Long-term stability of anterior open bite extraction treatment in the permanent dentition

Impact of vertical facial type on alveolar bone thickness and tooth morphology: A retrospective CBCT-based clinical study

INTRODUCTION

The relationship between vertical facial patterns and the morphology of the alveolar bone and teeth is crucial for successful orthodontic treatment planning. This study aimed to evaluate the relationship between vertical facial patterns, bone thickness, and root-crown dimensions in the maxillary anterior teeth.

METHODS

This retrospective study screened 300 cone-beam computed tomography (CBCT) scans of orthodontic patients between December 2022 and November 2023, with 115 meeting the inclusion criteria. Buccal and lingual alveolar bone thickness, along with crown and root lengths of maxillary anterior teeth, were measured and compared across short, normal, and long facial types, classified according to the Frankfort-Mandibular Plane Angle. One-way ANOVA, independent-samples Kruskal-Wallis, and post-hoc tests were used for statistical analysis.

RESULTS

Significant differences in alveolar bone thickness were observed across facial types, with short facial types showing consistently greater thickness in the apical and mid-palatal regions compared to normal and long facial types (p < 0.05). No significant differences in crown or root lengths were found among the facial types.

CONCLUSION

Facial type significantly influences alveolar bone thickness, particularly in short facial types, which demonstrate greater bone support. These findings underscore the importance of considering facial type in orthodontic treatment planning to minimize complications.

Skeletal and dental open bite treatment using clear aligners and orthodontic miniscrew-anchored fixed appliances in permanent dentition: A systematic review

BACKGROUND

The objective was to systematically review studies assessing the efficacy of clear aligner therapy (CAT) and miniscrew-anchored fixed appliances (MAFAs) in the correction of skeletal and dental open bite in the permanent dentition.

METHODS

A literature search was conducted across different databases, including PubMed, Cochrane Library, Science Direct, Web of Science, Medline, Scopus and Google Scholar, up to April 2024. Studies were chosen based on prespecified inclusion criteria. The dentoskeletal changes based on lateral cephalometry were evaluated from the included papers. Study selection, data extraction, and risk of bias (RoB) assessment were performed in duplicate. Risk of bias assessment was done using ROBINS-I (Risk of Bias in Non-Randomized Studies of Interventions) and Cochrane RoB 2 tools. GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessed certainty of evidence.

RESULTS

Out of the 22 studies that were selected, 13 papers covered MAFAs, while 9 articles focused on CATs. Since the included papers consist of prospective and retrospective observational studies, as well as two randomized controlled trials, the scientific evidence is at a low level. CATs primarily induced posterior teeth intrusion and anterior teeth extrusion, contributing to the reduction of the posterior vertical dimension and improved occlusal contacts. Conversely, MAFAs facilitated significant molars intrusion, and controlled anterior teeth extrusion, effectively addressing both dental and skeletal discrepancies.

CONCLUSIONS

This review supports the use of MAFAs and CATs for treating skeletal and dental open bite, highlighting their effectiveness and implications for orthodontic practice. The limitations of this study should be considered when interpreting the results.

Three-Dimensional Evaluation of Treatment Effects and Post-Treatment Stability of Maxillary Molar Intrusion Using Temporary Anchorage Devices in Open Bite Malocclusion

Background: We investigated treatment outcomes and post-treatment stability in 10 patients with an anterior open bite and nonsurgical orthodontics. Methods: The patients underwent maxillary molar intrusion using temporary anchorage devices (TADs) to deepen the overbite due to mandibular autorotation. Lateral cephalograms and dental cast models were obtained before treatment (T0), immediately after it (T1), and >1 year after it (T2). Skeletal and dental cephalometric changes and three-dimensional movements of the maxillary dentitions were evaluated. Results: At T0, cephalometric analysis indicated that patients had skeletal class I with tendencies for a class II jaw relationship and a skeletal open bite. During active treatment (T0 to T1), the maxillary first molar intruded by 1.6 mm, the mandibular first molar extruded by 0.3 mm, the Frankfort-mandibular plane angle decreased by 1.1°, and the overbite increased by 4.1 mm. Statistically significant changes were observed in the amount of vertical movement of the maxillary first molar, Frankfort-mandibular plane angle, and overbite. Three-dimensional (3D) dental cast analysis revealed that the maxillary first and second molars intruded, whereas the anterior teeth extruded, with the second premolar as an infection point. In addition, the maxillary molar was tipped distally by 2.9° and rotated distally by 0.91°. Statistically significant changes were observed in the amount of vertical movement of the central incisor, lateral incisor, canine and first molar, and molar angulation. From T1 to T2, no significant changes in cephalometric measurements or the 3D position of the maxillary dentition were observed. The maxillary and mandibular dentitions did not significantly change during post-treatment follow-up. Conclusions: Maxillary molar intrusion using mini-screws is an effective treatment for open bite correction, with the achieved occlusion demonstrating 3D stability at least 1 year after treatment.

Management Strategies for Open Bite Relapse: A Systematic Review and Meta-Analysis

The purpose of orthodontic therapy is to correct malocclusion and produce a stable outcome that endures over time. Long-term stability can be difficult to achieve, and many patients relapse after treatment, particularly in instances of open bite relapse (OBR). This systematic review aimed to analyze different types of management strategies for OBR and conduct a meta-analysis to find the best method of dealing with relapse. A comprehensive search was carried out across six major online databases using relevant keywords pertaining to our study, including "open bite relapse," "orthodontic retention," "orthodontic surgery," "orthodontic appliance," "orthodontic management," "orthodontic treatment," "orofacial myofunctional therapy (OMT)," "skeletal anchorage," and "treatment follow-up period." Eleven studies were selected after the application of relevant inclusion and exclusion strategies. The mean follow-up period of treatment for the studies ranged from six months to 4.5 years. Of all the management strategies assessed, OMT was found to be the least effective for OBR management. Surgical management modalities, such as mandibular repositioning and molar intrusion using skeletal anchorage, in conjunction with the usage of orthodontic appliances, were found to be noticeably effective, especially in the cases of participants who were <18 years of age. However, when utilized on a singular basis, either of them was found to be lacking the desired effect. The overall odds ratio (OR) of 0.48 (0.37, 0.64) and risk ratio (RR) of 0.62 (0.51, 0.74) were obtained after the meta-analysis of the different interventions for OBR, indicating statistical significance. There were only 11 studies included in the study, so it's possible that not all management strategies for OBR were fully understood. The limited number of studies may also have affected the generalizability of the findings. Although statistical differences were obtained to a certain degree, more clinical trials are needed to assess the effect of such surgical modalities as a viable management tool for OBR, since these represent a significant limiting factor in terms of the overall cost of the treatment placed upon the patient. Prior to the start of the research, registration was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. The research protocol was created to meet the goals and was properly filed with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023401991).

Long-term stability of Class II malocclusion treatment with the cantilever bite jumper

INTRODUCTION

This study aimed to assess the long-term stability of Class II malocclusion treatment with the Cantilever Bite Jumper (CBJ) after 13 years of follow-up.

METHODS

The treatment group comprised 10 Class II Division 1 malocclusion patients treated with the CBJ, followed by fixed appliances, analyzed at 3 stages: pretreatment (aged 11.56-14.32 years), posttreatment (aged 16.34-19.58 years), and long-term posttreatment (aged 29.04-32.33 years). The control group included 15 subjects with normal occlusion. Intragroup treatment changes comparison was performed with repeated measures and analysis of variance followed by Tukey tests. Intergroup comparisons regarding the long-term posttreatment changes were performed with t tests.

RESULTS

No statistically significant relapse was observed during the follow-up period. Morever, the treated group presented a significantly smaller increase in lower anterior facial height and greater retrusion of the lower lip than the control group in the posttreatment period.

CONCLUSIONS

Treatment with the CBJ, followed by fixed appliances, is a stable alternative for Class II Division 1 malocclusion correction. The dentoskeletal and soft-tissue changes obtained during treatment remained stable in the long-term posttreatment follow-up.

Nonsurgical Orthodontic Treatment of a Severe Open Bite Case Using Miniscrews with Modified Multiloop Edgewise Arch Wire Technique

Skeletal open bite is one of the most challenging malocclusions to treat and maintain due to the difficulty and instability of correction. Although a combination of orthodontic treatment and orthognathic surgery may be the ideal approach in most cases, the complications, risks, and costs of surgery have sparked an interest in alternative treatment options that use temporary anchorage devices to achieve orthognathic-like effects. Adult patients can be treated without the need for special compliance using temporary anchorage devices such as miniscrews. This case report demonstrates a goal-oriented strategy for nonsurgical treatment of a complex skeletal open bite malocclusion in an adult patient using miniscrews and a modified multiloop edgewise arch wire (MEAW) technique, with the results evaluated clinically and cephalometrically.

Combined orthodontic and surgical open bite correction

OBJECTIVES

To present a clinical description of the team's treatment techniques.

MATERIALS AND METHODS

In Part 1, 30 patients underwent segmental maxillary orthodontics, multisegment Le Fort I, and bilateral sagittal osteotomies of the mandible. Part 1 reported excellent occlusal stability at a mean follow-up of 49.43 months (range, 36-92 months). Cases presented in Part 2 were selected based on availability of excellent technique photographs. The same techniques described in Part 2 cases were used on all Part 1 patients.

RESULTS

The coordination of arch widths and forms, overbite, overjet, and maxillary curve of Spee corrections were stable using the team protocols for orthodontic and surgical treatment.

CONCLUSIONS

In the study group, long-term three-dimensionally stable occlusal results were achieved. To duplicate these results, specific orthodontic preparation, intraoperative surgical steps, and postsurgical steps must be carefully planned and executed. These steps are described in this article, Part 2.

Combined orthodontic and surgical open bite correction

OBJECTIVES

To examine the stability of combined surgical and orthodontic bite correction with emphasis on open-bite closure. All study patients were treated with strict and consistent orthodontic and surgical protocols.

MATERIALS AND METHODS

Study inclusion required all patients to have anterior open bites, maxillary accentuated curve of Spee, 36-month minimum follow-up, and no temporomandibular joint pathology. Thirty patients met the inclusion/exclusion criteria. Importantly, segmental upper arch orthodontic preparation (performed by EG) was used. Surgery consisted of a multisegment Le Fort I (MSLFI) combined with a bilateral sagittal osteotomies (BSSO). Surgery was performed (by ADA and LT) at the Department of Dentistry and Maxillofacial Surgery of the University of Verona, Italy.

RESULTS

The long-term open bite and overjet relapse were not statistically significant. The mean transverse relapse of the upper and lower molars was statistically significant. Of great importance, the upper and lower arch widths narrowed together, maintaining intercuspation of the posterior dentition which prevented anterior open bites from developing.

CONCLUSIONS

This study revealed stability of three-dimensional occlusal correction including anterior open bite. Stable open bite closure was achieved by using rigid protocols for orthodontic preparation, surgical techniques, surgical follow-up, and orthodontic finishing.

Stability of anterior open bite treatment with molar intrusion using skeletal anchorage: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis is to assess the degree of stability of anterior open bite (AOB) treatment performed through the molar intrusion supported with skeletal anchorage at least 1 year posttreatment.

METHODS

This study was registered in PROSPERO (CRD42016037513). A literature search was conducted to identify randomized (RCT) or non-randomized clinical trials based including those considering before and after design. Data sources were electronic databases including PubMed, Cochrane Library, Science Direct, Google Scholar, Scopus, Lilacs, OpenGrey, Web of Science, and ClinicalTrials.gov . The quality of evidence was assessed through the JBI tool and certainty of evidence was evaluated through the GRADE tool. Random effects meta-analysis was conducted when appropriate.

RESULTS

Six hundred twenty-four articles met the initial inclusion criteria. From these, only 6 remained. The mean posttreatment follow-up time was 2.5 years (SD = 1.04). The overbite showed a standardized mean relapse of - 1.23 mm (95% CI - 1.64, - 0.81, p < 0.0001). Maxillary and mandibular incisors presented a non-significant mean relapse, U1-PP - 0.04 mm (95% CI - 0.55, 0.48) and L1-MP - 0.10 mm (95% CI - 0.57, 0.37). Molar intrusion showed a relapse rate around 12% for the maxillary molars and a 27.2% for mandibular molars.

CONCLUSION

The stability of AOB through molar intrusion using TADs can be considered relatively similar to that reported to surgical approaches, since 10 to 30% of relapse occurs both in maxillary and mandibular molars. The level of certainty ranged between very low and low. RCTs reporting dropout during the follow-up are in dire need.

Comparison of Postoperative Stability Between BSSRO and Le Fort 1 Osteotomy with BSSRO in Skeletal Class III Malocclusion with Severe Open Bite

Introduction

We aimed to investigate postoperative stability after orthognathic surgery in patients with skeletal class III malocclusion with severe open bite by comparison between bilateral sagittal splitting osteotomy (BSSRO) and BSSRO with Le Fort 1 osteotomy.

Materials and methods

Seventeen patients with skeletal class III malocclusion with severe open bite who were needed more than 6 degree counterclockwise rotation of distal segment by only BSSRO in preoperative cephalometric prediction. The subjects were divided into group A, where 9 patients were treated by BSSRO, and group B, where 8 patients were treated by BSSRO with Le Fort 1 osteotomy. Patient's characteristics of age, gender, preoperative over jet (OJ) and over bite (OB) were not found to be significantly different between the two groups. Counterclockwise rotation of distal segment in preoperative cephalometric prediction by only BSSRO was not found to be significantly different between group A of 7.6 (6-10.6) degree and group B of 9 (6-13) degree. The amount of rotation was reduced to 5.4 (3-10) degree by bimaxillary surgery using BSSRO and Le Fort 1 osteotomy in group B. OJ and OB were measured as occlusal stability factor. Distance between ANS-to-PNS plane and the edge of upper incisor (NF-U1Ed), and distance between Menton and edge of lower incisor (Me-L1Ed) were measured as skeletal stability factor using cephalometric analysis. These lengths were measured at pre-surgery (T0), 2 weeks after surgery (T1) and 1 year after surgery (T2), and these differences between the two groups were statistically analyzed.

Results

OJ and OB kept a good relation at any experimental periods. The change of Me-L1Ed was significantly larger in group A (1.21 mm at T0-T1, 1.02 mm at T0-T2) than in group B (0.14 mm at T0-T1, 0.16 mm at T0-T2). The change of NF-U1Ed was not significantly different between group A (1.07 mm at T0-T1, 0.57 mm at T0-T2) and group B (0.51 mm at T0-T1, - 0.05 mm at T0-T2).

Conclusion

In case with more than 6 degree counterclockwise rotation of distal segment, skeletal stability was better after bimaxillary surgery than only BSSRO; however, OJ and OB kept a good relation.

Three-dimensional analysis of condylar changes in surgical correction for open bite patients with skeletal class II and class III malocclusions

The aim of this study was to quantify three-dimensional condylar displacements as a result of two-jaw surgery for open bite correction in patients with skeletal class II and class III malocclusion. Pre-surgical (T1) and post-surgical (T2) cone beam computed tomography scans were taken for 16 patients with skeletal class II (mean age 22.3±9.47years) and 14 patients with skeletal class III (mean age 25.6±6.27years). T2 scans were registered to T1 scans at the cranial base. Translational and rotational condylar changes were calculated by x,y,z coordinates of corresponding landmarks. The directions and amounts of condylar displacement were assessed by intra- and inter-class Mann-Whitney U-test or t-test. Class II patients presented significantly greater amounts of lateral (P=0.002) and inferior (P=0.038) translation than class III patients. The magnitudes of condylar translational displacements were small for both groups. Skeletal class III patients had predominantly medial (P=0.024) and superior (P=0.047) condylar translation. Skeletal class II patients presented greater condylar counterclockwise pitch (P=0.007) than class III patients. Two-jaw surgery for the correction of open bite led to different directions and amounts of condylar rotational displacement in patients with skeletal class II compared to class III malocclusion, with greater rotational than translational displacements.

Nonsurgical treatment and stability of an adult with a severe anterior open-bite malocclusion

OBJECTIVES

A skeletal anterior open-bite is a challenging malocclusion for the orthodontist due to the difficulty and instability of correction. Treatment options for the adult patient include extractions, anterior extrusion with intermaxillary elastics, posterior intrusion using skeletal anchorage, occlusal adjustment, and orthognathic surgery. Patient compliance plays a key role in posttreatment stability. The present case report demonstrates the orthodontic treatment of an adult patient who presented with a complex open-bite malocclusion.

MATERIALS AND METHODS

Treatment involved the placement of four miniscrews to assist intrusion of maxillary molars by applying posterior vertical maxillary elastics and extrusion of the anterior segments using anterior vertical interarch elastics.

RESULTS

Ideal intercuspation was successfully achieved and good stability was maintained during 3 years following treatment.

CONCLUSION

The intrusion of the maxillary molars with miniscrews is an interesting option in selected cases of skeletal anterior open bite. The retention protocol should be specific in these cases.

Root surface areas of maxillary permanent teeth in anterior normal overbite and anterior open bite assessed using cone-beam computed tomography

Purpose

The aim of this study was to compare the root surface areas of the maxillary permanent teeth in Thai patients exhibiting anterior normal overbite and in those exhibiting anterior open bite, using cone-beam computed tomography (CBCT).

Materials and Methods

CBCT images of maxillary permanent teeth from 15 patients with anterior normal overbite and 18 patients with anterior open bite were selected. Three-dimensional tooth models were constructed using Mimics Research version 17.0. The cementoenamel junction was marked manually. The root surface area was calculated automatically by 3-Matic Research version 9.0. The root surface areas of each tooth type from both types of bite were compared using the independent t-test (P<.05). The intraclass correlation coefficient was used to assess intraobserver reliability.

Results

The mean root surface areas of the maxillary central and lateral incisors in individuals with anterior open bite were significantly less than those in those with normal bite. The mean root surface area of the maxillary second premolar in individuals with anterior open bite was significantly greater than in those with normal bite.

Conclusion

Anterior open-bite malocclusion might affect the root surface area, so orthodontic force magnitudes should be carefully determined.

Long-term stability of Class II treatment with the Jasper jumper appliance

INTRODUCTION

Treatment of Class II Division 1 malocclusion with orthopedic devices combined with fixed orthodontic appliances has shown excellent results when used in growing patients. We aimed to evaluate the long-term stability of the cephalometric changes obtained during Class II malocclusion correction with the Jasper jumper associated with fixed appliances.

METHODS

The treatment group comprised 24 patients who were evaluated at 3 stages: pretreatment, posttreatment, and long-term posttreatment. The control group comprised 15 subjects with normal occlusion. Intratreatment group comparisons among the 3 stages were performed with repeated measures analysis of variance, followed by Tukey tests. Intergroup comparisons of posttreatment changes and normal growth changes of the treatment group were performed with t tests.

RESULTS

Apical base relationship, maxillary incisor anteroposterior position, and overjet demonstrated significant relapses in relation to the control group.

CONCLUSIONS

Most dentoalveolar changes obtained with the Jasper jumper followed by fixed appliances during treatment remained stable in the long term. However, apical base relationship, maxillary incisor anteroposterior position, and overjet demonstrated significant relapses in relation to the control group. Therefore, active retention time should be increased in the posttreatment period.

Posterior teeth angulation in non-extraction and extraction treatment of anterior open-bite patients

Backgound

This study cephalometrically evaluated the posterior teeth angulation changes of anterior open-bite non-extraction and extraction treatment in the permanent dentition, with anterior vertical elastics.

Methods

The sample consisted of initial and final lateral headfilms of 60 patients divided into 2 groups: Group 1 consisted of 30 patients treated with non-extraction with an initial mean age of 15.26 years and treated with fixed appliances for a mean period of 2.46 years. Group 2 consisted of 30 patients treated with extractions, with an initial mean age of 14.03 years, and treated with fixed appliances for a mean period of 2.49 years. Within-group treatment changes were evaluated with paired t tests. Results were considered statistically significant at P < 0.05.

Results

The mandibular posterior teeth were significantly uprighted in both groups with both treatment protocols.

Conclusions

Correction of anterior open bite with either non-extraction or extractions with continuous archwires and vertical anterior elastics uprights the mandibular posterior teeth.

The Factors Affecting Long-Term Stability in Anterior Open-Bite Correction - A Systematic Review

Objective

The present systemic review was conducted with the main purpose to evaluate the quantitative effects of orthognathic surgeries, extraction versus non-extraction treatment, and the type of malocclusion in the stability of anterior open-bite (AOB) correction over the long-term.

Methods

The systematic search for studies was conducted through MEDLINE, CINAHL, EMBASE, Scopus, PsychINFO, various key journals, and review articles; November 30, 2016, was the last date for the search. The Quality Assessment Tool for Quantitative Studies was used to grade the methodological quality of the studies.

Results

The present review included 14 studies. Stability of the corrected AOB ranged from 61.9% to 100%. The studies with orthognathic surgeries showed a stability of 70-100%. The studies without orthognathic surgeries showed the stability of 61.9-96.7%. All of the studies were retrospective. The mean change in AOB before (T1) and after treatment (T2-T1) was 0.1 mm to 6.93 mm and the mean change in overbite from T2 to T3 (T3-T2) was -0.06 mm to 2.5 mm.

Conclusion

Studies with orthognathic surgeries presented with high amount of long-term stability in corrected AOB. No significant difference was noticed in relation to the type of malocclusion and extraction or non-extraction cases.

Morphology of open bite

OBJECTIVES

The purpose of this work was to define and illustrate the skeletal morphology of open-bite patients against the background of sagittal jaw relationships on the basis of lateral cephalograms.

MATERIALS AND METHODS

Lateral cephalograms of 197 untreated adults were analyzed in dental imaging software (Onyx Ceph 3™; Image Instruments, Chemnitz, Germany). Four groups were formed based on vertical (Index scores) and sagittal (individualized ANB values) parameters. Ninety-nine patients were defined as the control group due to their neutral sagittal and vertical relationships. The remaining patients were found by their vertical relationships to represent open-bite cases and were divided by their sagittal relationships into three study groups: neutral (Class I, n = 34), distal (Class II, n = 26), and mesial (Class III, n = 38). A geometric morphometric approach was used to analyze the x,y-coordinates of 28 skeletal landmarks on each cephalogram. Relative size was captured based on centroid size (CS). The shape-determining factors in the groups were compared by permutation testing after Procrustes transformation, and intergroup differences were visualized in the form of thin-plate splines.

RESULTS

While size (CS) was significantly increased in the Class III group, the other two groups were not different from the control group. After Procrustes transformation, characteristic and invariably significant (p < 0.001) differences in shape were detected. Neutral (Class I) open bite involved compression in the mandibular ramus and the upper anterior facial third, including vertical expansion in the lower molar and anterior nasal spine areas. Mesial (Class III) open bite was associated with pronounced vertical and sagittal size reductions in the upper posterior segments and reduced lengths of the mandibular ramus. Distal (Class II) open bite involved expansion in the pterygoid area and compression in the mandibular ramus.

CONCLUSION

Open bite is not a homogeneous group. Our geometric techniques of morphometric analysis revealed typical patterns, thus, confirming the differences observed by traditional morphometry. True skeletal overdevelopment appears to be present only in open-bite cases having a mesial jaw relationship. All open-bite groups have in common that the mandibular ramus is compressed, but marked differences are seen in terms of vertical development of the maxilla. This differentiated view of open-bite cases should be taken into consideration during individual etiology assessment and treatment planning.

Evaluation of the stability of open bite treatment using a removable appliance with palatal crib combined with high-pull chincup

OBJECTIVE: The aim of this prospective study was to cephalometrically analyze the stability of dentoalveolar and skeletal changes produced by a removable appliance with palatal crib associated to high-pull chincup in individuals with anterior open bite treated for 12 months, and compare them to individuals with similar malocclusion and age, not submitted to orthodontic treatment, also followed for the same period. METHODS: Nineteen children with a mean age of 9.78 years old treated for 12 months with a removable appliance with palatal crib associated with chincup therapy were evaluated after 15 months (post-treatment period) and compared with a control group of 19 subjects with mean age of 9.10 years with the same malocclusion that was followed-up for the same period. Seventy-six lateral cephalograms were evaluated at T1 (after correction) and T2 (follow-up) and cephalometric variables were analyzed by statistical tests. RESULTS: The results did not show significant skeletal, soft tissue or maxillary dentoalveolar changes. Overall, treatment effects on the experimental group were maintained at T2 evaluation with an increase of 0.56 mm in overbite. Overjet and maxillary incisors/molars position (vertical and sagittal) remained essentially unchanged during the study period. Only mandibular incisors showed significant changes (labial inclination and protrusion) compared to control group. CONCLUSIONS: Thus, it can be concluded that the early open bite treatment with a removable appliance and palatal crib associated with high-pull chincup therapy provided stability of 95%.

Treatment effects of bonded spurs associated with high-pull chincup therapy in the treatment of patients with anterior open bite

INTRODUCTION

The aim of this prospective clinical study was to investigate the cephalometric changes produced by bonded spurs associated with high-pull chincup therapy in children with Angle Class I malocclusion and anterior open bite.

METHODS

Thirty patients with an initial mean age of 8.14 years and a mean anterior open bite of -3.93 mm were treated with bonded spurs associated with chincup therapy for 12 months. An untreated control group of 30 subjects with an initial mean age of 8.36 years and a mean anterior open bite of -3.93 mm and the same malocclusion was followed for 12 months for comparison. Student t tests were used for intergroup comparisons.

RESULTS

The treated group demonstrated a significantly greater decrease of the gonial angle, and increase in overbite, palatal tipping of the maxillary incisors, and vertical dentoalveolar development of the maxillary and mandibular incisors compared with the control group.

CONCLUSIONS

The association of bonded spurs with high-pull chincup therapy was efficient for the correction of the open bite in 86.7% of the patients, with a 5.23-mm (SD, ±1.69) overbite increase.

Relationships between the root-crown ratio and the loss of occlusal contact and high mandibular plane angle in patients with open bite

OBJECTIVE

To determine the root-crown (R/C) ratio and dental root length of teeth in patients with open bite and seek any relationships with occlusal contact (OC) and the mandibular plane (Mp) angle.

MATERIALS AND METHODS

Thirty-one patients with open bite with negative overbite of at least four anterior teeth and 31 control patients with clinically normal overjet and overbite were enrolled. R/C ratios, dental root length, OC, and Mp angle were measured using panoramic radiographs, dental casts, and cephalograms, respectively. Mean differences between the groups, and variations between the R/C ratio or root length and Mp angle in patients with open bite were statistically analyzed.

RESULTS

R/C and OC ratios from the incisors to premolars were significantly lower for patients with open bite than for controls, and some teeth had short dental roots. Relationships between low R/C ratio or root length and high Mp angle were significant in patients with open bite.

CONCLUSION

Patients with open bite, especially those with a high Mp angle, have an unfavorable R/C ratio and short dental roots in some teeth, which may be related to the loss of OC.

Osteotomy assisted maxillary posterior impaction with miniplate anchorage

This case report presents orthodontic treatment with miniplate anchorage accelerated by osteotomy-assisted maxillary posterior impaction in a severe open bite case. A 14-year-old girl with a severe anterior open bite was treated by intrusion of the maxillary posterior teeth. A segmental osteotomy was applied, and the miniplates were fixed to the zygomatic buttress area. The intrusive force was applied with nickel-titanium closed coil springs using a force of 250 g between the miniplates and the upper first and second molar buccal tubes. The intrusion was completed 2.5 months after osteotomy. The treatment was continued with the fixed orthodontic appliances and completed after 12 months. At the end of treatment, optimal occlusion and the correction of the anterior open bite were achieved. The maxillary molars were impacted 4.0 mm, and the mandibular plane showed a counterclockwise autorotation of 3.0 degrees . The results showed that osteotomy-facilitated orthodontic treatment clearly reduced the treatment time and had no adverse effects. In conclusion, this one-stage osteotomy technique can be an effective option to help molar intrusion in severe open bite cases.

Noncompliance Open-Bite Treatment with Zygomatic Anchorage

Objective: To evaluate the dentoalveolar and skeletal effects of the new-generation open-bite appliance.

Subjects and Methods: The study group was composed of 11 subjects with a mean age of 19.5 years who underwent intrusion of the posterior dentoalveolar segment using an open-bite appliance supported by bilateral zygomatic implants. The study was carried out on lateral cephalograms of the subjects taken before treatment and after intrusion. The mean intrusion time was 9.6 months.

Results: The mean intrusion measured as the distance of the U6 to the palatal plane was 3.6 ± 1.4 mm (P &lt; .001). This resulted in an average of 3.0° ± 1.5° of closure of the Go-Gn-SN angle (P &lt; .001). The gain in the overbite was 5.1 ± 2.0 mm (P &lt; .001), and the overjet was reduced by 1.4 ± 1.5 mm (P &lt; .01). The change in the occlusal plane angle was an average of 2.4° ± 1.4° counterclockwise rotation (P &lt; .001). The lower facial height was also decreased significantly by 2.9 ± 1.3 mm (P &lt; .001). No significant changes were observed in the SNA angle and incisor positions (P &gt; .05), except for the interincisal angle, which was increased by 3.5° (P &lt; .05).

Conclusion: Zygomatic anchorage can be used effectively for open-bite correction through posterior dentoalveolar intrusion.

Evaluation of root resorption after open bite treatment with and without extractions

INTRODUCTION

In this study, we evaluated the root resorption degree in open bite and normal overbite patients, treated with and without premolar extractions.

METHODS

A sample of 120 patients was selected and divided into 4 groups. Group 1 comprised 32 patients treated with premolar extractions with an initial mean age of 14.01 +/- 2.58 years and an initial mean overbite of -3.45 +/- 0.23 mm. Group 2 included 28 open bite patients treated without extractions, with an initial mean age of 13.27 +/- 2.75 years and an initial mean overbite of -3.10 +/- 0.24 mm. Group 3 comprised 30 patients with normal overbite, treated with premolar extractions, having a mean age of 13.28 +/- 1.79 years and a mean overbite of 1.09 +/- 0.24 mm at the beginning of treatment. Group 4 consisted of 30 patients with normal overbite, treated without extractions, at a mean age of 12.87 +/- 1.43 years and a mean overbite of 1.67 +/- 0.24 mm at the beginning of treatment. The groups were matched by initial age, treatment time, and malocclusion type. Pretreatment and posttreatment periapical radiographs were used to evaluate the amount of root resorption. The groups were compared by using the Kruskal-Wallis and Dunn nonparametric tests. Correlations between the degree of root resorption and amount of tooth movement, usage time of anterior vertical elastics, and treatment time were investigated with the Spearman correlation coefficient.

RESULTS

No statistically significant difference was found between the root resorption degrees of open bite vs normal overbite groups, but the extraction groups had statistically significant greater root resorption than the nonextraction groups. Significant correlations were observed in the extraction groups between root resorption degree and amount of overjet correction and retraction of maxillary incisor apex.

CONCLUSIONS

Root resorption was similar between open bite and normal overbite treatment protocols, but extraction treatment showed greater root resorption than nonextraction treatment. There was a statistically significant correlation of overjet correction and retraction of maxillary central incisor apices with the degree of root resorption.

Orthodontic and orthopaedic treatment for anterior open bite in children

BACKGROUND

Anterior open bite occurs when there is a lack of vertical overlap of the upper and lower incisors. The aetiology is multifactorial including: oral habits, unfavourable growth patterns, enlarged lymphatic tissue with mouth breathing. Several treatments have been proposed to correct this malocclusion, but interventions are not supported by strong scientific evidence.

OBJECTIVES

The aim of this systematic review was to evaluate orthodontic and orthopaedic treatments to correct anterior open bite in children.

SEARCH STRATEGY

Search strategies were developed for MEDLINE and revised appropriately for the following databases: Cochrane Oral Health Group Trials Register; CENTRAL (The Cochrane Library 2005, Issue 4); PubMed (1966 to December 2005); EMBASE (1980 to February 2006); Lilacs (1982 to December 2005); Brazilian Bibliography of Odontology (BBO) (1986 to December 2005); and SciELO (1997 to December 2005). Chinese journals were handsearched and the bibliographies of papers were retrieved.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials of orthodontic or orthopaedic treatments or both to correct anterior open bite in children.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of all reports identified. Risk ratios (RRs) and corresponding 95% confidence intervals (CIs) were calculated for dichotomous data. The continuous data were expressed as described by the author.

MAIN RESULTS

Twenty-eight trials were potentially eligible, but only three randomised controlled trials were included comparing: effects of Frankel's function regulator-4 (FR-4) with lip-seal training versus no treatment; repelling-magnet splints versus bite-blocks; and palatal crib associated with high-pull chincup versus no treatment. The study comparing repelling-magnet splints versus bite-blocks could not be analysed because the authors interrupted the treatment earlier than planned due to side effects in four of ten patients.FR-4 associated with lip-seal training (RR = 0.02 (95% CI 0.00 to 0.38)) and removable palatal crib associated with high-pull chincup (RR = 0.23 (95% CI 0.11 to 0.48)) were able to correct anterior open bite.No study described: randomisation process, sample size calculation, there was not blinding in the cephalometric analysis and the two studies evaluated two interventions at the same time. These results should be therefore viewed with caution.

AUTHORS' CONCLUSIONS

:There is weak evidence that the interventions FR-4 with lip-seal training and palatal crib associated with high-pull chincup are able to correct anterior open bite. Given that the trials included have potential bias, these results must be viewed with caution. Recommendations for clinical practice cannot be made based only on the results of these trials. More randomised controlled trials are needed to elucidate the interventions for treating anterior open bite.

Long-term stability of orthodontic treatment and patient satisfaction. A systematic review

OBJECTIVE

To evaluate morphologic stability and patient satisfaction at least 5 years after orthodontic treatment.

MATERIALS AND METHODS

Published literature was searched through the PubMed and Cochrane Library electronic databases from 1966 to January 2005. The search was performed by an information specialist at the Swedish Council on Technology Assessment in Health Care. The inclusion criteria consisted of a follow-up period of at least 5 years postretention; randomized clinical trials, prospective or retrospective clinical controlled studies, and cohort studies; and orthodontic treatment including fixed or removable appliances, selective grinding, or extractions. Two reviewers extracted the data independently and also assessed the quality of the studies.

RESULTS

The search strategy resulted in 1004 abstracts or full-text articles, of which 38 met the inclusion criteria. Treatment of crowding resulted in successful dental alignment. However, the mandibular arch length and width gradually decreased, and crowding of the lower anterior teeth reoccurred postretention. This condition was unpredictable at the individual level (limited evidence). Treatment of Angle Class II division 1 malocclusion with Herbst appliance normalized the occlusion. Relapse occurred but could not be predicted at the individual level (limited evidence). The scientific evidence was insufficient for conclusions on treatment of cross-bite, Angle Class III, open bite, and various other malocclusions as well as on patient satisfaction in a long-term perspective.

CONCLUSIONS

This review has exposed the difficulties in drawing meaningful evidence-based conclusions often because of the inherent problems of retrospective and uncontrolled study design.

Cephalometric evaluation of anterior open-bite nonextraction treatment, using multiloop edgewise archwire therapy

There are very few reports of extensive and detailed cephalometric investigations of nonextraction treatment changes for patients with anterior open bite. The purpose of this study was to evaluate changes in dentomaxillofacial morphology by way of lateral and oblique cephalograms of patients who had undergone multiloop edgewise archwire (MEAW) therapy for anterior open-bite correction. The subjects consisted of 21 Japanese female patients who received MEAW therapy without premolar extraction. The mean pre- and posttreatment ages were 16 years 9 months and 19 years, respectively. Lateral and oblique cephalograms were taken before and after treatment. Fifteen angular and 29 linear measurements were obtained from the lateral cephalograms; 17 angular and 20 linear measurements were obtained from the oblique cephalograms. Treatment changes were evaluated by the paired t-test. The upward and forward rotational changes of the mandible consequent to the use of the MEAWs and anterior vertical elastics were larger than the downward and backward rotational changes of the mandible, due to the extrusion of the posterior teeth by leveling and alignment. The uprighting and retrusion of the premolars and molars, and the extrusion, uprighting, and/or retrusion of the incisors and canines played important roles in the anterior open-bite nonextraction treatment by dint of the MEAW technique.

Stability of anterior open-bite extraction and nonextraction treatment in the permanent dentition

INTRODUCTION

Although stability of anterior open-bite extraction and nonextraction treatment has been investigated, results suggesting that extraction treatment is more stable have not been confronted. Therefore, the purpose of this cephalometric study was to compare the long-term stability of anterior open-bite extraction and nonextraction treatment in the permanent dentition.

METHODS

Group 1 consisted of 21 patients treated without extractions, and group 2 included 31 patients treated with extractions who had orthodontic treatment with fixed appliances. Cephalometric headplates were obtained at pretreatment, posttreatment, and postretention. The groups were compared at these 3 times and during the treatment and posttreatment periods with independent t tests. The number of patients with a clinically significant relapse of the open bite was compared between the groups with chi-square tests.

RESULTS

During treatment, the maxillary incisors had greater retraction amounts, and the mandibular incisors had greater retraction and lingual tipping, and less extrusion in the extraction group. In the posttreatment period, the extraction group demonstrated statistically greater stability of the overbite. However, there was no statistically significant difference in the percentages of patients with clinically significant relapse of the open bite between the groups.

CONCLUSION

Open-bite extraction treatment has greater stability of the overbite than open-bite nonextraction treatment.

Mordida aberta anterior: uma fórmula para o diagnóstico diferencial

TEMA: diferenciar a mordida aberta anterior dental da mordida aberta anterior esquelética é necessário para que se estabeleça as metas e as condutas de tratamento ortodôntico e fonoaudiológico, tendo em vista que estas má oclusões têm etiologia e características morfofisiológicas distintas. OBJETIVO: estabelecer uma fórmula para o diagnóstico diferencial entre mordida aberta anterior dental e mordida aberta anterior esquelética, baseado na análise cefalométrica composta pelos ângulos que medem a inclinação do plano mandibular (NS.GoGn), a direção do crescimento mandibular no sentido vertical e ântero-posterior (NSGn), e a direção de crescimento mandibular e a posição vertical do mento (Eixo Facial). MÉTODO: 78 radiografias em norma lateral, de sujeitos com idade variando de 6 a 13 anos, foram analisadas e divididas em dois grupos - mordida aberta anterior dental e mordida aberta anterior esquelética. Resultado: Houve diferença significante entre os grupos quanto aos valores das medidas angulares, sendo que no grupo mordida aberta anterior esquelética as medidas dos ângulos NS.GoGn e NSGn foram maiores e do ângulo Eixo Facial menores em comparação ao grupo mordida aberta anterior dental. O ajuste dos dados à função linear resultou numa fórmula que permite definir o tipo de mordida aberta anterior a partir das referidas medidas angulares, com apenas 3,5% de margem de erro. CONCLUSÃO: foi possível estabelecer uma fórmula para o diagnóstico diferencial da mordida aberta anterior dental e mordida aberta anterior esquelética, o qual pode ser realizado com alto grau de confiança, a partir das medidas angulares NS.GoGn, NSGn e Eixo Facial. A fórmula estabelecida para o diagnóstico diferencial possui aplicabilidade em pesquisas e na clínica.