Kyösti Oikarinen

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.

Visibility of foreign bodies in soft tissue in plain radiographs, computed tomography, magnetic resonance imaging, and ultrasound: An in vitro study

We compared conventional plain radiography, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US) with respect to their suitability for detecting foreign bodies in soft tissue in an in vitro model using a cow tongue to simulate orofacial soft tissues. Four samples of different sizes of fractured tooth crown, pieces of amalgam, glass, asphalt, composite, dry wood, and stone were each embedded under a 2-cm-thick flap on the caudal surface of the tongue. Plain radiographs revealed all the materials except wood, and there was some variation in the subjectively evaluated radiopacity of the materials which indicated the nature of the foreign bodies concerned. MRI proved to be the least suitable imaging method, as particles with a metallic content gave rise to powerful interference artifacts. CT and especially US proved to be suitable imaging methods for foreign-body detection in soft tissue. Amalgam produced a metallic streaking artifact in CT, which visualized wood as gas density, and depicted all the other materials as similar hyperdense masses. Ultrasound was both sensitive and specific in detecting foreign bodies in soft tissue. The particles were better defined in form and size with CT and US than with MRI or plain radiography. We conclude that when plain radiographs, history, and clinical examination fail to reveal the presence of superficial foreign bodies, US or CT can serve as an alternative method.

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 Townes 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.

Effects of orthognathic surgery on temporomandibular joint dysfunction: A controlled prospective 4-year follow-up study

A prospective follow-up study was performed to examine the influence of contemporary orthognathic treatment on signs and symptoms of TMJ dysfunction. Sixty consecutive patients were examined once preoperatively and twice postoperatively, and Helkimos Anamnestic and Dysfunction Indices (Ai and Di) were determined. The prevalence of headache was also assessed. The average follow-up was 4 years from the initial examination. A group of 20 patients with a similar type and grade of dentofacial deformity, who did not wish to have surgery or other occlusal therapy, served as a control group. The majority (73.3%) of the patients had signs and symptoms of TMJ dysfunction (TMD) in the initial phase. At final examination the prevalence of TMD had been reduced to 60% (P=0.013). There was a dramatic improvement in headache: initially 38 (63%) patients reported that they suffered from headache, but at the final visit only 15 (25%) did so. It is concluded that functional status can be significantly improved and pain levels reduced with orthognathic treatment. The risk for new TMD is extremely low. No association, however, could be shown between TMD and the specific type or magnitude of dentofacial deformity.

Comparison of different tests assessing neurosensory disturbances after bilateral sagittal split osteotomy

Different methods of assessing functional impairment of the inferior alveolar nerve after sagittal split osteotomy were compared with subjective reports. Thirty patients were tested preoperatively as well as after four days, three weeks, three months, six months, and one year of follow up. All the patients underwent bilateral mandibular ramus sagittal split osteotomy. The sensation of the mandibular teeth was assessed by an electric vitality scanner. Other neurosensory assessments included light touch, two-point discrimination, tactile discrimination, and thermal discrimination. It was shown that electric sensibility-testing of mandibular teeth is a useful method for evaluating neurosensory disturbance after sagittal split osteotomy, and it correlated even better with the patients subjective evaluation than the other tests used in this study.

Postoperative pain after mandibular third-molar surgery

The pain experienced after 116 operative removals of mandibular third molars was studied in a homogeneous group of patients consisting of 85 healthy university students. Pain was recorded daily on a visual analogue scale during the postoperative week. It was shown that preoperative inflammation and the difficulty and duration of the operation increased the intensity of pain.

Association Between Symptoms of Temporomandibular Disorders and Depression: An Epidemiological Study of the Northern Finland 1966 Birth Cohort

ABSTRACT Facial pain and other symptoms of temporomandibular disorders (TMD) are rather common in the adult population. According to clinical studies, psychological factors play an important role in the etiology and maintenance of these symptoms. On the other hand, chronic pain can cause depression. The aim of this study was to evaluate the association between symptoms of TMD and depression in a large population sample of young adults. The study was a part of the 31-year follow-up study of the Northern Finland Birth Cohort consisting of 12,058 live births from the year 1966. Questionnaire information concerning TMD symptoms was collected from a subsample of 5,696 subjects. Depression was measured with a question about reported depression (diagnosed by a doctor) and with the Symptom Checklist depression subscale (SCL-25 DS). Of the TMD symptoms, those related to pain had the most significant relations to indicators of depression. In both genders, the proportion of depression indicated with the SCL-25 DS was significantly higher in subjects with pain-related symptoms of TMD, i.e., facial pain and “pain at jaw rest”, and in men with “pain on jaw movement”, compared with non-pain subjects (p<0.05). Other symptoms of TMD also associated significantly with SCL-25 DS (p>0.05), except “difficulties in mouth opening” among women. Among women, the prevalence of recognized depression was also significantly higher in subjects with pain-related symptoms of TMD, compared with subjects with no pain (p≤0.05). Almost all the associations remained significant after adjusting for marital status, education, and self-rated general health. In conclusion, the results show that depression has an association with TMD symptoms, especially those related to pain. When treating patients with facial pain, dentists should consider the possible presence of psychopathology and, if necessary, consult appropriate mental health professionals.

Facial pain and temporomandibular disorders: an epidemiological study of the Northern Finland 1966 Birth Cohort.

ABSTRACT Recent clinical studies have shown an association between temporomandibular disorders (TMD) and facial pain. The aim of this epidemiological study was to investigate the prevalence of facial pain and TMD, their relation to each other, and also their relation to previous traumas, occlusal factors and pain in other areas of the body. The study is a part of the Well-Being and Health Research of the Northern Finland Birth Cohort 1966 using questionnaires where data on facial pain, TMD symptoms, occlusal divergencies, traumas in the face and other pain areas of the body were registered. Data were obtained from 5696 subjects born in the year 1966 in northern Finland. Twelve percent of the men and 18% of the women had suffered from facial pain during the last year. The most often reported symptom of TMD was clicking of the temporomandibular joints (TMJs) (21% in men, 28% in women), while prevalence of more severe symptoms was 13% or under. Facial pain was related to symptoms of TMD, as well as to traumas in the face or TMJs, distal occlusion and other pain areas (neck, shoulders, arms, lower back, jaws, tooth). The results suggest that facial pain is a usual symptom in adult population, and has an association with TMD, as well as with other musculoskeletal pain symptoms. Traumas to face and TMJs, certain occlusal factors and dental pathology may have a remarkable role in the etiology.

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 Tonque 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.

Changes in electric activity of masseter and temporal muscles after mandibular sagittal split osteotomy

The functioning of the masseter and anterior temporal muscles was assessed by electromyography in 18 patients before orthognathic surgery and 6 weeks, 3 months, 1 year, and 2 years afterwards. Electromyogram (EMG) recordings were made during maximal bite in intercuspal position and chewing. The mean electric activity in the masseter and anterior temporal muscles decreased markedly 6 weeks after surgery but increased clearly for 1 year in both functions. Only a slight further increase was observed at 2-year follow-up during chewing, but not during maximal bite in intercuspidation. The mean changes in electric activity increased more clearly in patients with hyperplastic mandible than in patients with hypoplastic mandible and in those with long shift of the mandible. The same finding was also more visible in men and older patients than in women and younger patients.