Biomedical subjects

K Oikarinen

Publications and source records attributed to K Oikarinen.

At least 37 records · Page 2Linked to original sources

PubMed1996

Clinical and computed tomographic findings in costochondral grafts replacing the mandibular condyle.

PURPOSE: The aim of this study was to evaluate by computed tomography (CT) and clinically the structure and function of costochondral grafts (CCG) used to replace the mandibular condyles. MATERIAL AND METHODS: CT and clinical examination were performed in 11 patients with CCGs (9 female, 2 male; mean age at surgery, 25 years; range, 9 to 44 years) approximately 4.5 years after surgery (range, 5 months to 10.5 years). One mandibular condyle was replaced in six patients and two in five patients. RESULTS: Facial asymmetry was observed in two cases and palpation tenderness of the TMJs or clicking and crepitation were found in 10 of 16 operated TMJs. In three cases coronal CT scans showed the graft to be situated laterally in the mandibular fossa, and lateral overgrowth of the graft was seen in three cases. In two cases, coronal CT slices showed that a new fossa had developed. In most cases translatory movement of the graft was minimal. The graft was either partially or almost completely mineralized, especially in cases with longer follow-up. CONCLUSIONS: Most of the patients in this study seemed to have benefitted from replacement of the deformed mandibular condyle with a CCG as estimated by improved range of mandibular movements and decreased symptoms. There were some problems related to unpredictable growth and location of the graft, as well as restricted movement of the replaced condyle. In the future, care should be taken to ensure proper postoperative functional therapy and to examine the role of cartilage thickness on future growth in young patients.

Adolescent↗

PubMed1996

Detection of pulse in oral mucosa and dental pulp by means of optical reflection method.

This paper describes a new system in which optical reflectance is used to test the pulse and vitality of oral mucosa or dental pulp. Radiation at red (660 nm) and near infra-red (850 nm) wavelengths are directed through a thin probe. The beam is directed into tissue and reflected back. Plethysmography is used to measure the pulse rate from the right forefinger. Reflected radiation is related to plethysmogram using a computer. Preliminary findings relating to the lips and gingiva in 9 healthy volunteers were promising. Preliminary tests showed that vital and nonvital pulps reflected the radiation differently. Pulpal pulse did not always correspond to plethysmogram from the right forefinger.

Adult↗

PubMed1996

Effects of dexamethasone and cell proliferation on the expression of matrix metalloproteinases in human mucosal normal and malignant cells.

Matrix metalloproteinases (MMPs) have an important role in many biological processes, such as tumor metastasis, wound healing, and inflammation. The regulation of MMPs and their inhibitors is still not known in detail, and the aim of this study was to investigate the effects of dexamethasone on cultured oral benign and malignant cell lines. The expression of MMPs in culture was studied: in four gingival (GF) and one periodontal ligament (PLF) fibroblast cell lines; in six gingival keratinocyte (GK) cell lines; and in UNR (UNR-108, rat osteogenic sarcoma) and SCC (SCC-25, human tongue squamous cell carcinoma) cell lines. In the GFs, PLFs, and UNR cells, only MMP-2 (72 kDa gelatinase) was detected by gelatin zymography, while in most of the GK cell lines only MMP-9 (92 kDa gelatinase) was observed. In confluent SCC cultures, both MMP-2 and MMP-9 were found, while only MMP-2 was seen in rapidly growing SCC cells, demonstrating that cell proliferation influenced gelatinase expression in these cells, but not in the other cell lines studied. Dexamethasone at concentrations of 10(-5) mol/L and 10(-7) mol/L decreased the production of gelatinases in the GFs and PLFs, but not in the GKs, SCC, or UNR cells. The expression of mRNAs for matrix metalloproteinases (MMP-1 [interstitial collagenase] and MMP-2) and their inhibitors (TIMP-1 and TIMP-2) was also studied in the GFs by Northern hybridization. Dexamethasone markedly decreased the amount of MMP-2 mRNA in the GFs. The mRNA level of MMP-1 decreased even more in the same GFs. The mRNA levels for TIMP-1 and TIMP-2 were also decreased by dexamethasone in the GFs. Cell proliferation influenced the degree to which dexamethasone decreased these mRNA levels. The results indicate that glucocorticoids decrease the levels of MMPs and TIMPs in oral fibroblastic cells, whereas they do not appear to affect the production of gelatinases in either normal or malignant oral epithelial cell lines.

Cell Division↗

PubMed1995

Surgical treatment of condylar process fractures using axial anchor screw fixation: a preliminary follow-up study.

PURPOSE: The aim of this study was to evaluate use of the axial anchor screw system in the treatment of condylar process fractures. PATIENTS AND METHODS: Seven adult patients with displaced condylar process fractures were treated using axial anchor screw fixation. Indications for surgery were severe dislocation of the condyle and occlusal changes. Clinical and radiologic examinations were performed 6 weeks, 6 months, and approximately 2 years postoperatively (range, 18 to 30 months). Clinical factors recorded were occlusion, range of mandibular movement, and findings on palpation of the temporomandibular joints. Ramus height and angulation between the mandibular ramus and the dislocated condyle were measured and compared with the contralateral side preoperatively and at the last follow-up. RESULTS: The postoperative course was uneventful in most patients. All were free of pain, and the occlusion and facial symmetry were normal. Radiographs generally showed excellent fracture reduction. Translation of the condyles on mouth opening was symmetrical. No signs of resorption or osteoarthrosis were evident in most cases. However, some patients had complications. These involved unsatisfactory reduction in one patient causing osteolysis at the fracture line. In another patient bone over the screw fractured and the condyle and the screw tilted in a medial direction. CONCLUSION: Treatment of condylar process fractures using the axial anchor screw system is ideal in certain cases. The complications and difficulties seen may be avoidable by appropriate patient selection and techniques.

Adult↗

PubMed1995

Prosthetic possibilities using endosseal implants as anchorages--an epidemiological study in 65-year-old subjects.

In order to evaluate the possibility of using endosseal implants (ITI Dental Implant System) and implant-retained prostheses for 65-year-old patients from a medium-sized Finnish city, 431 such patients were examined by means of panoramic radiographs. The population represents 61% of the total age group in the city (born in 1923). The possibility to construct a prosthesis, anchored on implants, was evaluated in three different groups. It was shown that in group I (edentulous maxilla and mandible, 256 patients) all male and 97% of female subjects could have been treated with implant-retained over-dentures in the lower jaw. Corresponding figures in the upper jaw were 62% for males and 59% for females. In patients with edentulous maxilla and dentulous or partially edentulous mandible (group II, 84 subjects) implant-retained overdenture in the maxilla could have been possible in 52% of male and 43% of female participants. In subjects with own teeth left in both jaws (group III, 91 participants) some kind of implant-retained bridge or single implants could have been constructed in 70% in maxilla and in 92% in mandible.

Aged↗

PubMed1995

General and local contraindications for endosseal implants--an epidemiological panoramic radiograph study in 65-year-old subjects.

In order to evaluate general and local contraindications for implantation for 65-yr-old subjects from a medium-sized Finnish city, 431 such persons were examined anamnestically and by means of panoramic radiographs. The population represents 61% of the total age group in the city (born in 1923). It was shown that several degrees of cardiac problems and increased blood pressure followed by pulmonary diseases and diabetes were the most commonly encountered relative contraindications for implantation. Eleven percent of the patients said that they smoked regularly and the bone quality was estimated to be less suitable for implantation in 21% of the cases. Implantation was evaluated according to the Bonefit system (implant lengths between 6 and 16 mm) in 10 regions in the maxilla and 6 regions in the mandible and was shown to be possible in 38% of the regions in the partially edentulous maxillae and 50% of those in the partially edentulous mandibles, the corresponding figures for the edentulous jaws were 55% in the maxilla and 61% in the mandible.

Aged↗

PubMed1995

Systemic oral isotretinoin therapy and flow rate, pH, and matrix metalloproteinase-9 activity of stimulated saliva.

Systemic retinoids are known to cause dryness of the mouth and changes in oral and lip mucosa. The purpose of this study was to evaluate changes in salivary variables during treatment with oral isotretinoin in patients receiving the drug for 3 months for cutaneous acne. Patients were examined 1 month after initiation of medication and approximately 3.7 months after its discontinuation. Salivary flow and pH could be measured in 8 and the relative amount of matrix metalloproteinase-9 (MMP-9) of stimulated saliva in 17 patients. The mean flow rate of stimulated saliva was lower during medication than at control examination (P = 0.0277), but no change in the mean pH value was observed during medication. The mean activity of MMP-9 during medication was higher than at control examination (P = 0.0442). The enzyme activity increased in 13 of 17 and decreased in 4 of 17 cases.

Acne Vulgaris↗

PubMed1994

Analysis of possible factors leading to problems after nonsurgical treatment of condylar fractures.

PURPOSE: An attempt was made to identify types of condylar fractures that, despite active nonsurgical treatment, lead to unsatisfactory clinical results. PATIENTS AND METHODS: Ninety-two dentate adult patients with unilateral condylar fractures were studied clinically and radiologically. On the basis of the information collected, problematic cases were identified. These consisted of patients with persistent occlusal change and/or marked deviation of the mandible on mouth opening after removal of maxillomandibular fixation or during follow-up. Radiologic analyses were performed using panoramic and Towne's views, and the results of problematic and nonproblematic cases were compared. RESULTS: Using clinical parameters, two problem groups were found. In patients with persistent malocclusion, ramus height was significantly reduced, irrespective of degree or direction of angulation between the fragments. Deviation of the jaw on mouth opening, but no occlusal disturbances, occurred in those with dislocated condyles. CONCLUSION: Problematic condylar fractures can often be identified preoperatively by means of simple radiographic measurements and these cases should probably be treated surgically.

Adolescent↗

PubMed1994

Chronic sclerosing osteomyelitis of the mandible in monozygotic twins.

Identical female twins with chronic sclerosing osteomyelitis of the mandible are presented. The diagnoses of both at the age of 12 years were based on typical history, and on clinical, radiographic, and histologic findings. High concentrations of IgA and IgG were detected in the serum of both patients, but deviations were not observed in other immunologic variables. The normally commensal organism, Propionibacterium acnes grew from a bone biopsy specimen from the mandible of one twin. No oral focus of the disease was confirmed in either case. We suggest that hereditary factors must have played a role in the pathogenesis of these cases of chronic osteomyelitis.

Child↗

PubMed1993

Mandibular fractures in northern Finland in the 1980s--a 10-year study.

A total of 317 mandibular fracture patients treated and diagnosed at the Oulu University Hospital and at the Department of Oral and Maxillofacial Surgery, University of Oulu, Finland, between 1981 and 1990 were analyzed from patient files and radiographs. The mean number of mandibular fracture patients per year was 31.7 (range 21 and 45) and the mean age of the patients 31.3 years (range 4-78 years). The female:male ratio was 1:3.1. There seemed to be a tendency for decrease in the proportion of violence and traffic accidents as causes of mandibular fractures toward the end of the period concerned, reflecting partly the influence of mandatory use of safety belts and partly that the hospital in the northernmost part of Finland, where the consumption of alcohol is higher than in the province of Oulu, could treat all mandibular fractures itself during the last year studied thus decreasing the injuries caused by violence at the Oulu University Hospital. It was also noted that fewer fractures were caused at weekends than on weekdays during the latter years of the decade and that the proportion of male victims decreased except for the last year examined, 1990.

Accidents, Traffic↗

PubMed1993

Treatment of mandibular fractures in the 1980s.

Treatment of 317 mandibular fracture patients between 1981 and 1990 at the Department of Oral and Maxillofacial Surgery, Institute of Dentistry, University of Oulu and Oulu University Hospital were analysed on the basis of patient files and radiographs. The patients had suffered altogether 452 mandibular fractures, most in the condylar region. The treatment was operative in 24% of cases and conservative in 76%. Operative treatment was commoner in edentulous than in partially edentulous or dentate patients. The proportion of operatively treated mandibular fractures increased toward the end of the period. The type of osteosynthesis also changed over the decade as wire and plate osteosynthesis gave way to compression plating and then to titanium miniplate and screw fixation of fractures. The advantages and disadvantages of the treatment methods are discussed and some typical cases using various modern fixation techniques are presented.

Adolescent↗

PubMed1993

Dental injuries in association with mandibular condyle fractures.

A total of 356 patients with mandibular condyle fractures were studied regarding associated dental injuries. One third of the patients had injured teeth, on average, 3.7 teeth had been injured per accident. Dental traumas were distributed equally between the anterior (incisors and canines) and posterior teeth (premolars and molars) in both jaws. In unilateral condylar fracture cases maxillary dental injuries involved more often premolars and/or molars of the fracture side than those of the nonfracture side. The mean number of dental traumas in the mandible was higher in cases of simultaneous mandibular body fracture than without, whereas the presence of mandibular body fracture did not affect number of associated dental injuries in the maxilla. The dental injuries were mostly to hard tissue (78%), which were commonest in men, 20 to 29 years of age, and in victims of violence or fall accidents. Severe dental injuries in association with mandibular condyle fractures were more common in accidents due to traffic and miscellaneous causes than in those due to violence. Severe dental injuries were more often encountered when simultaneous mandibular body fracture was present than when it was not and more so in bilateral than unilateral condylar fracture cases. The most important factor correlating with the severity of dental injuries was the presence of bilateral condylar fracture.

Accidental Falls↗

PubMed1993

Occlusal interferences in association with teeth left in the line of mandibular fractures.

In order to evaluate whether teeth left in the line of mandibular fracture can predispose to occlusal interferences, the contact relationships between the maxillary and mandibular teeth in 37 mandibular corpus fracture patients were examined on the average 41 months after the injury. Control group consisted of 27 healthy dental students. It was shown that occlusal interferences were encountered in 38% (16/42) of teeth in the line of mandibular fracture in 38% (16/42) of their anterior and in 32% (9/28) of their posterior ones. Similar examination in the control group revealed interferences in 28% (113/400) so the ones found in teeth in the line of mandibular fractures can be supposed to have been caused by the injury and/or its treatment. It is also concluded that whether or not the interferences found in these patients were caused by the injury or its treatment or were signs of individual range they should be corrected with occlusal adjustment to prevent further pathological changes in these teeth and in the function of the masticatory system.

Adolescent↗

PubMed1993

Dental tissues involved in exarticulation, root resorption and factors influencing prognosis in relation to replanted teeth. A review.

Prognosis in relation to an exarticulated, replanted tooth is poor. Late complications are frequent and often lead to tooth loss. However, the root of a replanted, avulsed tooth may be slowly resorbed preserving alveolar width and postpones replacement of the tooth to a more convenient time. During healing following transplantation or replantation of teeth, various dental and oral structures are involved. Late complications relate to various factors. Tissues and factors involved are reviewed. Knowledge of this subject derives mostly from results of transplantation studies in animals.

Humans↗

PubMed1993

Failures in the osseointegration of endosseous implants.

A total of 68 patients, 26 men and 42 women, aged 21 to 86 years, were treated with 204 endosseous implants (TPS, ITI, Bonefit, or Biolox) from 1985 to 1990. They were examined at their latest recall visit approximately 22.5 months after surgery, the range varying greatly between the implant systems used (from 4 to 60 months). Fourteen implants were lost during the observation period because of failures in osseointegration. There were no statistically significant differences in success rates between the implant systems during the observation period. The Periotest values, however, differed between the Bonefit and ITI implants in maxillae (P < .001) and mandibles (P < .01), and between successful and failed TPS implants (P < .001, unpaired t test). In four of the failures, all ITI implants, the prosthetic restorations (fixed dentures and single crowns) had been lost. All other failures were treated by using the previous complete denture. Possible causes of failure included advanced age and poor general health of the patient, complications in the surgical procedures, and compromised oral hygiene.

Adult↗

PubMed1992

Different patterns of condylar fractures: an analysis of 382 patients in a 3-year period.

Three hundred eighty-two patients with 443 condylar fractures, accounting for 52.4% of all mandibular fractures, were given diagnoses and treated in our department between 1987 and 1989. A high proportion of the fractures (44%) were caused by interpersonal violence, followed in incidence by falls (29%) and road traffic accidents (21%). The type of condylar fracture seems to be influenced directly by its cause. Severe fractures in which the condyle was dislocated out of the glenoid fossa resulted more often from falls (22%) and road traffic accidents (26%) than from violence (8%). Fractures caused by violence showed a uniform type characterized by a subcondylar location and nondisplacement or deviation at the fracture line. A relatively large number of patients (56, 15%) were considered to have an indication for open reduction of the fracture.

Accidental Falls↗

PubMed1992

Dental health behavior in fathers of young families in Finland.

The purpose of this study was to examine dental health behavior in young fathers by means of a questionnaire for subjective evaluation of dental status, frequency of caries and visits to the dentist. Cariogenic diet was estimated by the consumption of sweets, confectionary and soft drinks. The participation rate 18 months after the birth of the family's first child was 73.1%. The mean age of the respondents was 28.1 yr (range 17-49; SD 4.6). When background factors were considered, it was observed that cariogenic diet was more often mentioned by participants from the lower social groups. The standard of the wife's knowledge level was an important indicator of dental care behavior in the fathers. If the wife's knowledge level was high, the father assessed the future condition of his child's teeth as good.

Age Factors↗

PubMed1992

Mobility and percussion sound of healthy upper incisors and canines.

In order to evaluate the correlation between mobility and percussion sound, 126 upper incisors and canines in 21 student volunteers were measured by means of the Periotest (Siemens), by evaluating the percussion sound subjectively and by analyzing its spectrum. The attenuation time and frequency of the sound were measured for each tooth. A logical mobility and percussion sound existed in accordance with the sizes of the teeth. Spearman correlation coefficients close to 1.00 were noted in individual cases between the Periotest and the three other tests describing the percussion sounds.

Adult↗