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Biomedical subjects

Peter Proff

Publications and source records attributed to Peter Proff.

At least 19 recordsLinked to original sources

Influence of examiner differences on KIG-classification when assessing malocclusions.

OBJECTIVE: Indication systems such as the German KIG system (Kieferorthopädische Indikationsgruppen = Orthodontic Indication Groups) presuppose the objective assessment of underlying malocclusions. In this survey, we aimed to investigate the degree of agreement among the findings of several examiners in the assessment of different malocclusions and their classification according to the KIG system. SUBJECTS AND METHODS: Calibrated examiners assessed in the clinical evaluation and on plaster models orthodontic malocclusions in 180 adults (aged 20-49, 64 male, 116 female) from the population-based Study of Health in Pomerania (SHIP). Clinical examination was carried out by an experienced orthodontist, and the plaster models were also analysed by an examiner experienced in orthodontics. To compare inter- and intra-individual model examiners, we had two examiners with differing orthodontic experience carry out additional analyses of 60 of the 180 models (29 male, 31 female). RESULTS: The examiner differences yielded various KIG classifications and hence different assessments (i. e., whether KIG case-costs should be borne by health insurance). The comparison "clinical examination versus model analysis" revealed differences regarding 16.7% of the study participants in the assessment of whether the expense would be borne by the statutory health insurance fund. At 5.0-8.3%, the number of participants whose assessments had differed was much smaller in the inter-individual comparison of model-examiners and was smallest (at 3.3-6.7%) when comparison was made between intra-individual assessments (by a sole examiner). With regard to overall malocclusion assessment, the greatest examiner differences were again revealed when comparing the clinical examination with the model analysis (median kappa 0.57). The model-examiner comparison revealed larger differences among examiners with less orthodontic experience (median kappa 0.61 and 0.62) than the comparison between examiners with orthodontic experience (median kappa 0.70). CONCLUSIONS: There can occasionally be considerable examiner differences in the classification of participants according to orthodontic indication groups and hence varying assessments of whether such persons are KIG cases or not. Various means of data collection (clinical evaluation-plaster models) in the assessment of malocclusions by multiple examiners and by those with little orthodontic experience may negatively influence agreement among examiners.

Female↗

Problems of supernumerary teeth, hyperdontia or dentes supernumerarii.

Supernumerary teeth are extra teeth or toothlike structures which may have either erupted or unerupted in addition to the 20 deciduous teeth and the 32 permanent teeth. This article provides an overview of frequency, distribution and classification of supernumerary teeth. The etiology of supernumerary teeth is still unknown, yet various theories have been presented based on epidemiological studies. Four clinical cases representing the possible manifestations of supernumerary teeth are discussed.

Humans↗

The face-physiognomic expressiveness and human identity.

The facial structure develops through the harmonious interaction of bones, mandibular and cervical joints, masticatory, facial and cervical muscles, connective and fatty tissue as well as tracts of conduction. The face represents the personal identity. Ten basic types of faces exist, although they are difficult to classify. No face is symmetrical (biological variance). The expressions are generated by muscles and tension of the elastic facial skin and enable the face to be an organ of expression. The cranial position supports and influences the expression. Certain diseases change the expression in such typical ways that diagnosis and prognosis of some diseases may be concluded from it.

Face↗

Morphological and clinical considerations of first and second permanent molar eruption disorders.

Tooth eruption is a complex biological process which starts from the site of development in the jaw bone until the teeth reach their final functional position in the chewing plane. Various factors can disturb this process. Besides mechanical obstacles on the eruption path, a pathological position or axial orientation of the tooth germ, morphological aberrations of the tooth or pathological alterations of the periodontium, primary disorders of the eruption mechanism may lead to complete or partial retention of the tooth in the jaw bone. These morphological features bear upon the prognosis of orthodontic correction which is dependent upon the underlying cause. First and second molars are rarely affected by eruption disorders, with a prevalence of 0.01 to 0.08 per cent, however, marked consequences for function such as posterior open bite or elongation of the antagonists may result. Following an overview of pathogenetic factors of tooth eruption disorders, selected cases of impacted first and second permanent molars are presented with respect to their morphological causes.

Child↗

In vivo study of apoptosis as a creative agent of embryonic development of the primary nasal duct in rats.

INTRODUCTION: The first embryonic part of the nasal cavity is the primary nasal duct, beginning with the olfactory placode and ending with the oronasal membrane. Aim of this study was to investigate the cellular processes (apoptosis, proliferation) being responsible for development and opening of the primary nasal duct. MATERIAL AND METHODS: In this study developmental processes in at least three regions of the primary nasal duct (opening, middle, end) were examined by sectioning 38 rat fetuses on day 13.5 after conception. Apoptotic cells were detected by active caspase-3 antibodies and proliferating cells were examined by Ki-67 antibodies. RESULTS: Multiple apoptotic events were diagnosed on the basis and proliferative cells on the top of this duct. CONCLUSION: Apoptosis and proliferation play an important role in the process of opening the bottom of the primary nasal duct and for development of the nasal septum, philtrum as well as the primary palate. Mesenchymal proliferation seems to play a minor role in the process of opening the primary nasal duct.

Animals↗

Apoptosis as a creative agent of embryonic development of bucca, mentum and nasolacrimal duct. An in vivo study in rats.

INTRODUCTION: For embryonal facial development several fusion processes between different facial prominences are necessary. If fusion fails to appear, various facial clefts may occur, known as median (e.g. lower median cleft lip), oblique (e.g. open nasolacrimal duct) or lateral facial clefts (macrostomia, lateral cleft). MATERIAL AND METHODS: The development of 3 different facial regions (bucca, mentum, and nasolacrimal duct) was examined in rats using serial histological sections on day 13.5 after conception. Common procedures were used (staining for active caspase-3 and for Ki-67) for histological assessment about the role of apoptotic and proliferative processes in the fusion zones of buccal, mental and nasolacrimal areas. RESULTS: Multiple apoptotic events were detected in epithelial cells of the respective regions, the proliferative centers were located in the mesenchymal surroundings of fusion zones. CONCLUSION: A substantial precondition for fusion of facial prominences are proliferative and apoptotic processes in epithelial and mesenchymal cells. Apoptosis contributes to the development of bucca, mentum and the nasolacrimal duct. Absence of apoptoses may be responsible for facial clefts.

Animals↗

Prenatal diagnostics of cleft deformities and its significance for parent and infant care.

INTRODUCTION: This study aimed to demonstrate clefts of the secondary palate in embryos found to have cleft lip in order to evaluate the validity of prenatal ultrasound examination and, thus, to assess the significance of this diagnostic method for coordination and care of parents and infant. PATIENTS AND METHODS: Over a period of 2.5 years, 7 fetuses with cleft deformities were examined sonographically during the 20th and 25th gestational week. The results were compared to postnatal clinical diagnosis. This study was made by two experienced examiners using 2D ultrasound devices (Acuson 128 XP-10/ C7; Toshiba Aplio XV). Postnatal clinical diagnosis was made by an orthodontist. RESULTS: Three of the ultrasound-based diagnoses coincided with the postnatal result. In three of the examined cases the extent of the cleft was underestimated, whereas a greater extent suspected in one patient could not be confirmed clinically. CONCLUSION: The results of the present study support the propositions of current literature: Diagnosis of a cleft of the lip and the alveolar process could correctly be made by an experienced ultrasound diagnostician. However, problems arise with clefts of the secondary palate.

Cleft Lip↗

Treatment of patients with cleft lip, alveolus and palate--a short outline of history and current interdisciplinary treatment approaches.

Clefts of lip, alveolus and palate have been known for a long time. First tangible evidence of surgical therapy in terms of cheiloplasty, however, does not date further back than the 4th century after Christ. It was Werner Hagedorn from Magdeburg who laid the foundations of geometrical anatomical surgical lip repair in 1884. The procedures designed by LeMesurier, Tennison, Randall or Millard in the 1950s, and by Pfeifer in 1970 are part of today's cleft therapy applied by the different schools of surgery.

Bone Plates↗

Functional 3-D analysis of patients with unilateral cleft of lip, alveolus and palate (UCLAP) following lip repair.

INTRODUCTION: Particular importance is attached to lip repair cleft surgery, as numerous functional and aesthetic aspects have to be taken into account simultaneously. Spatial assessment of function and depiction of dynamic deviations is reasonable for describing surgical outcome in addition to long standing static analysis. This study aimed at 3D analysis of the oral area after reconstruction in patients with unilateral cleft lip, alveolus and palate. PATIENTS AND METHODS: Twelve patients with unilateral cleft lip, alveolus and palate who underwent surgery according to Tennison-Randall were enrolled in this study. Soft tissue dynamics was analysed during passive stretching and active contraction of the lips, and photogrammetry was used for comparing relative changes of length and displacement vectors. The spatial coordinates of surgically significant and reproducible landmarks along the red-white lip junction were analyzed. RESULTS: Static analysis of the lips revealed a good result with far-reaching symmetry in all cases. Regarding dynamic behaviour, two groups could be distinguished showing clear differences of passive distension and contraction behaviour. CONCLUSION: Despite nominally identical surgical techniques and comparable static-morphological outcomes, dynamic analysis revealed differences pointing to a need for optimization.

Alveolar Process↗

Evaluation of patient satisfaction after therapy of unilateral clefts of lip, alveolus and palate.

INTRODUCTION: Cleft lip, alveolus and palate (CLAP) is a craniofacial abnormality and is one of the most frequent human developmental anomalies. Therapy of clefts does not only comprise surgical closure of the cleft, but rather aims at an aesthetically and functionally optimal result at adult age. MATERIAL AND METHODS: Thirty-three cleft patients with total clefts of lip, alveolus and palate were enrolled in this study. Osseous bridging of the alveolar cleft (osteoplasty) was performed in all patients followed by different types of subsequent treatment. All patients answered a questionnaire to assess their satisfaction with the treatment result and their facial appearance. Patient satisfaction was correlated to the type of alveolar cleft repair. RESULTS: The returned questionnaires revealed varying patient satisfaction with their appearance, occlusal conditions, and dental aesthetics depending on the type of dental treatment in the alveolar cleft area. Questionnaire analysis by gender revealed clear gender-dependent differences in self-rated satisfaction. CONCLUSION: Aesthetics gain increasing importance for self-perception. Therefore, patient satisfaction with her facial appearance should move even more into focus of therapy of clefts.

Adolescent↗

Cartilaginous septum deviation in children with cleft lip, alveolus and palate--an MRI analysis.

INTRODUCTION: This study aimed to investigate by MRI examination the degree of deviation of the cartilaginous septum in relation to cleft size in patients with cleft lip, alveolus and palate. MATERIAL AND METHODS: Six children with cleft lip, alveolus and palate at age 5-20 days were examined with a 1.0 Tesla scanner using a head coil. The following parameters were evaluated: maximal cleft size (millimeter) and degree of the nasal septum deviation from the median-sagittal plane (degrees). RESULTS: Two children with bilateral clefts had no deviation; 3 children with unilateral (left-sided) cleft had a deviation to the right and 1 patient with a unilateral right-sided cleft a deviation to the left side. In all 4 patients, the degree of the nasal septum deviation increased with cleft size. CONCLUSION: Cartilaginous nasal septum deviation was noticed only in patients with unilateral cleft lip and palate toward the non-cleft side and was greater with increasing cleft sizes.

Alveolar Process↗

Evaluation of bone availability in the cleft area following secondary osteoplasty.

INTRODUCTION: Osteoplasty in cleft patients provides a basis for shaping a closed dental arch. This study aimed at a radiological appraisal of transplantation success following secondary osteoplasty by means of alveolar bone height as related to some selected influencing factors. MATERIAL AND METHODS: In this study, postoperative radiographs of 46 patients with unilateral or bilateral clefts of lip, alveolus and palate were analyzed retrospectively. Alveolar bone height was typed according to Abyholm and Bergland and evaluated in consideration of dentition at the time of surgery and existence of the lateral incisor. RESULTS: In total, 76% (n = 35) successes (type I/II) were observed. 6 out of 46 patients (13%) had to be re-operated for osteoplasty at a later date. A non-significantly higher rate of successes occurred during the early mixed dentition. In patients with existing lateral incisor, a higher rate (78% vs. 68%) of alveolar bone heights type I/II was obtained. CONCLUSION: The successful surgical outcome in terms of alveolar bone height is facilitated by treatment onset preferably during early mixed dentition and in presence of the lateral incisor. Although maximal success rates cannot be obtained using this method, the utility and effectiveness of secondary osteoplasty in cleft patients has been confirmed.

Adolescent↗

Potential and limits of achieving neutral occlusion in patients with clefts of lip, alveolus and palate.

INTRODUCTION: Therapy of cleft patients aims to control bone growth and tooth development so as to ensure a secure occlusion with good function. This paper aims to uncover the potential and limits of achieving neutral occlusion in patients with clefts of lip, alveolus and palate. Two treatment approaches are presented and compared with respect to the best long-term results. PATIENTS AND METHODS: The first method implies occlusal rehabilitation using maximum intermaxillary orthodontic fixation with the Jasper Jumper. Thus, orthodontic dental-alveolar compensation of the anomaly is obtained. The second method represents orthognathic surgery to achieve ideal intermaxillary relations and a neutral occlusion. Two patients are described - one each for both treatment regimens. DISCUSSION: The methods presented are meant to illustrate possible options for sagittal jaw development/movement in patient management. Orthodontic treatment has to rely on cooperation with maxillofacial surgery to achieve a neutral occlusion. Optimal management is ensured by a combination of both orthodontic and maxillofacial therapy. The orthodontic and surgical techniques for managing unilateral or bilateral clefts are continuously being further developed. CONCLUSION: Although orthodontic treatment can achieve good neutral occlusion in some patients, there are limitations and surgical measures may become necessary.

Adolescent↗

Special features of planning and application of orthodontic miniscrews in cleft patients.

Patients with clefts of lip, alveolus and palate or some facial syndromes need complex and long-lasting orthodontic therapy. The possibility of orthodontic anchorage is often limited by congenital absence of teeth, disturbed skeletal growth or failing compliance with extraoral sources of force. Correct positioning and insertion provided, miniscrews can serve as anchorages and shorten the period of active treatment in patients with clefts. With the help of a case presentation, an outline of using orthodontic miniscrews (like: Titan, Forestadent) for anchorage in patients with clefts of lip, alveolus and palate is given along with a discussion of advantages and disadvantages. Thus miniscrews are suited for use in cleft patients. However, they require careful orthodontic and surgical planning.

Bone Screws↗

Orthognathic surgery in cleft patients.

Orthognathic surgery has become a standard procedure in cranio-maxillo-facial surgery during the past five decades. Based upon the elementary works by Obwegeser who introduced sagittal split ramus osteotomy in the early 1950s, this procedure has become the worldwide gold standard in mandibular orthognathic procedures by now. When devices for ensuring the centric condylar position throughout the entire surgery were introduced by Luhr in the early 1980s, modern understanding of complete functional rehabilitation in orthognathic surgery was further enhanced. Even though Le Fort I osteotomy was performed by Wassmund already in the 1920s, it took almost another 50 years until this procedure became accepted in surgery, mainly due to concerns for severe haemorrhage that may occur during surgery. Application of a compound condylar positioning device which was established to ensure and keep the exact condylar position throughout maxillary, mandibular, as well as during bimaxillary osteotomies, and to permit the targeted use of distraction devices. Among those, cleft patients also sometimes need orthognathic correction of typical micrognathia and pseudoprogenia in late adolescence or at early adult age as secondary cleft surgery procedures. In this overview, special emphasis will be placed on orthodontic treatment as well as on the technical prerequisites for the surgical procedure.

Cleft Palate↗

Prevalence of single-tooth gaps in a population-based study and the potential for dental implants--data from the Study of Health in Pomerania (SHIP-0).

INTRODUCTION: The aim of this study was to show the prevalence of single-tooth gaps in a population-based study. MATERIAL AND METHODS: The data of 3989 subjects (20-74 years of age) were taken from the Study of Health in Pomerania (SHIP-0) and classified by age, gender, and level of education. A single-tooth gap was defined as a gap of one tooth missing bordered by one or more natural teeth on either side. RESULTS: The tooth missing most in all age groups was the first molar. There were more single-tooth gaps in the maxilla than in the mandible. The lowest single-tooth gaps were found in the mandibular anterior region (<1.1%). There were no significant differences in gender (p > 0.05). The highest frequency of single-tooth gaps among all groups was found in subjects with a medium level of education and the lowest frequency was found in subjects with a high level of education. One single-tooth gap was found in 25%, whereas 16% of all subjects had 2 single-tooth gaps. The prevalence of having 1 single-tooth gap was between 3.8% and 13.1% whereas it was less than 0.5% for subjects with 5 and more single-tooth gaps. CONCLUSION: There was a high potential for dental implants to fill single tooth gaps.

Adult↗

Histological and histomorphometric study of growth-related changes of cranial sutures in the animal model.

INTRODUCTION: During the early development, numerous histological and morphometric changes occur in the cranial sutures the exact knowledge of which is of fundamental significance for understanding clinically relevant cranial anomalies. In this paper a histological and histomorphometric longitudinal study of the coronal, sagittal and lambdoid sutures in the rat is reported in relation to age. MATERIAL AND METHODS: Forty-eight male Wistar rats (Rattus norvegicus Berkenhout) were raised under standard conditions. Eight animals each were sacrificed at defined time points (10, 14, 28, 42, 70, 98 days post partum) for specimen preparation. Histological preparations of the sagittal, coronal and lambdoid sutures were produced and examined morphologically and histomorphometrically (suture width, height, and area). RESULTS: Histologically, three phases of sutural growth with characteristic structural features were found. Histomorphometry reveals a quasi linear increase in height from the 30th to the 98th day post partum. Suture width remained relatively constant in the area of dura mater and periosteum. CONCLUSION: The sutures of the test animals studied had a similar growth behaviour primarily consisting of an increase in height with almost constant width. The three-phases of development could be demonstrated histologically in all sutures.

Animals↗

Influence of Cyclosporin A on human gingival keratinocytes in vitro.

PURPOSE: Gingival hyperplasia is a well known side effect of Cyclosporine A therapy. The aetiology of this is not totally understood and there is debate whether it is hyperplasia of the gingival epithelium or of the submucosal connective tissue, or both, and what roles play factors like age and gender of the patients, duration and dosage of the drug. MATERIAL AND METHODS: The influence of different Cyclosporine A concentrations (10(-6) g/ml; 5 x 10(-7) g/ml; 10(-9) g/ml) and of no medication (controls) on growth and proliferation of cultured human gingival keratinocytes was investigated after a culture period of 3, 6 and 9 days. Cell proliferation was assessed by counting anti Ki-67 stained nuclei, cell growth by counting total number of nuclei and by the EZ4U-assay. RESULTS: There was no significant correlation of the cell proliferation rate and cellular growth with either gender (p > 0.568) or duration of medication (p > 0.876); but Cyclosporine A concentration showed a highly significant influence on cellular growth (p = 0.0001). Inhibition of cell growth was dependent on drug dosage, but a low concentration of 10(-9) g/ml even stimulated cell growth. CONCLUSIONS: There is evidence that Cyclosporine A in low concentrations (10(-9) g/ml as applied in long-term therapy) stimulates gingival keratinocyte growth and therefore might be related to hyperplasia of the gingiva. However, high Cyclosporine A concentrations may inhibit cell growths and factors like gender of the patient did not show any influence in-vitro.

Adolescent↗