Treatment outcome in patients with TMD--a survey of 123 patients referred to specialist care.

Temporomandibular disorders (TMD) are a group of functional disorders of the masticatory system. Signs and symptoms of TMD are very common in different age groups in both genders. Treatment need varies greatly, ranging from 5 to 27% of the population. The treatment of TMD patients is generally initiated using reversible conservative methods and if necessary, irreversible and surgical methods are used. Altogether 123 patients (93 females, 30 males, mean age 39 years, range 12 to 72 years) were referred to the Oral and Maxillofacial Department of Oulu University Hospital between the years 2005 and 2008. The treatment outcome was evaluated using the anamnestic and clinical dysfunction indices of Helkimo, before and after treatment. The results of the study showed that the outcome of the conservative treatment methods of TMD and of surgical treatment, if needed, was beneficial, with a subjectively and clinically statistically significant decrease in signs and symptoms.

Association of stress level with facial pain: the role of coping.

It has been noted that stress factors, including coping with stress, are involved in pain problems. The aim of the present study was, firstly, to investigate the association of stress level with facial pain, and secondly, to assess the influence of coping strategies on this association. The study was part of the Northern Finland Birth Cohort 1966 project. The original material consisted of all people born in 1966 in Northern Finland. Of these, 5,696 participated in a follow-up study at the age of 31. As part of the study, data on facial pain, stress level of the subjects (measured with three items from the Work Ability Index), coping strategies in stressful situations (measured using the Ways of Coping Checklist) and sociodemographic background data were collected using questionnaires in 1997-98. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using generalized linear models. After adjustment for gender, education, and work history, facial pain was associated with a high stress level (OR 2.3, 95% CI 1.7-3.0). When coping strategies were added to the model, the strength of the association did not change essentially. The results emphasize the role of psychological stress in the background of facial pain. The association is independent of the coping strategy of the individual.

Generalized pain and pain sensitivity in community subjects with facial pain: a case-control study.

AIMS: To investigate the existence of pain outside the facial area as well as pain sensitivity in a population-based sample of 34-year-old subjects with facial pain. METHODS: Fifty-two facial pain cases (10 men, 42 women) and 52 pain-free controls (10 men, 42 women) included in the Northern Finland Birth Cohort of 1966 underwent a clinical musculoskeletal examination. Pain outside the facial area during the week prior to the examination was defined by means of a pain drawing. Eighteen fibromyalgia points were palpated in response to digital palpation with an algometer. Pressure pain thresholds were measured from the dorsal side of the wrist and from the highest points of the temporalis muscles. RESULTS: Compared to controls, pain cases reported significantly more pain in areas outside the face, with the exception of the shoulder and lower back. The number of painful fibromyalgia points was significantly higher in cases than in controls. Mean pressure pain thresholds were slightly lower in cases than in controls; the difference was significant in the left wrist. CONCLUSION: Subjects with facial pain reported more pain and had more mascular tenderness outside the facial area compared to controls. Pain symptoms outside the facial area should be assessed in patients seeking treatment for facial pain, and they should be taken into account when treatment is planned.

An instrument for the optimal guiding of osseointegrated dental implants.

The purpose of this study was to design an instrument for the optimal guiding of osseointegrated implants intraoperatively to achieve parallelism or desired angulations. Seven patients (4 males and 3 females) were enrolled in the investigation. They ranged in age from 44 to 61 years. Using an instrument designed by the senior author that permitted optimal guiding of the osteotomy instruments (33 Osteofix Oy, Oulu, Finland) we placed in these patients, root form, single stage implants. The difference in angulations between the first and the remaining implants was measured using the abutment replicas on the working models. It was found that the mean deviation angle between the first and the adjacent implant replicas was 2.2 degrees (SD = 0.4 degrees). The largest deviation angles were 2.3 degrees (SD = 0.5 degrees) and 3.1 degrees (SD = 0.8 degrees). The study indicated that the instrument had been designed in a functional manner and that all implants in such relationships can be inserted into their desired positions, either parallel to one another or with the desired angle for the planned prostheses.

Accuracy of clinical and radiological classification of the jawbone anatomy for implantation--a survey of 374 patients.

The aim of this study was to investigate the anatomical features of edentulous jaw dental segments (eJDS) in order to offer the most reliable clinical and radiological classification of such segments in planning for implant treatment. A total of 374 patients, 156 men and 218 women, participated in the investigation. The mean age of the patients was 46 years (SD 12.7), ranging between 17 and 73 years. The eJDS were estimated by means of orthopantomogram, computerized tomography, and intraorally with special ridge-mapping callipers for measurement of alveolar process width. A total of 792 screw-shaped and 1-stage Osteofix Dental Implant System (Oulu, Finland) implants were inserted. Dental segments were divided according to the results of the commonly accepted eJDS assessments into 3 clinical-anatomical types. Type I indicated insignificant or no atrophy of eJDS (232 patients with 476 implant sites; 60.1% of the total number). Type II indicated mild to moderate vertical or horizontal atrophy of eJDS (100 patients with 222 sites; 28% of the total number). Type III indicated significant vertical or horizontal atrophy of eJDS (42 patients with 94 sites; 11.9% of the total number). The accuracy of the clinical and radiological classification was adjudged to have been 95.8%. By the process of establishing clinical and radiological classification of the jawbone segments, more reliability was anticipated regarding the insertion of implants both in maxillae and mandibles.

MR abnormalities of the lateral pterygoid muscle in patients with nonreducing disk displacement of the TMJ.

The aim of this study was to investigate the pathological changes of the lateral pterygoid muscle (LPM) using magnetic resonance imaging (MRI) in patients with anterior disk displacement with nonreduction (ADDnr) of the temporomandibular joint (TMJ) and to compare the abnormal findings of the LPM with the clinical symptoms and other pathological MRI alterations of the TMJ. Bilateral or unilateral ADDnr was demonstrated in 142 patents by MRI (176 TMJs; 106 females; 36 males; range 19 to 72 years; mean 43.9 years). In 123 TMJs, the LPMs were clearly observed in MRIs and analyzed in this study. Pathological changes of the LPM were found in 92 TMJs (74.8%) in MRI. Hypertrophy, atrophy and/or contracture were detected in the superior belly of the LPM (SBLPM) (35.8%, 44/123) or in the inferior belly of the LPM (IBLPM) (9.8%, 12/123) or in both bellies (29.3%, 36/123). The pathological changes of the LPM in MRI presented a significant association with the main clinical symptoms of TMJs with ADDnr, i.e. pain on jaw movement (P<0.01), pain in the LPM (P<0.01), pain in TMJ (P<0.05) and restricted jaw opening (P<0.05). The proportion of the abnormalities in LPM was significantly lower in TMJs with condylar limitation (63.6%) than in TMJs with condylar hypermobility (83.3%) and normal motion (88.9%)(P=0.008). Osteoarthritis was found to be correlated with condylar limitation (P<0.01). The results of this study indicate that the pathological changes of the LPM in TMJs with ADDnr could be detected by MRI and have a significant association with the main clinical symptoms of the patients. When condylar limitation happened, on the contrary, the pathological changes of the LPM in MRI were reduced. The alteration of the clinical symptoms in the patents with ADDnr might be associated with the pathological situations and symptoms of the LPM.

Temporomandibular disorders, occlusion, and neck pain in subjects with facial pain: a case-control study.

The etiology of facial pain is multifactorial. Based on the results of a questionnaire included in the study of the 1966 Northern Finland Birth Cohort, performed in 1997-98, we found an association of facial pain with subjective symptoms of temporomandibular disorders (TMD), neck pain and with occlusal factors reported by 5,696 subjects. The aim of the present study was to examine these associations clinically. In the year 2000, a new inquiry was sent to the following subjects living in Oulu: 1. all subjects who had reported facial pain in the former questionnaire (n=162) (case group); and 2. to a randomly selected group of nonpain controls (n=200), group matched for gender. Those who reported willingness to participate were invited to a clinical examination. Finally, the total number of subjects was 104, including 52 (10 men, 42 women) cases and 52 (10 men, 42 women) controls. Anamnestic data were collected, and clinical stomatognathic and musculoskeletal examinations were performed, both the clinicians and the subjects being unaware of the case-control status. Anamnestically, stress was the most often reported provoking factor for facial pain. Facial pain associated significantly with reported TMD symptoms and allergies. Based on clinical findings, most of the cases were classified in the myogenous subgroup of TMD. The risk for facial pain was six-fold in subjects with clinically assessed TMD, defined as moderate (DiII) or severe (DiIII) by Helkimo's clinical dysfunction index, almost six-fold in subjects with protrusion interferences and approximately three-fold in subjects with clinically assessed tenderness of distinct fibromyalgia (FM) points in the neck. According to the adjusted logistic regression analyses, TMD had the strongest influence on facial pain, followed by protrusion interferences, anamnestically reported allergies and "other headaches". The present study shows that as well as being connected with TMD, facial pain is associated with pain and muscle tenderness in the neck area.

Stress distribution in bone: single-unit implant prostheses veneered with porcelain or a new composite material.

The purpose of this study was to simulate dynamic and static occlusal loading on one unit fixed, implant-supported prostheses veneered with porcelain and with GRADIA in a 3-dimensional finite element model of the human mandible to analyze and compare the resultant stresses in the superstructures and in the supporting bone. Calculation and visualization of stress, deformation, and displacement of complex structures under simulated forces were evaluated by finite element analysis (FEA) using ANSYS. The device employed was from the OSTEOFIX Dental Implant System (Oulu, Finland), and the veneering materials used were standard dental porcelain and GC GRADIA (Tokyo, Japan), a new composite material. Two different loading conditions were considered: static and transitional or impact, each delivered in three different directions: horizontal (Fh) at 0 degrees , vertical (Fv) at 90 degrees , and oblique (Fo) at 120 degrees . The proportion of the force: magnitude was fh:fv:fo = 1:3.5:7. A vertical load of 500 N, a horizontal load of 143 N, and an oblique load of 1000 N were applied. The results showed that the highest stresses in the bone-implant interface occurred in the region of cortical bone adjacent to the first thread of implants in all models and varied within 6.5%. Maximum stresses and displacements were higher (7%) in those models with statically loaded implants as compared with those that had been dynamically loading. The direction of loading played a major role in determining stress levels and they varied at up to 85%. It was shown that with dynamic loads, the peak of 1.568 mm was registered in the model with the GRADIA veneering material. This displacement was 6.5% higher than that found with the Vita VMK 68 veneers. These results suggest that the implant superstructure-fixed single crown veneering materials-porcelain and GRADIA played minor influences to the displacements and stresses in the implant supported bone with a 1% variance. One of the reasons for this element resulting in so minor a contribution to stress relief was the relatively small volume of the veneers as compared with the far greater volume and stiffness of the superstructures and implants. One of the advantages of GC GRADIA is that it reduces impact force under dynamic load up to a 6.5%.