Bionator Treatment Research Articles

Changes in pharyngeal airway space and hyoid bone position after Bionator treatment of skeletal Class II malocclusions

Abstract Objectives The objective of this study was to investigate the treatment effectiveness of long-term Bionator use on the craniofacial pattern, nasopharynx, oropharynx, hypopharynx, hyoid bone, and cervical vertebrae in patients presenting with a skeletal Class II malocclusion involving mandibular retrognathia. Methods A treatment group of 27 patients with a skeletal Class II malocclusion treated using a Bionator was compared with a control group of 27 patients presenting with a skeletal Class I malocclusion managed without Bionator treatment. The Bionator was worn in the subject group until the complete eruption of the second molars. Lateral cephalograms of the group before (T0) and after Bionator treatment (T1) were compared. A two-way analysis of variance and a paired t-test were applied for statistical analyses. Results A significant increase in the SNB angle and a decrease in the ANB angle were apparent in the Bionator treatment group. The dimensions of the oropharyngeal and hypopharyngeal airways and the hypopharyngeal area increased significantly. Conclusion Long-term treatment using a Bionator resulted in the advancement of a retrognathic mandible. In addition, the dimensions of the oropharyngeal and hypopharyngeal airways and the hypopharyngeal area increased significantly, reaching the same level as that of skeletal Class I subjects.

Twenty-year follow-up of functional treatment with a bionator appliance (part 2): a retrospective cephalometric analysis of skeletal and dentoskeletal changes.

To investigate skeletal and dentoskeletal changes 20 years after bionator treatment. Analog lateral cephalograms of 18 subjects treated with a bionator appliance during growth were digitized with a transmitted light scanner. Inclusion criteria were: increased overjet (≥4 mm), skeletal Class II, available lateral cephalograms before (T0), after (T1), and 20 years after (T2) treatment with only a Bionator. To assess standard cephalometric parameters, the software ivoris analyze was used. Data were analyzed using Friedman's two-way analysis of variance by ranks followed by Dunn's post hoc tests (P ≤ .05). During therapy (T0-T1), ANB decreased significantly by 1.9° and remained unchanged long term. SNA slightly decreased (-0.6°) during treatment, SNB and SNPg increased (+1.4°, +1.7°). All three parameters showed a significant increase at T2 (+1.2°, +1.6°, +1.6°). Vertical measurements (ML-NL, ML-NSL, NL-NSL) remained almost unchanged during therapy. NL-NSL also was unchanged during the long-term interval; ML-NSL and ML-NL decreased significantly (-3.4°, -4.9°). During treatment, the maxillary incisors retroclined (OK1-NL: -1.6°, OK1-NA: -0.6°), the mandibular incisors proclined (UK1-ML: +3.5°, UK1-NB: +4.9°), neither significantly. Long term, there was a nonsignificant tendency toward proclination of upper (OK1-NL: +0.1°, OK1-NA: +0.7°) and retroclination of lower incisors (UK1-ML: -1.5°, UK1-NB: -5°). Changes of ANB after bionator treatment without additional fixed appliances remained stable after 20 years. The observed long-term changes are probably consequences of well-known physiological and age-related processes.

Twenty-year follow-up of functional treatment with a bionator appliance: A retrospective dental cast analysis.

To investigate changes in dental arch configuration, relationship, and malocclusion directly after Class II malocclusion treatment with a Balters bionator modified by Ascher as well as 20 years after treatment. Orthodontic dental cast analysis of 18 patients with skeletal Class II treated with a bionator without any additional fixed therapy was performed with a digital caliper at three stages: before (T0), after (T1) and 20 years after (T2) treatment. Arch perimeter and depth, intermolar and intercanine distance, overjet, overbite, sagittal molar and canine relationship, mandibular incisor irregularity (Little's index), and malocclusion (PAR index) were assessed. During treatment (T0-T1), upper arch perimeter significantly increased with a significant decrease in the upper and lower arch perimeter long-term (T1-T2), whereas corresponding arch depths changed only slightly in both periods. Transverse intermolar width increased significantly during treatment, remaining almost constant from T1 to T2. Lower intercanine distance remained fairly unchanged during treatment, but decreased significantly during follow-up. Lower incisor irregularity improved slightly during treatment but increased significantly long-term. After treatment, sagittal molar relationships on both sides were improved, overjet and overbite reduced; these significant changes remained stable long-term. The peer assessment rating (PAR) index was significantly lower after treatment and increased insignificantly during follow-up. 20 years after bionator treatment without additional fixed appliances, the improved sagittal relationship and the reduced overjet and PAR index remained fairly stable. Long-term changes are most likely due to physiological aging processes and are not associated with bionator treatment.

Influence of fixed appliances on two-phase orthopedic-orthodontic treatment

Aim: The purpose of this retrospective study was to investigate the effects of phase 2 with fixed appliances, after phase 1 Bionator treatment of Class II division 1 malocclusion, as compared to a matching control group. Methods: The experimental group consisted of 20 patients who were evaluated after orthodontic treatment with fixed appliances subsequently to functional therapy with the Bionator in phase 1. A control group consisting of 20 Class II, division 1 individuals. Results: During phase 1 there was significant forward growth restriction in the maxillary complex, improvement of the maxillomandibular relationship and decrease in facial convexity. There was also significant reduction of the maxillary incisor proclination and protrusion, protrusion of the mandibular incisors, and vertical development of the mandibular molars. The overjet was significantly reduced and the molar relationship was significantly improved. Treatment during phase 2, with fixed appliances, resulted in significant maxillary forward growth restriction and facial convexity reduction. Conclusion: Major Class II skeletal and dentoalveolar anteroposterior correction was obtained during phase 1, with the Bionator. Phase 2, with fixed appliances only produced a significant maxillary forward growth restriction and facial convexity reduction, without any significant dentoalveolar change.

Morphometric analysis of long-term dentoskeletal effects induced by treatment with Balters bionator.

To evaluate the long-term effects of the standard (Class II) Balters bionator in growing patients with Class II malocclusion with mandibular retrusion by using morphometrics (thin-plate spline [TPS] analysis). Twenty-three Class II patients (8 male, 15 female) were treated consecutively with the Balters bionator (bionator group). The sample was evaluated at T0, start of treatment; T1, end of bionator therapy; and T2, long-term observation (including fixed appliances). Mean age at the start of treatment was 10 years 2 months (T0); at posttreatment, 12 years 3 months (T1); and at long-term follow-up, 18 years 2 months (T2). The control group consisted of 22 subjects (11 male, 11 female) with untreated Class II malocclusion. Lateral cephalograms were analyzed at the three time points for all groups. TPS analysis evaluated statistical differences (permutation tests) in the craniofacial shape and size between the bionator and control groups. TPS analysis showed that treatment with the bionator is able to produce favorable mandibular shape changes (forward and downward displacement) that contribute significantly to the correction of the Class II dentoskeletal imbalance. These results are maintained at a long-term observation after completion of growth. The control group showed no statistically significant differences in the correction of Class II malocclusion. This study suggests that bionator treatment of Class II malocclusion produces favorable results over the long term with a combination of skeletal and dentoalveolar shape changes.

Long-term pharyngeal airway changes after bionator treatment in adolescents with skeletal Class II malocclusions

ObjectiveThe aim of this study was to evaluate long-term changes in the pharyngeal airway dimensions after functional appliance treatment in adolescents with skeletal Class II malocclusions.MethodsPharyngeal airway dimensions were compared between subjects with skeletal Class II malocclusions (n = 24; mean age: 11.6 ± 1.29 years) treated with a Class II bionator and age-matched control subjects with skeletal Class I occlusions (n = 24; mean age: 11.0 ± 1.21 years) using a series of lateral cephalograms obtained at the initial visit (T0), after treatment (T1), and at the completion of growth (T2).ResultsThe length of the nasopharyngeal region was similar between adolescents with skeletal Class I and Class II malocclusions at all time points, while the lengths of the upper and lower oropharyngeal regions and the pharyngeal airway areas were significantly smaller in the skeletal Class II adolescents before treatment when compared to the control adolescents (p < 0.05). However, following treatment with a functional appliance, the skeletal Class II adolescents had increased pharyngeal airway dimensions, which became similar to those of the control subjects.ConclusionsFunctional appliance therapy can increase the pharyngeal airway dimensions in growing adolescents with skeletal Class II malocclusions, and this effect is maintained until the completion of growth.

Comparative Study of the Bionator and Multi. P Appliances in the Treatment of Class II Malocclusion: a Cephalometric Study

Background: Functional appliances such as Bionator have been used to treat Class II malocclusion. The purpose of this study was to compare the skeletal, dental and soft tissue effects of Bionator appliances with Multi-P (a newly developed appliance) in the treatment of Class II malocclusion.&#x0D; Subjects and methods: 45 class II children were chosen and randomly assigned to either the Bionator or Multi-P treatment group. After excluding 13 patients from the study, 21 patients in Bionator and 11 patients in Multi-P group have participated in the study. Lateral cephalograms were analyzed at the beginning (To) and at the end of treatment (T1) to evaluate the changes in both groups. The paired t.test and Leven’s test were enrolled for statistical analysis.&#x0D; Results: Reduction of ANB angle was detected in both treatment groups. The Bionator group underwent insignificant greater mandibular advancement as measured by the SNB angle. (p= 0.737) The mandibular plane angle increased insignificantly in both groups. (p&gt; 0.05) The inclination of upper incisors decreased significantly in Multi-P group. (p= 0.042)&#x0D; Conclusion: Both appliances are effective therapeutic means for class II treatment associated with mandibular deficiency and may lead to normalization of the dentoskeletal parameters at the end of the treatment.

アングルI I 級不正咬合に対するバイオネーターによる5症例からの臨床的検討:側貌頭部X線規格写真による作用効果を中心に

アングルI I 級不正咬合に対するバイオネーターによる5症例からの臨床的検討:側貌頭部X線規格写真による作用効果を中心に

Effectiveness of bionator therapy for Class II malocclusions

The goal of this retrospective study was to examine the effectiveness of isolated bionator therapy in Class II patients both longitudinally and over the long term. We aimed to determine whether skeletal and/or dentoalveolar reactions differ in relationship to the Angle Class (II, Division 1 vs. II, Division 2). A total of 50 juvenile patients with Class II malocclusion (♀ n = 26, ♂ n = 24) were included. A total of 24 patients presented an Angle Class II, Division 1 and 26 an Angle Class II, Division 2. We compared the patients' lateral cephalograms taken at the beginning of treatment (t1: 10.1 years), after active therapy (t2: 13.8 years), and at the end of retention (t3: 16.4 years) analyzing the following cephalometric parameters: SNA, SNB, ANB, ANB(ind), SNPog, Wits appraisal, U1-SN, U1-SpP, L1-MeGo, interincisal angle. Mean and standard deviations of each of the variables were calculated. Differences between t1-t2 and t2-t3 were tested for statistical significance. Changes in the variables were then analyzed biometrically for specific differences in terms of Angle Class (II, Division 1 vs. II, Division 2). Between t1 and t2, SNB (p = 0.000) and SNPog (p = 0.000) increased significantly, as did ANB (p = 0.000), while the difference between ANB and ANB(ind) (p = 0.000) and Wits appraisal (p = 0.000) decreased significantly. The dentoalveolar variables U1-SN, U1-SpP, and the interincisal angle changed significantly in both groups. The inclination of the upper incisors was corrected by retrusion in the Class II, Division 1 and by protrusion in the Class II, Division 2 group. Only marginal changes in all variables between t2 and t3 were observed. A significant skeletal effect (even in long-time stability) through bionator treatment could be confirmed in this study of Class II, Divisions 1 and 2 patients. The desired effect on the upper front teeth was realized, and there was no appreciable dentoalveolar compensation in the mandible.

Changes in the Pharyngeal Airway and Position of the Hyoid Bone After Treatment With a Modified Bionator in Growing Patients With Retrognathia

Background To understand changes in (1) the anteroposterior dimensions of the pharyngeal airway and (2) the position of the hyoid bone after newly modified bionator treatment in growing patients with retrognathia. Methods Data of 86 patients (51 males aged 10.83 ± 1.40 years and 35 females aged 10.25 ± 1.47 years) with an Angle class II, Division I malocclusion, and a retruded mandible in mixed dentition were analyzed. All patients were treated using a modified bionator. The average treatment time was 1.86 years. After treatment, 56 patients were followed-up for approximately 2 years, and 22 patients were followed-up for 4 years. Lateral cephalometric radiographs were taken in four stages: before treatment (T0), at the time bionator treatment was stopped (T1), at 2 years of follow-up (T2), and at 4 years of follow-up (T3). Nine linear and 17 angular items of the craniofacial morphology, five linear items of the pharyngeal airway dimensions, and six linear items of the hyoid bone position were measured. Analysis of variance was used to compare measurements in the four stages. Results The anteroposterior dimensions of the pharyngeal airway did not change after the modified bionator treatment, except for the nasopharynx area in both genders and the hypopharynx area in males. Vertically, the hyoid bone remained in a constant position relative to the mandible and third cervical vertebra through the four stages in both genders. Horizontally, the hyoid bone moved forward during treatment but returned to a posterior position after use of the modified bionator was stopped. Conclusions Even with mandible advancement by the modified bionator in growing patients with retrognathia, there were no significant changes in the anteroposterior dimensions of the pharyngeal airway, and the hyoid bone remained in a vertical position relative to the mandible during the pubertal growth phase.

Interceptive Orthodontic Treatment of Class II Malocclusions is Slightly More Successful with Headgear/Biteplane than with Bionator Treatment

Article Title and Bibliographic Information Effectiveness of early treatment of Class II malocclusion. Wheeler TT, McGorray SP, Dolce C, Taylor MG, King GJ. Am J Orthod Dentofacial Orthop 2002;121:9-17. Reviewer Anne-Marie Bollen, DDS, MS, PhD Purpose/Question To investigate the success of early treatment with a headgear/biteplate or a bionator in patients with Class II malocclusion and compare this to changes over a similar time period in untreated observation subjects. Source of Funding Government: National Institute of Dental Craniofacial Research Grant No. DE08715 Type of Study/Design Randomized controlled trial Level of Evidence Level 1: Good-quality, patient-oriented evidence Strength of Recommendation Grade Grade B: Inconsistent or limited-quality patient-oriented evidence

Long-Term Dentoskeletal Effects and Facial Profile Changes Induced by Bionator Therapy

To evaluate the long-term skeletal and soft tissue changes induced by the bionator in Class II subjects. The treatment sample consisted of 20 Class II patients (6 males and 14 females) treated consecutively with the bionator. The sample was evaluated at T1, start of treatment; T2, end of bionator therapy; and T3, long-term observation (including fixed appliances). Mean age at the start of treatment was 10 years 2 months (T1); at posttreatment, 12 years 4 months (T2); and at long-term follow-up, 18 years 11 months (CS 6). The control group consisted of 20 subjects (8 males and 12 females) with untreated Class II malocclusions. Lateral cephalograms were analyzed at the three time points for all groups. Student's t-tests were used for comparisons of starting forms, and of the T1-T2 and T1-T3 changes between groups. The bionator group showed significant, favorable T1-T2 changes both at the skeletal and dentoalveolar levels. The vertical dimension was increased. Significant modifications were assessed for the soft tissues as well. The treated group showed a final improvement in soft tissue pogonion of about 2.5 mm. Significant mandibular changes were noted in the treated group, with a net average 3.3 mm long-term increase in mandibular length compared with untreated Class II controls. This study suggests that bionator treatment of Class II malocclusion maintains favorable results over the long-term with a combination of skeletal, dentoalveolar, and soft tissue changes.

Treatment effects of headgear biteplane and bionator appliances

The purpose of this investigation was to evaluate the dentoalveolar and skeletal cephalometric changes produced by headgear (HG) biteplane and bionator appliances in subjects with Class II Division 1 malocclusion. The sample comprised 60 patients with Class II Division 1 malocclusion; 30 (15 boys, 15 girls; mean age, 10.02 years) were treated with the HG biteplane for a mean period of 1.78 years, and 30 (15 boys, 15 girls; mean age, 10.35 years) were treated with a bionator for a mean period of 1.52 years. For comparison, a control group of 30 untreated Class II children (15 boys, 15 girls) with an initial mean age of 10.02 years, followed for 1.48 years, was established. Lateral cephalometric headfilms were obtained at the beginning and at the end of the treatment or observation period. The results showed that forward growth of the maxilla was restricted in the HG biteplane group. Bionator treatment, however, produced a statistically significant increase in mandibular protrusion. Both appliances provided increases in total mandibular and ramus lengths. There were no statistically significant differences in craniofacial growth direction. The mandibular incisors were tipped labially with bionator treatment and lingually in the HG biteplane group. The maxillary incisors were retruded with both appliances; there also were a significant increase in mandibular posterior dentoalveolar height and a restriction in the vertical development of the maxillary molars. Class II treatment with HG biteplane and bionator appliances is efficient over the short term, with pronounced dentoalveolar movements and smaller but still significant skeletal effects. The stability of these results should be examined in a long-term study.

Avaliação cefalométrica do efeito do tratamento da má oclusão Classe II, divisão 1, com o bionator de Balters: estudo com implantes metálicos

OBJETIVOS: julgamento descritivo dos efeitos do bionator no tratamento da má oclusão Classe II, divisão 1, quando está presente uma retrusão mandibular ou uma deficiência do crescimento mandibular. METODOLOGIA: são apresentados os resultados do tratamento em três pacientes que foram acompanhados sem tratamento por um período de um ano e, posteriormente, tratados com o bionator por um período de dois anos. Em todos os pacientes foram inseridos implantes metálicos que serviram como referência para as sobreposições dos traçados cefalométricos que, em conjunto com algumas medidas cefalométricas tradicionais, geraram dados para a avaliação do efeito ortopédico e ortodôntico do tratamento da má oclusão Classe II com este aparelho. RESULTADOS E CONCLUSÕES: foi observada uma restrição do crescimento da maxila e um estímulo do crescimento da mandíbula, assim como alteração na direção do crescimento condilar. Foi também observada uma verticalização dos incisivos superiores e, no arco inferior, aumento na tendência natural de vestibularização dos incisivos inferiores.

Third molar position following Bionator treatment

Third molar eruption is an unpredictable event. The position of the third molar continuously changes during development. The purpose of this study was to evaluate the influence of Bionator treatment on third molar position against an untreated control group. A Bionator is a loose-fitting intra-oral appliance that postures the mandible forward, thereby producing skeletal and dentoalveolar changes. Data were obtained from direct measurements of existing longitudinal panoramic radiographs taken during the course of a randomized study investigating Class II malocclusion treatment options. The following variables were analyzed: mandibular third molar depth in relation to the cemento-enamel junction of the second molar; anterior–posterior (A–P) position in relation to the anterior border of the ramus; and angulation registered at the functional occlusal plane. Analysis of variance and ordinal logistic regression were used to investigate relationships between the variables. Angulation of the third molars changed substantially with varying depths (p<0.0008) and A–P positions (p<0.0001), but did not appear to relate appreciably to dental age (p>0.5) or treatment condition (p>0.4). The A–P position was significantly correlated to dental age (p>0.004) and Bionator treatment (p<0.0001), whereas depth was marginally associated with dental age (p<0.07) and not influenced by Bionator treatment (p>0.5). Third molars adopt a position further anterior in relation to the ramus with Bionator treatment than they do in controls. As dental age increases, Bionator use appears to positively influence third molar position.

Mandibular response to orthodontic treatment with the Bionator appliance

A group of 20 subjects who underwent successful Bionator treatment was compared with 20 subjects who were treated less successfully with the same appliance. Both groups had similar advancements in their bite registrations, as well as similar treatment times and growth-prediction parameters. Success was judged not on the final occlusion (all patients were treated to a Class I molar relationship) but on the posttreatment position of skeletal pogonion. The successful group experienced 3.5 mm or more of advancement in skeletal pogonion, whereas the less successful group had less than 3 mm of advancement of this point. The two groups were comparable in all features except, as may be expected, total mandibular growth, which was greater in the group with the larger anterior pogonion advancement. The results of this study suggest that persons who have small mandibles (as determined by comparison with published growth standards) may benefit more from functional appliance therapy than patients with normal-sized mandibles. The subjects with delayed growth may experience more mandibular development than those with average growth during treatment under the favorable growth environment created by functional appliance therapy.

Bionator treatment in Class II, division 1.

Twenty cases treated with a Bionator followed by fixed appliance therapy are compared to an untreated sample and a group treated with fixed appliances only. The most notable differences in Bionator effects are increased vertical dimension and mandibular plane angle. The first appliance used, whether Bionator or fixed, produced similar changes.

The effects of second molar extraction in conjunction with bionator treatment: M. Toufic JeiroudiLoma Linda University, 1982

The effects of second molar extraction in conjunction with bionator treatment: M. Toufic JeiroudiLoma Linda University, 1982