The influence of a mandibular advancement plate on polysomnography in different grades of obstructive sleep apnea

Objectives

The purpose of this study was to investigate the effect of a mandibular advancement device on different grades of obstructive sleep apnea using a relatively simple test for the apnea-hypopnea index to determine if a mandibular device will be effective.

Material and Methods

A total of 68 patients with obstructive sleep apnea syndrome (OSAS) including, 31 with mild, 23 with moderate and 14 with severe OSAS were treated with a mandibular advancement device (MAD) and monitored with polysomnography.

Results

25 of the 31 mild, 15 of the 23 moderate and 2 of the 14 severe OSAS patients were cured of their OSAS if a post treatment apnea-hypopnea index of less than 5 is regarded as cured. The odds ratios for success with MAD therapy are 3 for women over men, 14.9 for mild obstructive sleep apnea, 5.42 for moderate obstructive sleep apnea if severe obstructive sleep apnea is assigned an odds ratio of 1.

Conclusions

The use of the apnea-hypopnea index alone is useful in mild and moderate disease to predict the effectiveness of mandibular advancement device. Treatment with a mandibular advancement device is very effective in treating mild and moderate obstructive sleep apnea. Conservative treatment with a mandibular advancement device can be successful in less severe grades of sleep apnea and may be an alternative for non-surgical patients with severe obstructive sleep apnea intolerant of Continuous Positive Airway Pressure management.

Dental traumas during the military service

BACKGROUND

Dental traumas are most frequent during the first three decades of life and more frequent among males than females. Approximately 80% (n = 28 000) of the male age cohort performs military service annually in Finland. As little is known of dental, head, and neck traumas during the military service, our aim was to study the etiology, number and occurrence of traumas of the Finnish conscripts during one calendar year. Our hypothesis was that above-mentioned traumas comprise a remarkable proportion of military accidents.

MATERIALS AND METHODS

The data comprised of all the Finnish conscripts' trauma cases in the year 2009 (mean age 20.1 years, SD 1.1). The frequency, mechanism, and time of the incidences were analyzed.

RESULTS

Of the total 1432 trauma cases, 303 (23%) involved head, neck, or dentition. The occurrence rate of dental traumas was 6.5 cases/1000 persons/year. Dental traumas comprised 14.3% of all traumas. The most common mechanism for dental traumas was a blow-type force. First 4 months of the service and winter time were periods of increased risk of dental traumas. Two-thirds of the dental traumas, one-third of the body traumas and a quarter of the head and neck traumas occurred during military field exercises. Most dental traumas required a visit to a military dental clinic and also needed follow-up care.

DISCUSSION AND CONCLUSION

Head, neck, and dental injuries are common during the military service in Finland. Prevention of dental traumas and need for first aid dental skills of the personnel should be emphasized.

Radiological signs indicating infection of dental origin in elderly Finns

OBJECTIVE

The aim was to assess the prevalence and background factors of signs of infection of dental origin in elderly Finns.

MATERIALS AND METHODS

Every third birth cohort between 60-78 years of age (n = 1733) in a southern and a northern region in Finland were invited. Altogether, 1069 subjects attended radiographic examination. Of those, 660 were dentate and formed the study sample. In the analysis an index as a sum of points (scale per lesion 0-3, range 0-420) indicating the severity of infection from periapical lesions, furcal lesions, vertical bone pockets, horizontal bone loss and severe dental caries was used.

RESULTS

The index ranged individually from 0-91. Horizontal bone loss was found in 94%, vertical bone loss in 19%, periapical lesions in 46%, furcal lesions in 19% and carious lesions in 39% of the subjects. Only 3% of the subjects were free of dental infections, while 2% had mild, 17% moderate and 78% severe risk of dentogenic infection. Statistically significant background factors were region, level of education, number of regular drugs in use, drugs reducing salivation, alcohol consumption, cardiovascular disease, asthma and rheumatoid arthritis.

CONCLUSIONS

Elderly Finns have high a prevalence of signs of infections of dental origin, which is associated with several socio-demographic and health-related factors.

Bimaxillary advancement as the initial treatment of obstructive sleep apnea: five years follow-up of the pori experience

Objectives

Bimaxillary advancement surgery has proven to be effective treatment of obstructive sleep apnea syndrome. According to the Stanford protocol upper airway soft tissue surgery or advancement of tongue by chin plastic surgery is first carried out and if obstructive sleep apnea persists, then bimaxillary advancement is done. This study describes the 5 year outcome of 13 obstructive sleep apnea patients in whom the Stanford protocol was omitted and bimaxillary advancement was carried out as initial surgical treatment.

Material and Methods

Patients were divided in two groups. Group A comprised patients with obstructive sleep apnea (OSAS) confirmed by polysomnography in whom ODI-4 (oxygen desaturation index) was 5 or more. Group B consisted of patients with occlusal problems needing orthognathic surgery and with OSAS symptoms but no clear disease on polysomnography, where the ODI-4 index was less than 5. Both groups were treated with bimaxillary advancement surgery (BAS) as initial therapy.

Results

In the group A mean ODI-4 was 17.8 (SD 12) before treatment and 3.5 (SD 3.4) at 5-year follow-up (P = 0.018 in paired differences t-test). In group B the ODI-4 remained below 5. In group A mean saturation improved from 94.3% (SD 1.6) to 96.3% (SD 2), P = 0.115 and in group B from 96.3% (SD 1.2) to 97.8% (SD 1.7), P = 0.056 (in paired differences t-test). The static charge sensitive bed evaluation showed improvement in all patients except one.

Conclusions

Bimaxillary advancement surgery is safe and reliable as an initial surgical treatment of obstructive sleep apnea syndrome.

Change in subjective oral health after single dental implant treatment

PURPOSE

The aim of this study was to evaluate changes in subjective oral health among patients receiving single dental implants in different anatomic locations.

MATERIALS AND METHODS

Subjective oral health was surveyed with the Oral Health Impact Profile 14 (OHIP-14) questionnaire after implant placement but prior to uncovering and 3 months after the completion of treatment. The locations of the implants and age and gender of the patients were recorded. Mean OHIP-14 severity scores were compared before and after treatment (paired t test).

RESULTS

Ninety consecutive self-referred patients were enrolled in the study, and 80 of them (28 men and 52 women) completed the OHIP-14 both before and after treatment. The mean age of the patients at the time of surgery was 52 years (range, 24 to 75 years). The patients received a total of 131 commercially available dental implants (Astra Tech) and appropriate prosthetic constructions. The mean OHIP-14 severity score decreased significantly, from 10.4 before treatment to 3.1 after treatment (P < .001). The drop was from 13.4 to 1.5 (P < .001) if the missing tooth was replaced with an implant in the anterior area, from 11.2 to 4.3 (P < .001) if it was replaced in the premolar area, and from 6.5 to 3.0 (P = .085) if it was replaced in the molar area. In general, both before and after treatment, women reported subjective oral impacts approximately three times more often than men did.

CONCLUSION

Replacement of missing teeth with single dental implants in anterior and premolar areas, but not necessarily in molar areas, may significantly improve subjective oral health, especially among women.

Prevalence of single crowns and fixed partial dentures in elderly citizens in the southern and northern parts of Finland

The epidemiology of oral rehabilitation using fixed prosthodontics has received little attention. The aim of this study was to evaluate the prevalence of single crowns, fixed partial dentures (FPDs), resin-bonded FPDs and implants in elderly Finnish patients and to identify factors that might be associated with the findings. The survey was carried out in the southern and northern parts of Finland. The target population consisted of all persons born in 1919, 1922, 1925, 1928, 1931, 1934 and 1937, who lived in Kirkkonummi and in Lakeus (n=1733) in 1996. The age range of the subjects was 60-78years. In addition to a clinical examination, panoramic radiograph was taken. Data on background factors were obtained using questionnaires and/or interviews. The presence of single crowns, FPDs, resin-bonded FPDs and implants were determined from the panoramic radiographs. Overall, 12·4% of men and 12·1% of women had single crowns, while 4·8% of men and 8·0% of women had FPDs. A logistic regression analysis showed that the presence of crowns and FPDs was significantly associated with a southern place of residence, high and middle levels of education and high frequency of dental visits.

[Management of facial bone fractures]

Although the number of patients suffering from facial bone fractures has decreased more resources due to complexity of the fractures are needed. The initial treatment and reconstruction phase require hospitalisation and close collaboration between several medical and dental specialists. Fractures cause alterations in occlusion and masticatory functions and are frequently associated with soft tissue injuries. The primary radiographic examination is panoramic radiography in mandibular and computed tomography in maxillary and mid face fractures. The treatment principles have changed during the last three decades. Long-term maxillomandibular immobilisation has given way to internal fixation and direct osteosynthesis. The greatest innovations of the treatment have taken place in materials. Steel has been replaced by Titanium or resorbable plates, screws and meshes.

Influence of edentulousness on gonial angle, ramus and condylar height

It has been shown that the shape of the mandible correlates with occlusal condition and the function of the masticatory muscles. Edentulous subjects have a wider gonial angle than dentate subjects, and a gender difference has also been shown. However, some studies have reported differing results. Less is known about the effect of dental status and gender on the ramus and condylar height. The aim of this study was to evaluate the association of tooth loss on the shape of mandible (i.e., gonial angle, ramus height and condylar height) in subjects aged 60 years and older. A total of 1036 subjects (667 dentate, 389 edentulous; 554 women and 482 men) were included in the study. Interviews and clinical and panoramic radiographic examinations were carried out. The gonial angle of the mandible and the mandibular and condylar height were measured using panoramic radiographs. In edentulous subjects, the gonial angle was significantly larger, while the ramus and condylar height was significantly smaller on both sides compared with dentate subjects. Women had a significantly larger gonial angle and smaller ramus and condylar height on both sides compared with men. In conclusion, the morphology of the mandible changes as a consequence of tooth loss, which can be expressed as a widening of the gonial angle and shortening of the ramus and condylar height. These findings highlight the importance of rehabilitation of the masticatory system to maintain good functioning of the masticatory muscles for as long as possible.

Prevalence of edentulousness and related factors among elderly Finns

Edentulousness is a multifactor phenomenon. While its overall prevalence is diminishing, it is increasing in older age groups. The aim of this study was to assess the prevalence of edentulousness among the elderly in two municipalities in Finland and to estimate different factors related to it. All persons born in the years 1919, 1922, 1925, 1928, 1931, 1934 and 1937 living in two municipalities (Kirkkonummi in the southern part of Finland and Lakeus in the northern part of Finland) were invited to participate in the study in 1997. The target population consisted of 1733 subjects of whom 1191 were disposed to participate in a clinical examination performed by two dentists. Of the subjects, 624 were from the southern district (Kirkkonummi) and 566 were from the northern district (Lakeus). The participation rates were 62% and 78%, respectively. The subjects answered a questionnaire comprising sociodemographical data, questions on dental and general health and health behaviour. Logistic regression analysis was used to assess the associations between edentulousness and potential associating factors. The overall prevalence of edentulousness was 37%; being 53% in the northern region and 22% in the southern region. Edentulousness was positively associated with high age [odds ratio (OR = 1.09), confidence interval (CI = 1.06-1.12)], female gender (OR = 2.06, CI = 1.43-2.94), northern place of residence (OR = 2.01, CI = 1.45-2.78), low level of education (OR = 7.09, CI = 3.18-15.81), cardiovascular diseases (OR = 1.51, CI = 1.03-2.21) and current smoking versus never smoking (OR = 1.73, CI = 1.17-2.55). Social factors were more prominently associated with edentulousness than factors related to general health.

Differences in the etiology of mandibular fractures in Kuwait, Canada, and Finland

We studied causes of mandibular fractures treated in oral and maxillofacial units in three countries in years 1990-2000 in Kuwait (n=596), 1995-2000 in Canada (n=228), and 1990-99 in Finland (n=268). Of the Finnish patients, 27% were women. Corresponding percentages in Kuwait and Canada were 13 and 17%, respectively. Traffic crashes were the cause of injury in 55% of the cases in Kuwait and 33% in Oulu, but only 7% in Toronto. In Kuwait, the victims were often young people, which is why more traffic education, more control of speed, and more control of the use of safety belts should be implemented. Assault was the cause in 54% in Toronto, 12% in Kuwait, and 37% in Oulu. Falling was the cause in 22% of the cases in Kuwait. Alcohol was implicated in 21% of cases in Canada and 15% in Finland.

Neurosensory deficits after bilateral sagittal split ramus osteotomy of the mandible—influence of soft tissue handling medial to the ascending ramus

Deficits in the neurosensory function (NF) of the inferior alveolar nerve (IAN) are often encountered after bilateral sagittal split osteotomy of the mandible. A prospective follow-up study was performed to examine the long-term effect of especially gentle handling of the soft tissues on the medial side of the ascending ramus. After the initial incision, the soft tissues of the ramus were either retracted extremely gently and minimally (test side) or, as was the earlier routine, more widely (contralateral control side). NF was tested with 2-point discrimination (2-PD) and vitality scanner tests (VST) preoperatively and four times postoperatively up to 1 year. Patients' subjective sensations were also assessed. The results showed a difference between the sides, which was most distinct at the 6-month follow-up (P=0.028) measured with VST, while 2-PD did not show any statistical differences. Our findings support the earlier intraoperative neurophysiologic reports that dissection trauma to the IAN around the mandibular foramen may cause NF deficits in the IAN even before the actual splitting of the mandible. Therefore, minimal distraction of the soft tissues in the ramus is indicated. Higher age is an evident risk factor, and subjective sensation correlates with 2-PD in the lower lip.

Comparison of three radiographic methods used to locate the mandibular canal in the buccolingual direction before bilateral sagittal split osteotomy

OBJECTIVE

Panoramic radiographs, computerized tomography (CT), and conventional spiral tomographic (Scanora, Soredex, Helsinki, Finland) radiographs were compared for their ability to locate the mandibular canal in the buccolingual direction. Furthermore, the relationship between the cortication of the mandibular canal in panoramic radiographs and the location of the canal in both computerized and conventional tomographic radiographs was assessed.

STUDY DESIGN

The buccolingual location of the mandibular canal was determined bilaterally in twenty consecutive patients scheduled for bilateral sagittal split osteotomy. The position of the mandibular canal was evaluated by means of panoramic radiography, Scanora, and CT. The three imaging methods were compared for their ability to locate the mandibular canal in the buccolingual direction. The subjective neurosensory deficit of the lower lip and chin on both sides was registered preoperatively and at 4 days, 3 weeks, and 3 months after surgery, and the operative outcome was analyzed in relation to the distance from the mandibular canal to the buccal cortex of the mandible.

RESULTS

CT gave better visualization of the mandibular canal than Scanora imaging. Cortication of the mandibular canal on the panoramic radiograph did not serve as a predictor of the proximity of the mandibular canal to the cortices of the mandible. At 3-month follow-up, there were only eight operated sides with abnormal sensation of the lower lip and chin. In seven of these sides, the distance from the mandibular canal to the buccal cortex was less than 2 mm.

CONCLUSION

The buccolingual location of the mandibular canal is visualized better with CT than with Scanora or panoramic radiographs.

Repeatability of 5 clinical neurosensory tests used in orthognathic surgery

Many patients undergoing orthognathic surgery experience some degree of neurosensory impairment as a normal consequence of surgery. This may also occur as a complication after mandibular third molar surgery. The condition is usually reversible, but it may also be permanent. Neurosensory tests are essential in making decisions regarding the nature of the nerve injury, the potential for recovery, and the possible need for secondary microneurosurgical intervention. The aim of this study was to evaluate the repeatability of 5 clinical neurosensory tests assessing the neurosensory function of the inferior alveolar nerve (IAN). Twenty healthy subjects (9 males, 11 females) ranging in age from 21 years to 27 years participated in this study. The methods of assessment were light touch (LT), 2-point discrimination (2-P), pin tactile discrimination (PIN), thermal discrimination, and sensibility (ST) testing of the mandibular teeth with a vitality scanner. All the measurements were evaluated by 2 examiners and repeated at an interval of 6 months. In the statistical analysis, intraexaminer and interexaminer variability, as well as the variability between the 2 observations at a 6-month interval, were calculated. All the subjects reacted positively to LT and thermal discrimination in every observation. For the 2-P and PIN tests, intraexaminer variability was smaller than interexaminer variability, and repeatability of the 2 observations at 6 months was also good. Repeatability of ST was best at incisors, but it was not numerically very accurate at any site. However, all teeth that reacted positively to the vitality scanner in the first observation also reacted positively in the second observation; this instrument thus provides a more meaningful measurement of neurosensory function as a positive/negative assessment than as a numeric value.

Incidence of complications and problems related to orthognathic surgery: a review of 655 patients

PURPOSE

This retrospective report evaluates the incidence of pre-, intra-, and postoperative complications of orthognathic surgery and their significance to the patient.

PATIENTS AND METHODS

The clinical records and radiographs of 655 patients operated on in Vaasa Central Hospital, Finland during a 13-year period between 1983 and 1996 were examined. The total number of operations was 689. All notes referring to problems or complications from the orthodontic phase to the varying postoperative follow-up times were gathered and analyzed.

RESULTS

The most common complication was a neurosensory deficit in the region innervated by the inferior alveolar nerve; mild in 32% of patients (183 of 574 patients with an osteotomy in the mandible) and disturbing in 3% of patients (18/574). The most serious complication was severe intraoperative bleeding in 1 patient necessitating major blood transfusions and later embolization of the internal maxillary artery. There were no fatal complications. The incidence of other problems was low, and there were very few patient complaints.

CONCLUSIONS

Despite the great variety of severe complications reported in the literature, their frequency seems to be extremely low, and orthognathic surgery treatment can be considered to be a safe procedure.

Increased lifetime prevalence of dental trauma is associated with previous non-dental injuries, mental distress and high alcohol consumption

The purpose of the study was to assess the lifetime prevalence of dental injuries and risk factors involved in a general population-based birth cohort. The study population consisted of 5737 subjects who had participated in a health survey at the age of 31 years. Altogether 52% of the participants were women. This partly computer-based health survey included two questionnaires on previous dental and non-dental injuries, general health, occupational status and lifestyle. The current study was based on these questionnaires. The lifetime prevalence of dental fractures was 43% and the lifetime prevalence of dental luxations and exarticulations 14%. Men more commonly had dental injuries than women. Particularly mental distress and a history of previous injuries were shown to increase the risk for dental injuries. Furthermore, overweight and high alcohol consumption were positively associated with a high lifetime prevalence of tooth trauma. Regular physical activity decreased trauma occurrence. Socioeconomic status further affected the lifetime prevalence of dental injuries. The conclusion of the study was that personal, social and physical factors played a role in the occurrence of dental trauma.

Factors affecting neurosensory disturbance after mandibular bilateral sagittal split osteotomy

PURPOSE

The current study evaluated the incidence of subjective neurosensory disturbances after bilateral sagittal split osteotomy (BSSO) in relation to gender, age, indication for osteotomy, magnitude of mandibular movement, degree of manipulation of the inferior alveolar nerve at operation, side of the mandible operated, and complications during and after surgery.

PATIENTS AND METHODS

Thirty patients (60 sides) who had undergone a BSSO were followed up for 1 year after operation. The patients were classified into different groups according to gender, age, indication for osteotomy, magnitude of mandibular movement, degree of manipulation of the nerve, and complications during or after surgery. A self-administered questionnaire was used at every follow-up to evaluate the sensations in the mental region.

RESULTS

A statistically significant positive correlation was found between subjective neurosensory loss and the patient's age (P = .039), magnitude of mandibular movement (P = .044), and degree of manipulation of the nerve (P = .0007). However, no significant correlation was found between disturbances of sensation and gender, indication for osteotomy, side of the operated mandible, or intraoperative and postoperative complications. Even if all patients evaluated their sensation as "normal" 1 year postoperatively, 31% of them reported slightly altered sensation in the mental region.

CONCLUSIONS

After BSSO, a prolonged neurosensory deficit is strongly related to age, the intraoperative magnitude of mandibular movement, and the degree of manipulation of the inferior alveolar nerve. However, a long-term sensory loss is very rare, and patients seem to adapt to a mild neurosensory deficit and report sensory function as "normal" despite slightly altered sensation.

Prediction of recovery from neurosensory deficit after bilateral sagittal split osteotomy

OBJECTIVE

To observe the suitability of different combinations of readily available tests to predict recovery from a neurosensory deficit after bilateral sagittal split osteotomy (BSSO).

STUDY DESIGN

Thirty patients scheduled for BSSO were examined before surgery and 4 days, 3 weeks, 3 months, 6 months, and 1 year after surgery. At each follow-up, the patients self-evaluated the subjective neurosensory deficit of the lower lip and chin of both sides. Neurosensory function was also measured by tests consisting of light touch, 2-point discrimination, pin tactile discrimination, thermal discrimination, and sensibility testing of the mandibular molars. The positive predictive values (PPV) of each test for recovery from the neurosensory deficit were calculated. Furthermore, different tests were combined, and the PPVs for recovery from the neurosensory deficit of these combinations were analyzed.

RESULTS

A positive response to sensibility testing of the mandibular first and second molars 4 days and 3 weeks after surgery was related to a PPV of 100% and 87%, respectively, for full recovery from sensation loss at 1 year. However, none of the tests alone could reliably predict recovery from the neurosensory deficit after BSSO. When 3 different tests were combined, the best results were achieved by the combinations of a light test or a 2-point discrimination test and a pin tactile test with the sensibility testing of mandibular molars.

CONCLUSIONS

Sensibility testing of mandibular molars can be used to predict recovery from the neurosensory deficit after BSSO. The best positive predictive ability can be achieved by combining a mechanoceptive test, a nociceptive test, and sensibility testing of mandibular molars.

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 Helkimo's 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.

[Conceptual system of health portrait]

The purpose of this paper is to introduce a nursing science perspective to health research. The perspective is outlined using the following key concepts: life control, life situation, health and health choices, resources, and process of change. This conceptual system of health portrait includes concepts used to study health in nursing science. It also reflects a research approach by using empirical examples. As a starting-point, life control is assumed to be reflected in the life situation as well as in health and health choices. As a consequence, life control is also related to each individual's resources in everyday life. Further attention is given to the assessment of the process of change pertaining to health choices during the person's course of life. As an empirical example of the application of the "health portrait" conceptual system, a research project titled Health portrait of adolescents in Kainuu is presented. This project aims to develop an instrument for measuring life control, health and life situation, to evaluate this instrument and to analyze life control data elicited from adolescents. Another aim of this paper is to assess how well an instrument created on the basis of the nursing science and the method of interventive interview used here served as tools for analysing life control and health in the health checkups of school-aged adolescents. On the basis of the knowledge obtained through these analyses we will develop further the conceptual system of health portrait, which could be used as a guideline in health research.

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 patient's subjective evaluation than the other tests used in this study.

Comparison of four bone collectors designed for oral and maxillofacial surgery--an in vitro study

Four bone collectors designed for oral and maxillofacial surgery were compared in an in vitro study. Two commercially available bone collectors (Osseus Coagulum Trap, Quality Aspirators and Frios, Friatec) with mesh sizes of 0.17 x 0.17 and 0.44 x 2.40 mm, respectively and models developed by the authors with mesh sizes of 0.355 x 0.355 or 0.50 x 0.50 (Model I) and 0.80 x 0.80 (Model II) were tested. All collectors are designed to be connected to the suction device. Five dissected pig mandibles were used to determine the harvesting capacity during drilling and suctioning for 30 s. All collectors harvested bone quite effectively, but the highest amount of bone chips was harvested by Model I which had been designed by the investigators.

Occlusal and temporomandibular joint disorders in patients with unilateral condylar fracture. A prospective one-year study

Adult dentate patients with unilateral condylar fractures were followed up for one year after injury. Patients were interviewed about subjective complaints, and mandibular excursions and function of occlusion and temporomandibular joints (TMJs) were recorded. Radiological characteristics were assessed from panoramic and Towne's views and compared between patients with occlusal disorders and patients without. During follow up, mandibular deviation on opening towards the fractured side was more pronounced in cases with marked reduction of ramus height and condylar dislocation. This restriction of translation movement of the fractured joint was also seen radiologically in one-third of cases while in two-thirds of the fractured condyles, malpositioning was observed when compared with the healthy side. In patients (39%) having subjective symptoms such as TMJ pain, altered occlusion or ability to bite only unilaterally, and objectively verified occlusal interferences, a marked reduction of the ramus height on the fractured side was observed. In such cases nonoperative treatment of condylar fractures may be compromised.

A method of harvesting corticocancellous bone chips for reconstructive maxillofacial surgery

A method is described to harvest bone chips for maxillofacial surgery with large burs and a special collecting net connected to a suction device. Three nets and four burs were tested in vitro on a pig mandible to determine the optimal combination. All burs produced bone chips of rather similar sizes. The midsized net (hole diameter 0.5 mm) collected most bone chips during a 1-min drilling.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Rigidity of various fixation methods used as dental splints

Horizontal and vertical rigidity of teeth fixed with seven types of dental splints were evaluated by two tooth mobility measuring devices. Altogether 21 dissected sheep mandibles including soft tissues were used for the experiments in which Fermit, flexible wire-composite, Kevlar, Fiber, Protemp, rigid wire-composite and Triad Gel splints were applied to four incisors. The mean rigidity of the central incisors within the splint was measured by means of Mühlemann periodontometer (horizontal mobility) and Periotest (horizontal and vertical mobilities). Mobility values of teeth before splinting were used as covariants and the values with the splints were illustrated as adjusted mobility. Statistical significance between the rigidity of various splints was analyzed by an unpaired t-test. It was shown that the most rigid splints both in horizontal and vertical directions were Triad Gel, rigid wire-composite and Fermit splints. Kevlar and Fiber splint allowed more horizontal movement than other splints. Protemp and flexible wire-composite splints proved to produce adequate lateral support for the fixed teeth and allowed vertical flexibility which is experimentally known to improve periodontal healing of luxated teeth.

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.

Toxic effects of various retrograde root filling materials on gingival fibroblasts and rat sarcoma cells

The aim of this in vitro study was to evaluate the effect of amalgam, glass ionomer, composite and titanium on the growth of gingival fibroblasts (GF) and rat sarcoma cells (UMR) in vitro. The cells were either obtained from gingival biopsies taken during deliberation of unerupted canines (GF) or were of commercial origin (UMR). Equal numbers of cells were placed on culture dishes and incubated for a period of two weeks with the freshly prepared test materials. The cultures were photographed through a light microscope after 7 days incubation and finally counted after 14 days. It was shown that the proliferation of gingival fibroblasts was less disturbed by titanium, being approximately 96% of the control value (cell cultures without test particles), followed by composite, amalgam and glass ionomer (61%, 49% and 35% of the control value respectively). The number of UMR cells after 14 days incubation with the various materials was 76% of the control value with titanium, 12% with composite and 5% with both amalgam and glass ionomer. Inhibition of cell growth (UMR) around the test particles was most prominent around amalgam and glass ionomer, followed by composite and titanium. These effects were noted only with freshly prepared components however, so that the toxic reaction was less pronounced or minimal in a second incubation using the same particles sterilized in between. The results demonstrated that potential retrograde root filling materials have a variable toxic effect on gingival fibroblasts and rat sarcoma cells. The fact that the influence on proliferation disappeared when the test was performed with materials already tested once may be of clinical importance when estimating the biocompatibility in vivo.

Frequency of alcohol-associated mandibular fractures in northern Finland in the 1980s

In order to evaluate the frequency of alcohol-associated mandibular fractures, information on patients treated and diagnosed at a University Hospital and Dental Institute in northern Finland between 1981 and 1990 was analysed. Altogether, 117 male patients (out of 239) and 23 female patients (out of 78) were under the influence of alcohol at the time of accident. The annual risk for men receiving a mandibular fracture under the influence of alcohol (odds ratio) varied between 0.6 and 6.6, compared with female patients. More alcohol-associated mandibular fractures occurred in late summer and autumn and fewer in spring. Patients suffering mandibular fractures at weekends were more often under the influence of alcohol than those injured on weekdays. There seemed to be a tendency for the proportion of alcohol-associated mandibular fractures to decrease towards the end of the decade.