Paramedian vertical palatal bone height for mini-implant insertion: a systematic review.

Paramedian insertion of orthodontic mini-implants is increasingly used to anchor molar distalizers. The aim of this review was to systematically examine the available measurements of vertical palatal bone height (VBH). PUBMED, MEDLINE and the Cochrane Controlled Trials Register were searched using specific search terms. Hand searches of bibliographies of articles were also performed to identify studies measuring VBH or bone thickness in the human palate. Sixteen studies were included, arising from 19 published articles. Repeat presentations were excluded. Ten of the 11 computed tomogram (CT)-based studies presented data from 956 orthodontic patients on average VBH and its variation at a range of palatal sites. Individual data were not available, and pooling of data was not feasible because of heterogeneity of subjects, different measurement sites, different CT methods and their associated software. The compilation of data did indicate that the region 3-4mm behind the incisive foramen and 3-9mm lateral to the midpalatal suture should normally provide sufficient VBH to anchor molar distalizers. The risks of unwanted effects during distalization should be small, but the limitations listed above and the small numbers of studies available impair the precision of the estimates and do not allow the results to be generalized. Paramedian anchorage in the anterior palate can be recommended for molar distalization but, given the great inter-individual variability of the palatal bone height, it must be preceded by reliable CT-based imaging in patients identified by routine investigations as being at risk.

Selective adhesion of osteoblastic cells to different integrin ligands induces osteopontin gene expression.

Skeletal homeostasis is partly regulated by the mechanical environment and specific signals generated by a cell's adhesion to the matrix. Previous studies demonstrated that osteopontin (OPN) expression is stimulated in response to both cellular adhesion and mechanical stimulation. The present studies examine if specific integrin ligands mediate osteoblast selective adhesion and whether opn mRNA expression is induced in response to these same ligands. Embryonic chicken calvaria osteoblastic cells were plated on bacteriological dishes coated with fibronectin (FN), collagen type I (Col1), denatured collagen/gelatin (G), OPN, vitronectin (VN), laminin (LN) or albumin (BSA). Osteoblastic cells were shown to selectively adhere to FN, Col1, G and LN, yet not to VN, OPN or BSA. Opn mRNA expression was induced by adhesion to Col1, FN, LN and G, but neither OPN nor VN induced this expression. Examination of the activation of the protein kinases A and C second signaling systems showed that only adhesion to FN induced protein kinase A and protein kinase C (PKC) activity while adherence to Col1 induced PKC. Evaluation of the intracellular distribution of focal adhesion kinase (FAK) and p-tyrosine within cells after adherence to FN, VN or BSA demonstrated that adherence to FN stimulated FAK translocation from the nucleus to the cytoplasm and high levels of p-tyrosine localization at the cell surface. However, cell adherence to VN or BSA did not show these morphological changes. These data illustrate that osteoblast selective adhesion is mediated by specific integrin ligands, and induction of intracellular second signal kinase activity is related to the nature of the ligand.

Elastic fibers in the human temporo-mandibular joint disc.

The elastic fiber content of 12 articular discs, removed from 12 patients with complete anterior or medio-anterior disc displacement, was examined. Eight to 12 sagittal sections (3 microm each) were acquired for each disc and stained with modified resorcin-fuchsin for visualization of elastic fibers. The program "CUE-2 Image Analyzer Morphometry" digitized all sections with 800x magnification, calculated the elastic fiber content and reconstructed it 3-dimensionally. The calculated volume density of the entire disc was a mean x(tot)= 0.339 +/- 0.060% of the total tissue. The highest fiber content of 2-4% was found in the posterior area at the transition to the bilaminar zone. 61% of the elastic fibers were located in the bilaminar zone, 10% in the posterior, 2% in the intermediary and 26% in the anterior band. There were substantially more fibers in the cranial part of the posterior region and at the medial edge as compared to the mean fiber distribution of the posterior band and the bilaminar zone. A third of these fibers were found in the inferior layer, particularly in the lateral part. Exactly the opposite fiber distribution was seen in the anterior band. The fibers frequently appeared in the caudal layer, especially in the lateral periphery, but there were fewer fibers in the medial cranial layer.

Rehydration of lyophilised cartilage grafts sterilized by different methods.

In in vitro experiments weight increase and rehydration speed of lyophilised cartilage grafts sterilized by different methods were determined. For periods of up to 72 h the increase in weight during rehydration was measured. The methods of sterilization used is only of little significance for such weight increase. Differences in rehydration speed clearly correlate with the initial weight of the lyophilised cartilage grafts. Smaller grafts are completely rehydrated after 5 to 6 h. This may explain the discrepancies in rehydration speed reported in the literature.

Effects of mandibular advancement surgery combined with minimal maxillary displacement on the volume and most restricted cross-sectional area of the pharyngeal airway.

The purpose of this study was to evaluate changes in the volume and most restricted cross-sectional area of the pharyngeal airway as a result of mandibular advancement surgery with minimal maxillary displacement, and to ascertain the change in height of this restricted area and whether gender and age could influence these results. Cone beam computed tomography scans were obtained from 25 patients (seven male and 18 female, average age 35.5 years). The measurements were done using the InVivoDental software (version 5.0). Comparisons were made between measurements taken prior to treatment (T1) and postsurgery (T2, average 6.3 months after surgery). No variation was detected on the scans with regard to head position, which could influence the pharynx airway. Surgery significantly increased the pharynx airway volume at the total (P<0.0001), upper (P=0.0001), and lower (P<0.0001) levels, with respective enlargements of 54.5%, 37.0%, and 91.3%. Gender and age did not influence this increase. A significant enlargement in the minimum area of the pharynx airway was detected (P<0.0001), which changed in shape from a tapering to a rounded shape. Using binomial and multiple logistic regression tests, this constricted site presented an unpredictable change in position as a result of surgery, with no association to gender (P=0.0745) or age (P=0.5879).

[Instant-picture motography in dentistry]. / Sofortbild-Motografie in der Zahnheilkunde.

In technical applications instant-picture motography is used for recording motion traces. The process involves a photographic pulse light procedure based on the Polaroid instant-picture technique. Its applications include, among others, robot motion analysis in developing ergonomic workplaces and, recently, functional diagnosis in dentistry. The advantages lie in the touch-free representation of mandibular movements involving minimal recording weight. Functional disorders can be detected immediately. The results obtained provide a first information basis for the dentist to decide on the proper treatment concept. The experiments on the diagnostic and therapeutic utilization of the recorded border movements have not been concluded yet.

Behavior of differently sterilized allogenic lyophilized cartilage implants in dogs.

The behavior of beta-propriolactone-sterilized, radiation-sterilized, and gas-sterilized lyophilized cartilage implants was histiologically investigated at various intervals up to 328 days. Beta-propriolactone-sterilized lyophilized cartilage implants were completely resorbed after 230 days and had only undergone partial osseous substitution. The radiation-sterilized lyophilized cartilage implants behaved similarly after 125 days. Despite partial resorption of the gas-sterilized lyophilized cartilage after 328 days, constant form was maintained and complete bony substitution of the resorbed regions had occurred in each case.

[Significance of the upper neck joints in the etiology of pain in the head and neck area]. / Die Bedeutung der oberen Kopfgelenke bei der Atiologie von Schmerzen im Kopf-, Hals-, Nackenbereich.

The function of the atlantooccipital joints is intimately connected with the function of the spine in total and the temporomandibular joint in special. The present investigation gives report of the frequent combination of headache, facial pain and pain in the temporomandibular joint, which could be found in patients of an orthopedic practice. The role of the atlantooccipital joints is stressed in a special manner and explained with the function of the arthromuscular control loop.

[Diagnosis and treatment of compression joints]. / Zur Diagnostik und Therapie des Kompressionsgelenkes.

A clear-cut diagnosis of "compression joint" is usually difficult in daily practice. The two main reasons for this seem to be a lack in specific diagnostic examination procedures and of an unambiguous nomenclature. The results of the treatment of 148 patients and those of a long term study on 50 patients with "compressed joints" provided us with a foundation for establishing a specific method of examination which might be very useful in diagnosis and therapy of the "compression joint".

[Influence of different local anesthetics on the in vitro collagen synthesis of periodontal fibroblasts]. / Einfluss von Lokalanästhetika auf die In-vitro-Kollagensynthese von Desmodontalfibroblasten.

The influence of different local anesthetic fluids in an in-vitro-experiment of periodontal ligament cells was researched. Mepivacain, articain, lidocain and prilocain were used in the study. The common commercial local anesthetic fluids were in a proportion 1:1, 1:10 and 1:30 diluted, before they were placed in the incubator with cultures of periodontal ligament cells. At the 1st and 14th day after the experiment the synthesis of collagen type I, III, V and VI were determined with an ELISA. The mepivacain dilution of 1:30 had, compared with the controls the slightest influence on the collagen synthesis of periodontal ligament cells. Further clinical investigations must show if through dilution of the local anesthetic solution an adequate anesthesia can be reached.

[Perioperative treatment of patients with chronic TMJ diseases]. / Die perioperative Behandlung von Patienten mit chronischen Kiefergelenkerkrankungen.

The concept of perioperative diagnosis and treatment of patients with chronic TMJ disease has been confirmed by a follow-up examination of ten female patients after surgical treatment. Eight of the ten patients were pain-free after observation periods of 3 to 20 months. Following an initial bite-guard splint therapy, instrumental functional analysis, MR tomography and arthrographic visualization of dynamic movement profiles are indispensable. The results have also shown that, depending on the intraoperative finding, a postoperative splint therapy should be performed for six months.

[Pilot study on the clinical use of instant-picture motography]. / Pilotstudie zur klinischen Verwertbarkeit der Sofortbild-Motografie.

Articulator experiments using instant-picture motography (Bumann et al. 1988) have shown that the extent and form of mandibular border movements can be recorded with a coefficient of variation of less than 5% in a "model", when recorded close to the axis. Within the framework of the pilot study the reproducible accuracy of +/- 2 degrees was within the range of the adjustment accuracy of the articulators, as compared with the Meyer reference system (1986). It is not until the evaluation of a large-scale clinical study that we will know if programming individually adjustable articulators is permissible or not.

[Effects of different articulator adjustments on motography traces]. / Auswirkungen unterschiedlicher Artikulatoreinstellungen auf Motografiespuren.

In an articulator model the accuracy and conclusiveness of instant-picture motography has been studied. After correction for projection errors, system accuracy was found to be better than +/- 2 degrees in all projections.

[Compression joint as a differential diagnosis in chronic facial pain]. / Das Kompressionsgelenk als Differentialdiagnose bei chronischen Gesichtsschmerzen.

"Costen's syndrome" is generally used to label chronic pain in the periauricular region. This article presents the results of a post-treatment evaluation of 50 patients, 25 of whom were referred to hospital with Costen's syndrome indicated in the diagnosis. As a result of this study it is proposed that the term "compression joint" be used instead of "Costen's syndrome". The importance of proper diagnostic procedures is pointed out.

[Position of the disc in collum mandibulae fractures--a magnetic resonance tomography study]. / Zur Position des Diskus bei Collum-mandibulae-Frakturen--eine magnetresonanztomographische Studie.

39 condylar mandibular fractures were examined by magnetic resonance imaging (MRI) within the first 12 hours after trauma prior to therapy. A new classification has been applied on the traumatic disc displacements. Three types A, B, C can be distinguished. Type A means no displacement in relation to the condylar fragment and the fossa. Type B means a displacement in the transversal plane exceeding the physiologic range of movement. Type C means displacement in the sagittal as well as in the transversal plane which exceeds the physiologic range of movement of the disc. The classified type of displacement could not be correlated exactly with dislocation and position of the bony fragments. Therefore the type of displacement cannot be predicted from conventional radiographs. Three cases of evident rupture of the disc in the biconcave zone could be shown by MRI. This kind of displacement has not been represented in the classification yet. In a presented case a rupture of the disc had been depicted preoperatively and the disc could be repaired via an preauricular approach. By means of MRI surgeons in future are able to pay more attention to the traumatology and reconstructive surgery of the temporomandibular disc.

[The significance of the fissurae petrotympanica, petrosquamosa and tympanosquamosa for disk displacements in the temporomandibular joint]. / Die Bedeutung der Fissurae petrotympanica, petrosquamosa und tympanosquamosa für Diskusverlagerungen im Kiefergelenk.

The correlation between disc displacements in the temporomandibular joint and the petrotympanic, petrosquamous and tympanosquamous fissures was investigated in 38 corpses. Only 12 joints had no ossification of the fissures, while 26 joints were partially ossified. With one exception, none of the joints with non-ossified fissures revealed disc displacement. In contrast, all the joints with ossified fissures revealed disc displacement. Women proved to have more displaced discs than men. On the basis of the findings, a model of the etiology of disc displacement is discussed.

[The value of electronic axiography in clinical functional diagnosis]. / Zur Wertigkeit der elektronischen Axiographie in der klinischen Funktionsdiagnostik.

Recent years have brought an increasing number of electronic jaw-tracking devices for instrumental analysis on the market. However sophisticated they may be, their diagnostic value for temporomandibular diseases is not well supported by scientific evidence. On the other hand, "manual examination"--a very refined diagnostic means acknowledged by orthopedians and adapted to the properties of the TMJ--yields a more reliable diagnosis which fits well to MRT data. We were hereby solicited to compare the information gained by jaw-tracking and manual examination. It was found that the recorded condylar movements gave no additional, diagnostically relevant insight that went beyond the manual examination. Nevertheless, the accuracy of jaw-tracking, with regard to the visualisation of internal derangements of the TMJ, was enhanced by the techniques of manual examination.

[Value of bite-guard splints for dysfunctions of the masticatory system]. / Der Stellenwert der Aufbissschienentherapie bei Funktionsstörungen im stomatognathen System.

Based on a clinical post-treatment evaluation of 184 patients, the value of bite-guard splints in the treatment of dysfunctions of the masticatory system was assessed. The results clearly showed that successful results (83-89%) could be achieved, if the indications were considered with differentiation. Intracapsular joint diseases could be successfully treated with bite-guard splints, while other treatment concepts had to be applied for myalgia, bruxism and condylar displacement or dislocation.

[Effects of different sterilizing techniques on osseous regeneration of grafted lyophilized cartilage]. / Einfluss unterschiedlicher Sterilisationsverfahren auf die ossäre Regeneration allogener gefriergetrockneter Knorpelimplantate.

The suitability of variably sterilized lyocartilage grafts as potential bone substitutes was investigated in animal experiments with special attention to configurational stability. In 3 Beagles corticocancellous implant beds were prepared by box-type ostectomies and lyophilized costal cartilage blocks sterilized with X-rays,ethylene oxide gas and beta-propriolactone solution were placed into them. Implants sterilized with X-rays and beta-propriolactone appeared to be unsuited for recontouring facial bone defects, since they showed complete loss of configuration after a follow-up time of 125 and 230 days, respectively. By contrast, cartilage implants sterilized with ethylene oxide gas retained their configuration after no less than 328 days. In light of these results, methods for sterilizing other biomaterials should be re-considered.

Collagen synthesis from human PDL cells following orthodontic tooth movement.

The dynamic remodelling processes in the periodontal ligament (PDL) account for the reaction of PDL cells to different orthodontic force simulations. These occur mostly by degradation and synthesis of collagen types I, III, V, VI, XII and XIV. The purpose of this study was to quantify specific collagen types in the PDL from zones of tension and compression of experimental teeth. Such changes could then be correlated with the processes of orthodontic-stimulated tissue breakdown. Maxillary and mandibular premolars of three females and one male patient were orthodontically moved with a box loop for a total of 14 days, prior to tooth extraction. Teeth from the contralateral side of either the maxilla or the mandible served as the untreated controls. A total of seven experimental and seven control teeth were used in this investigation. PDL fibroblasts from the cervical third of the roots corresponding to the compression and tension zones of the experimental and control teeth, respectively, were scraped and cultured in vitro at 37 degrees C in a humidified incubator with 5 per cent CO2/95 per cent air. Collagen synthesis of types I, III, V and VI was quantified by using an ELISA. Application of orthodontic forces in the experimental teeth showed a significant increase (P < 0.05) of the synthesis of all collagen types in the compression as opposed to the tension zones. Collagen synthesis on the compression zone of experimental teeth was not significantly different in the mandible when compared with those of the maxilla. In addition, the proportional distribution of different types of collagen was also not significantly different in the PDL fibroblasts from either zone of experimental teeth of either the maxilla or the mandible. Collagen metabolism in response to orthodontic stimulation appears to be higher in the compression zones and lower in the tension zones. Contrary to what is traditionally assumed in the literature, such findings indicate that in addition to bone resorption, tissue remodelling is very active in zones of compression following the disappearance of the hyalinized areas. These findings constitute a model for future studies on collagen metabolism during orthodontic-stimulated tooth movement.