclusions and Class Ⅰ malocclusion patients. More attention should be paid to the temporomandibular joint in initial clinical examination and clinical orthodontic treatment.

Quantifying changes in incisor inclination before and after orthodontic treatment in class I, II, and III malocclusions

BACKGROUND

This study was designed to determine if orthodontic treatment significantly changes the upper incisor position in Class I, II, and III dental and skeletal malocclusions.

METHODS

Ninety nonextraction-treated patients were included in this retrospective cohort study and divided into three groups: Class I, Class II, and Class III. All cephalometric measurements (ANB, Wits, U1-PP, U1-SN, U1-NA, U1 perpendicular to FH and U1-L1) were taken using the Dolphin Management and Imaging Software, Version 05.05.5070.221436 (United States and Canada).

RESULTS

The posttreatment values of ANB, Wits appraisal, U1-NA mm, U1-FH mm, IMPA and U1-L1° are statistically significant (P < 0.05) among the Class I, II, and III when compared with the normal values. Also ANB° changes after orthodontic treatment in Class I, II, and III were statistically significant with the greater changes in Class III malocclusion.

CONCLUSIONS

There is a significant amount of dento-alveolar compensation for the maxillary incisors not only in patients with Class II and III but also in Class I malocclusions that underwent nonextraction treatments.

Value-addition of lateral cephalometric radiographs in orthodontic diagnosis and treatment planning

OBJECTIVE

To investigate the value-addition of obtaining lateral cephalometric radiographs during the treatment planning phase of orthodontic treatment.

MATERIALS AND METHODS

The records of 100 orthodontic patients were presented to seven scorers during two phases that were 6 weeks apart. In the first phase, scorers completed a seven-question survey with questions regarding treatment planning. They were given various diagnostic records that did not include a lateral cephalometric radiograph. Six weeks later, the same scorers completed the same survey for the same patient cases with the same diagnostic records that additionally included a lateral cephalometric radiograph. Correlation coefficients were used to calculate intrarater agreement and inter-rater agreement within the study.

RESULTS

Cohen's kappa values showed moderate to almost perfect agreement for the majority of survey questions. Intrarater agreement ranged between 0.430 and 1. Cronbach's alpha reliability statistics showed good interrater agreement for all questions in the survey. Agreement ranged from 0.710 to 0.913 across the survey questions. Diagnosing Angle classification of occlusion had the highest level of agreement and differentiating between skeletal and dental malocclusion had the lowest level of agreement.

CONCLUSIONS

The lateral cephalometric radiograph is not a necessary diagnostic tool for most cases in orthodontic diagnosis and treatment planning. Weighing the usefulness of a lateral cephalometric on a case-by-case basis should be recommended to align with the principle of ALARA (as low as reasonably achievable), especially in a primarily pediatric population.

Condyle modeling stability, craniofacial asymmetry and ACTN3 genotypes: Contribution to TMD prevalence in a cohort of dentofacial deformities

Craniofacial asymmetry, mandibular condylar modeling and temporomandibular joint disorders are common comorbidities of skeletally disproportionate malocclusions, but etiology of occurrence together is poorly understood. We compared asymmetry, condyle modeling stability and temporomandibular health in a cohort of 128 patients having orthodontics and orthognathic surgery to correct dentofacial deformity malocclusions. We also compared ACTN3 and ENPP1 genotypes for association to clinical conditions. Pre-surgical posterior-anterior cephalometric and panometric radiographic analyses; jaw pain and function questionnaire and clinical examination of TMD; and SNP-genotype analysis from saliva samples were compared to assess interrelationships. Almost half had asymmetries in need of surgical correction, which could be subdivided into four distinct morphological patterns. Asymmetric condyle modeling between sides was significantly greater in craniofacial asymmetry, but most commonly had an unanticipated pattern. Often, longer or larger condyles occurred on the shorter mandibular ramus side. Subjects with longer ramus but dimensionally smaller condyles were more likely to have self-reported TMD symptoms (p = 0.023) and significantly greater clinical diagnosis of TMD (p = 0 .000001), with masticatory myalgia most prominent. Genotyping found two significant genotype associations for ACTN3 rs1671064 (Q523R missense) p = 0.02; rs678397 (intronic SNP) p = 0.04 and one significant allele association rs1815739 (R577X nonsense) p = 0.00. Skeletal asymmetry, unusual condyle modeling and TMD are common and interrelated components of many dentofacial deformities. Imbalanced musculoskeletal functional adaptations and genetic or epigenetic influences contribute to the etiology, and require further investigation.

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.

[Morphometric features of the temporomandibular joints according to MR studies in adult patients with dislocations of the articular discs and malocclusion of the anterior teeth]

THE PURPOSE OF THE STUDY

To study the morphological features of the temporomandibular joints (TMJ) according to MR studies in adult patients with impaired occlusion of the anterior teeth and dislocations of the articular discs.

MATERIAL AND METHODS

The clinical study included 51 patients aged 17 to 47 years (mean age 28.12±7.44 years): 14 men and 37 women. On the basis of a clinical examination and MR findings of TMJ in 30 patients (mean age 26.77±7.48 years; 8 men and 22 women), TMJ dysfunction in the form of dislocation of articular discs was confirmed. In 21 patients (mean age 30.05±7.12; 15 women, 6 men), TMJ dysfunction without dislocation of articular discs was confirmed. The patients measured the value of vertical incisive overlap (overbite). Analyzing data from MR studies of TMJ, we measured the following values of both TMJs of each patient: the depth and transverse size of the articular fossa, the height of the articular tubercles and the transverse size of the head of the lower jaw.

RESULTS

The examined patients with joint dislocations of TMJ had morphological features: statistically significantly deeper and narrower articular fossae, higher articular tubercles and narrower in the sagittal plane of the head of the lower jaw compared to TMJ of patients with dysfunction without dislocation of articular disks. In addition, in patients with articular disk dislocations, a statistically significant (<0.05) increase in vertical incisal overlap was noted.

CONCLUSION

.TMJ in patients with dysfunction in the form of dislocations of articular discs had morphological features that allowed them to be classified as type 3.

Further opportunities for digital imaging in dental epidemiology

Dental epidemiological research permits accurate tracking of the prevalence and distribution of oral disease across population groups, enabling planning and evaluation of public health interventions and healthcare service provision. This first section of this paper aimed to review traditional assessment methods in dental epidemiology and to consider the methodological and logistical benefits provided by digital imaging, both generally and specifically in relation to an established dual-camera system. The remainder of this paper describes the results of a semi-structured examination of an image archive from previous research utilising a dual-camera system, exploring whether the diagnostic yield of the images might be increased. Common oral conditions are presented alongside suggestions of the diagnostically useful data displayed in example images. Possible scoring mechanisms are discussed with consideration of the limitations that might be encountered for each condition. The retrospective examination suggests further data is obtainable from images acquired using the dual-camera system, however, consideration should be given to how best to validate this clinically. Additionally, other imaging modalities are discussed whilst taking into account the potential limitations of the dual-camera system.

Three-dimensional imaging control of osteogenesis induced by minimally invasive corticotomies: Perspectives from a case report

Corticotomies are now an integral part of the orthodontist's therapeutic arsenal in adult orthodontics. In recent years, the number of publications about different surgical techniques has increased significantly. This shows that practitioners and patients have a common interest. It is now accepted that corticotomies cause a regional acceleratory phenomenon, which enables a faster dental movement, a reduction in treatment time, as well as a reduction in the risk of root resorption. The perspective of osteogenesis induced by corticotomies has already been mentioned in literature. It could provide a real advantage in maintaining the periodontium, reducing the risk of fenestration or dehiscence and the stability of long-term treatment by increasing the dental bone envelope. Through a clinical case, treated by mini- invasive surgical technique (as described in the previous article), we highlight the potential for osteogenesis induced by alveolar corticotomies and the utility of this procedure in adults.

Comparative study between different groups of esthetic component of the Index of Orthodontic Treatment Need and eye tracking

INTRODUCTION

The objective of this study was to determine how different people perceive distinct malocclusions with the use of eye tracking and to compare the results with scores from the subjective visual attractiveness scale (VAS) following 3 grades obtained from the Aesthetic Component of the Index of Orthodontic Treatment Need (AC-IOTN) scale.

METHODS

Ninety participants were equally distributed into 3 groups-dentists, orthodontists, and laypeople-and underwent 1 eye-tracking session. After being positioned and calibrated, they were shown 3 dental images. The images reflected the AC-IOTN grades of 1 (close to ideal), 5 (borderline need for treatment), and 8 (definite need for treatment). During the viewing, eye-tracker data were collected for fixation points, duration, and attractiveness (according to the VAS) for each image. The variables were statistically tested with the use of 2-way analysis of variance and complete factorial model (between groups, grades, and for the interactions between them).

RESULTS

Grade 1 received the highest subjective score independently from the participant group. This was in contrast to grades 5 and 8, which received similar scores, although the means of fixation points and duration were not significantly different among the grades (P > 0.05). The scores obtained from the dentist group were significantly higher than those from the other groups when the comparison was independent from the grade. In terms of fixation points, there were differences between dentists and orthodontists and between orthodontists and laypeople. The fixation point mean was higher for orthodontists than for dentists and was similar to that for laypeople.

CONCLUSIONS

Orthodontists were able to closely analyze the occlusal problems presenting with more severe malocclusions, and the specialists noticed more fixation points. Duration times, however, were not significantly different, because the orthodontists had greater interest, even in situations of unfavorable esthetics.

Postoperative CT of the Mandible Following Trauma: Review of Normal Appearances and Common Complications

RATIONALE AND OBJECTIVES

Surgeons aim to restore occlusion and jaw function to baseline status for patients with mandibular fractures using either closed treatment or reduction and fixation.

MATERIALS AND METHODS

Occlusion is defined as the relationship between the maxillary and mandibular teeth as they approach each other.

RESULTS

Radiologists should be familiar with the goals of repair to help identify which treatment is adequate as well as to diagnose potential complications. Some of the more common complications encountered are infection, nonunion or malunion, and malocclusion.

CONCLUSION

We provide a comprehensive review of both the desired and untoward CT findings after surgical repair of traumatic mandibular injuries.

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.

Effects of rapid maxillary expansion on upper airway volume: A three-dimensional cone-beam computed tomography study

OBJECTIVE

To compare changes in pharyngeal airway volume and minimal cross-sectional area (MCA) between patients undergoing rapid maxillary expansion (RME) and a matched control group and to identify markers for predicting airway changes using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Pre- and posttreatment CBCT scans were selected of children who had RME (14 girls and 12 boys; mean age, 12.4 years) along with scans of a control group (matched for chronological age, skeletal age, gender, mandibular inclination) who underwent orthodontic treatment for minor malocclusions without RME. Changes in airway volume and MCA were evaluated using a standardized, previously validated method and analyzed by a mixed-effects linear regression model.

RESULTS

Upper airway volume and MCA increased significantly over time for both the RME and matched control groups (P < .01 and P = .05, respectively). Although the RME group showed a greater increase when compared with the matched controls, this difference was not statistically significant. A reduced skeletal age before treatment was a significant marker for a positive effect on the upper airway volume and MCA changes (P < .01).

CONCLUSIONS

Tooth-borne RME is not associated with a significant change in upper airway volume or MCA in children when compared with controls. The younger the skeletal age before treatment, the more positive the effect on the upper airway changes. The results may prove valuable, especially in RME of young children.

Association Between Variations In Sella Turcica Dimensions And Morphology And Skeletal Malocclusions

BACKGROUND

The growth of sella turcica is completed early in life, therefore it can be used as a stable landmark for the prediction of future skeletal malocclusions. This early diagnosis may help in planning less complicated treatment modalities. Therefore, this study aimed to evaluate the relationship between sella turcica dimensions and morphology with various skeletal patterns.

METHODS

A cross sectional study was conducted using the pre-treatment cephalograms of 180 subjects aged 13-19 years. The subjects were divided into two groups based on skeletal patterns. The dimensions of sella turcica and skeletal patterns were digitally measured using View Pro-X software. One-way ANOVA was applied to compare sella turcica dimensions among skeletal patterns. Sella dimensions and vertical growth patterns were compared using Post-hoc Tukey test. Chi-square test was applied to compare sella morphology among malocclusion groups. Results were taken as statistically significant at p-value of ≤0.05.

RESULTS

Sella dimensions showed insignificant differences among sagittal groups whereas, significant differences were found for sella length (p≤0.02) and depth (p≤0.03) among the vertical groups. Multiple comparisons showed significant differences between sella length (p≤0.03) and diameter (p≤0.04) between normodivergent versus hyperdivergent groups. Moreover, significant differences were found in the sella turcica morphology among sagittal malocclusion (p≤0.03).

CONCLUSIONS

Increased dimensions of sella turcica were associated with hyperdivergent growth pattern. Bridging of the sella turcica was found to be prevalent in class III malocclusion.

Facial asymmetry: virtual planning to optimize treatment predictability and aesthetic results

Facial asymmetry is a condition that compromises function and social interactions and, consequently, the quality of life. Orthodontic-surgical treatment may be indicated to achieve a stable occlusion and significant improvement in facial aesthetics. The virtual planning of the maxillary, mandibular and chin movements can be done prior to surgery. These movements can be successfully performed with the use of prototyped guides obtained from virtual planning. The aim of this article is to show the state of the art of treatments of facial asymmetries, and emphasize how important is the multi-disciplinary approach to achieve predictable aesthetic and functionally stable results in a patient with facial asymmetry and chin protrusion.

A Study on the Evaluation of Pharyngeal Size in Different Skeletal Patterns: A Radiographic Study

AIM

The aim of this study was to evaluate the upper and lower pharyngeal airway dimensions were affected by different skeletal malocclusions.

MATERIALS AND METHODS

Lateral cephalograms of 120 subjects were used to measure the pharyngeal airway and were divided into three groups (each group included 40 subjects) according to ANB angle: Class I (ANB angle 2° ≤ ANB ≤ 4°), Class II (ANB angle(ANB ≥ 6°), and Class III (ANB angle ≤ 0°). Various linear cephalometric airway measurements (14 measurements) were used to evaluate pharyngeal airway at various levels. Statistical analyses were performed Using the ANOVA and student t-test.

RESULTS

PNS-ppwl (p < 0.001) and McNamara' lower pharynx dimension (p < 0.05) showed a statistically significant difference between the groups. Two out of 14 variables ie Ba-PNS and t-ppw showed a statistically significant difference between male and female. In both measurements, the difference is significant only in the Class II group with the level of significance being (p < 0.001) in Ba-PNS measurement, and (p < 0.05) in t-ppw measurement. In both measurements males have statistically significant higher mean values than the females.

CONCLUSION

The dimensions of pharyngeal structures were not affected by the changes of the ANB angle. The sagittal skeletal pattern does not seem to influence the variations in the upper airway dimension. There was no significant difference in the dimensions of pharyngeal structures among males and females.

CLINICAL SIGNIFICANCE

The upper and lower pharyngeal airway dimensions are affected by different skeletal malocclusions can significantly aid in Orthodontic treatment planning.

Surgical Orthodontic Approach for the Retreatment of a High Angle Skeletal Class III Patient: Case Report

The aim of this article is to describe the retreatment ofa high angle skeletal Class II patient with a moderate anterior crossbite who had previous mandibular orthognathic surgery. A traditional orthodontics/orthognathic surgery approach was selected for treatment. Facial balance was improved, and the final occlusal relationships were good.

Simple Elastomeric Chain Ligation Method for Palatally / Linguall Placed Lateral or Canines

Palataly-displaced incisors or canines are typically extruded. The crossbite must be corrected without occlusal interference during alignment. Occlusal interference associated with such extrusion can prevent proper tooth positioning, and therefore, the temporary use of a bite plate may be necessary' However, unnecessary bite raising may occur when a bite plate is used in adults, and the patient's discomfort due to such an appliance cannot be ignored. Most of the time, conventional ligation fails and also ends with debonding of the bracket. A slin shot use ofan elastic chain forfaster correction of instanding tooth is suggested.

A New Approach to Maxillary Protrusion with an Unstable Mandibular Position Accompanied with Unidentified Complaints: Case Report

This case report describes the importance of combining morphological and functional examination with psychological examination in the establishment ofstable mandibular position in the treatment of maxillary protrusion with unstable mandibular position accompanied by unidentified complaints, which ensures safe orthodontic treatment.

A new method for the treatment of unilateral posterior cross-bite: a three-dimensional finite element stress analysis study

BACKGROUND

Stress relieving corticoto mies during the treatment of maxillary expansion are needed in adult patients.

METHODS

Three-dimensional (3D) finite element model was prepared, and finite element analysis was processed to evaluate the stress distributions within the skull and maxillary teeth during surgically assisted rapid maxillary expansion (SARME) treatment.

RESULTS

Expansion forces generated more stress on the corticotomy-applied part of the maxilla. The stress levels decreased dramatically above the corticotomy line.

CONCLUSION

Asymmetric transveral maxillary expansion might be achieved from a symmetric force generating screw during SARME treatment. SARME osteotomies may concentrate the stress in the expanding maxilla and reduce the pain in other parts of the cranium.

Evaluation of miniscrew-supported rapid maxillary expansion in adolescents: A prospective randomized clinical trial

OBJECTIVES:

To evaluate and compare the dental and skeletal changes with conventional and miniscrew-supported maxillary expansion appliances in adolescents.

MATERIALS AND METHODS:

Forty patients were divided into two groups, with one group receiving a tooth-borne expander and the other group receiving an expander supported by four miniscrews (bone-borne). Multiplanar coronal and axial slices obtained from cone-beam computed tomography images were used to measure the changes in transverse skeletal widths, buccal bone thickness, tooth inclination, and root length. Paired t-tests and independent-sample t-tests were used to compare the two expansion methods.

RESULTS:

Bone-borne expansion increased the maxillary suture opening more than 2.5 times than tooth-borne expansion both anteriorly and posteriorly. Between the maxillary first premolars, sutural expansion accounted for 28% and 70% of the total transverse width increase in the tooth-borne and bone-borne expander groups, respectively. Similarly, 26% and 68% of the total expansion was of skeletal nature in the tooth-borne and bone-borne expander groups between the maxillary first molars. The pattern of expansion was variable, with most of the patients in both groups demonstrating a triangular-shaped sutural opening that was wider anteriorly. Subjects in the conventional group experienced significantly more buccal bone reduction and greater buccal inclination of the teeth. No significant differences were observed for root length measurements between the two groups.

CONCLUSION:

Use of bone-borne expansion in the adolescent population increased the extent of skeletal changes in the range of 1.5 to 2.8 times that of tooth-borne expansion and did not result in any dental side effects.

The influence of orthodontic non-extraction treatment on the change in the inclination and position of incisors in the Europoid race

AIM

To detect post-treatment change in the inclination and position of incisors in cases treated with orthodontic non- extraction therapy.

MATERIALS AND METHODS

The group consisted of 102 patients without extractions in lower and upper dental arch during orthodontic treatment. Cephalogram examination evaluated the position of the lower incisor to point A by Downs-pogonion line (-1 to APo) and inclination of the lower incisor to mandibular line (-1 to ML), position of the upper incisor to nasion-pogonion line (+1 to NPo), inclination of the upper incisor to nasion-sella line (+1 to NS) and the size of the inter-incisival angle between upper and central lower incisor (-1 to +1).

RESULTS

In 58 % of cases, the difference in post-treatment and pre-treatment changes in the position of the (-1 to Apo) was within ± 2 mm, which we considered stable. Statistically significantly higher values after treatment were in unstable rather than in stable cases with values (-1 to Apo), (-1 to ML), (+1 to NPo). Statistically significantly lower value after the treatment was measured in unstable cases rather than in stable cases with a value (-1 to +1). There was no statistically significantly different value in stable and unstable cases after treatment in values (+1 to NS).

CONCLUSION

The number of stable post-treatment cases was only 16 % higher than the number of unstable cases. With the increasing value (-1 to Apo), the value (-1 to ML) and (+1 to NPo) increased, the value (+1 to -1) decreased. The value (-1 to NS) not after treatment was not statistically significantly different in stable and unstable cases (Tab. 6, Fig. 4, Ref. 27).

Comparison of single versus two non-compression miniplates in the management of unfavourable angle fracture of the mandible: a prospective randomized clinical study

PURPOSE

The purpose of this study was to compare the efficacy of single versus two non-compression miniplates in the management of unfavourable angle fracture of mandible.

MATERIALS AND METHODS

A total of 28 patients who required open reduction of mandibular angle fracture were included in the study. The patients were randomly divided into two groups. Group I comprised of patients treated with two miniplates and those in group II were treated with single non-compression miniplate. The parameters of assessment were malocclusion, surgical site infection, need for implant removal, duration of surgery, inter-incisal mouth opening and cost of implants used, in both the groups. Statistical analysis was carried out to compare all the parameters.

RESULTS

Out of 14 patients in group II, inadequate reduction was noticed in three patients, whereas screw loosening had occurred in two cases. Screw loosening was always associated with chronic infection. In these cases, hardware removal was deemed necessary. Plate bending was observed in two cases resulting in malocclusion and difficulty in eating. Non-union of fracture occurred in one patient treated in group II. In group I, no plate bending, screw loosening, surgical site infection, non-union or malocclusion was observed. No patient had to undergo implant removal in group I.

CONCLUSION

In the management of unfavourable mandibular angle fracture, two miniplates must be preferred over the use of single miniplate as using two miniplates results in better results with minimal complications.