Britta A. Jung

Success rate of second-generation palatal implants.

OBJECTIVE To analyze the clinical outcome of a prospective two-center study of second-generation palatal implants 6 months after functional loading. MATERIAL AND METHODS From 2005 to 2006, 30 patients aged 12 to 41 years were included in the study. In all patients, orthodontic treatment required stationary anchorage. The palatal implants (Straumann, Basel, Switzerland) were placed in the median region of the anterior palate. RESULTS All implants were initially stable at the time of placement. However, two (6.7%) were lost during the unloaded healing period. The remaining 28 (93.3%) were subjected to functional loading after a mean healing period of 12 weeks. Typical signs of slight superficial inflammation were observed in the peri-implant mucosa (n = 28). During the orthodontic loading phase, the implants were equipped with either a modified pendulum appliance for distalization or a transpalatal arch for stationary anchorage to the posterior teeth. No implant loosening or loss was registered during the active treatment period. CONCLUSIONS The failure rate of palatal implants of the second generation was low (6.7%). Slight inflammatory reactions of peri-implant tissue caused neither implant loss nor pain.

Vertical palatal bone dimensions on lateral cephalometry and cone-beam computed tomography: implications for palatal implant placement.

OBJECTIVES To evaluate the necessity of three-dimensional imaging (computed tomography [CT]/cone-beam computed tomography [CBCT]) for paramedian insertion of palatal implants. MATERIAL AND METHODS Lateral radiographs and CBCT scans were performed from 18 human skulls. For lateral cephalometry, the nasal floor (right/left) and the oral hard palate of all skulls were lined with a tin foil for contrast enhancement. The quantity of vertical bone as measured on lateral radiographs was compared with CBCT measurements obtained in median and parasagittal planes and at minimum bone height. Spearmans rank correlation coefficients were determined for bivariate correlation analysis. RESULTS The median palatal bone height on CBCT (mean 8.98 mm; standard deviation [SD] 3.4) was markedly higher than the vertical height seen on lateral radiographs (mean 6.6 mm; SD 3.2). Comparing lateral cephalometry with CBCT, the strongest association was observed at the minimum palatal bone height (r=0.926; P<0.001; Spearmans rank correlation coefficient). CONCLUSIONS Lateral radiographs allow accurate and adequate assessment of vertical bone before paramedian insertion of palatal implants. The vertical bone dimension as displayed on lateral cephalometry reflects the minimum bone height rather than maximum bone in the median plane. Therefore, a preoperative CT or CBCT is only indicated when the lateral cephalometry reveals a marginal quantity of bone.

Preoperative Diagnostic for Palatal Implants: Is CT or CBCT Necessary?

OBJECTIVE To evaluate (a) the diagnostic value of lateral radiographs and (b) whether computed tomography (CT) or cone beam computed tomography (CBCT) is necessary in preoperative diagnostics for orthodontic anchorage implants. PATIENTS AND METHODS We reviewed all patients who had presented for insertion of a palatal implant between January 2003 and December 2007 at the University Hospital Mainz. On the basis of lateral radiographs, the palatal bone was assessed as follows: (a) sufficient (bone height > 4 mm in the implant axis), (b) ambiguous, or (c) insufficient (bone height < 4 mm in the implant axis). In group A the surgical insertion procedure was performed without further radiological investigation. Group C required other types of anchorage. In cases of an ambiguous bone situation (group B), further diagnostic procedures (CT/CBCT) were performed. RESULTS During the observation period, 105 patients were screened. Fourteen patients opted for alternative treatment leaving 91 patients for final evaluation. In 89 patients (97.8%), the lateral radiographs showed sufficient bone in the vertical dimension. In all of these cases, the availability of sufficient bone was confirmed intraoperatively. Further investigations were performed in two patients (2.2%) of group B (one CT, one CBCT). Finally, one patient had insufficient bone whereas the second had sufficient bone. CONCLUSIONS Nearly 98% of the patients included in this study had sufficient bone for palatal implant insertion. Lateral radiographs permit correct and reliable evaluation of the quantity of bone in preoperative diagnosis of palatal implants. Additional imaging (CT or CBCT) is only required in rare cases of borderline dimensions.

Early loading of plalatal implants (ortho-type II) a prospective multicenter randomized controlled clinical trial.

BackgroundIn orthodontic treatment, anchorage control is a fundamental aspect. Usually conventional mechanism for orthodontic anchorage control can be either extraoral or intraoral that is headgear or intermaxillary elastics. Their use are combined with various side effects such as tipping of occlusal plane or undesirable movements of teeth. Especially in cases, where key-teeth are missing, conventional anchorage defined as tooth-borne anchorage will meet limitations. Therefore, the use of endosseous implants for anchorage purposes are increasingly used to achieve positional stability and maximum anchorage.Methods/DesignThe intended study is designed as a prospective, multicenter randomized controlled trial (RCT), comparing and contrasting the effect of early loading of palatal implant therapy versus implant loading after 12 weeks post implantation using the new ortho-implant type II anchor system device (Orthosystem Straumann, Basel, Switzerland).124 participants, mainly adult males or females, whose diagnoses require temporary stationary implant-based anchorage treatment will be randomized 1:1 to one of two treatment groups: group 1 will receive a loading of implant standard therapy after a healing period of 12 week (gold standard), whereas group 2 will receive an early loading of orthodontic implants within 1 week after implant insertion. Participants will be at least followed for 12 months after implant placement.The primary endpoint is to investigate the behavior of early loaded palatal implants in order to find out if shorter healing periods might be justified to accelerate active orthodontic treatment. Secondary outcomes will focus e.g. on achievement of orthodontic treatment goals and quantity of direct implant-bone interface of removed bone specimens. As tertiary objective, a histologic and microtomography evaluation of all retrieved implants will be performed to obtain data on the performance of the SLA surface in human bone evaluation of all retrieved implants. Additionally, resonance frequency analysis (RFA, Osstell™ mentor) will be used at different times for clinically monitoring the implant stability and for histological comparison in order to measure the reliability of the resonance frequency measuring device.Trial registrationCurrent Controlled Trials ISRCTN97142521.

Immediate Nonfunctional Loading of NobelPerfect Implants in the Anterior Dental Arch in Private Practice – 5‐Year Data

BACKGROUND The concept of scalloped implants to maintain the natural contour of the alveolar ridge has been a source of controversy for many years. PURPOSE This study examined the long-term clinical performance of the scalloped NobelPerfect implant in a one-stage procedure (immediate loading in the esthetic zone). MATERIALS AND METHODS In 20 patients, immediate prosthetic restorations were placed on 31 NobelPerfect implants in a private practice and followed for up to 78 months. Twenty-one implants were placed immediately after extraction, seven implants were placed after osseous consolidation of the extraction sockets, and three implants were placed secondary to extended alveolar ridge augmentation procedures. All implants were provisionalized on the day of implant placement and adjusted to clear all contacts in centric occlusion and during eccentric movements. Outcome variables were success rates, marginal bone levels, and pink esthetic score (PES) assessed per implant. RESULTS One implant failed after 1.4 months. Five patients with six implants in total were scored in the 5-year follow-up as dropouts. Mean follow-up period of remaining 24 implants was 65 months (range, 55-78 months). Cumulative success rates according to the criteria specified by Smith and Zarb were 96.8%. Marginal bone levels averaged 1.1 mm above the first thread. Mean PES ratings were 10.5 (range, 3-13). CONCLUSIONS Survival rates, marginal bone levels, and esthetic results suggest proof of principle for the preservation of the interproximal bony lamella with a scalloped implant design in long-term data.

New method of temporary rehabilitation after traumatic tooth loss in a juvenile patient: a case report

We report a 12-year-old female patient who had experienced traumatic loss of one of her permanent central incisors. In the course of interdisciplinary treatment, the gap in the front teeth was filled with a prosthetic plastic tooth fastened to an orthodontic palatal implant by means of a wire extension (stainless steel 1.2 mm; laser-welded). A palatal implant is a temporary orthodontic anchorage device which, in contrast to a conventional single tooth implant, is not inserted in the toothless alveolar bone but in the palatal region to permit unhindered maxillary growth. The advantages of this treatment compared with traditional treatment options are that it permits secure fixation, adjustment to vertical growth and good hygiene. Besides, it is an economical treatment modality, can be used as anchorage in conjunction with orthodontic treatment and provides good comfort, esthetics and phonetics.

Immediate vs. conventional loading of palatal implants in humans.

OBJECTIVES To analyze the clinical performance and bone-to-implant contact (BIC) rate of two loading concepts on successfully healed and explanted palatal implants in humans. METHODS From 2000 to 2006, two independent groups of patients, requiring maximum anchorage, were treated. Group 1 (n=36) was subjected to immediate functional loading within the first 24 h after insertion while group 2 (n=40) received conventional implant loading after 12 weeks. The magnitude of orthodontic forces ranged between 1 and 3 N. After orthodontic treatment, the implants were removed with a trephine drill. Histological workup by the cutting and grinding technique was performed for nearly the last third of palatal implants. Outcome variables were clinical implant survival and histological BIC rates. RESULTS The implants in both groups were initially stable at the time of insertion. However, 3/36 in group 1 and 1/40 in group 2 were lost. The remaining implants were clinically stable and no mobility was recognized. The median BIC rates were 76% (SD, 25) in group 1 (n=10) and 84% (SD, 13) in group 2 (n=12) (P=0.262; Mann-Whitney U-test, not significant). CONCLUSIONS The data support the concept of immediate indirect loading on palatal implants with forces of up to 3 N. On histological evaluation, immediate loading yielded similar BIC rates as conventional loading.

Bone-to-implant contact of orthodontic implants in humans—a histomorphometric investigation

The purpose of the present study was to evaluate the percentage of direct bone-to-implant contact (BIC) of orthodontic anchorage implants (Orthosystem) after active orthodontic treatment. Twenty orthodontic implants (diameter, 3.3 mm; length, 4 or 6 mm) were inserted for orthodontic anchorage in different anatomical regions of 18 adult patients (nine males, nine females) aged 18-63 years. Fifteen implants (one per patient) were placed in the mid-palatal area, one implant (one patient) in the retromolar area of the mandible, one in the retromolar area and the mid-palatal area (one patient), and two (bilaterally, one patient) in the zygomatic area. The duration of the unloaded healing period was 3 months while that of the loading period ranged from 9 to 22 months. Subsequently, the implants were removed with a bone drill and prepared for histological and histomorphometric evaluation. Histological analysis was performed using the ground thin-section technology. Outcome variables were clinical implant survival and BIC rates. Statistical evaluation included analysis of the measured values, minimum, maximum, means, and standard deviations of the means. The mean percentage of direct BIC at the endosseous implant body was 68.22 per cent for the palatal implants [n = 16, standard deviation (SD): 14.35], 64.85 per cent (SD: 2.89) for the retromolar implants (n = 2), and 60.45 per cent (SD: 0.49) for the zygomatic implants (n = 2). A relatively high BIC was registered at the surfaces of the loaded implants. This finding might favour the maintenance of osseointegration during orthodontic loading of length-reduced implants.

Spectrum of Indications for Palatal Implants in Treatment Concepts Involving Immediate and Conventional Loading

Aim:To analyze the spectrum of indications for second-generation palatal implants in relation to two different loading concepts in a prospective, multicenter, randomized controlled trial (RCT).Patients and Methods:Forty-one patients were recruited to the study from 2006 to 2009. All implants (Orthosystem®, Straumann, Basel, Switzerland; dimensions: 4.1 mm × 4.2 mm) were inserted in the median or paramedian region of the anterior palate, and each patient was randomized to one of two loading groups (immediate loading within the first week after insertion versus conventional loading after a 12-week healing phase). In this interim evaluation, we report preliminary results obtained six months after functional loading.Results:All palatal implants were primarily stable at the time of insertion. One implant loss (12 weeks after surgical insertion) was documented in the cohort subjected to conventional loading, and one patient dropped out of the immediate-loading group. At the time of this investigation, 39 palatal implants are experiencing functional loads. Using both loading concepts, we had various orthodontic objectives, such as intrusion of anterior and/or posterior teeth, and the mesialization and distalization of posterior teeth. Both loading groups presented nearly identical indications, and the distribution of direct vs. indirect anchorage forms was also very similar during the active treatment.Conclusion:Comparison of the two treatment concepts revealed no clinical differences in implant stability. Patients undergoing immediate-loading therapy were subject to no limitations regarding indications at 6 months after functional loading compared with the patients who experienced conventional loading.ZusammenfassungZiel:Im Rahmen einer prospektiven multizentrischen RCT-Studie (Randomized Controlled Trial) wird das Indikationsspektrum von Gaumenimplantaten der zweiten Generation bei zwei verschiedenen Belastungskonzepten analysiert.Patienten und Methodik:Im Zeitraum von 2006 bis 2009 wurden insgesamt 41 Patienten in die Untersuchung eingeschlossen. Alle Implantate (Orthosystem®; Straumann, Basel, Schweiz; Dimension: 4,1 mm × 4,2 mm) wurden im medianen bzw. paramedianen Bereich des anterioren Gaumens inseriert und über eine Randomisierung auf zwei Belastungsgruppen (Frühbelastung innerhalb der ersten Woche nach Insertion vs. Spätbelastung nach einer Einheilphase von 12 Wochen) verteilt. In dieser Zwischenauswertung berichten wir über erste Ergebnisse 6 Monate nach funktioneller Belastung.Ergebnisse:Alle Gaumenimplantate waren bei der Insertion primär stabil. In der Gruppe der Spätbelastung gab es einen Implantatverlust (12. Woche nach chirurgischer Insertion) und einen Drop-out in der Gruppe der Sofortbelastung. 39 Gaumenimplantate befanden sich zum Zeitpunkt dieser Untersuchung unter funktioneller Belastung. In beiden Belastungskonzepten wurden verschiedene kieferorthopädische Behandlungsaufgaben (z.B. Intrusion von Front- und/oder Seitenzähnen, Mesialisieren und Distalisieren von Seitenzähnen) gelöst. In den Belastungsgruppen war die Verteilung der Indikationen sowie von direkten und indirekten Verankerungsformen in der aktiven Behandlungszeit annähernd gleich.Schlussfolgerung:Der Vergleich beider Belastungskonzepte ergab klinisch keine Unterschiede bezüglich der Implantatstabilität. Das frühzeitige Belastungskonzept zeigte gegenüber der Spätbelastung keine Indikationseinschränkungen 6 Monate nach funktioneller Belastung.

Biomechanical strain-induced modulation of proliferation coincides with an ERK1/2-independent nuclear YAP localization

Abstract Biomechanical strain induces activation of the transcriptional co‐activator yes‐associated protein (YAP) by nuclear re‐distribution. Recent findings indicate that the mechanically responsive mitogen‐activated protein kinase (MAPK) extracellular signal‐regulated kinase (ERK) 1/2 is involved in the amount of nuclear YAP, reflecting its activation. In this context, we conducted experiments to detect how biomechanical strain acts on the subcellular localization of YAP in periodontal cells. To this end, cells were subjected to 2.5% static equiaxial strain for different time periods. Western blot and fluorescence imaging‐based analyses revealed a clear modulation of nuclear YAP localization. This modulation fairly coincided with the altered course of the KI‐67 protein amount in conjunction with the percentage of KI‐67‐positive and thus proliferating cells. The inhibition of the ERK1/2 activity via U0126 yielded an unchanged strain‐related modulation of nuclear YAP localization, while YAP amount in whole cell extracts of strained cells was decreased. Administration of the YAP‐inhibiting drug Verteporfin evoked a clear reduction of KI‐67‐positive and thus proliferating cells by approximately 65%, irrespective of strain. Our data reveal YAP as a regulator of strain‐modulated proliferation which occurs in a MAPK‐independent fashion. Graphical abstract Figure. No Caption available. HighlightsStrain‐induced modulation of nuclear YAP amount coincides with proliferation.YAP‐inhibiting drug Verteporfin yields distinct reduction of KI‐67‐positive cells.This demonstrates regulatory involvement of nuclear YAP in proliferation.Strain‐induced YAP modulation is mechanistically independent from ERK1/2 activity.ERK1/2 activity influences total YAP amount, exclusively in strained cells.