Treatment Of Anterior Open Bite Research Articles

Dentoalveolar comparative study between removable and fixed cribs, associated to chincup, in anterior open bite treatment

ObjectiveThe aim of this prospective study was to compare the dentoalveolar effects produced by two types of palatal crib, removable (Rpc+C) and fixed (Fpc+C), combined with chincup in growing patients with anterior open bite.Material and MethodsEach group comprised 30 patients, in the mixed dentition phase, with similar cephalometric characteristics and skeletal ages. Group 1 (Rpc+C) presented initial mean age of 8.3 years and mean anterior open bite of 4.0 mm. Group 2 (Fpc+C) presented initial mean age of 8.54 years and mean anterior open bite of 4.3 mm. The evaluation period comprised 12 months between initial (T1) and second lateral radiograph (T2). The T2-T1 changes were compared cephalometrically in the 2 groups using the non-paired t-test.ResultsVertical changes in the posterior dentoalveolar region were similar between the groups (about 1 mm) and no significant differences were found in molar mesialization. The Fpc+C group had in average 1.6 mm more improvement of the overbite as a result of greater maxillary incisor extrusion (1.3 mm). Patients in this group also presented less lingual tipping of maxillary incisors and more mandibular incisors uprighting. ConclusionsThe Fpc+C combination was more efficient in the correction of the negative overbite mainly due to greater extrusion of the maxillary incisors. However, the Rpc+C appliance promoted better upper and lower incisor inclination, resulting in a more adequate overjet.

Poster 41: Stability of Anterior Open Bite Correction in Class III Patients Using Bimaxillary Surgery Involving Intraoral Vertical Ramus Osteotomy

There is currently limited data on the use of intraoral vertical ramus osteotomy (IVRO) in the surgical treatment of anterior open bite and class three malocclusion. The purpose of this study is to investigate the stability of Le Fort I osteotomy with IVRO in the correction of anterior open bite with concomitant class III malocclusion. Chart reviews of patients who underwent surgical correction of anterior open bite with class three malocclusion were obtained from the years 2004-2009. Preoperative, postoperative, and 1 year postoperative lateral cephalograms were obtained. Anterior open bite was measured clinically from the edge of the maxillary central incisor to the edge of the mandibular central incisor along its axis. Angular measurements were used to evaluate jaw movement in the horizontal and vertical directions. Anterior-posterior movement of the jaws was determined by changes in the SNA and SNB angles. Vertical movements of the maxilla were calculated from changes in the Maxillary Occlusal Plane (MOP) and Palatal Plane (PP) angles to SN. Mandibular vertical movement was based on changes in the mandibular plane (MP) angle to SN. Dental compensation was determined by changes in MOP and MP angles. All cephalograms were traced and measured digitally with Dolphin© software. Statistical analysis was performed with the SAS procedure PROC MIXED (SAS/STAT software, SAS institute Inc., Cary, NC, USA). The accuracy of landmark identification, superimposition, and measurements were confirmed by retracing all cephalograms 7 days later by the same investigator. Sixty patient records were identified with 27 meeting the inclusion criteria. Six patients failed to have positive incisal overlap at 1 year postoperative (23%). Comparing preoperative data between the 2 groups, patients in the relapse group had a more significant open bite (OB −6.07 mm vs. −3.48 mm, p<0.05), overjet (−2.14 mm vs. −0.79 mm, p<0.05), maxillary posterior vertical excess (SN-PP: 0.75° vs. 3.74°, p<0.05), and a steeper mandibular plane angle (SN-MP: 41.98° vs. 36.35°, p<0.05). Surgically, the relapse group also had more maxillary clockwise movement compared to the non-relapse group (SN-PP +5.72° vs. +3.39°, p<0.05), but less mandibular counterclockwise movement (SN-MP −0.93° vs. −2.46°, p<0.05). When separating patients based on the severity of their preoperative open bite: no patients failed in the mild group (1–3 mm open bite; 0/9, 0%), 3 patients failed in the moderate group (3–6 mm open bite; 3/13, 23%), and 3 patients failed in the severe group (>6 mm open bite; 3/5, 60%). IVRO, when performed with maxillary Le Fort I osteotomy, has a success rate (78% positive incisal overlap at 1 year post operative) that is comparable to other surgical techniques when treating patients with anterior open bite and concomitant class III malocclusion. Patients likely to relapse have a severe preoperative open bite, a high preoperative mandibular plane angle, or inadequate mandibular counterclockwise movement during surgery. This study provides an evidence-based alternative to current techniques.

Skeletal class III and anterior open bite treatment with different retention protocols: a report of three cases

The treatment of skeletal class III and anterior open bite can be unstable and orthodontists frequently observe relapse. Here, we report on the management of three patients with skeletal class III profiles and open bites treated by orthodontic camouflage. Each received a retention protocol involving the use of two separate appliances during the night and day accompanied by myofunctional therapy. Long-term follow-up revealed a stable outcome.

Success rate of anterior open-bite orthodontic-orthognathic surgical treatment

The aim was to evaluate the short-term success rate of combined orthodontic-orthognathic surgical correction of anterior open bite. Fifteen patients (ages, 15-28 years) with open bite treated with a combined orthodontic-surgical approach were examined. Lateral cephalograms from before treatment, after treatment, and after an average of 18 months (range, 10-26 months) of retention were evaluated. Overbite was classified as normal (2-3.5 mm), borderline (0-1.5 mm), or relapse (<0 mm), and overjet as normal (2-3.5 mm) or relapse (≥4 and ≤1.5 mm). The average overbite was -3.2 mm before treatment, 1.8 mm after treatment, and 1.3 mm after retention. During active treatment, overbite and overjet were normalized in 53.3% and 66.7% of the subjects, respectively. After the retention period, 1 patient (6.7%) showed a negative overbite, whereas a borderline overbite was found in 53.3% of the subjects. Overjet relapsed in 40% of the subjects. Only 40% of the patients had a completely successful treatment with incisal contact and normal overjet and overbite. Orthodontic-surgical treatment of anterior open bite improves the overbite, but an excellent treatment outcome with normal overjet and overbite and proper incisal contact was achieved in only 40% of the subjects.

Editor's Comment and Q&A: Long-term stability of anterior open-bite treatment by intrusion of maxillary posterior teeth

Introduction Anterior open bite results from the combined influences of skeletal, dental, functional, and habitual factors. The long-term stability of anterior open bite corrected with absolute anchorage has not been thoroughly investigated. The purpose of this study was to examine the long-term stability of anterior open-bite correction with intrusion of the maxillary posterior teeth. Methods Nine adults with anterior open bite were treated by intrusion of the maxillary posterior teeth. Lateral cephalographs were taken immediately before and after treatment, 1 year posttreatment, and 3 years posttreatment to evaluate the postintrusion stability of the maxillary posterior teeth. Results On average, the maxillary first molars were intruded by 2.39 mm (P <0.01) during treatment and erupted by 0.45 mm (P <0.05) at the 3-year follow-up, for a relapse rate of 22.88%. Eighty percent of the total relapse of the intruded maxillary first molars occurred during the first year of retention. Incisal overbite increased by a mean of 5.56 mm (P <0.001) during treatment and decreased by a mean of 1.20 mm (P <0.05) by the end of the 3-year follow-up period, for a relapse rate of 17.00%. Incisal overbite significantly relapsed during the first year of retention (P <0.05) but did not exhibit significant recurrence between the 1-year and 3-year follow-ups. Conclusions Most relapse occurred during the first year of retention. Thus, it is reasonable to conclude that the application of an appropriate retention method during this period clearly enhances the long-term stability of the treatment. Anterior open bite results from the combined influences of skeletal, dental, functional, and habitual factors. The long-term stability of anterior open bite corrected with absolute anchorage has not been thoroughly investigated. The purpose of this study was to examine the long-term stability of anterior open-bite correction with intrusion of the maxillary posterior teeth. Nine adults with anterior open bite were treated by intrusion of the maxillary posterior teeth. Lateral cephalographs were taken immediately before and after treatment, 1 year posttreatment, and 3 years posttreatment to evaluate the postintrusion stability of the maxillary posterior teeth. On average, the maxillary first molars were intruded by 2.39 mm (P <0.01) during treatment and erupted by 0.45 mm (P <0.05) at the 3-year follow-up, for a relapse rate of 22.88%. Eighty percent of the total relapse of the intruded maxillary first molars occurred during the first year of retention. Incisal overbite increased by a mean of 5.56 mm (P <0.001) during treatment and decreased by a mean of 1.20 mm (P <0.05) by the end of the 3-year follow-up period, for a relapse rate of 17.00%. Incisal overbite significantly relapsed during the first year of retention (P <0.05) but did not exhibit significant recurrence between the 1-year and 3-year follow-ups. Most relapse occurred during the first year of retention. Thus, it is reasonable to conclude that the application of an appropriate retention method during this period clearly enhances the long-term stability of the treatment.

Long-term stability of anterior open-bite treatment by intrusion of maxillary posterior teeth

Anterior open bite results from the combined influences of skeletal, dental, functional, and habitual factors. The long-term stability of anterior open bite corrected with absolute anchorage has not been thoroughly investigated. The purpose of this study was to examine the long-term stability of anterior open-bite correction with intrusion of the maxillary posterior teeth. Nine adults with anterior open bite were treated by intrusion of the maxillary posterior teeth. Lateral cephalographs were taken immediately before and after treatment, 1 year posttreatment, and 3 years posttreatment to evaluate the postintrusion stability of the maxillary posterior teeth. On average, the maxillary first molars were intruded by 2.39 mm (P<0.01) during treatment and erupted by 0.45 mm (P<0.05) at the 3-year follow-up, for a relapse rate of 22.88%. Eighty percent of the total relapse of the intruded maxillary first molars occurred during the first year of retention. Incisal overbite increased by a mean of 5.56 mm (P<0.001) during treatment and decreased by a mean of 1.20 mm (P<0.05) by the end of the 3-year follow-up period, for a relapse rate of 17.00%. Incisal overbite significantly relapsed during the first year of retention (P<0.05) but did not exhibit significant recurrence between the 1-year and 3-year follow-ups. Most relapse occurred during the first year of retention. Thus, it is reasonable to conclude that the application of an appropriate retention method during this period clearly enhances the long-term stability of the treatment.

Stability of anterior open-bite treatment with occlusal adjustment

In this study, we aimed to evaluate the long-term stability of anterior open-bite treatment with occlusal adjustment and the dentinal sensitivity caused by this procedure in the long term. The sample comprised 17 open-bite patients who experienced relapse of the negative vertical overbite after orthodontic treatment and were retreated with occlusal adjustment. The cephalometric changes were evaluated on lateral cephalograms obtained before and after the occlusal adjustment and in the long term (mean, 3.4 years after occlusal adjustment). Dentinal sensitivity was also evaluated before the occlusal adjustment, and 1.35 months, 4.61 months, and 3.4 years later. The cephalometric statuses between the 3 evaluations were compared with analysis of variance (ANOVA) and Tukey tests. The percentages of clinically significant relapse were calculated. To compare dentinal sensitivity at the several stages, nonparametric Friedman and Wilcoxon tests were performed. Statistically significant relapse of anterior open bite occurred in 33.3% of the patients. Those who had the procedure before 21 years of age were most likely to experience relapse. Dentinal sensitivity remained within the normal range in the long term. Despite the statistically significant relapse of anterior open bite, clinically significant stability was found in 66.7% of the patients.

Editor's Comment and Q&A: Stability of anterior open-bite treatment with occlusal adjustment

Introduction In this study, we aimed to evaluate the long-term stability of anterior open-bite treatment with occlusal adjustment and the dentinal sensitivity caused by this procedure in the long term. Methods The sample comprised 17 open-bite patients who experienced relapse of the negative vertical overbite after orthodontic treatment and were retreated with occlusal adjustment. The cephalometric changes were evaluated on lateral cephalograms obtained before and after the occlusal adjustment and in the long term (mean, 3.4 years after occlusal adjustment). Dentinal sensitivity was also evaluated before the occlusal adjustment, and 1.35 months, 4.61 months, and 3.4 years later. The cephalometric statuses between the 3 evaluations were compared with analysis of variance (ANOVA) and Tukey tests. The percentages of clinically significant relapse were calculated. To compare dentinal sensitivity at the several stages, nonparametric Friedman and Wilcoxon tests were performed. Results Statistically significant relapse of anterior open bite occurred in 33.3% of the patients. Those who had the procedure before 21 years of age were most likely to experience relapse. Dentinal sensitivity remained within the normal range in the long term. Conclusions Despite the statistically significant relapse of anterior open bite, clinically significant stability was found in 66.7% of the patients.

Bimaxillary Protrusion: An Overview of the Surgical-Orthodontic Treatment

Bimaxillary protrusion is a commonly seen deformity in Asian populations. This condition is characterized by protrusive and proclined upper and lower incisors and an increased procumbency of the lips. It is usually combined with lip incompetence, gummy smile, mentalis strain, and anterior open bite. Facial aesthetics is the primary concern of these patients. Successful treatment depends on a thorough evaluation and understanding of this dentofacial deformity. Typical orthodontic treatment includes retraction and retroclination of maxillary and mandibular incisors after extraction of the four first premolars. Orthognathic surgery is required to correct significant skeletal problems. Anterior subapical osteotomies and extraction of premolars can correct sagittal excess of the jaw bones and relieve dental crowding. Segmental maxillary osteotomies are performed to treat patients with an associated exaggerated curve of Spee and vertical maxillary excess. Differential intrusion of anterior and posterior maxilla/maxillary segments with clockwise rotation of the occlusal plane is a useful technique for treatment of anterior open bite and creation of a consonant smile arc. Le Fort I osteotomy with setback sometimes provides an alternative to segmental maxillary osteotomies. Meticulous planning and execution of osteotomies in accordance with surgical planning are essential for aesthetic and functional outcome.

Effects of maxillary second molar extraction on dentofacial morphology before and after anterior open-bite treatment: a cephalometric study

The purpose of the present study was to probe into the effects of maxillary second molar extraction on dentofacial morphology by the use of cephalometric radiographs taken before and after anterior open-bite treatment. The subjects were 30 Japanese patients who had received multiloop edgewise archwire therapy without premolar extraction. They were divided into two groups. Group 1 consisted of 15 patients who had their maxillary second molars removed. Group 2 comprised 15 patients who had been treated without extraction of maxillary second molars. Lateral cephalograms were taken before and after treatment. Seventeen angular and 31 linear measurements were obtained from the lateral cephalograms. Paired and unpaired t tests were used to determine the significance of differences in measurements. The retrusion and extrusion of the maxillary incisors, the distal movement of the maxillary first molars, and the uprighting of the maxillary first premolars and the mandibular first molars were greater in group 1 than in group 2. Moreover, the maxillary first molars intruded significantly in group 1 but extruded insignificantly in group 2. Extraction of maxillary second molars, as well as nonextraction, can be an effective operating procedure for open-bite correction of the permanent dentition.

CORRECTION OF ANTERIOR OPEN BITE BY MULTILOOP EDGEWISE ARCHWIRE (A CASE REPORT)

This case report was a treatment of anterior open bite with multiloop edgewise archwire (MEAW). The patient was a class II skeletal pattern nineteen year old girl. The possible etiology of this case was sucking habit and skeletal dysplasia. In 14 months the ideal class I molar and canine relationship was achieved.

Editor's Summary, Q & A, Reviewer's Critique: Evaluation of anterior open-bite treatment with occlusal adjustment

Introduction The purpose of this study was to evaluate the cephalometric and occlusal changes, the functional occlusion, and the dentinal sensitivity of anterior open-bite treatment with occlusal adjustment. Methods The sample comprised 20 patients who experienced relapse of the anterior open bite (mean, –1.06 mm). Occlusal adjustment was performed until a positive overbite was established. Cephalometric changes were evaluated on lateral cephalograms taken before and after the occlusal adjustment. The functional occlusion analysis consisted of evaluating immediate anterior and canine guidance and the number of teeth in contact before and after the procedure. Dentinal sensitivity was evaluated before, shortly after, and 4.61 months after the occlusal adjustment. Pretreatment and posttreatment cephalometric changes and the number of teeth in contact were compared with dependent t tests. Percentages of anterior and canine guidance before and after the adjustment procedure were compared with the McNemar test. To compare dentinal sensitivity at several stages, the nonparametric Friedman test was used, followed by the Wilcoxon test. Results Significant increases in overbite and mandibular protrusion were seen, as were significant decreases in apical base discrepancy, facial convexity, and growth pattern angles. The percentages of immediate anterior and canine guidance increased significantly, as did the number of teeth with occlusal contacts. Dentinal sensitivity increased immediately after the adjustment but decreased to normal levels after 4.61 months. Conclusions Occlusal adjustment is a viable treatment alternative for some open-bite patients; it establishes positive vertical overbite and improves the functional occlusion with only transient dentinal sensitivity. The purpose of this study was to evaluate the cephalometric and occlusal changes, the functional occlusion, and the dentinal sensitivity of anterior open-bite treatment with occlusal adjustment. The sample comprised 20 patients who experienced relapse of the anterior open bite (mean, –1.06 mm). Occlusal adjustment was performed until a positive overbite was established. Cephalometric changes were evaluated on lateral cephalograms taken before and after the occlusal adjustment. The functional occlusion analysis consisted of evaluating immediate anterior and canine guidance and the number of teeth in contact before and after the procedure. Dentinal sensitivity was evaluated before, shortly after, and 4.61 months after the occlusal adjustment. Pretreatment and posttreatment cephalometric changes and the number of teeth in contact were compared with dependent t tests. Percentages of anterior and canine guidance before and after the adjustment procedure were compared with the McNemar test. To compare dentinal sensitivity at several stages, the nonparametric Friedman test was used, followed by the Wilcoxon test. Significant increases in overbite and mandibular protrusion were seen, as were significant decreases in apical base discrepancy, facial convexity, and growth pattern angles. The percentages of immediate anterior and canine guidance increased significantly, as did the number of teeth with occlusal contacts. Dentinal sensitivity increased immediately after the adjustment but decreased to normal levels after 4.61 months. Occlusal adjustment is a viable treatment alternative for some open-bite patients; it establishes positive vertical overbite and improves the functional occlusion with only transient dentinal sensitivity.

Evaluation of anterior open-bite treatment with occlusal adjustment

<b>Introduction:</b> The purpose of this study was to evaluate the cephalometric and occlusal changes, the functional occlusion, and the dentinal sensitivity of anterior open-bite treatment with occlusal adjustment. <b>Methods:</b> The sample comprised 20 patients who experienced relapse of the anterior open bite (mean, –1.06 mm). Occlusal adjustment was performed until a positive overbite was established. Cephalometric changes were evaluated on lateral cephalograms taken before and after the occlusal adjustment. The functional occlusion analysis consisted of evaluating immediate anterior and canine guidance and the number of teeth in contact before and after the procedure. Dentinal sensitivity was evaluated before, shortly after, and 4.61 months after the occlusal adjustment. Pretreatment and posttreatment cephalometric changes and the number of teeth in contact were compared with dependent <i>t</i> tests. Percentages of anterior and canine guidance before and after the adjustment procedure were compared with the McNemar test. To compare dentinal sensitivity at several stages, the nonparametric Friedman test was used, followed by the Wilcoxon test. <b>Results:</b> Significant increases in overbite and mandibular protrusion were seen, as were significant decreases in apical base discrepancy, facial convexity, and growth pattern angles. The percentages of immediate anterior and canine guidance increased significantly, as did the number of teeth with occlusal contacts. Dentinal sensitivity increased immediately after the adjustment but decreased to normal levels after 4.61 months. <b>Conclusions:</b> Occlusal adjustment is a viable treatment alternative for some open-bite patients; it establishes positive vertical overbite and improves the functional occlusion with only transient dentinal sensitivity.

Microscrew Anchorage in Skeletal Anterior Open-bite Treatment

To evaluate the effectiveness of miniscrew anchorage for intrusion of the posterior dentoalveolar region to correct skeletal open bite. The study was comprised of 12 patients (aged 14.3 to 27.2 years; mean 18.7 years) with anterior open bites. All the patients presented a Class II skeletal pattern and excessive posterior growth. Self-drilling miniscrew implants were inserted into the posterior midpalatal area and the buccal alveolar bone between the lower molars. A transpalatal and a lingual arch were used to maintain the molars on each side in order to avoid overrotation during intrusion. A force of 150 g was applied to the microscrews on each side to intrude the posterior teeth. Lateral cephalograms of all 12 patients were taken preintrusion and immediately after completion of the intrusion. The cephalometric films were measured and compared. The results showed that the anterior open bites in 12 patients were all corrected in a mean of 6.8 months. Overbite increased by a mean of 4.2 mm (P < .001), from -2.2 mm in preintrusion to 2.0 mm in postintrusion. The maxillary and mandibular first molars were intruded for an average of 1.8 mm (P < .001) and 1.2 mm (P < .001), respectively. The mandibular plane angle was reduced by 2.3 degrees (P < .001), which led to a counterclockwise rotation of the mandible with a significant decrease in the anterior facial heights (mean of 1.8 mm; P < .001). Miniscrew anchorage has the advantages of being a simpler procedure, being minimally invasive, and requiring minimal patient cooperation.

Early treatment of skeletal open-bite malocclusion

Studies were identified by searching the Cochrane Controlled Clinical Trials Register and Medline. Randomised clinical trials (RCT), prospective and retrospective studies that had concurrent untreated as well as normal controls, and clinical trials that compared at least two treatment strategies but did not have any untreated or normal control group were included. The following were excluded: case series; descriptive studies; case reports; studies concerning treatment in the permanent dentition/ adult patients, surgically assisted treatment, treatment combined with extractions, treatment with full-fixed appliances; and discussion or debate articles. Year of publication, study design, materials, dropouts, measurements, treatment time, success rate, decrease of open bite and divergence, side effects, costs, and authors' conclusions were recorded. Two independent reviewers assessed the articles independently and a quality evaluation and qualitative summary were performed. A total of 1049 articles were identified of which seven were included in the review. No RCT of early treatment of anterior open bite have been performed. Two controlled clinical trials of early anterior open bite were identified, and these both indicated the effectiveness of treatment in the mixed dentition with headgear or functional appliances (or both). Most of the studies had serious problems with lack of power because of small sample size, bias and confounding variables; lack of method-error analysis or blinding in measurements; and deficient or lack of statistical methods. The quality of the studies was insufficient to allow any evidence-based conclusions to be drawn. RCT of sufficient sample size are still needed to determine which treatment is the most effective for early correction of skeletal open bite. Future studies should also include the assessment of long-term stability as well as an analysis of the cost and side-effects of the interventions.

Corticotomy and compression osteogenesis in the posterior maxilla for treating severe anterior open bite

A new technique is described for outpatient treatment of anterior open bite. The compression osteogenesis method with a two-stage corticotomy was used in the posterior maxilla to treat a woman with severe anterior open bite. Three-week post-surgical compression using anchor plates and elastics repositioned the posterior maxillary bone/teeth segments by 7 mm to the ideal superior position. The patient had a stable skeletal position of the maxilla at 14-month follow-up with satisfactory results and no complications after orthodontic treatment. This technique appears to be an efficient option for treating patients with anterior open bite.

Early orthodontic treatment of skeletal open-bite malocclusion: a systematic review.

The aim of this study was a systematic review of the literature to assess the scientific evidence on the actual outcome of early treatments of open-bite malocclusions. A literature survey was done by applying the Medline database (Entrez PubMed). The survey covered the period from January 1966 to July 2004 and used the MeSH, Medical Subject Headings. The following study types that reported data on the treatment effects included: randomized clinical trials (RCT), prospective and retrospective studies with concurrent untreated as well as normal controls, and clinical trials comparing at least two treatment strategies without any untreated or normal control group involved. The search strategy resulted in 1049 articles. After selection according to the inclusionary/exclusionary criteria, seven articles qualified for the final review analysis. No RCTs of early treatment of anterior open bite have been performed. Two controlled clinical trials of early anterior open bite have been performed, and these two studies indicated the effectiveness of treatment in the mixed dentition with headgears or functional appliances (or both). Most of the studies had serious problems of lack of power because of small sample size, bias and confounding variables, lack of method error analysis, blinding in measurements, and deficient or lack of statistical methods. Thus, the quality level of the studies was not sufficient enough to draw any evidence-based conclusions.

Initial intrusion of the molars in the treatment of anterior open bite malocclusions in growing patients.

The treatment of the hyperdivergent phenotype and/or anterior openbite is one of the common problems facing orthodontists. The purpose of this study is to present a new appliance (Molar Intruder) for molar intrusion and to determine its effects in the treatment of anterior openbite. The study group comprised 14 patients (eight girls and six boys), with a mean age of 10 years and 7 months. All presented anterior open bite malocclusions between the second premolars. The study was carried out on lateral head films taken before (T1) and after (T2) molar intrusion. Periapical radiographs, study models, and standard photographs of all the patients were also obtained before and after molar intrusion. The paired sample t-test was used to determine the differences between the parameters. The average treatment time with the Molar Intruder was five months. The mean intrusion of maxillary and mandibular molars was 1.86 mm and 1.04 mm, respectively. Maxillary incisors extruded 0.54 mm with a labial tipping of 1.46 degrees and overbite increased by 4.00 mm. The mandibular plane angle was decreased by 1.57 degrees, and the anterior face height was decreased by 1.86 mm on average. The mandible showed a counterclockwise rotation, the chin moved forward, and the posterior facial height/anterior facial height ratio was increased. Anterior openbites of the patients were significantly rehabilitated at the end of the intrusion period, simplifying further orthodontic treatment.

Skeletal and dental effects during observation and treatment with a magnetic device.

The aim of this study was to evaluate the effects of a magnetic appliance, MAD IV, on the treatment of anterior open bites in growing patients. The study material included the lateral cephalograms and hand-wrist radiographs of 16 patients who had an anterior open bite malocclusion. The radiographs were taken at the beginning (T1) and at the end of observation period (T2) and at the end of MAD IV application (T3). At the beginning of the study, the mean age of the subjects was 11 years two months. To define the direction of facial growth, the patients were first observed for nine months without any orthodontic or orthopedic approach. At the end of the observation period, patients who had shown a vertical growth direction, resulting in an increase in open bite, were given an MAD IV appliance and were instructed to wear the appliance 18 hours a day for 7.5 months. Thirty-two different parameters were evaluated from the lateral cephalograms. Paired t-tests were used for statistical evaluation of differences that occurred during the periods and between the periods. During the observation period, the patients continued their mandibular posterior rotation resulting in an increase in lower facial height (P < .001) and an open bite (P < .01). During the treatment period, the patients showed an anterior mandibular rotation with statistically important decreases in lower facial height and open bite (P < .001). In the treatment of anterior open bite with the MAD IV appliance, skeletal changes played a role along with dental and dentoalveolar effects.

The causes, diagnosis and treatment of anterior open bite.

Anterior open bite has multiple aetiologies, but can be broadly described as being dental or skeletal in origin. Accurate differentiation is essential in determining the appropriate treatment plan: dental open bites may close spontaneously in the growing patient and are generally amenable to orthodontic treatment, whereas skeletal open bites frequently worsen with growth and usually require a combination of orthodontics and orthognathic surgery. The incidence of post-treatment relapse is high, making these malocclusions a challenge to treat successfully.