Correction of Class?II, Division 2 malocclusions using a completely customized lingual appliance and the Herbst device

Aim

The purpose of the present study was to examine the efficiency of correcting a Class?II, Division?2 malocclusion using a completely customized lingual appliance.

Materials and methods

In 18 consecutively completed, Class?II, Division?2 malocclusion patients, the correction of the upper incisor inclination, deep and distal bite were assessed by means of plaster casts, digital lateral cephalograms, and intraoral photographs taken at the time of debond. Furthermore, two independent calibrated examiners determined the weighted Peer Assessment Rating index (PAR Index) of the initial and end models.

Results

All Class?II, Division?2 patients were treated successfully: upper incisor inclination using the palatal plane as a reference improved on average from 95.4° to 111.2°. The deep bite was reduced on average from 3.6?mm to 1.7?mm. Neutral occlusion was achieved in all patients who had undergone correction of an initially pronounced distal occlusion (4.5?mm on average). An 86.2% marked improvement was observed in the weighted PAR index score from an average of 24.7 at the beginning of treatment to 2.9 at the end of treatment, with no patient classified as ??worse or no different.??

Conclusion

Class?II, Division?2 malocclusions can be efficiently and reliably treated by a combination of a completely customized lingual appliance and the Herbst device.     

Study on equilibrium and stabilization of mandibular intercuspal position in Class Ⅱ Division Ⅰ malocclusions

Objective To analyze the dynamic occlusal contacts in ClassⅡDivision Ⅰ Malocclusions during mandibular movement from muscular contact position(MCP)to intercuspal position(ICP),and to investigate the equilibrium and stabilization of ICP as well as dental morphological factors related to the MCP-ICP discrepancy.Methods 60 subjects with Class Ⅱ Division Ⅰ Malocclusions with no history of orthodontic treatment were employed.T-scan Ⅱ system was used to record and analyze the dynamic occlusal contacts during mandibular movement from MCP to ICP.Dental morphological data were determined by measuring plaster mold.SPSS 12.0 was used for statistics.Resuits There was no significant difference among three repeated measurements of the vertical distance from the center of occlusive force to the midline,D-value of occlusive force between the right and the left side,the numbers of occlusal contacts in the intercuspal position.Significant difference of the posterior arch-widths was observed between the group with and without ICP-MCP discrepancy.There was no significant difference between the groups in the depth fluency of curve of spee,and index of molar relationship.Conclusions Class Ⅱ Division Ⅰ Malocclusions is characterized by stability with intercupided occlusion.ICP-MCP discrepancy maybe associate with abnormal posterior arch-width,and is independent of the vertical and sagittal discrepancy.     

Skeletally anchored forsus fatigue resistant device for correction of Class II malocclusions—A systematic review and meta-analysis

The use of skeletal anchorage with fixed functional appliances (FFA) has been proposed by various authors to produce skeletal changes and reduce lower incisor proclination. To compare the skeletal and dentoalveolar effects of Forsus Fatigue Resistant Device (FFRD) with or without skeletal anchorage (miniplates and mini-implants). The electronic database PubMed, Cochrane Library, Medline, Embase and Google Scholar along with a manual search of orthodontic journals till the year 2019. Only randomized control trials (RCTs) were included in the systematic review. One controlled clinical trial (CCT) which involved FFRD was included in the review since it was a continuation of an RCT which was expanded to a CCT. Skeletal and dentoalveolar outcome data were extracted to collect study characteristics. After evaluating risk of bias, the standardized mean differences (SMDs) and 95% confidence intervals (CIs) were calculated. Three RCTs and one prospective CCT were evaluated. The analysis included data from 116 Class II subjects [(58) treated with FFA along with skeletal anchorage and (58) treated with FFA]. There were no significant difference between the two groups with respect to mandibular length changes (P value = .10) and SNB angle changes (P value = .22). With respect to lower incisor inclination however, there was a significant difference between the two groups (P value = .005) signifying better results with respect to skeletal anchorage. The studies reviewed provide insufficient evidence to form a conclusion regarding the effects of the use of skeletal anchorage with FFRD. The available weak evidence suggests that the use of skeletal anchorage with FFRD has no superior skeletal effects but is able to reduce proclination of the lower incisors. Control of lower incisor proclination remains the most significant advantage of skeletal reinforcement, and miniplate-anchored FFRD showed more promising results in preventing lower incisor proclination than miniscrew-anchored FFRD.     

Long term clinical performance of ‘open sandwich’ and ‘total-etch’ Class II composite resin restorations showing proximal deterioration of glass-ionomer cement

ObjectivesTo compare clinical performance of resin composite posterior Class-II restorations placed with etch-and-rinse adhesive or open sandwich technique using glass-ionomer cement.MethodsData on Class II restorations placed by one dentist between 1990 and 2016 were collected from patient files, including caries risk, tooth related variables, applied materials and dates of last check-up visit and restoration placement.Open sandwich restorations were placed before 2001, while after 2001, a total-etch technique using etch-and-rinse 3-step adhesive was used when placing a Class II composite restoration. For statistical analysis, Kaplan-Meier statistics and a multilevel Cox-Regression was conducted (p < 0.05). Annual Failures Rates (AFR) were calculated.Results675 Class II restorations were placed in 91 patients, 491 total-etch restorations (observation time 2–18 y), and 184 open sandwich restorations (observation time 19–29 y) showing AFRs at 15 years as 2.9 % for total-etch and 9.7 % for open sandwich restorations.Secondary caries as failure was equally distributed among the 2 groups and 27 % of the failures in the open sandwich group were due to proximal deterioration of glass-ionomer cement. The Cox-regression showed a significant higher risk for failure for the open sandwich technique compared to total-etch class-II composite restorations (HR = 2.9; p < 0.001).SignificanceApplication of glass-ionomer cement using the open sandwich technique cannot be recommended for class-II restorations as being more complex and showing poorer clinical performance.     

A Cephalometric Study on the Relationship Between the Occlusal Plane, Ala-Tragus and Camper’s Lines in Subjects with Angle’s Class I, Class II and Class III Occlusion

Considering the importance of the occlusal plane orientation in complete denture prostheses, a study was conducted on the relationship between this plane with ala-tragus and Camper’s lines in soft tissue among individuals with class I, class II and class III occlusion. The aim of the present study was to define the best soft tissue index by which the location and inclination of the occlusal plane in complete dentures could be established. A total of 60 subjects were selected for the study. Lateral cephalograms of these subjects were obtained. Tracings and analysis was done to confirm to the skeletal relationship of subjects to be class I (normal), class II (prognathic maxilla) and class III (retrognathic maxilla). 20 Subjects of each group were screened for further analysis. Radiopaque markers were attached to the intended points on soft tissue and then standard lateral cephalograms were obtained from each subject. The angles between the following lines were measured: Occlusal line, Camper’s line (ala-porion), AT1 (ala-superior border of tragus), AT2 (ala-mid-tragus) and AT3 (ala-inferior border of tragus). The mean values and standard deviations were calculated for all the groups. The mean values calculated were subjected to repeated ANOVA test and significance was evaluated. Comparison of the results by the ANOVA test exhibited a significant difference. In class I subjects, it was evaluated that in 75 % individuals, the posterior reference point was found to be the mid-tragus; of class II subjects, in 60 % individuals, the posterior reference point was found to be the mid-tragus; and of class III subjects, in 75 % individuals, the posterior reference point was found to be the inferior border of tragus.     

Molar bands for ‘precision’ bonding of lingual retainers

Abstract

Bonded retainers have been used principally for long-term retention of treated cases. Various methods of bonding lingual retainers have been described in the literature over the past two decades. However, accurate and passive placement of retainers has always been a matter of concern. This report presents a simple and economical method for accurate and passive placement of bonded lingual retainers that enables the operator to save considerable chair time.     

Peer assessment rating index analysis of different extraction modality in skeletal Class Ⅲ malocclusions

Objective To assess the effect of different extraction modalities on treatment outcomes in skeletal Class Ⅲ malocclusions. Methods One hundred and nine skeletal Class Ⅲ patients (50 males and 59 females) with a mean age of 16.11±4.47 years were collected. The subjects were divided into four groups according to the extraction modality. They were T0 (non-extraction group), T1 (premolar extraction group), T2 (molar extraction group) and T3 (lower incisor extraction group). The PAR (peer assessment rating) index of each of the pre- and post-treatment cast was assessed. The differences of pre- and post-treatment weighed PAR score, reduction in weighed PAR score, percentage reduction in weighed PAR score and the degree of improvement between the four groups were compared. Results (1) Significant differences (P＜0.001＝ of the reduction in weighed PAR score and percentage reduction in weighed PAR score existed between different extraction modality groups. And the order of reduction from high to low was premolar extraction group, molar extraction group, non-extraction group and lower incisor extraction group.(2) There were no "Worse-no different" cases among the four groups. 97 cases were greatly improved and accounted for 89%. There were 12 cases (11%) in improved category. (3) Greatest improvement was found in premolar extraction group and the least improvement was found in lower incisor extraction group. Conclusions Treatment outcomes of the four extraction modalities in skeletal Class Ⅲ were all satisfied. Cautions should be paid in lower incisor extraction.     

Peer assessment rating index analysis of different extraction modality in skeletal Class Ⅲ malocclusions

Objective To assess the effect of different extraction modalities on treatment outcomes in skeletal Class Ⅲ malocclusions. Methods One hundred and nine skeletal Class Ⅲ patients (50 males and 59 females) with a mean age of 16.11±4.47 years were collected. The subjects were divided into four groups according to the extraction modality. They were T0 (non-extraction group), T1 (premolar extraction group), T2 (molar extraction group) and T3 (lower incisor extraction group). The PAR (peer assessment rating) index of each of the pre- and post-treatment cast was assessed. The differences of pre- and post-treatment weighed PAR score, reduction in weighed PAR score, percentage reduction in weighed PAR score and the degree of improvement between the four groups were compared. Results (1) Significant differences (P＜0.001＝ of the reduction in weighed PAR score and percentage reduction in weighed PAR score existed between different extraction modality groups. And the order of reduction from high to low was premolar extraction group, molar extraction group, non-extraction group and lower incisor extraction group.(2) There were no "Worse-no different" cases among the four groups. 97 cases were greatly improved and accounted for 89%. There were 12 cases (11%) in improved category. (3) Greatest improvement was found in premolar extraction group and the least improvement was found in lower incisor extraction group. Conclusions Treatment outcomes of the four extraction modalities in skeletal Class Ⅲ were all satisfied. Cautions should be paid in lower incisor extraction.     

Electromyographic analysis of anterior temporalis and superficial masseter muscles in mandibular angle fractures—a pilot study

Introduction

Fracture of the mandible occurs more frequently and the surgical anatomy of the mandible and adjacent structures is extremely important in understanding the pattern of fracture, the displacement of fractured fragments, and factors necessary for uncomplicated healing. In the field of dentistry, surface electromyography, electrokinesiography, and more recently, TMJ sound analysis have been particularly important developments. Previous electromyographic studies involving anterior temporalis and superficial masseter have been conducted in mandibular condylar fractures and in orthognathic and cosmetic procedures of the jaws.

Materials and methods

This experimental study was undertaken to measure the electrical activity of the anterior temporalis and superficial masseter muscles in mandibular angle fracture cases (n?=?6) and the changes in the electrical activity over a period of 6?months.

Results

The study shows that muscle activity increases significantly over a period of time but never matches the muscle activity of the normal subjects of same sex and age in a follow-up of 6?months post-trauma.

Discussion

Electrodiagnostic testing is a potentially valuable tool for the management of patients who have suffered craniomaxillofacial trauma. Electromyography is being employed in clinical practice, and allows the inclusion of quantitative data on the qualitative aspects of a diagnosis. These data are often of significant importance in the correct management of therapy and patient follow-up, particularly if the subject is at risk of developing a different and/or more serious disease.     

Outcomes of alveolar segmental ‘sandwich’ osteotomy with interpositional particulate allograft for severe vertical defects in the anterior maxilla and mandible

The purpose of this study was to report the outcomes of interpositional osteotomy with mineralized allograft in the treatment of alveolar vertical defects in preparation for implant placement. Thirteen defects (11 maxillary and two mandibular) were treated with osteotomy segments ranging in length from two to five missing teeth. The segments were positioned 5–7 mm coronally, with the gap space filled with allograft and then fixated with titanium hardware. Vertical bone augmentation was analyzed by superimposing pre- and post-surgical cone beam computed tomography images and stratified based on the length and number of missing teeth in each edentulous segment. The mean vertical bone gain was 3.7 ± 1.6 mm in the area of greatest vertical defect and the mean length of the transport segment was 20.5 ± 8.1 mm. These segments represented two-, three-, four-, or five-tooth edentulous sites; the mean vertical bone gain for these segments was 1.7 ± 0.5 mm, 3.8 ± 1.0 mm, 4.6 ± 0.9 mm, and 6.7 ± 0.0 mm, respectively. Stability of vertical height gain was found to be directly proportional to the span length of the osteotomy segment, with the largest five-tooth segment achieving the greatest gain. Vertical bone gain in two-tooth segments was minimal, indicating a moderate amount of resorption.     

Effects of fixed appliances in correcting Angle Class?II on the depth of the posterior airway space

Objective

The objective of this retrospective study based on the metric evaluation of lateral cephalograms was to investigate the extent to which treatment with two different fixed appliances for the correction of Angle Class?II influenced the morphology of the extrathoracic airway space (the posterior airway space, PAS).

Patients and methods

A total of 43?patients with Angle Class?II malocclusion were classified into two groups according to the appliance used for treatment: the functional mandibular advancer (FMA; n?=?18) or the Herbst appliance (n?=?25). Lateral cephalograms were taken of each patient at the start of functional jaw orthopedic treatment (time point T1) and at its completion (time point T2). Specific distances and angles were measured and analyzed in a cephalometric analysis.

Results

We observed major differences among the 43?patients in the depth of the posterior airway space during treatment with fixed appliances for Angle Class?II correction. Regression analysis revealed that changes in sagittal and vertical positions had different effects on the depth of specific PAS sections: increases in anterior facial height are associated proportionately with increases in PAS width, particularly in the upper region. On the other hand, increases in posterior facial height and in the mandible??s forward displacement correlated inversely to the decreases in depth, particularly in the central and lower PAS regions. The two treatment appliances (FMA, Herbst appliance) had the same effects on extrathoracic airway depth.

Conclusions

Analyses of lateral cephalograms indicate that Angle Class?II treatment with fixed appliances does not prevent sleep apnea in patients at risk. Nevertheless, this study does not permit absolutely reliable conclusions about the dimensions of the pharyngeal airway space. As the lateral cephalogram provides good images of structures in the midsagittal plane but is incapable of imaging the transverse dimension, there is an automatic lack of information concerning the precise width and volume of the extrathoracic airway space.     

Class II treatment effects of the Fränkel appliance

The objective of this work was to evaluate prospectively and cephalometrically the effects of the function regulator (FR) on dentoskeletal components during a treatment period of 28 months. The subjects consisted of 18 patients presenting with a Class II division 1 malocclusion, with a mean chronological age of 9 years 3 months at the beginning of treatment. The treated group was compared with a compatible control group of 23 untreated subjects observed during the same time period. Lateral cephalometric head films were obtained for the treated group at the beginning and after 28 months of treatment. The subjects in the control group belonged to a serial growth study sample from the Orthodontic Department at Bauru Dental School, University of S?o Paulo, for whom cephalometric head films were obtained annually from 4 to 18 years of age. The data for the control group were calculated from these head films. A student's t-test was used to compare the changes observed in the treated group with those in the control group. Differences were considered statistically significant at P < 0.05. The results demonstrated that the FR produced a statistically significant increase in the mandibular body, in the proportional size of the mandible to the maxilla and in lower anterior face height (LAFH); induced greater vertical development of the mandibular molars; reduced the overjet and overbite and produced an improvement in the molar relationship. Retrusion and palatal tipping of the maxillary incisors was also observed. However, the appliance did not produce any changes in maxillary development, in the growth pattern, or any improvement in the basal relationship. Therefore it was concluded that the effects of the FR in the correction of Class II malocclusions are primarily dento-alveolar, with a smaller participation of skeletal changes.     

‘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.     

Efficacy of the split-thickness labial flap method for soft tissue management in anterior ridge horizontal augmentation procedures: A clinical prospective study in the anterior maxilla

Objective

To introduce a novel method of split-thickness labial flap in maxillary anterior ridge horizontal augmentation and to evaluate its efficacy and morbidity.

Combined fixed–functional treatment of skeletal class II malocclusions with the EVAA appliance

Objectives

The aim of this study was to compare the skeletal and dental effects of the EVAA appliance with those of an activator appliance in growing children with skeletal Class II anomalies.

Materials and methods

A total of 34 subjects with Class II anomalies were recruited for this study. They were divided into three groups: the EVAA group (n=13; mean chronological age: 11 years 9 months), activator group (n=13; mean chronological age: 11 years 8 months) and control group (n=8; mean chronological age: 10 years 8 months). Lateral cephalometric radiographs were taken at the beginning and end of functional therapy. Fixed orthodontic treatment was completed in the EVAA group. A statistical software program (SPSS 18) was used for one-way analysis of variance and multiple comparisons with the Duncan test.

Results

We observed a significant decrease in the ANB, convexity, and 1┴NA (°), while a significant increase appeared in upper anterior facial height, posterior facial height, 1┴NB (mm), SN-lower occlusal plane values in the EVAA and activator groups after treatment (p<0.05). No significant difference in study parameters in the control group during the treatment period except for the increase in SNA and 1┴NA (mm) values (p<0.05) were observed. There were no significant differences between EVAA and activator treatment groups in terms of study parameters except for the articular angle, which was significantly higher in the EVAA group after therapy (p<0.05).

Conclusion

The effects of EVAA appliances were similar to those of activator treatment.