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Objective: To study if it was possible to move, by orthodontic means, a tooth into an area of the jaw that had been augmented with Bio-Oss®. Material and Methods: 5 beagle dogs were used. The 1st, 2nd, and 4th mandibular premolars on each side were removed. The defect at the left 4th premolar site was filled with a biomaterial (Bio-Oss®) while the corresponding defect in the right side was left for spontaneous healing. 3 months later, an orthodontic device was inserted in each side of the mandible. The device was designed to allow distal, bodily movement of the 3rd premolars. When the experimental teeth had been moved into the extraction sites of the 4th premolars, the animals were sacrificed and biopsies of the premolar-molar regions of the mandible sampled. The tissues were prepared for histological analysis using standard procedures. In the sections, 3 zones were identified: zone A=the bone tissue within the distal portion of the previous extraction site (4th premolar), zone B=the pressure side of the 3rd premolar, zone C=the tension side of the 3rd premolar. The area occupied by mineralized bone, Bio-Oss® particles and bone marrow was determined by a point counting procedure. The width of the periodontal ligament as well as the percentage of the root surface (in zone B) that exhibited resorption was determined. Results: The findings demonstrated that it was possible to move a tooth into an area of an alveolar ridge that 3 months previously had been augmented with a biomaterial. It was also demonstrated that 12 months after grafting, Bio-Oss® particles remained as inactive filler material in the not utilized part of zone A. The biomaterial was not present in zone C but present in small amounts in zone B. Conclusion: During the orthodontic tooth movement the graft material (Bio-Oss®) was degraded and eliminated from the part of the alveolar ridge that was utilized for the experiment. In the non-utilized part of the ridge the biomaterial, however, remained as a seemingly inactive filler material.

This follow-up study on transalveolar transplantation includes 56 maxillary impacted canines in 47 patients, with a post-operative control period of 2-10 years (mean 4.7 years). The prognosis of the transplanted teeth is still very good; only two canines have been lost, due to poor oral hygiene or fracture of the tooth. These positive follow-up results indicate that transalveolar transplantation will offer greater flexibility in the treatment of impacted maxillary canines in adults.

Objective To study if it was possible to move, by orthodontic means, a tooth into an area of the jaw that had been augmented with Bio-Oss. Material and methods 5 beagle dogs were used. The 1st, 2nd, and 4th mandibular premolars on each side were removed. The defect at the left 4th premolar site was filled with a biomaterial (Bio-Oss) while the corresponding defect in the right side was left for spontaneous healing. 3 months later, an orthodontic device was inserted in each side of the mandible. The device was designed to allow distal, bodily movement of the 3rd premolars. When the experimental teeth had been moved into the extraction sites of the 4th premolars, the animals were sacrificed and biopsies of the premolar-molar regions of the mandible sampled. The tissues were prepared for histological analysis using standard procedures. In the sections, 3 zones were identified: zone A=the bone tissue within the distal portion of the previous extraction site (4th premolar), zone B=the pressure side of the 3rd premolar, zone C=the tension side of the 3rd premolar. The area occupied by mineralized bone, Bio-Oss particles and bone marrow was determined by a point counting procedure. The width of the periodontal ligament as well as the percentage of the root surface (in zone B) that exhibited resorption was determined. Results The findings demonstrated that it was possible to move a tooth into an area of an alveolar ridge that 3 months previously had been augmented with a biomaterial. It was also demonstrated that 12 months after grafting, Bio-Oss particles remained as inactive filler material in the not utilized part of zone A. The biomaterial was not present in zone C but present in small amounts in zone B. Conclusion During the orthodontic tooth movement the graft material (Bio-Oss) was degraded and eliminated from the part of the alveolar ridge that was utilized for the experiment. In the non-utilized part of the ridge the biomaterial, however, remained as a seemingly inactive filler material.

The aim of the study was to find out if implant-supported crowns in the upper incisor region run the risk of coming into an infraoccluded position later in life. Ten adolescents with 15 implant-supported crowns were included in the study. The age of the patients at the implant surgery ranged between 14 and 19 years. They were followed up during an 8-year period. No implant loss was observed. A good or acceptable aesthetic appearance at the last observation was found in most subjects. In some of them a change in the vertical position of the implant-supported crown, resulting in infraocclusion, could be registered, especially in subjects with no incisor contact. Throughout the follow-up period, only minor loss of marginal bone support was observed at the implants. At the teeth adjacent to the implant, a reduction of the marginal bone level was observed in some patients. Of importance to consider in single implant therapy is that a fixed chronological age is no guidance for implant placement, due to a slight continuous eruption of the adjacent teeth post adolescence. An orthodontic treatment should be performed not only in order to gain space in the implant area, but also to attain good incisor stability to reduce the risk of infraocclusion of the implant-supported crown. Furthermore, 3 cases will exemplify that infraocclusion also may occur in patients who had received single implants at adult ages.

The prevalence of breathing obstruction was determined in a cohort of 4-year-old children. Craniofacial morphology was studied in obstructed children and compared with data from a control group of 4-year-old children with ideal occlusion. Dental arch morphology was compared in obstructed and non-obstructed children in the group. Parents of 95.5 per cent of the study base of 644 children answered a questionnaire concerning their child's nocturnal behaviour and related questions. The 48 children who, based on parental report, snored every night or stopped breathing when snoring (the 'snoring group'), showed a higher rate of disturbed sleep, mouth-breathing, and a history of throat infections as compared with the rest of the cohort. These children were examined by both an orthodontist and an otorhinolaryngologist and, when indicated, they were also monitored in a sleep laboratory. Twenty-eight of the children were diagnosed as having a breathing obstruction (4.3 per cent of the cohort) and six children (0.9 per cent) had sleep apnoea (mean apnoea-hypopnoea index of 17.3), using the same definition as that for adults. Cephalometric values among the obstructed children differed from those of a Swedish sample of the same age with ideal occlusion. Thy had a smaller cranial base angle and a lower ratio of posterior/anterior total face height. Small, but not significant differences were seen for NSL-ML and NL-ML. Compared with 48 asymptomatic children from the same cohort, the obstructed children had a narrower maxilla, a deeper palatal height, and a shorter lower dental arch. In addition, the prevalence of lateral crossbite was significantly higher among the obstructed children.

In this investigation, the tissue reactions towards titanium implants inserted in growing jaws of pigs were studied by means of histology. At the age of 12 weeks, 5 test pigs each received 4 Brånemark System titanium implants (fixtures). The fixtures were inserted immediately after extraction of the mesial root of the second deciduous premolar (P2) and the deciduous canine (C) on one side of the mandible and the mesial root of the first deciduous premolar (P1) on the other side. The fourth implant was placed after extraction of the deciduous lateral incisor (L) on one side in the upper jaw. Furthermore, 1 pig in which no extractions or fixture installations were performed served as a control. All pigs were followed for 165 days with clinical, radiographic and biometric examinations, the results of which have been previously presented. In this study, 10-microns-thick ground sections were produced for histology after the jaws had been fixed by immersion in formalin and further processed and embedded in plastic resin. Six of the fixtures originally inserted were lost during the experimental period, and the remaining implants were found to be involved with mineralized bone to varying degrees. Regarding the fixture-to-teeth relationship, it was found that, in the premolar region of the lower jaw, the teeth were positioned superior to and buccally angulated in relation to the fixtures. In the upper jaw, the implants were positioned below the adjacent teeth but centrally in the alveolar process. Tooth germs adjacent to the fixture had a displaced eruption path, buccally or lingually to the fixture. If the bud developed in close contact with the fixture, a changed morphology of the germ could be observed.

During an excavation of the Carmelite monastery in New Varberg, 178 skeletons were found. Many of the skulls were in a bad condition. Thus, the material in the present study consists of 12 complete and 47 partial skulls (maxilla and/or mandible) of 22 monks and 37 ordinary inhabitants. The information collected involved direct inspection of the skulls, segments of the jaws and radiographic examination of the complete skulls. Malocclusion, attrition, temporomandibular joints and arch dimensions were analysed. From the results it is tempting to assume that lack of forceful masticatory function and consequent absence of evenly distributed attrition and observed differences in craniofacial morphology can be a major explanation to the high prevalence of severe malocclusion in modern man.

Two-hundred-and-thirty-eight subjects in three different age-groups (7, 11, and 15 years) were followed over a period of 4-5 years in respect of morphological malocclusions, and signs and symptoms of functional disturbances. About half of the 7-year-olds had at least one of the morphological malocclusions registered while the corresponding figure was 38 per cent at the age of 20. Some subjects had received corrective orthodontic treatment. When compared with subjects without such treatment, there were no differences in prevalences of occlusal interferences, nor in signs or symptoms of craniomandibular disorders (CMD). The associations between CMD and different morphological malocclusions were low. Nevertheless, some malocclusions were found to be more important than others. In a long-term perspective cross-bite, both uni- and bilateral, anterior open bite, post-, and prenormal occlusion had some association with the development of CMD.

Gebisanomalien mit Klasse-III-Okklusion haben ein groses kieferorthopadisches Behandlungsbedurfnis mit Rucksicht sowohl auf asthetische als auch auf funktionelle Indikationen. Bei der Behandlungsplanung unterscheiden wir zwischen Fallen mit und ohne Ruckbismoglichkeiten. Fur die letzten ist die Differentialdiagnostik sehr wichtig, um die Ursache der Anomalien feststellen zu konnen (mandibulare Prognathie oder maxillare Retrognathie). Es ist wichtig, das individuelle Wachstumsmuster zu analysieren sowie den Zeitpunkt festzustellen, an dem sich das Kind in der Wachstumskurve befindet. Die gunstigste Prognose ist ein Behandlungsbeginn in der juvenilen Wachstumsstufe.

An experimental study in dogs, in which 15 teeth were bodily moved and 9 teeth were tipped with the same amount of horizontal force. Less resorption was found with tipping, and less was found on the mesial root surfaces moved into the extraction sites than on the furcation side of the distal roots.

The effects of orthodontic tooth movement upon the supporting tissues of teeth with periodontal breakdown are conflictingly reported. Recent studies in beagle dogs have, however, enlarged our understanding of the effects of tipping and bodily movements of teeth and of factors important in retention after orthodontic treatment. Such treatment should always be preceded by the treatment of periodontal inflammation and the elimination of deep pockets.

The purpose of this report is to compare a Swedish so-called normal material (Thilander et al.1983) with previously presented normal materials of Scandinavian origin and with standards for parameters in some frequently used roentgencephalometric systems. The material comprises Swedish children and young adults who fulfil special criteria of normal occlusion and harmonius skeletal relations and in whom roentgencephalometric data were collected. Parts of the material here reported are designated the 10-, 13- and 16-year-old groups. Comparison of the cephalometric data for the age-group 10 years in our material and a previously presented Norwegian normal material (Humerfelt 1970) showed remarkably good agreement for both angular and linear measurements in both sexes. Good agreement was also found between angular measurements in the 16-year-old group and those presented by Werner(1954) for Swedish 13-16-year-old children, but there seem to be differences for certain mandibular parameters. Comparison with data for 12-year-old Swedish boys with varying occlusion, presented by Björk(1947), reveals differences for several angular mandibular measurements. The highly significant differences between the linear measurements in the two materials are probably partly explained by age differences but also tend to corroborate the indications of differences in skeletal pattern suggested by the angular measurements, which are due to the selection criteria. Finally, comparison with the Bergen norms for the straight face (Hasund 1973) shows that the agreement is generally acceptable for angular measurements and the standards may be considered sufficiently reliable for use in clinical orthodontics. They should be supplemental with the age-related variations, however.

Some aspects of normal obliteration of sutures in rabbit and man were studied histologically and it was found that suture closure took place by intramembranous ossification in specific areas of trans-suturally arranged, tendon-like tissue. Histochemically these areas demonstrated high activity of oxidative enzymes.

The formation of a hyperplastic gingival tissue with invagination was observed in the extraction areas in seven patients aged 12 to 17 years who, after extraction of the maxillary first premolars, were undergoing orthodontic treatment with an edgewise appliance. This tissue was excised when about 2 mm. of the space remained to be closed. Histologic and histochemical analyses of the biopsy areas demonstrated hyperplasia and increased metabolism in the invaginated epithelium as well as increased production of glucose aminoglycans in the surrounding connective tissue. Loss of collagen was noted in the same regions. There was evidence of bone remodeling rather than only bone resorption in the biopsy area. It was concluded that stimulation from the orthodontic forces was responsible for the hyperplastic tissue reaction and that the increased amounts of glucose aminoglycans may be responsible for possible relapses.

Infraocclusion of deciduous molars that also lack a permanent successor is found to progress more than where a successor is present, while exfoliation is severely retarded. The aplasia is the most important factor in treatment planning and timing.

The aim of this investigation was to study the influence of orthodontic treatment on facial growth in subjects with maxillonasal dysplasia. The subjects were followed longitudinally from early childhood until growth was completed or almost completed. Fifteen patients, 9 boys and 6 girls, were orthodontically treated by conventional methods. They were compared with (1) another longitudinal group consisting of 13 orthodontically untreated children, 7 boys and 6 girls with the same syndrome, and (2) with a control material taken from computer-filed data on Swedish children and young adults with orthognatic profiles and normal occlusion. The orthodontic treatment led to acceptable dental conditions in 10 of the patients. No influence on craniofacial growth could be demonstrated. However, the mean facial polygons of the children showed that certain differences already existed at early ages between the treated subjects with a generally more severe form of the syndrome and the untreated children. The growth pattern seemed, however, to follow about the same rate in both groups. In six patients the orthodontic treatment was followed by surgical correction at adult age to solve their craniofacial problems. The optimum care of these patients requires an interdisciplinary treatment approach with thorough treatment planning by orthodontists in collaboration with oral and plastic surgeons.

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.