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Biomedical subjects

B Ingervall

Publications and source records attributed to B Ingervall.

At least 109 records · Page 6Linked to original sources
PubMed1977

A clinical study of the relationship between crowding of teeth, plaque and gingival condition.

A clinical trial was undertaken to assess whether crowded teeth were more likely to accumulate plaque and develop gingivitis than non-crowded teeth. A tooth was considered crowded if it was displaced by 2 mm and/or rotated 15 degrees or more from the normal position in the arch. The material consisted of 50 dental students aged 21 to 32 years. An initial examination comprised assessment of Plaque Index, Gingival Index and pocket depths. After this examination the subjects refrained from using interdental cleaning aids but continued with their normal toothbrushing for 40 days. After re-examination they were instructed in the effective use of dental floss. A final examination was carried out after 140 days. At the start of the trial no difference was found in regard to the Plaque Index between crowded and non-crowded teeth. The Gingival Index for growded front teeth, but not for crowded premolars, was somewhat higher than for the corresponding controls. The cessation of interdental cleaning resulted in a similar increase in plaque accumulation and gingival inflammation in both non-crowded and crowded teeth. The use of dental floss for approximal tooth cleaning resulted in a similar decrease in the Plaque- and Gingival Indices for both types of teeth. The results demonstrate that in a group of young adults, crowding of teeth (1) did not favour plaque accumulation on approximal tooth surfaces and (2) influenced the degree of gingival inflammation only to a minor extent.

Adult↗
PubMed1976

Facial morphology and activity of temporal and lip muscles during swallowing and chewing.

The correlations between facial and bite morphology and the activity in the temporal muscle and in the musculature of the lip during swallowing and chewing were studied in 50 girls, aged 9-13 years. The activity was recorded electromyographically by determining the maximal mean voltage amplitude and morphologically by analysis of profile roentgenograms and dental casts. The activity in the lower lip during the swallowing was not correlated with any of the variables of the facial morphology with the exception of the width of the upper dental arch. On the other hand, the activity of the upper lip during swallowing, as in the anterior and posterior portions of the temporal muscle, was correlated with a number of variables used for measuring facial form. The activity was low in girls with a facial shape with anterior inclination of the maxilla and mandible, small face height, and pronounced prognathism. The activity in the upper lip during chewing varied, as in the lower lip, independently of facial form, while the activity of the temporal muscle during chewing showed the same relation to facial form as during swallowing. The number of chewing cycles required for trituration of the test media (apples and peanuts) was negatively correlated with the number of teeth and with age. This was interpreted as adaptation in such a way that the number of cycles decreased with development of the dentition.

Adolescent↗
PubMed1976

Relation between functional disturbances of the masticatory system and some anthropometric, physiological and psychological variables in young Swedish men.

The relation between functional disturbances of the masticatory system and anthropometric, physiological and psychological variables was studied in 248 Swedish men, aged 18-25 years. No physiological variables and only a few anthropometric variables were found to be correlated with symptoms of functional disorders or to the state of the dentition. Thus, for example, face height was greater in the presence than in the absence of disturbances of the occlusion (mainly occlusal interferences). The psychological variables were found to be most closely correlated with symptoms of functional disorders and the state of the dentition. Men with clinical dysfunction had a lower general level of intelligence than men without. Social adaptation at school was poor in those who reported parafunctions. Men with parafunctions, frequent headache, general muscle and joint symptoms and balancing side interferences had low emotional stability compared with those without such symptoms. Individuals completely free from symptoms of functional disturbances had high emotional stability.

Adolescent↗
PubMed1976

Postnatal development of the human temporomandibular joint. II. A microradiographic study.

Temporomandibular joint specimens from 22 subjects aged 1 month to 23 years were examined microradiographically. There occurred considerable interindividual variations in mineralization of the joints but nevertheless, systematic changes in mineralization were demonstrated during the periods of development and growth. A continuous compact bony layer formed early in the fossa and tubercle while the outer mineralized layer of the condyle consisted of calcified cartilage. A continuous bony layer around the periphery of the condyle was not fully developed before about 20 years of age. Growth of the articular tubercle was characterized by a spongy appearance of the bony layer over the tuberculum up to the end of puberty. No corresponding growth changes could be seen in the fossa. No mineralized parts could be seen in the disk or the fibrous layers of the articular surfaces.

Adolescent↗
PubMed1976

Postnatal development of the human temporomandibular joint. I. A histological study.

Temporomandibular joints from 61 humans, aged 2 days to 27 years, were examined histologically. Four layers of the condyle were studied in detail. The outermost layer was richly vascularised in new-borns but by 3 years of age it had become avascular and contained few cells. In neonates the cartilage layer constituted a large part of the condyle but soon decreased in thickness and by 5-6 years of age it constituted only a thin zone of the top of the condyle. In the proliferative zone, mitoses occurred up to 13-15 years of age. This zone then decreased in thickness; the number of cells decreased, while the amount of intercellular substance increased. At birth, the temporal component was flat and was lined by vascularised connective tissue which became richer in collagen with increasing age. The cartilage layer was lacking in the fossa but was present on the tuberculum. A proliferative zone in this cartilage could be seen up to the age of 17-18 years and cartilage having only few cells was found in adults. Remodelling processes were seen in all components of the joints. The significance of the remodelling seen in the fossa and on the mandibular neck is discussed with relation to condylar and periosteal growth of the mandible.

Adolescent↗
PubMed1975

Activity of temporal and masseter muscles in children with a lateral forced bite.

The activity of the temporal and masseter muscles with the mandible in postural position and during chewing, maximal bite in the intercuspal position, and swallowing were recorded electromyographically in nineteen children with laterally forced bite. Of the children, aged 8-12 years, sixteen had unilateral crossbite. In all of the individuals there was lateral deviation between the retruded contact position and the intercuspal position. The magnitude of the lateral deviation was measured with a modified gnathothesiometer. The muscle activity was recorded bilaterally from the temporal muscle and from the masseter muscle. In the postural position asymmetric activity was found in the temporal muscle suggesting that the mandible in postural position was still displaced to the side of forced bite. During chewing the activity was asymmetric both in the anterior and the posterior temporal portions. This asymmetric muscle activity was interpreted as an adaptation to avoid cuspal interferences. Also in maximal bite the muscle activity was asymmetric, while the activity during swallowing was affected less than in the other functions. The swallowing activity was, however, less in children with a forced bite than in children with normal occlusion.

Child↗
PubMed1975

Oral ability to recognize forms and oral motor ability in 11-year-old children.

Oral ability to recognize forms and oral motor ability were examined in twenty children, aged 11 years, with normal occlusion. In the RF-test (recognition of form) the children identified the test pieces quicker but with a higher frequency of misidentification of the test pieces than a group of 17-year-old boys studied earlier. The effect of learning on the children was substantial with much quicker and greater certainty from one examination to another. Identification time and misidentification were positively correlated (individuals with long identification time also had a high frequency of errors). In the MA-test (oral motor ability) the children required a longer time to assemble the halves of the test pieces than did 17-year-old boys. A considerable effect of learning was found in the MA-test. The results of the RF-test and the MA-test varied independently of each other for which reason the two tests measure different components of oral ability.

Adolescent↗
PubMed1975

Prevalance of malocclusion in young Finnish Skolt-Lapps.

Two hundred Skolt Lapps aged 8 to 16 years were examined for malocclusion with the aid of intraoral radiography and dental casts. The frequency of loss of permanent teeth was high, particularly of the first molars. Also, many teeth were severely defective because of caries. Hypodontia was very common. The frequency of tipped and rotated teeth was high, probably as a consequence of the frequent loss of neighboring teeth. Space and occlusal anomalies were roughly as common as in urbanized Swedish and Danish materials. The need for orthodontic treatment, judged on a 5-grade scale by one examiner, was found to be greater than in Swedish materials.

Adolescent↗
PubMed1975

Traumatic injuries to enamel formation in rat incisors.

Twenty-three fullgrown white male rats were fitted with an inclined plane on the mandibular incisors with consequent raising of the bite by 2.5 mm. After an observation period of between 1 and 30 d the animals were killed. In all cases traumatic injuries to the enamel organs were seen. The defects were mainly of four different types. Type 1 occurred in the early maturation zone of the enamel as a local defect with dedifferentiated ameloblasts. Vascular injury was moderate and deformation of the dentin was seen. After 30 d there was still a local defect of the enamel organ. Type 2 occurred apically to the maturation zone and caused a two-layered ameloblastoma resembling a sandwich. Hemorrhages were commmon in the surrounding connective tissue, with accompanying appearance of phospholipids in the tissue. After 30 d some restitution of the enamel formation was seen. Type 3 was necrosis was seen in the surrounding tissue. After 30 d a new ameloblastoma had developed in some areas. These three types appeared separately or combined. Type 4 occurred as a folding of newly formed apical dentin in areas without differentiated ameloblastoma and was seen in all of the experimental animals.

Ameloblasts↗
PubMed1975

Index for need of orthodontic treatment.

The demands placed on an index for evaluating the need of orthodontic treatment are described. An index designed by the Swedish Medical Health Board is discussed against the background of the above mentioned demands. A new index for the need of orthodontic treatment is presented. It consists of a morphological part in which essential abnormalities are recorded and allotted points according to their severity. The index also has a functional part in which selected functional disorders of the masticatory system as well as occlusal disharmonies are recorded and allotted points. The reasons are given for the choice of the various features included in the index. Practical instructions for the use of the index are given. The new index for need of orthodontic treatment was tried under clinical conditions in two series of children, aged 6--16 years. The variation between the recordings by the same examiner on two occassions was studied by double determinations. With but few exceptions no systematic errors were found between the double determinations. The precision of the new index for need of treatment was found to be the same as of that given by the Swedish Medical Health Board. No systematic differences were found between recordings made by orthodontists and inexperienced examiners. The accidental error of the method was of the same order for orthodontists as for inexperienced examiners. Comparison of recordings made by four orthodontists showed systematic errors between the recordings of functional but not of morphological deviations. Ranking of the children according to the need of orthodontic treatment as judged with the new index differed from that obtained with the system of the Swedish Medical Health Board. The new index attached more importance to functional deviations. This was the main requirement in the construction of the new index.

Adolescent↗