Relation between malocclusion and mandibular dysfunction in Swedish men.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to B Ingervall.
Explore the source record for details and available documents.
Subjective and clinical symptoms of mandibular dysfunction and cuspal interferences were studied in 389 Swedish men (median age 32 years). Impaired chewing function was noted in about 10%, different types of parafunction in 26%, frequent headaches in 5%, TMJ or muscle pain in 3% and difficulties in mouth opening in 10% of the men. Locking or luxation of the mandible was the most prevalent clinical symptom (24%), followed by reduced movement capacity and deviation on opening of the mandible, TMJ-sounds and muscle tenderness. Sixty per cent of the men had one or more clinical symptoms of dysfunction. Subjective symptoms of dysfunction were positively correlated with reduced movement capacity of the mandible and tenderness of the masticatory muscles and temporomandibular joints upon palpation. Positive correlations were found between subjective symptoms of dysfunction and non-working side interference as well as single tooth contact on the working side. Locking or luxation of the mandible and TMJ-sounds were positively correlated with single tooth contact on the working side and TMJ-sounds and muscle tenderness with interferences in the retruded position of the mandible.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Dental history, dental status, the need for prosthetic treatment and dental treatment habits were studied in 389 men aged 21--54 years. The men were selected from a group undergoing military refresher training in the south of Sweden. One percent of the men were toothless. About 3% had full dentures in one or both jaws and an equal percentage had partial dentures. About 3% of the men had bridges in the maxilla and 2% in the mandible. Tooth loss was greatest in the mandibular molar segment, followed by the maxillary molar segment. By means of an index for dental status about 8% of the men were judged to be in great need of prosthetic treatment for aesthetic reasons and/or to improve occlusion. Age, place of birth, educational level and smoking habits were among the factors which seemed to be related to dental status. Seventy percent of the men reported that they went to the dentist once a year, while about 10% seemed rarely or never to seek dental treatment. Dental treatment habits were correlated to place of birth, number of brothers and sisters, edentulousness and the need for prosthetic treatment, among other factors.
The silent period in the masseter and in the anterior portion of the temporal muscle during tooth tapping, the rate of tooth tapping and the jaw jerk reflex evoked by a tap on the chin were compared in individuals with oral implant bridges and with natural teeth. Thirteen women with osseointegrated oral implant bridges in one or both jaws, aged 42-59 years, were compared with 10 women, aged 42-64 years, with natural teeth. There was no difference between women, aged 42-64 years, with natural teeth. There was no difference between women with implant bridges and those with natural teeth in tooth tapping rate or in the occurrence, latency or duration of the jaw jerk reflex. A silent period during tooth tapping was found in 12 of the 13 women with implant bridges. The latency of the silent period was the same as in the subjects with natural teeth but the duration tended to be somewhat longer. The jaw jerk and the silent period were the same in individuals with implants in both jaws as in the whole implant group. It is therefore concluded that periodontal or mucous membrane receptors cannot be solely responsible for the silent period.
The function of the masticatory system of 13 women, aged 42-59 years, with osseointegrated oral implant bridges (OIB) made within the last seven years was compared with that of 10 matched dentate controls by means of a questionnaire, clinical examination, bite force measurements and electromyographic recordings of biting and of postural muscle activity. Both groups were satisfied with their masticatory capacity according to the questionnaire. The clinically determined state of the masticatory system, as judged from the clinical dysfunction index, was normal in both groups. Three levels of bite force 1) gentle biting, 2) biting as when chewing and 3) maximal biting, were recorded with a bite force apparatus and electromyographically. There was no statistically significant difference between the groups at any level of bite force for any of the methods of registration. Nor was there any difference of the two groups in the activity of the masticatory muscles with the mandible in the postural position. It is concluded that patients with osseointegrated oral implant bridges have a masticatory muscle function equal to or approaching that of patients with natural teeth, or with tooth-supported bridges, with the same number of chewing units as the OIB-patients.
The activity of the anterior and posterior portions of the temporal muscle, the masseter and the upper lip has been studied with electromyography in 13 women with osseointegrated oral implant bridges and compared with that in 10 subjects with natural teeth. The functions examined were chewing and swallowing of apple, bread and peanuts. There was no difference between implant and control subjects in the number of chewing cycles nor in duration of the act of chewing or in the amplitude of the muscle activity during chewing and swallowing. However, the duration of the activity during chewing was longer in the implant than in the control subjects. The number of years of wearing a maxillary implant bridge was found to be of importance for the number of chewing cycles during an act of chewing and for the muscle activity during chewing. Other factors influencing the muscle activity were age, number of occluding tooth units and the extension of the lower implant bridge. It was concluded that patients with osseointegrated oral implant bridges have a masticatory muscle function equal to or approaching that in patients with natural teeth or with bridges supported on natural teeth with the same extension of the dentition.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Multiple stepwise regression was used in the selection of mixed dentition variables capable of predicting the total breadth of the unerupted permanent canine and premolars. The material consisted of 77 children. Stone casts were made before and after eruption of the canine and premolars. At the first examination when the children were, on the average, 10 years old, intraoral roentgenograms were obtained of the canine and the premolars. To predict the total breadth of the upper canine and premolars the buccolingual breadth of the upper first permanent molar and measurements on roentgenograms of the breadths of the upper canine and premolars proved most useful. In the prediction of the total breadth of the lower canine and premolars the best results were obtained with measurement of the breadths of the teeth in the roentgenograms. The breadth of the incisors proved less useful as a predictor of the breadths of unerupted canines and premolars.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Previous orthodontic treatment, the awareness of malocclusion, the demand for orthodontic treatment and the prevalence of malocclusion were studied in 389 Swedish men, aged 21-54 years (mean age 32 years). Nine percent had been treated with an orthodontic appliance and 15% reported that permanent teeth had been extracted on orthodontic indications. Malposition of teeth was found in 75%, with rotation as the most common type of malposition. Crowding was recorded in 43% and spacing in 18%. Fifty-seven percent had some occlusal anomaly. The need for orthodontic treatment was rated on a four-point scale. It was found that 76% were in need of treatment. The need for treatment was only slight in half of the men but moderate to urgent in 25% of the sample. About a quarter of the men were aware of malposition of front teeth, equally often for maxillary and mandibular teeth, but only about 1% were aware of malposition of posterior teeth. Only a few percent thought they were in need of orthodontic treatment. The presence of malocclusion was correlated to age, place of birth and educational level. This might perhaps be a consequence of tooth loss.
The precision (reproducibility) of active and passive recordings of the retruded position of the mandible was studied by two examiners on 10 patients with mandibular dysfunction symptoms. The position of the mandible was recorded with an intra-oral graphic method, before and after treatment of the symptoms. The precision of the recording was highest when the retruded position was recorded by passive hinge movement and lowest when it was recorded by active hinge movement and when recording habitual closure. Both systematical and accidental errors tended to be somewhat larger among these patients than that previously found among individuals without signs or symptoms of mandibular dysfunction. The accidental errors in antero-posterior and medio-lateral directions were the same fo both examiners and of the same magnitude before and after treatment of the symptoms. Both examiners recorded the retruded position on the average 0.20 mm more posterior after treatment than before. The results showed that because of its good reproducibility the retruded position of the mandible can be recommended as a reference position in functional analysis of occlusion and for jaw recordings also in patients with TMJ muscle-pain dysfunction symptoms. During the recording the conventional technique with passive hinge movement and a posterior pressure should be used.
Explore the source record for details and available documents.