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Biomedical subjects

P Alberius

Publications and source records attributed to P Alberius.

At least 37 records · Page 2Linked to original sources
PubMed1993

Osteopromotion: a soft-tissue exclusion principle using a membrane for bone healing and bone neogenesis.

The research reviewed in this paper constitutes a series of investigations intended to develop and evaluate a new membrane technique, which provides improved conditions for osteogenesis during healing of bone defects and restitution of earlier existing bone. The technique has also been shown to aid in bone grafting as well as having the capacity to create new bone for reconstructive purposes. According to this methodology, membranes are utilized to create a space in the tissue in which osteogenesis can occur relatively unimpeded. The paper provides a review of our initial animal experimental work as well as some clinical studies with special emphasis on membrane use in conjunction with dental implants. Possible mechanisms behind the efficacy of the membrane technique are reviewed, and future perspectives of development are also discussed. The osteopromotive membrane technique represents a principally new and major advance in bone biology and reconstructive skeletal surgery. Based on the results obtained by us and by others, the technique is presently utilized clinically in some routine applications.

Animals↗
PubMed1993

A simple variant of surgical correction of prominent ears. Description of the surgical technique and follow-up examination in 36 patients.

A technically simple technique of otoplasty has been developed. An ovular skin excision is made on the posterior side of the auricle and then a transcartilaginous incision that corresponds to the future dorsal part of the antihelical fold. A parallel anterior incision of the anterior aspect of the cartilage helps to create a normal and harmonious configuration by smoothing the inward bending. Thirty-six patients were operated on and followed up for between six months and two years. The surgical results are satisfactory and there have been only two recurrences.

Adolescent↗
PubMed1992

Role of osteopromotion in experimental bone grafting to the skull: a study in adult rats using a membrane technique.

This study explores the effect of an osteopromotive membrane technique in a mature animal model on the survival of membranous and endochondral bone inlays in mandibular defects and membranous bone onlays on the calvarial roof. Twenty-eight adult male rats received fibular or mandibular inlay bone grafts to trephine defects in the mandibular angle, as well as mandibular disc onlay grafts to the parietal and frontal bone regions. The results were assessed by gross inspection and light microscopy after 12 weeks. Membrane use markedly promoted bone deposition in the defects. The membranous bone inlays showed complete incorporation to the margins of the defect, whereas the endochondral grafts at all times were covered by a thin fibrous capsule and failed to incorporate. Onlay grafts generally resorbed substantially, but the grafts covered by a membrane seemed more active, developed an increased cancellous component, and showed less pronounced volumetric loss. The findings confirm the fact that a biological difference exists between membranous and endochondral bone. They also confirm the osteopromotive effect of the membrane technique, and suggest that the amount of bone needed for transplantation can be reduced using this method.

Animals↗
PubMed1992

Osseous response to implanted natural bone mineral and synthetic hydroxylapatite ceramic in the repair of experimental skull bone defects.

The purpose of this study was to assess and compare the osseous responses to implanted particles of resorbable anorganic xenograft bone mineral and non-resorbable dense synthetic hydroxylapatite of two different granule sizes. Four trephine calvarial defects were produced in each of 13 adult rabbits. The experimental materials were subsequently implanted in three defects, leaving the fourth defect for control purposes. Six animals were killed 4 weeks after surgery and seven at 14 weeks. The tissue responses were assessed by contact radiography, light microscopy, and histometry. The biocompatibility of the implants was confirmed. All defects healed uneventfully, although the resorbable hydroxylapatite seemed to promote initial bone regeneration. The importance to orthognathic surgery of early and effective healing of bone gaps, as well as of the advantage of implant resorbability to bone remodeling, are discussed.

Absorption↗
PubMed1992

Maxillary alveolar ridge augmentation with onlay bone-grafts and immediate endosseous implants.

Management of the atrophic maxilla can be a taxing surgical problems. One treatment alternative is to use autogenous bone transplants and immediate titanium fixture implantation. Despite the extensive literature on routine implant treatment of the edentulous jaws, only very few reports have dealt with the outcome of bone graft reconstructive surgery as part of the dental implant restoration. This study presents the treatment and healing results of 8 consecutive patients, who, over a period of 2 years and 8 months, were treated using onlay iliac bone grafts to atrophic maxillary alveolar ridges with immediate implant insertion. The patients were followed for 32-64 months. 83% of the fixtures (n = 46) were well-integrated. Two fixtures in each of 2 patients were lost due to traumatic bone-graft fractures. Palpatory bone-graft volume and prosthetic function were, with the exception of 1 patient, good. Radiological examination demonstrated preservation of the major part of the vertical dimension of the grafted bone. Patient's assessment was of good aesthetics and intraoral function; 2 patients had minor phonetic problems. In conclusion, similar success to routine maxillary implant treatment can be achieved in the event of extreme maxillary bone deficiency, by bone grafting and immediate fixture insertion.

Adult↗
PubMed1992

Contribution of autogeneic membranous bone chips and bone paste to healing of rabbit skull defects.

In skeletal surgery, bone chips and bone paste are often used to facilitate bony repair. However, no comparative investigation between these forms of bone graft implantation has been undertaken. In this study four trephine skull defects were produced in each of 14 adult rabbits and inlays of bone paste and two separate amounts of bone chips were then implanted in each animal. The results were compared relative to a control defect and assessed by gross inspection, light microscopy, and contact radiography after periods of 4 and 15 wk. Bone chips offered only minor advantages over controls in the defects investigated and differences in bony regeneration between the diversified amounts of bone chips were negligible. After bone paste implantation, a cellular and mature bone was rapidly produced. The clinical significance of these findings is discussed.

Animals↗
PubMed1992

Regenerative response to membranous and enchondral lyophilized allogeneic bone in rabbit skull defects.

The regenerative responses of inlays of lyophilized allogeneic bone of membranous (skull) and enchondral (tibia) origin were studied in an experimental cranioplasty model in rabbits. The lyophilized bone particles were also bioassayed for inductive bone production in an orthotopic critical size defect rat model. Three trephined calvarial defects were evaluated in each of 14 adult rabbits. The experimental materials were implanted into two of the defects and the third was left empty for control purposes. The implants disclosed no major structural divergences as assessed by scanning electron microscopy. Healing was evaluated by light microscopy and contact radiography after periods of four and 15 weeks. The lyophilized bone allografts of both embryonic origins displayed a similar fashion of bone regeneration, bone marrow reappearance, and volumetric density of trabecular bone substance and displayed no obvious differences between experimental groups or intervals. The two materials exhibited low osteoinductive potential.

Animals↗
PubMed1991

Association between development of lower lip cancer and tobacco habits.

Tobacco use is considered to increase the risk of tumor induction. The purpose of this case-controlled investigation was to assess the association of tobacco habits and development of squamous cell carcinoma of the lower lip. Sixty-one patients treated for lower lip cancer, aged between 42 and 90 years, were studied. Age- and sex-matched healthy controls showed a similar exposure to tobacco in years and a comparable distribution of tobacco habits. Although the mean exposure factor (duration times exposure) was greater in the tumor group, no intimate correlation between lip cancer and tobacco was demonstrated. However, an increased, although small, occurrence of herpes labialis lesions was found in cancer patients. The hypothesis is presented that smokers experiencing recurrent herpes simplex virus 1 (HSV-1) infections are more liable to tumor initiation, which issue will be subjected to a future study.

Adult↗
PubMed1991

Repair of intra-membranous bone fractures and defects in rats. Immunolocalization of bone and cartilage proteins and proteoglycans.

Osseous healing of experimental fractures and defects in membranous bone was studied in an animal model and the appearance and localization of selected bone and cartilage proteins and proteoglycans determined by polyclonal antibodies. The bone lesions were made in the parietal bone of young rats and subsequently studied on days 3, 5, 8, 15, 30, and 100 after surgery. The bone matrix proteins investigated (62 kDa, bone sialoprotein I and II, and osteopontin) appeared early, adjacent to the periosteal surfaces (pericranium and dura mater) and the marginal bone. The staining reactions were maximal at days 8 or 15 after trauma. Similar patterns were discerned for some cartilage macromolecules studied (58 kDa, 59 kDa, and chondrocalcin), although others showed no labelling whatsoever (148 kDa, and 400 kDa proteins). The proteoglycans PG-S1, PG-S2, and PG-LA were not identified. No callus or cartilage formation were associated with the bone healing process, and the differences between the regenerative pattern of the fractures and defects were limited. The findings emphasize the importance of rigid fixation in craniomaxillofacial surgery.

Animals↗
PubMed1991

Correction of ectropion of the lower lid by upper eyelid skin transposition.

A technique for the correction of ectropion of the lower lid by transposition of a full-thickness skin flap from the ipsilateral upper eyelid to the lower lid has been used in seven patients. The technique allows great flexibility in the extent of the approximation of the lower lid to the eye globe. The pedicle is based medially to obtain close contact between the lower punctum and the eye globe. There were no complications. We believe that the eyelid skin flap transposition technique is a useful operation for the correction of moderate to severe senile and paralytic ectropion.

Aged↗
PubMed1991

Repositioning of craniofacial tumorous bone after autoclaving.

Thirteen bone tumours that were invading the craniofacial skeleton were operated on by intracranial procedures. The resected tumorous bone was autoclaved and put back. Follow up of no less than one year included 122mTc scanning, computed tomography, radiography, bone biopsy and clinical examination. In every case, when rigidly fixed, most of the autoclaved bone was gradually revitalised by invading new and normal bone. We conclude that autoclaved bone will be replaced by normal bone, and that the present technique is justified for reconstruction of complicated structures or large areas of bone after operations for tumours invading the craniofacial skeleton.

Adolescent↗
PubMed1991

Osteopromotion for cranioplasty. An experimental study in rats using a membrane technique.

Various techniques for treatment of large cranial defects have been reported, but the use of alloplastic materials still seems to predominate. The authors have applied and explored a new approach for bone repair which appears promising, even for use in less osteogenic environments such as the adult calvaria. Seventy-two adult Sprague-Dawley rats each received bilateral 8-mm trephine defects in the temporoparietal area; this defect size precludes spontaneous osseous healing during the lifetime of the animal. Five surgical procedures, employing various alternatives of biologically inert expanded polytetrafluoroethylene membrane positioning and intramembranous bone-chip implantation, were performed and compared to control defects. Slight improvement of bone regeneration was demonstrated with subperiosteal ectocranial and endocranial membranes, alone or in combination, and with bone chips alone or in combination with an outer or inner membrane. Virtually complete bone healing was observed in animals receiving both an outer and an inner membrane with interpositioned bone chips. The latter appeared to function primarily as space-holders by keeping the membranes separated throughout the defect. Consequently, this technique seems to significantly promote bone repair by excluding soft-tissue components from the bone-healing site.

Animals↗
PubMed1990

Variability of measurements of cranial growth in the rabbit.

This study concerns techniques used in experimental cranial growth research: roentgen cephalometry, roentgen stereophotogrammetry, and gross measurements (osteometry). A comparison of the precision of these methods has not been found in the literature. Computation of technical errors is fundamental to the sound evaluation of registered findings, and such a presentation must be obligatory in all biometric reports. We compared the measurement error of roentgen cephalometric and osteometric data with that obtained by roentgen stereophotogrammetry (RSA). RSA demonstrates a superior replicability, and this technique gives possibilities for kinematic and volumetric determinations simultaneously with distance evaluation. Roentgen cephalometry has the advantage of enabling distance and angular measurements between any well-defined skeletal points or lines. This technique, preferably after implantation of bone markers, is a reliable alternative, but optimal results necessitates calculations of the magnification factor for each bone segment involved. Direct osteometry does not contribute additional information, but problems of image magnification are omitted. Preferably, one individual should perform all measurements regardless of the method used. Growth rates and values calculated by one technique cannot be directly transformed to some other approach. In all probability, assessments of distance changes would gain substantially by using one technical approach consistently throughout actual age intervals. The least variable measurements of sutural growth are made for sutures growing primarily in one plane and with substantial growth rates. One must realize that differences among studies may be due to the limitations of, in particular, the cephalometric and osteometric techniques.

Animals↗
PubMed1990

Adrenergic innervation of the calvarium of the neonatal rat. Its relationship to the sagittal suture and developing parietal bones.

The presence and distribution of adrenergic nerves in the developing calvarium of the newborn rat documented by means of the formaldehyde-induced fluorescence technique in rats aged 2 or 7 days. Nerve fibres exhibiting catecholamine-specific fluorescence were seen within the developing calvarium of all animals. In coronal sections, these fibres could be seen in the developing bone, especially in the lamina interna, while in sagittal sections, they were seen to traverse the tissue to reach the central of the diploë. These fibres originate from a denser plexus within the dura mater. Especially in the younger age group, the fluorescent fibres often exhibited an immature appearance, being coarse and devoid of varicosities. In the older animals the fibres were often varicose. The sutural tissue proper was always found to be devoid of adrenergic innervation. The possible origin and functional significance of the adrenergic innervation in the developing bone in relation to skull growth and sutural closure are discussed.

Adrenergic Fibers↗
PubMed1990

Regeneration of cranial suture and bone plate lesions in rabbits. Implications for positioning of osteotomies.

The positioning of osteotomies in intramembranous cranial bone was studied by exploring the pattern of bone regeneration in growth areas (the sutural region) as compared to that of the bone plate proper. Trephine defects in the left coronal suture area and the right parietal bone were produced in fifty-nine young rabbits. A pilot study to refine operative and analytical methods comprised 22 animals. The experiments were terminated at one, three, and six weeks after surgery. The bone regenerative response was assessed by x-ray planimetry, plain microscopy, enzyme histochemistry, and fluorescent labelling. Only minor divergences in healing capacity between the two defects were found. No adverse effects on the growth process were indicated. As to clinical management, the findings suggest that osteotomies designed to traverse sutural areas will, under normal circumstances, regenerate in a similar manner and rate to adjoining bone plates.

Acid Phosphatase↗
PubMed1990

Trigonocephaly: clinical and cephalometric assessment of craniofacial morphology in operated and nontreated patients.

Craniofacial parameters were studied clinically and by cephalometry in 11 trigonocephalic patients from infancy to 4 years of age. Six of the most severe patients had surgery between 6 and 18 months of age. Analysis of morphology indicated that bony interorbital distance was reduced in patients selected for surgery and hypotelorism persisted at final examination. All patients demonstrated orbital width measurements above the mean for the norm, while orbital height was essentially normal. All but one of the patients had a variably prominent forehead bony ridge that was eliminated or reduced as a result of surgery and/or growth. However, the forehead of most patients, whether operated or not, was too narrow when compared to normal skulls. Thus, although some of the striking features of trigonocephaly are eliminated, minor characteristics of the anomaly still persevere at 4 years of age.

Cephalometry↗
PubMed1990

Immunohistochemical assessment of cranial suture development in rats.

The present study investigated, by immunohistochemistry, the postnatal occurrence and anatomical localisation of some bone and cartilage proteins and proteoglycans in the rat coronal sutural region. Thirty two Sprague-Dawley rats, four in each group, were killed at ages 3, 5, 8, 10, 15, 30, 50 and 100 days and the sutural region subsequently subjected to histological examination. The biochemical constituents investigated were: 36 kDa, 58 kDa, 59 kDa, 62 kDa, 148 kDa, 400 kDa proteins, chondrocalcin, bone sialoproteins I and II (BSP I and II), osteopontin (ost I), small cartilage 1 and 2 as well as large cartilage proteoglycans (PG-S1, PG-S2, PG-LA). Standard haematoxylin-eosin and laminin staining was also carried out. In general, detectable constituents were visualized until Day 50. Labelling of the proteins 59 kDa protein, BSP I and II, and ost I was distinct along the sutural bone margins and, initially, cells and fibrillar structures within the sutural ligament were also labelled. The 58 kDa protein was localised unspecifically to the suture tissue proper at Days 50 and 100. PG-S1 labelling was concentrated primarily at the sutural edge. Remaining substances were indistinguishable throughout the entire observation period. The dual response of proteoglycans in bone mineralisation and the potential importance of cartilaginous tissue in sutural closure is discussed.

Animals↗