Residual ridge resorption, lower denture stability and subjective complaints among edentulous individuals.

Residual ridge resorption in the mandible after tooth loss may lead to worsening of complete denture stability and to various subjective complaints. The aim was to evaluate the association between radiologically assessed residual ridge resorption in the mandible, clinically assessed stability of lower complete denture and subjective complaints among elderly denture wearers. The study population consisted of 326 (115 men and 211 women) edentulous subjects aged 60-78years, all of whom were wearing complete dentures in the mandible. Data on subjective complaints were obtained from questionnaires and interviews. Denture stability was assessed clinically. Residual ridge resorption was analysed from panoramic radiographs. The results showed that women were significantly more often satisfied with their lower dentures and reported fewer problems with eating than men. They also had significantly more often residual ridge resorption than men. Among women, residual ridge resorption was significantly associated with poor chewing ability, low satisfaction with dentures and poor denture stability. Among men, residual ridge resorption did not associate with subjective complaints or denture stability. Poor satisfaction with dentures associated significantly with poor denture stability in both genders. In conclusion, these results highlight the importance of denture maintenance treatment. As the extent of residual ridge resorption in the mandible was the most important factor that increased dissatisfaction with lower complete dentures, it is also important to inhibit the progression of resorption by preventing tooth loss or by using implant-retained dentures.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.