Michael Knösel

Universitätsmedizin Göttingen · Department of Orthodontics

Objective: The aim of this prospective study was to evaluate the re-colonisation pattern of Streptococcus mutans (MS) in high-level MS-colonised patients with fixed orthodontic appliances following 40% chlorhexidine varnish application prior to bracket placement. Materials and methods: The subjects of this single-blinded clinical trial were 13-14-y...

Aim: To assess whether the efficacy of external tooth bleaching differs between untreated and orthodontically treated teeth. Materials and method: Three groups of subjects were formed; group Debonded included 24 consecutive orthodontically treated patients evaluated immediately after removal of fixed appliances. The Retention group included 24 c...

Objective: To assess possible color changes of natural teeth after surgical orthodontic treatment. Methods: This prospective controlled clinical pilot trial included 6 consecutively treated surgical orthodontic patients with class III malocclusion and neutral vertical relation (ST: surgical treatment), 3 of which received double jaw osteotomies...

PurposeTo test the null hypothesis of no significant deviation between the center of rotation (CROT) and the center of resistance (CRES) during space closure in Angle class II division 2 subjects achieved using a completely customized lingual appliance (CCLA) in combination with class II elastics and elastic chains.Methods This retrospective study...

Introduction: There is no consensus regarding which mode of activation or mandibular advancement (stepwise [SW] or maximum bite-jumping [BJ]) of fixed or removable functional appliances (FFA; RFA) for correction of Angle class II malocclusion is advantageous to produce dental, skeletal or condylar effects and has the lowest rate of undesired denta...

Background: Post-orthodontic white-spot lesions (WSL) in esthetically relevant incisor and canine areas impair dentofacial esthetics, and preventive dentistry treatment is definitely required in case of enamel cavitations. The incidence of lingual post-orthodontic WSL and cavitation following lingual MB treatment has been reported to be distinctiv...

Background: Controlled space closure in cases of isolated lower second premolar aplasia (ILSPA) without maxillary counterbalancing extraction is challenging. Anterior anchorage loss may occur during space closure resulting in compromised occlusal results in terms of an absence of proper canine guidance during laterotrusive mandible movements. In o...

Background Intraorally, a common instrumental approach for measuring tooth color is reflectance spectrophotometry. Objective To evaluate the precision of a reflectance spectrophotometer in accurately measuring anterior tooth color. Methods The twelve labial surfaces of the anterior teeth of sixteen patients were measured spectrophotometrically (S...

Objectives:: To reassess the long-term camouflage effects of resin infiltration (Icon, DMG, Hamburg, Germany) of white spot lesions (WSL) and sound adjacent enamel (SAE) achieved in a previous trial. The null hypothesis was tested that there were no significantly different CIE-L*a*b*-ΔE-values between WSL and SAE areas of assessment after at least...

Purpose: To provide an overview of different indications suitable for treatment with the technique of resin infiltration (Icon, DMG), such as white-spot lesions (WSL), enamel fluorosis, and molar-incisor hypomineralisation (MIH), and to propose a valid and strategy feasible in dental surgeries for screening of dental color improvement and -stabilit...

Background and objectiveWhite spot lesions (WSLs) are an undesirable side effect of fixed orthodontic appliance therapy and are reported to occur in 2–96 % of orthodontic patients. In this study, the efficacy of a new sealant to prevent WSLs during fixed orthodontic treatment was compared to a control group that did not receive sealant. Patients an...

Enamel decalcification, or the presence of white spot lesions (WSLs), is among the most common side effects of fixed orthodontic treatment. A broad spectrum of prophylactic measures enables orthodontists to reduce the severity of the problem (eg, controlling nutritional habits, motivating patients regarding oral hygiene, or applying fluoride-releas...

To treat initial caries lesions using the technique of resin infiltration for a restoration of natural enamel appearance. Case report of a 19 year old female who presented with moderate post-orthodontic white-spot lesions (WSLs) at the upper central and lateral incisors following two years of active treatment with a fixed orthodontic appliance, and...

Objective: To test the null hypothesis of no significant difference in terms of intraoral pressure curve characteristics assessed simultaneously at the subpalatal space (SPS) and the vestibular space (VS), during different oral postures, between four groups with either an Angle Class II/1 (II1), Angle Class II/2 (II2), anterior open bite (O) maloc...

Hintergrund und Zielsetzung: Das Kräftegleichgewicht zwischen Lippen und Zunge beeinflusst die Zahnstellung und kann Malokklusionen mitbedingen und verstärken. Die biologischen Funktionen des orofazialen Systems sind bisher nur unzureichend differenziert worden: Die Rolle des weichen Gaumens ebenso wie die Dynamik weiterer am Schluckvorgang beteili...

Hintergrund und Zielsetzung: Das Entstehen von Schmelzentkalkungen oder White-Spot-Läsionen (WSL) ist eine häufig auftretende unerwünschte Begleiterscheinung der herkömmlichen festsitzenden kieferorthopädischen Behandlung. Die Lingualtechnik kann einen Beitrag dazu leisten, die Schwere der Nebenwirkungen zu mindern, indem die Bracketplatzierung in...

Background: Using lingual enamel surfaces for bracket placement not only has esthetic advantages, but may also be suitable in terms of reducing frequencies of enamel decalcifications. Objective: To test the null-hypothesis that there is no significant difference in enamel decalcification or cavitation incidence adjacent to and beneath bracket ba...

Objective To assess the types and frequencies of clinical complications experienced when using a modified lingual Herbst appliance and to compare these with those associated with conventional Herbst appliances reported in the literature. Methods Treatment records for 35 consecutive subjects treated during the observation period from October 2013 t...

The aim of this study was to assess the incidence of white spot lesions (WSLs) in subjects treated with customized lingual multibracket appliances-separately for maxillary anterior teeth 12 to 22 (according to the Fédération Dentaire Internationale numbering system) as well as for tooth groups 15 to 45, 16 to 46, and 17 to 47-and to determine the i...

There is a paucity of information with regard to the susceptibility of iatrogenic white spot lesion formation after inattentive, surplus orthodontic etching with 30% phosphoric acid and the subsequent provision or absence of adequate oral hygiene.Ninety sound enamel specimens were randomly allocated to 6 trial groups (N = 15 each) for etching with...

Objective: To test the null hypothesis of no significant difference between intraoral pressure characteristics in infants with cleft lip and palate (CLP) with or without presurgical orthopedic (PSO) plates (groups CLP and CLP-PSO), compared with noncleft infants. Materials and methods: Intraoral atmospheric pressure assessments were performed on...

Sealant application during fixed appliances orthodontic treatment for enamel protection is common, however, reliable data on its durability in vivo are rare. This study aims at assessing the durability of a sealant (OpalSeal, Ultradent) for protection against white-spot lesion formation in orthodontic patients over 26 weeks in vivo, taking into acc...

Introduction The occurrence of side-effects of fixed orthodontic therapy, such as white-spot lesions and root resorption, are known to be significantly more frequent with increasing duration of treatment. Multi-bracket treatment should be as short as possible, in order to minimize the risks of collateral damage to teeth. The aim of this non-randomi...

Objective: To assess camouflage effects by concealment of postorthodontic white-spot lesions (WSLs) to sound adjacent enamel (SAE) achieved over 12 months with resin infiltration (Icon, DMG, Hamburg, Germany). Methods: Twenty subjects (trial teeth nteeth = 111) who had received resin infiltration treatment of noncavitated postorthodontic WSLs we...

Obwohl die Vorteile festsitzender Multibracketapparaturen unbestritten sind, geht ihre Anwendung auch mit Nebenwirkungen einher. Den entstehenden Demineralisationen des Schmelzes kann durch Prophylaxestrategien und Camouflage durch mikroinvasive Infiltration entgegengewirkt werden.

White spot lesions that form during orthodontic treatment are a problem for patients and clinicians. Lesion infiltration with low-viscosity light-cured resin has been proposed as a treatment to inhibit further demineralization. The purpose of this study was to assess the durability of assimilation of white spot lesions and sound adjacent enamel ach...

The aim of this prospective study was to evaluate the re-colonisation pattern of Streptococcus mutans (MS) in highlevel MS-colonised patients with fixed orthodontic appliances following 40% chlorhexidine varnish application prior to bracket placement. The subjects of this single-blinded clinical trial were 13-14year-old adolescents (N = 14) with si...

Moderne Multibracket-Apparaturen ha-ben die orthodontische Breitenver-sorgung ermöglicht, bringen jedoch den Nachteil einer vorübergehend erschwerten Mundhygiene mit sich: Brackets stellen Pflegehindernisse dar und begünstigen eine vermehrte Plaqueakkumulation, aus der ein erhöhtes Schmelzdemineralisationsrisiko während der kieferorthopädischen Beh...

To systematically assess the informational value, quality, intention, source and bias of web 2.0 footage whose aim is peer-to-peer education about oral implantology. YouTube (http://www.youtube.com) was scanned on 15 October 2010 for oral implantology-related videos using an adequately pre-defined search query. Search results were filtered with the...

Sealant application is a common strategy for preventing enamel demineralization during multibracket treatment. The aim of this study was to assess the efficacy in enamel demineralization prevention of two fluoride-containing enamel varnishes compared to a non-fluoride varnish, weekly fluoride gel application, and a non-treated control group. Enamel...

There is a paucity of information with regard to the susceptibility of iatrogenic white spot lesion formation after inattentive, surplus orthodontic etching with 30% phosphoric acid and the subsequent provision or absence of adequate oral hygiene. Ninety sound enamel specimens were randomly allocated to 6 trial groups (n = 15 each) for etching with...

Habitual mouth breathing is often accompanied by habitual anterior tongue thrust, instead of a lip closure, in order to create the anterior seal necessary for the initiation of physiological deglutition. We tested the null hypothesis of no significant influence of oral maneuver and the use of oral screens on tongue coordination and position during...

The objective of this study was to systematically assess the informational value, intention, source, and bias of videos related to dentistry available on the video-sharing Internet platform YouTube. YouTube (www.youtube.com) was searched for videos related to dentistry, using the system-generated sorts "by relevance" and "most viewed" and two categ...

The concept of "ideal" occlusion in harmony with craniofacial structures is often proposed as an ultimate goal of orthodontic treatment. The aim of this study was to assess the impact of slight variations in posterior occlusion and the history of straight-wire orthodontic treatment on the predictability of incisor inclination and third-order angles...

To assess the sensitivity of digital dental photo CIE L*a*b* analysis compared to clinical spectrophotometer assessments over 6 months. CIE L*a*b* values for the upper right central incisors of 14 predoctoral dental students subjected to certain color-relevant exclusion criteria were recorded at baseline (T0), after 6 months (T1), and 1 week later...

The aim of this study was to assess the durability of bleaching results achieved with (1) 15% carbamide peroxide home bleaching and (2) 38% hydrogen peroxide in-office bleaching. A total of 231 extracted anterior teeth were randomly divided into three groups (n = 77 in each group) with comparable mean baseline L*-values (68.24 ± 0.8): a non-bleache...

To test the null hypothesis of no significant differences in (1) the duration of the post-deglutory, cranial tongue rest position (CTP) between different functional orofacial conditions and (2) the presence or absence of an oral screen (OS) in subjects with a habitual open-mouth posture. Twenty-nine subjects (aged 6-16; mean: 9.69 years; 13/16 girl...

To compare the influence of demineralized and variously pretreated demineralized enamel on the shear bond strength of orthodontic brackets. Sixty bovine enamel specimens were allocated to five groups (n  =  12). Specimens of group 1 were not demineralized and were not pretreated, but served as controls. The other specimens were demineralized to for...

The aim of present in vitro study was to evaluate and compare the influence of demineralized and variously pre-treated demineralized enamel on shear bond strength of orthodontic brackets. Five groups (n=12) of bovine enamel specimens with artificially formed carious lesions were treated with a infiltrating resin (group 1: Icon, DMG, Germany) or wi...

To assess the informational value, intention, source, and bias of videos related to orthodontics screened by the video-sharing Internet platform YouTube. YouTube (www.youtube.com) was scanned in July 2010 for orthodontics-related videos using an adequately defined search term. Each of the first 30 search results of the scan was categorized with the...

A thorough understanding of the intraoral pressure conditions of patients with different forms of malocclusion may help to characterize their aetiology in more detail and improve orthodontic treatment approaches by adding strategies to achieve a normalization of intraoral pressure levels. These pressure curve analyses should not only provide inform...

Aim: The study aims to provide objective data for the displacement of titanium screw implants in trabecular bone specimens. One hundred Semados implants (Bego, Bremen, Germany) were inserted in bovine type IV bone specimens. All implants had a diameter of 3.75 mm; 50 implants had a length of 8.5 mm and 50 implants had a length of 15 mm. Insertion t...

Oral posture is considered to have a major influence on the development and reoccurrence of malocclusion. A biofunctional model was tested with the null hypotheses that (1) there are no significant differences between pressures during different oral functions and (2) between pressure measurements in different oral compartments in order to substanti...

The Commission Internationale de l'Eclairage (CIE) L*a*b* three-dimensional coordinates suggest strong correlations between the data of a* (red-green axis) and b* (blue-yellow axis), as both are located on the same plane in the model and should therefore show a strong dependency. In order to assess the veridicality of colour determinations, the nul...

Objective To evaluate impulse debonding compared to three conventional methods for bracket removal in relation to the damage caused to the enamel surface Materials and Methods Ninety-six osteotomed third molars were randomly assigned to two study groups (n = 48) for bracket bonding with either a composite adhesive system (CAS) or a glass-ionomeric...

To evaluate impulse debonding compared to three conventional methods for bracket removal in relation to the damage caused to the enamel surface. Ninety-six osteotomed third molars were randomly assigned to two study groups (n = 48) for bracket bonding with either a composite adhesive system (CAS) or a glass-ionomeric cement (GIC). These two groups...

Orofacial biofunction comprises muscular and physical effects, which may contribute to stabilization of the oropharyngeal airway. The tongue-repositioning manoeuvre (TRM) provides physical stabilization of the tongue and the soft palate together with, as a prerequisite, a nasal breathing mode. The aim of the present study was to evaluate the influe...

The purpose of this study was to quantify the impact of oral screen (OS) application on intra-oral pressure characteristics in three malocclusion groups. Fifty-six randomly recruited participants (26 males and 30 females) who met the inclusion criteria of either an Angle Class I occlusal relationships or Angle Class II1 or II2 malocclusions, were a...

To test the null hypothesis that there are no significant differences in the reusability of debonded brackets with regard to debonding technique and adhesive used. Ninety-six osteotomed third molars were randomly assigned to two study groups (n = 48) for bonding of a 0.018-inch bracket (Ormesh, Ormco) with either a composite adhesive (Mono-Lok2; RM...

The aim of this study was to investigate retrospectively the incidence of inhibited root development by metric analysis of orthopantomograms, based on examination of the posterior teeth of 40 children and adolescents with Angle Class II, Division 1 malocclusion who received two different removable functional appliances to treat the distal intermaxi...

The aim of this retrospective study was to examine the effect of orthodontic extrusion on the pulpal vitality of maxillary incisors with a history of trauma. Pulpal condition was examined clinically (rating of crown color and sensitivity testing with a cryogenic spray) and radiologically (periapical and panoramic radiographs) after orthodontic extr...

To test the null hypothesis that third-order measurements are not correlated to lingual incisor features seen on radiographs. The lateral headfilms of 38 untreated, norm-occlusion subjects without incisor abrasions or restorations were used for third-order measurements of upper and lower central incisors and assessment of the inclination of four si...

To evaluate the significance of crown-root angles (CRAs) by testing the null hypothesis that there are no significant differences in deviations of third-order angles to axial inclination values between Angle Class II division 2 incisors and a neutral occlusion control sample. The study group comprised n(total) = 130 whites with either Angle Class I...

The aims of this study were to evaluate the relationship of third order measurements on dental casts with those on lateral radiographs, and to identify those incisor features on radiographs which can best explain third order measurements on dental casts. Lateral cephalograms and corresponding dental casts were obtained from 39 untreated Caucasians...

To evaluate the concordance and repeatability of two in vivo methods for dental color assessment and to clarify the influence of different ambient light conditions and subject's head position on the assessed color variables. Color assessments were performed by two examiners on 16 arbitrarily selected subjects under two different, standardized condi...

The objective of this study consisted in determining the variability of the ANB angle in relation to the position of the A- and B-points in the sagittal vertical plane. Using a theoretical model, we varied the position of the cephalometric points A and B in the sagittal vertical plane while its sagittal relationship was kept constant (Wits value =...

Different craniofacial properties require individual targets in incisor inclination. These requirements are mostly scheduled on the basis of cephalometric diagnosis, but, however, performed using straightwire appliances, which refer to third-order angles and not to cephalometric data. The objective of this study was to analyze the relationship betw...

To evaluate the effect of external bleaching on the color and luminosity of fluorotic stains and adjacent, normally mineralized enamel areas by means of CIE L*a*b* colorimetry. Eighteen adolescents with mild to moderate fluorotic stains were randomly assigned to either bleaching group A (n = 9) or control group B. Eligibility criteria were fluoroti...

To evaluate the effect of external bleaching on the color and luminosity of inactive white-spot lesions (WSLs) present after fixed orthodontic appliance treatment as means for achieving color matching of the WSLs with adjacent tooth surfaces. Ten patients with inactive WSLs after therapy with fixed orthodontic appliances were selected. At baseline,...

Estimating incisor inclination cephalometrically by reference lines NA and NB puts the orthodontist in the difficult position of relating these axial inclination data to the bracket's third-order prescription which refers to a perpendicular to the occlusal plane. Purpose of the present study was to evaluate the relationship between the cephalometri...

The primary aim of the study was to reveal whether the free opening movement of the mandible can be determined by only 2 rotational axes as suggested in recent literature. For this purpose, the free opening movement of the mandible was registered in 20 asymptomatic patients using an ultrasonic measuring system. Subsequently, the locations of the in...

To evaluate the relationship between the angular measurement data (incisor's long axis to NA line) and the third-order angle (TA) according to Andrews' description. The materials in the study included the lateral radiographs and corresponding dental casts of 32 males and 35 females between 10 and 25 years of age, regardless of their skeletal and de...

A number of muscles which pull over the tibiofemoral joint (possessing maximally four kinematic degrees of freedom) is larger than necessary in order to produce static equilibria in the physiologic positions of the tibiofemoral joint. Consequently, it should be possible to balance the knee in any arbitrary position by a set of combinations of isoto...