Julia von Bremen

Complications during Mandibular Midline Distraction

OBJECTIVE To analyze the number and type of complications during mandibular midline distraction. MATERIALS AND METHODS The records of 100 consecutive patients who underwent mandibular midline distraction were evaluated, and complications which occurred up to 2 weeks after surgery were recorded. RESULTS Fourteen patients had complications during the distraction period. In four cases the screw of the appliance rotated back between the activations. In three cases the osteotomy had to be repeated because the symphysis did not open; two cases developed scar strictures, in another two a lower incisor fractured. One case developed an abscess, one a mandibular swelling, and one a large gingival recession. CONCLUSIONS Complications during or shortly after mandibular midline distraction surgery are relatively rare and mostly mild or transient. Only 3% of the patients presented irreversible damage. Thus, mandibular midline distraction appears to be a relatively safe method of expanding the mandible.

Occlusal stability of adult Class II Division 1 treatment with the Herbst appliance

INTRODUCTION During recent years, some articles have been published on Herbst appliance treatment in adult patients, an approach that has been shown to be most effective in Class II treatment in both early and late adulthood. However, no results on stability have yet been published. Our objective was to analyze the short-term occlusal stability of Herbst therapy in adults with Class II Division 1 malocclusions. METHODS The subjects comprised 26 adults with Class II Division 1 malocclusions exhibiting a Class II molar relationship > or =0.5 cusp bilaterally or > or =1.0 cusp unilaterally and an overjet of > or =4.0 mm. The average treatment time was 8.8 months (Herbst phase) plus 14.7 months (subsequent multi-bracket phase). Study casts from before and after treatment and after an average retention period of 32 months were analyzed. RESULTS After retention, molar relationships were stable in 77.6% and canine relationships in 71.2% of the teeth. True relapses were found in 8.2% (molar relationships) and 1.9% (canine relationships) of the teeth. Overjet was stable in 92.3% and overbite in 96.0% of the patients; true relapse did not occur. CONCLUSIONS Herbst treatment showed good occlusal stability 2.5 years after treatment in adults with Class II Division 1 malocclusions.

Plaque control effectiveness and handling of interdental brushes during multibracket treatment—a randomized clinical trial

SUMMARY The aim of this randomized clinical trial was to compare the plaque control effectiveness and handling of an interdental brush with a short curved handle and a triangular cross-section of the brush head (IDB) and an interdental brush with a long straight handle in combination with a monotufted brush head (MTB). In a split-mouth design, 110 multibracket patients were randomly assigned to group A using the MTB in the first and third quadrants and the IDB in the second and fourth quadrants or to group B who proceeded the other way around. A crossover was performed after 3 months. The plaque index (PI) was scored every 6 weeks for a period of 24 weeks, and handling was evaluated using visual analogue scales (VAS). Wilcoxon tests were used to determine differences in PI and VAS scores between the two brushes and for PI differences between the different observation periods. Differences concerning personal preference and perceived cleaning efficacy were analysed with chi-square tests. The significance levels used were P < 0.001 and P < 0.01. The PI decreased significantly, but no statistically significant difference was found between the two brushes. Subjects experienced less pain and reported better access behind the archwire with the IDB. The use of an interdental brush reduced the PI irrespective of the design of the brush head. In direct comparison, adolescent patients preferred the IDB. Further trials are required to investigate the effectiveness of the IDB in reducing decalcification during orthodontic treatment.

Is Herbst-Multibracket Appliance Treatment More Efficient in Adolescents than in Adults?

OBJECTIVE To determine whether Herbst treatment is more efficient in adolescent than in adult Class II division 1 subjects. MATERIALS AND METHODS All Class II division 1 patients with a full secondary dentition who had been treated at the orthodontic department of the University of Giessen with a Herbst appliance between 1990 and 2000 were considered. The complete records of 77 patients were available. According to their skeletal maturity, as assessed on hand-wrist radiographs, the subjects were divided into an adolescent group (MP3-F to MP3-H; n = 49; mean age 13.5 years) and an adult group (R-IJ to R-J; n = 28; mean age 20.7 years). Pretreatment and posttreatment dental casts were evaluated using the Peer Assessment Rating (PAR) Index. The reductions in PAR scores of the two groups were compared. RESULTS Before treatment, both groups had a severe Class II division 1 malocclusion. The average PAR score of the adolescent patients was slightly lower (27.8) than that of the adult patients (28.8). After treatment, good results were reached for both groups, and the average PAR scores of the two groups were comparable (adolescents: 4.5; adults: 4.8). The average reductions in PAR score were 82.7% (23.3 points) for the adolescent group and 82.9% (24.0 points) for the adults, indicating great improvement in both groups. CONCLUSIONS Because good treatment results were achieved, with substantial improvement of the pretreatment situation in both groups, Herbst treatment can be considered equally efficient in adolescent and in adult Class II division 1 subjects.

Anchorage loss due to Herbst mechanics-preventable through miniscrews?

AIM To assess if mandibular incisor proclination and protrusion during treatment with the Herbst/multibracket appliance can be prevented through simple screws (MIs) anchorage. MATERIAL AND METHODS After a statistical power analysis, 12 Herbst patients with MIs (100% MIs survival) ligated to the Herbst/multibracket appliance to reinforce anchorage were investigated. A control group matched for gender and skeletal maturity treated without MIs anchorage was selected. Pre- and posttreatment cephalograms were analysed for overjet reduction, mandibular incisor proclination (IL/ML), protrusion (Ii-MLp) and intrusion (Ii-ML), as well as occlusal plane inclination (OP/ML) by a single-blinded examiner. RESULTS No statistically significant differences between the two groups were found concerning overjet reduction, incisor protrusion- and intrusion or occlusal plane tilt. Although the MIs group generally showed less lower incisor proclination (4.8°) than the group without skeletal anchorage (6.5°), a large interindividual variation was observed. CONCLUSION Interradicular MIs anchorage cannot prevent anchorage loss during Herbst treatment. For the individual patient, the amount of incisor proclination and protrusion remains unpredictable.

Complications during Herbst Appliance Treatment with Reduced Mandibular Cast Splints@@@Komplikationen während der Herbst-Behandlung mit verkürzten Unterkieferschienen: A Prospective, Clinical Multicenter Study@@@Eine prospektive, klinische Multicenterstudie

Objective:To assess and compare the prevalence, type and frequency of complications during Herbst treatment with reduced (canine to 2nd premolars) and total (canine to molars) mandibular cast splints.Subjects and Methods:Fifty consecutive Herbst patients treated with reduced mandibular splints (RMS) were compared to 182 consecutively treated Herbst patients with total mandibular splints (TMS). The prevalence, type and frequency of complications were analyzed.Results:The prevalence of patients with complications did not differ significantly between the groups, and amounted to 58% in the RMS- and 60% in the TMS-group. The most frequent type of complication in both groups was maxillary splint loosening, making up 56.3% of all complications in the RMS- and 66.9% in the TMS-group. The second most frequent complication was mandibular splint loosening, which amounted to 32.5% of the complications in the RMS- and 26.8% in the TMS-group. We observed telescope breakage twice as often (8.8%) in the RMS- as in the TMS-group (4.3%).Conclusions:Loosening of the maxillary splints is the main complication during Herbst treatment with RMS and TMS. A reduction in mandibular splint length does not increase the prevalence of complications, but it does reduce expenses, and can thus be recommended for further use.ZusammenfassungZiel:Untersuchung der Komplikationsprävalenz, -art und -frequenz bei der Herbst-Behandlung mit einer neuen, verkürzten Unterkieferschiene (Eckzahn bis zweiter Prämolar) im Vergleich zur herkömmlichen langen Unterkieferschiene (Eckzahn bis Molar).Probanden und Methodik:50 konsekutive Herbst-Patienten, die mit einer verkürzten Unterkieferschiene (RMS = reduced mandibular splints) behandelt wurden, wurden mit 182 konsekutiven Patienten verglichen, die mit einer Herbst-Apparatur mit langen Schienen (TMS = total mandibular splints) behandelt worden waren. Die Prävalenz, Art und Frequenz auftretender Komplikationen wurden analysiert.Ergebnisse:Die Komplikationsprävalenz unterschied sich mit 58% in der RMS- und 60% in der TMS-Gruppe nur unwesentlich zwischen den beiden Gruppen. Die häufigste Komplikationsart in beiden Gruppen war die Schienenlockerung im Oberkiefer, welche 56,3% aller Komplikationen in der RMS- und 66,9% in der TMS-Gruppe ausmachte. Die zweithäufigste Komplikationsart war die Schienenlockerung im Unterkiefer, mit 32,5% aller Komplikationen in der RMS- und 26,8% aller Komplikationen in der TMS-Gruppe. Frakturen des Teleskopmechanismus waren in der RMS-Gruppe doppelt so häufig zu beobachten (8,8%) wie in der TMS-Gruppe (4,3%).Schlussfolgerungen:Die Lockerung der Oberkieferschienen ist bei der Herbst-Behandlung sowohl mit kurzen als auch mit langen Unterkieferschienen die häufigste Komplikationsart. Eine reduzierte Verankerung mit gegossenen Schienen erhöht die Komplikationshäufigkeit nicht, reduziert jedoch die Kosten und kann somit für die Herbst-Behandlung empfohlen werden.

Stability of Class II fixed functional appliance therapy--a systematic review and meta-analysis.

OBJECTIVES To systematically search for scientific evidence concerning the stability of treatment (Tx) results achieved by means of Class II fixed functional appliance therapy and to assess possible differences between appliances. SEARCH METHODS An electronic search of databases and orthodontic journals was carried out (until December 2013), with supplemental hand searching. In addition to the names of all identified appliances, the term fixed functional was used in combination with each of the following search terms: long-term, post-Tx, relapse, retention, stability. SELECTION CRITERIA To be included in the review, the articles had to contain clear data on: Class II Tx with a fixed functional appliance (>5 patients), post-Tx period ≥ 1 year, assessment of ANB angle, Wits appraisal, molar relationship, soft-tissue profile convexity excluding the nose, overjet and/or overbite. DATA COLLECTION AND ANALYSIS The literature search revealed 20 scientific investigations which corresponded to only two of the 76 identified appliances (Herbst and Twin Force Bite Corrector). As only one publication was found for the Twin Force Bite Corrector, a meta-analysis could only be performed for Herbst Tx. The data were extracted, pooled and weighted according to the number of patients in each study. RESULTS The mean values for post-Tx relapse (percentages relative to the Tx changes) were: ANB angle 0.2 degrees (12.4 per cent), Wits appraisal 0.5mm (19.5 per cent), sagittal molar relationship 1.2mm/0.1 cusp widths (21.8 per cent /6.5 per cent); soft-tissue profile convexity excluding nose less than 0.1 degrees (1.0 per cent), overjet 1.8mm (26.2 per cent), overbite Class II:1 1.4mm (44.7 per cent), overbite Class II:2 1.0mm (22.2 per cent). CONCLUSIONS The scientific evidence concerning the stability of Tx results is inexistent for most fixed functional appliances for Class II correction except for Herbst appliance Tx. Even if the evidence level of most included studies is rather low, good dentoskeletal stability without clinically relevant changes was found for most variables.

Association between Björk's structural signs of mandibular growth rotation and skeletofacial morphology.

The aim of this study was to apply Björks structural signs of mandibular growth rotation to answer the questions: (1) Is a hyperdivergent or hypodivergent skeletofacial growth pattern characterized by a specific mandibular morphology? (2) Are severe skeletofacial hyperor hypodivergencies recognized more easily than mild ones? (3) Are skeletofacial hyper- or hypodivergencies recognized more easily in older than in younger subjects? Mandibular cuttings from lateral head films of 135 Class I or Class II subjects were surveyed twice by nine observers. Of the 135 subjects, 95 subjects exhibited a large (ML/NSL > 38 degrees) and 40 a small (ML/NSL < 26 degrees) mandibular plane angle. Using the structural signs of mandibular growth rotation, the observers had to categorize the subjects as having either a high-angle or low-angle skeletofacial morphology. In 14% (13 of 95) of the subjects with a large ML/NSL angle, the skeletofacial hyperdivergency was recognized in all registrations, but in 19% (18 of 95), the hyperdivergency was identified in less than half of the registrations. In 63% (25 of 40) of the subjects with a small ML/NSL angle, the skeletofacial hypodivergency was recognized in all registrations, whereas in only 2.5% (one of 40), the hypodivergency was identified in less than half of the registrations. There was no association between the degree of hypo- or hyperdivergency or the age of the subjects and the number of correct registrations. Using the structural method of Björk, it was difficult to categorize the subjects as having either a hyperor hypodivergent skeletofacial morphology. However, hypodivergency was recognized more easily than hyperdivergency.

Complications during Herbst Appliance Treatment with Reduced Mandibular Cast Splints

Objective:To assess and compare the prevalence, type and frequency of complications during Herbst treatment with reduced (canine to 2nd premolars) and total (canine to molars) mandibular cast splints.Subjects and Methods:Fifty consecutive Herbst patients treated with reduced mandibular splints (RMS) were compared to 182 consecutively treated Herbst patients with total mandibular splints (TMS). The prevalence, type and frequency of complications were analyzed.Results:The prevalence of patients with complications did not differ significantly between the groups, and amounted to 58% in the RMS- and 60% in the TMS-group. The most frequent type of complication in both groups was maxillary splint loosening, making up 56.3% of all complications in the RMS- and 66.9% in the TMS-group. The second most frequent complication was mandibular splint loosening, which amounted to 32.5% of the complications in the RMS- and 26.8% in the TMS-group. We observed telescope breakage twice as often (8.8%) in the RMS- as in the TMS-group (4.3%).Conclusions:Loosening of the maxillary splints is the main complication during Herbst treatment with RMS and TMS. A reduction in mandibular splint length does not increase the prevalence of complications, but it does reduce expenses, and can thus be recommended for further use.ZusammenfassungZiel:Untersuchung der Komplikationsprävalenz, -art und -frequenz bei der Herbst-Behandlung mit einer neuen, verkürzten Unterkieferschiene (Eckzahn bis zweiter Prämolar) im Vergleich zur herkömmlichen langen Unterkieferschiene (Eckzahn bis Molar).Probanden und Methodik:50 konsekutive Herbst-Patienten, die mit einer verkürzten Unterkieferschiene (RMS = reduced mandibular splints) behandelt wurden, wurden mit 182 konsekutiven Patienten verglichen, die mit einer Herbst-Apparatur mit langen Schienen (TMS = total mandibular splints) behandelt worden waren. Die Prävalenz, Art und Frequenz auftretender Komplikationen wurden analysiert.Ergebnisse:Die Komplikationsprävalenz unterschied sich mit 58% in der RMS- und 60% in der TMS-Gruppe nur unwesentlich zwischen den beiden Gruppen. Die häufigste Komplikationsart in beiden Gruppen war die Schienenlockerung im Oberkiefer, welche 56,3% aller Komplikationen in der RMS- und 66,9% in der TMS-Gruppe ausmachte. Die zweithäufigste Komplikationsart war die Schienenlockerung im Unterkiefer, mit 32,5% aller Komplikationen in der RMS- und 26,8% aller Komplikationen in der TMS-Gruppe. Frakturen des Teleskopmechanismus waren in der RMS-Gruppe doppelt so häufig zu beobachten (8,8%) wie in der TMS-Gruppe (4,3%).Schlussfolgerungen:Die Lockerung der Oberkieferschienen ist bei der Herbst-Behandlung sowohl mit kurzen als auch mit langen Unterkieferschienen die häufigste Komplikationsart. Eine reduzierte Verankerung mit gegossenen Schienen erhöht die Komplikationshäufigkeit nicht, reduziert jedoch die Kosten und kann somit für die Herbst-Behandlung empfohlen werden.

Long-term effects of Class II Herbst treatment on the pharyngeal airway width

Objective The aim was to assess the long-term effects of Class II malocclusion treatment with the Herbst appliance on the pharyngeal airway (PA) width in comparison to untreated individuals with Classes I and II malocclusion. Methods Lateral cephalometric radiographs of 13 male Class II patients from before (T1) and after (T2) treatment with the Herbst appliance as well as after the end of growth (T3) were retrospectively analyzed and compared to two untreated age- and gender-matched samples with Class I (n = 13) or Class II (n = 13) malocclusion. The PA dimensions were measured using the parameters p (narrowest distance between the soft palate and the posterior pharyngeal wall) and t (narrowest distance between the base of the tongue and the posterior pharyngeal wall). In addition, standard cephalometric measurements were performed. Results Relevant changes in PA dimensions were only seen for the post-treatment period, during which the distances p and t showed a significant increase in the Herbst group only (∆p: 2.3 mm, ∆t: 3.3 mm) while remaining similar in both untreated groups (∆p: 0.5 mm, ∆t: 0.5 mm, respectively, ∆p: 0.7 mm, ∆t: 1.6 mm). During the same period, posterior face height showed a significantly larger increase in the Herbst group than in both control groups (8.2 versus 5.8 mm, respectively, 5.4 mm), whereas anterior face height (NL-Me) showed a similar development in all groups (4.6 versus 4.4 mm, respectively 3.2 mm). Conclusion In the long term, Herbst treatment resulted in a significant post-treatment increase of PA width, possibly due to an increased lower posterior facial height development compared to untreated individuals.