The zygomatic bone as a potential donor site for alveolar reconstruction--a quantitative anatomic cadaver study.

The aim of this cadaver study was to evaluate the possibility of using the zygomatic bone as an intraoral bone harvesting donor site and to determine the safety of this harvesting procedure. In addition, the volume of bone material harvested from the zygomatic bone was measured. Twenty fixed adult cadavers were used to yield a total of 40 zygomatic bone harvest sites, from which bone was collected. The volume of bone obtained from the zygomatic harvests was measured with a water displacement method and by compressing the graft into a syringe. The safety of the technique was evaluated by assessing possible encroachment upon the neighbouring structures. After bone harvesting, the zygomatic sites were exposed and evaluated for visible perforations or fractures. Possible damage to the neighbouring tissues was also examined with computed tomography scans at 18 sites in nine cadavers. The average bone graft volume obtained from the zygomatic bone was measured to be 0.53 ml (SD 0.25) with water displacement and 0.59 ml (SD 0.26) with the syringe. The complications in the zygoma included 15 small perforations into the maxillary sinus and 7 perforations into the infratemporal fossa. CT scans showed that bone could be harvested safely without encroaching upon the orbital floor or the surrounding nerves and vessels in the zygoma. The zygomatic bone is a safe intraoral donor site for the reconstruction of small- to medium-sized alveolar defects.

Association of symptoms of TMD and orofacial pain with alexithymia: an epidemiological study of the Northern Finland 1966 Birth Cohort.

Alexithymia is a term denoting a deficit in the ability to differentiate emotional from physical states and to identify and describe one's feelings, as well as a preference for external oriented thinking. Alexithymia has been linked with various somatic and psychosomatic diseases, especially with chronic pain. The aim of this study was to evaluate the association between alexithymia and symptoms of temporomandibular disorders (TMD) as well as oro-lingual and dental pain, in a large representative population sample of young adults. The study was a part of the 31-year follow-up study of the Northern Finland Birth Cohort originally consisting of 12058 live births in the year 1966. In 1997, 4893 subjects living in northern Finland or in the capital area, who participated in a field study of the project and later returned a postal questionnaire, made up the sample of this study. Information concerning symptoms of TMD and oro-lingual and dental pain was collected from the subjects. To assess alexithymia, the Toronto Alexithymia Scale-20 (TAS-20) was used. In addition, information about depression, marital status and self-rated health was collected. The proportion of alexithymics (TAS score over 60) was higher in subjects with the most orofacial symptoms than in asymptomatic subjects. In men, alexithymia associated significantly with facial pain, difficulties in mouth opening, oro-lingual pain and dental pain, and in women with pain on jaw movement and dental pain. After adjusting for depression, marital status, and self-rated health, a significant association remained between alexithymia and the symptoms mentioned, except for facial pain in men. It can be concluded that alexithymia is connected with orofacial symptoms. Clinicians treating these symptoms should be familiar with the concept of alexithymia.

MRI findings concerning the lateral pterygoid muscle in patients with symptomatic TMJ hypermobility.

Clinical studies have shown a close association between temporomandibular joint hypermobility (TMJH) and temporomandibular disorders (TMD). While pathological change of the lateral pterygoid muscle (LPM) is one of the most emphasized in studies of TMD, there have been no detailed clinical reports of the LPM studies using magnetic resonance imaging (MRI) in TMJH. This study investigates structural and pathological alterations involving the LPM in patients with TMJH using MRI. A retrospective analysis was made of high-field MRI images from 98 patients with TMJH. LPMs of 143 joints were analyzed. In 110 joints (77%), hypertrophy, atrophy, and contracture were found in the superior belly and/or the inferior belly of the LPM. Pathological changes were more frequently found in the superior rather than the inferior belly of the LPM. In the cases with abnormalities in both bellies of the LPM, hypertrophy of the inferior belly was usually found combined with other changes of the SBLPM. The results of this study indicated that the pathological changes of the LPM or MRI are not infrequent in patients with symptomatic TMJH.

Association between symptoms of temporomandibular disorders and depression: an epidemiological study of the Northern Finland 1966 Birth Cohort.

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< or =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.

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.

The effect of surgical treatment of the temporomandibular joint: a survey of 70 patients.

Most patients with temporomandibular disorders (TMD) can be successfully treated by conservative methods, but approximately 10-20 percent have persistent symptoms. The aim of this study was to evaluate the signs and symptoms of TMD in patients treated with open surgery of the TMJ. Seventy-two patients (13 men, 59 women, mean age 37 years, range 14-68 years) were evaluated during an eight-year period. Altogether 45 right TMJs and 39 left TMJs were treated, including both TMJs during the same operation in eight of the cases. The patients were evaluated at follow-up in 1997. The degree of TMD at follow-up was assessed using the anamnestic and clinical dysfunction Helkimo indices. Most of the patients reported at the follow-up that they were subjectively satisfied with the surgical treatment. The main clinical findings in the post surgical patients at follow-up were TMJ sounds and deviation of the mandible during opening. The tenderness in the masticatory muscles and TMJs on palpation was reduced significantly and the ranges of mandibular movement were improved for all the patients. The mean anamnestic and clinical indices decreased with a statistical significance from the shortest follow-up group (Group I) to the longest on group (Group IV) (p = 0.000). The conclusion of this study was that after open surgical treatment of the TMJ, the patients have significantly better functioning of the masticatory system and reduced signs and symptoms of TMD in the long term.

Role of temporomandibular disorders (TMD) in facial pain: occlusion, muscle and TMJ pain.

Temporomandibular disorders (TMD) which comprise myogenic and arthralgic components have been reported to predispose subjects to headache and facial pain. The aim of this study was to evaluate the role of these components in patients with facial pain and to investigate the influence of treatment of TMD on pain of these patients. The subject group consisted of 25 patients suffering from facial pain. The clinical stomatognathic examination was performed before conservative treatment of TMD, and one-two weeks, three months and one year after treatment. The severity of TMD was assessed using the anamnestic (AI) and clinical dysfunction (DI) indices of Helkimo. The intensity of pain was evaluated on a numerical rating scale (NRS). According to clinical findings the patients were classified to following diagnostic subgroups: TMD myo (mainly myogenic), TMD arthro (mainly arthrogenous) and TMD comb (both myogenic and arthrogenous components involved). Fifteen patients were classified in the TMD myo group, nine in the TMD comb group and one in the TMD arthro group. The DI index decreased significantly one-two weeks after treatment and remained at this level at three month and one year follow-up examinations. At the first examination the TMD myo group had the highest level of NRS index, which decreased significantly during the time of follow-up, while no significant changes were found in other groups. Bruxism reported by the patient had a positive correlation with the amount of painful muscles on the right side at first examination. The results show that facial pain combined with TMD may be mostly of myogenic origin, and myogenic pain seems to have most favorable response to conservative treatment of TMD.

Densities and sizes of main masticatory muscles in patients with internal derangements of temporomandibular joint obtained by computed tomography.

Computed tomography (CT), due to its excellent resolution capacity, is a suitable method to examine the soft and bony structures of the masticatory system. The aim of this study was to compare densities and sizes of the masseter and medial and lateral pterygoid muscles obtained by CT between the symptomatic and asymptomatic side in patients with internal derangement of the temporomandibular joint (TMJ). The aim was also to correlate these variables to sex and age, duration of the symptoms, diagnosis and dentition. The material consisted of 33 patients (26 women, 7 men, mean age 37 years, range 14-74 years) whose TMJs were examined by CT and whose coronal CT scans were available. Diagnosis in the symptomatic TMJ was confirmed in operation. No statistically significant difference was seen in mean densities and sizes of the masticatory muscles between the symptomatic and asymptomatic side. The duration of the symptoms, however, correlated positively to the density of the lateral pterygoid muscles in patients with complete dentition. The age of the patients in this group correlated negatively to the size of the masseter muscles. It can be concluded that patients with internal derangements of TMJ with a long duration of symptoms have structural changes in their masticatory muscles which are detectable by CT.

Information of circulation from soft tissue and dental pulp by means of pulsatile reflected light: further development of optical pulp vitalometry.

OBJECTIVES: To show experimentally and clinically that information of blood circulation patterns can be obtained through dentin and enamel by means of reflected light. STUDY DESIGN: Several different experimental techniques were developed in vitro leading up to in vivo tests. RESULTS: Pulsatile information of back-scattered light at 560 nm was obtained in an experiment in which a thread with white and red sections was pulled through the empty pulp cavum. The pulsatile information of back-scattered light of 560 nm wavelength was detected from a forefinger of a volunteer through dental hard tissue plates. There was a difference in the radiant flux of back-scattered light in extracted teeth filled with various materials. Photoplethysmograms obtained from the vital pulp of a 24-year-old woman were analyzed with Fast Fourier Transformation (FFT). The analyzed data showed a dominant amplitude of heart rate near 1 Hz. CONCLUSIONS: Tests indicated that reliable information of circulation can be obtained from the dental pulp chamber by means of the optical reflection method. This could serve as a model for a new type of pulp vitalometer.

Changes in electrical activity of masseter and temporal muscles after temporomandibular joint surgery. A one-year follow up.

The functioning of the masseter and anterior temporal muscles was recorded by electromyography (EMG) in 15 patients with disc interference of the temporomandibular joints, before surgery and three months, six months and one year afterwards. EMG recordings were made during maximal bite in intercuspal position and while chewing. The mean electrical activity in the masseter and anterior temporal muscles, both on the operated and nonoperated sides, decreased markedly three months after surgery, especially during maximal bite in intercuspal position, but increased to above the preoperative values at the one-year recording in both functions. Statistically, significantly lower activities were seen on the operated side in patients with anterior dislocation of the disc without reduction, as compared to patients with reduction of the disc. The EMG activities of the masseter muscles on the nonoperated side were significantly lower in women and in older patients, as well as in patients with a longer duration of symptoms than in men and younger patients.

Factors related to Periotest values in endosseal implants: a 9-year follow-up.

Periotest values (PTV) of successful endosseal implants of 2 one-stage implant systems. TPS and ITI, were followed from 3 months to 9 years in order to determine the factors that contribute to the values. 128 TPS screw implants were inserted in the lower jaw of 34 subjects, (mean age 55 years), for retaining overdentures. 108 ITI implants were inserted in the upper and lower jaws in 50 subjects (mean age 42 years), for retaining overdentures, crowns and bridges. PTVs were first measured after the osseointegration period and thereafter annually. First of all there was a difference between the 2 implant systems. Mean PTVs of TPS bicortical screws were significantly lower (P < 0.05) than those of ITI implants (screws, hollow-screws, hollow-cylinders). Factors which significantly contributed to PTVs of ITI implants were jaw (upper/lower), implant length and region of the jaw in which the implant was inserted. PTVs of ITI implants in the lower jaw were lower than in the upper jaw (P < 0.05). The length of implant had no effect on PTVs in the lower jaw, but in the upper jaw, PTVs of ITI 8-10-mm implants were lower than 12-mm implants (P < 0.05). PTVs of implants inserted in the anterior region of the upper jaw were higher than those in the posterior region (P < 0.05). In conclusion, bone quality and implant length had a statistically significant effect on implant mobility in long-term follow-up. PTVs of various implant systems, however, differ, a fact that must be taken into account in evaluating the success of implants.

Influence of conventional forceps extraction and extraction with an extrusion instrument on cementoblast loss and external root resorption of replanted monkey incisors.

Cementoblast loss and root resorption on the root surface was registered histologically after removal and immediate replantation of maxillary central incisors in monkeys (Cecropithecus aethiops). Incisors were removed with either a conventional extraction technique using forceps or with a special designed extrusion instrument and in both cases teeth were immediately replanted. Altogether 18 monkeys were used for the experiments in which 9 monkeys were sacrificed after 3 d and 9 animals after 8 wk. Histological analysis was made in horizontal sections perpendicular to the long axis of the tooth using either 24 measuring points or 12 sections. Histometric analysis showed extensive cementoblast loss in the periodontal ligament (PDL) and with a maximum of damage occurring on the corner surfaces of the root. Extracted teeth showed significantly more extensive cementoblast loss than extruded teeth. Root resorption was also found in the corner locations and was significantly more frequent in extracted than in extruded teeth. There was a similarity in the distribution of cementoblast loss and root resorption indicating that root resorption develops in the same areas where cementoblast loss takes place, i.e. locations that are more compressed during removal of the tooth and must have caused by mechanical damage to the PDL exerted on the root surface during tooth removal.

Effect of treatment of palatal inflammatory papillary hyperplasia with local and systemic antifungal agents accompanied by renewal of complete dentures.

The aim of this study was to estimate the effect of local and systemic antifungal treatment, accompanied by renewal of complete dentures, on palatal inflammatory papillary hyperplasia (PIPH). The treatment groups consisted of 26 subjects treated with a local antifungal agent (miconazole, 2% gel) for 4 weeks and 13 subjects treated with a systemic antifungal agent (fluconazole, 50 mg) for 2 weeks (test groups). Ten subjects fitted with new complete dentures served as a control group. Variables examined before antifungal and prosthetic treatment included estimation of the size and color of the affected palatal area, measurements of the lengths of the papillae, and salivary variables. Six months after the completion of prosthetic treatment healing was determined as disappearance or marked reduction of the redness of the PIPH. Healing was more often observed in test groups (64%) than in the control group (20%) (p = 0.012). Fifty-eight per cent of the subjects treated with a local (miconazole, 2%) and 77% of those treated with a systemic (fluconazole, 50 mg) antifungal agent were healed. Even though papillary hyperplastic tissue did not disappear, the treatment of PIPH with an antifungal agent without surgery before renewal of dentures might be an alternative treatment in mild cases.

Clinical management of injuries to the maxilla, mandible, and alveolus.

Facial bone and especially mandibular fractures are injuries in which first aid and management of late complications require dental professionals, and consequently all dentists should be familiar with the modern principles of their treatment. Tooth involvement is common in mandibular and maxillary fractures and can require more treatment than does the jaw fracture. Nonsurgical treatment of bone fractures involves immobilization, which for the facial bones is achieved with maxillomandibular fixation (MMF) using dental fixed arch bars. Hence, associated tooth injuries are difficult or impossible to treat during immobilization, so that some treatment is necessary beforehand (for example, coverage of exposed dental areas, temporary filling of crown fractures, repositioning of luxated teeth, and endodontic treatment if the pulpal vascular supply is lost in the accident). Operative treatment of mandibular and/or maxillary fractures nevertheless involves some disadvantages and risks of complications. Teeth on the line of a mandibular fracture should not be extracted as a first-aid measure unless they impair repositioning of the jaw fragments. MMF can be avoided by means of direct internal fixation, which in principle allows treatment of associated dental injuries.

Influence of acid-etched splinting methods on discoloration of dental enamel in four media: an in vitro study.

The aim of this in vitro study was to assess the staining of enamel in relation to fixation of luxated teeth. Color changes induced by chlorhexidine, red wine, tea, and coffee were detected with a Minolta Chroma Meter (CR-121) after extracted teeth were treated to simulate construction of dental splinting. L*a*b* color readings were made before and after 7 days of incubation in the above-mentioned media in teeth treated 1) by acid-etching, 2) by acid-etching followed by resin, 3) by resin and composite, 4) by Triad Gel, and 5) by Protemp. L* is an indicator of black (0) and white (100). The a* values relate to the red (+100)-green (-100) color axes, and the b* values to the yellow (+100) and blue (-100) axes. Untreated teeth served as controls. One-way analysis of variance of mean L* values revealed no statistically significant differences in treatment. Discoloration was observed in all teeth, including the control ones. However, Protemp yielded the largest changes in mean L* values. Analysis of variance of mean L* values revealed statistically significant differences between incubation liquids because no increase in staining of enamel was noted after 7 days' incubation in chlorhexidine. Red wine increased the mean L* values more than coffee or tea. Changes in a*b* readings were toward red (+a*) after incubation in red wine, except in the case of teeth treated with resin. The color of all such teeth changed more toward yellow (+b*), because the resin used was yellow.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of arch bar splinting on periodontium and mobility of fixed teeth.

Altogether 17 patients treated with arch bar splints fixed onto teeth were tested at the time of splint removal and approximately 5 months later. Patients were treated with intermaxillary fixation (IMF) because of either orthognathic surgery (7 patients) or mandibular fractures (10). The CPITN index was used for estimating the periodontal status, and tooth mobility was measured with Periotest. Seven patients in the orthognathic surgery group could also be examined before splinting. Periodontal status, as shown with relative proportions of various CPITN indexes, worsened due to splinting but regained its original level at control examination a minimum of 5 months after splint removal. Since the mean Periotest values did not differ between the first and control examinations in the seven patients undergoing orthognathic surgery, the analysis of the effect of splinting on tooth mobility was performed from the values obtained immediately after splint removal and at control visit. Splinting was shown to increase Periotest values more in female patients, in younger ones, and in those who were splinted for a shorter period. Teeth with the smallest roots showed greater differences in Periotest values than those with large roots, and the greatest differences in mobility were observed in incisors.

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.

Clinical and radiologic assessment of possibilities for endosseous implants and osseointegrated prostheses in 55-year-old edentulous subjects.

To determine how many 55-year-old edentulous subjects were suitable candidates for implant-retained overdentures of fixed implant bridges and how many of them might be interested in such treatment, case histories were reviewed, and clinical and radiologic examinations were performed on 146 subjects (100 women, 46 men) in a medium-sized city in northern Finland. Numbers and lengths of implants required in altogether 16 regions in the upper and lower jaw were evaluated. The commonest implant length was 8 mm in the upper jaw and 16 mm in the lower jaw. Construction of an implant-retained fixed bridge would have been possible in the upper jaw in 121 subjects (83%) and of an overdenture in all lower jaws. Information about the benefits of the treatment is important because, although the percentage of subjects who were suitable candidates for implant-retained prostheses was high, few subjects were aware of or interested in this type of treatment.

The effect of removal of all third molars on the dental arches in the third decade of life.

The intent of this study was to evaluate any change in the dental arches of adults in the third decade of life after the removal of all third molars in relation to occlusal factors, gender and the status of the third molars prior to extraction. The subjects were 24 healthy students (9 women, 15 men; mean age 23.2; age range 20-32) whose third molars were all removed. All extractions in the lower arch were performed because of impaction and complicating symptoms such as pain and swelling. Full occlusal registrations were performed before the extractions and one year afterwards, including the production of dental casts. The dimensions of the lower dental arch showed a small, but significant, increase one year after the removal of all the third molars. No significant change took place in the lower anterior area during the year. In the maxillary arch (in the lateral and transversal dimensions), the direction of change was similar to that of the lower arch, but smaller than in the mandibular arch. This indicated a minor space gain during the year after the removal of all third molars. The changes in the dental arches did not correlate significantly with changes in craniomandibular disorders (CMDs). It can be concluded that the extraction of an impacted third molar allows at least the second molar to drift posteriorly and laterally in the dental arch. The results give no further indication, in this age group, to extract the lower third molars in order to prevent lower anterior crowding.

Comparison of the guarding capacities of mouth protectors.

The guarding capacity of seven mouth protectors (Erkoflex 3.0 and 4.0, Erkoloc 3.0, 4.5 and 5.5, TranSheet/Perform and TranSheet/LiteLine) was tested mechanically on 20 plaster models, two or three tests on each mouth protector. Two tests on a plaster model without the protector served as control. An appliance was constructed to simulate the impact of an ice-hockey puck on the teeth, the plaster model was fixed onto the device and the minimum force needed to break the plaster teeth under the protector was recorded. The average total thickness and that of the soft and hard layers of the labial plates of each mouth protector were recorded along with the average thickness of the cervical and incisal hard and soft layers. The results showed that the best protection was achieved with the TranSheet/LiteLine model, followed by TranSheet/Perform and Erkoloc 5.5 and 4.5 mouthgards. All these had a resilient layer against the teeth, and it was shown in stepwise regression analysis that the only property having a statistically significant effect on the guarding capacity was the thickness of this cervical soft layer.