An epidemiologic study of occlusal anomalies in relation to development of the dentition in Icelandic children

Long-term development of malocclusion traits in orthodontically treated and untreated subjects

INTRODUCTION

The purposes of this study were to analyze long-term changes in malocclusion traits and to compare the development in orthodontically treated and untreated subjects.

METHODS

The sample comprised 308 adolescents in the intermediate, late mixed, or early permanent dentition who were examined clinically at the ages of 8 to 17 years and again 25 years later. The treated subgroup of 58 subjects had received orthodontic treatment with fixed or removable appliances or both. All subjects had a full complement of teeth, except a subgroup of 19 who had premolar extractions as a part of their orthodontic treatment plan.

RESULTS

The prevalence of maxillary overjet was significantly reduced in the untreated group and the treated subgroups. The prevalence of distal molar occlusion was significantly reduced in the subgroup treated without extractions. Comparison of treated and untreated groups in terms of changes over time showed that development was significantly more favorable in all treatment categories regarding maxillary overjet, and in the nonextraction category regarding distal molar occlusion. Subjects treated without extractions had less favorable development than did untreated subjects regarding molar crossbite.

CONCLUSIONS

The long-term benefit of orthodontic treatment, with or without extractions, was confirmed regarding maxillary overjet, and the lasting effect of nonextraction treatment was confirmed regarding the distal molar relationship. The pattern of changes in treated and untreated subjects indicated that long-term development and individual variation can to some extent conceal the effects of a brief orthodontic intervention.

Development of occlusal traits and dental arch space from adolescence to adulthood: a 25-year follow-up study of 245 untreated subjects

INTRODUCTION

The purpose of this study was to examine longitudinally the development of specific occlusal traits and space conditions in an Icelandic sample.

METHODS

The sample comprised 245 adolescents examined clinically in the late mixed or permanent dentition and again 25 years later. All subjects were orthodontically untreated, and all had the full complement of teeth at both examinations.

RESULTS

A significant increase in the prevalence of mandibular anterior crowding and mesial molar relationships and a decrease in the prevalence of excessive overjet and maxillary anterior spacing were seen. The persistence of malocclusion traits ranged from 17.9% to 53.4% for maxillary anterior spacing and crowding, mandibular spacing, overjet, overbite, and distal molar occlusion, whereas anterior mandibular crowding and molar crossbite were still found in 72.7% and 75.0%, respectively, at the second examination. Normal occlusal traits and space conditions at adolescence stayed mostly unchanged, with the exception of 11.2% of the subjects, who developed mandibular anterior crowding between the first and second examinations.

CONCLUSIONS

Deterioration of normal occlusal traits and space relationships was uncommon in this study, whereas self-correction of malocclusion traits and space anomalies was relatively frequent.

Long-term Stability of Unilateral Posterior Crossbite Correction

OBJECTIVE

To evaluate the stability of orthodontically corrected unilateral posterior crossbite in patients treated either by rapid maxillary expansion or with slow expansion devices in the early (mean age 7.2 years, n = 50) or late mixed dentition (mean age 9.9 years, n = 50).

MATERIALS AND METHODS

The observation periods were approximately 8 years for the early treatment groups and 6.5 years for the late treatment groups. The measurements were made on plaster casts at the following time points: before treatment (T1), after crossbite correction (T2), at the end of active orthodontic treatment (T3), and about 2 years after the end of active treatment (T4). Midline deviation and the skeletal classification of the malocclusion were also evaluated.

RESULTS

Almost 80% of the treated patients showed long-term stability of the corrected unilateral posterior crossbite. More than 70% of the patients were treated for the mandibular midline deviation. At the end of active treatment, 50% of the patients showed a skeletal Class III craniofacial morphology.

CONCLUSIONS

The results emphasize that determination of the correct treatment approach for the individual patient is the basic principle underlying the therapeutic success in unilateral crossbite cases. In patients where a broad lower arch is a cofactor in the etiology of the lateral crossbite, the treatment approach should be focused on both arches and not be limited to the constricted upper arch.

Long-term stability of unilateral posterior crossbite correction

OBJECTIVE

To evaluate the stability of orthodontically corrected unilateral posterior crossbite in patients treated either by rapid maxillary expansion or with slow expansion devices in the early (mean age 7.2 years, n = 50) or late mixed dentition (mean age 9.9 years, n = 50).

MATERIALS AND METHODS

The observation periods were approximately 8 years for the early treatment groups and 6.5 years for the late treatment groups. The measurements were made on plaster casts at the following time points: before treatment (T1), after crossbite correction (T2), at the end of active orthodontic treatment (T3), and about 2 years after the end of active treatment (T4). Midline deviation and the skeletal classification of the malocclusion were also evaluated.

RESULTS

Almost 80% of the treated patients showed long-term stability of the corrected unilateral posterior crossbite. More than 70% of the patients were treated for the mandibular midline deviation. At the end of active treatment, 50% of the patients showed a skeletal Class III craniofacial morphology.

CONCLUSIONS

The results emphasize that determination of the correct treatment approach for the individual patient is the basic principle underlying the therapeutic success in unilateral crossbite cases. In patients where a broad lower arch is a cofactor in the etiology of the lateral crossbite, the treatment approach should be focused on both arches and not be limited to the constricted upper arch.

Orthodontic treatment experience and prevalence of malocclusion traits in an Icelandic adult population

INTRODUCTION

The objectives of this study were to record the extent of orthodontic treatment and the prevalence of occlusal anomalies in an adult sample in Iceland.

METHODS

The study was based on a random sample of 829 subjects, 342 men and 487 women, aged 31 to 44 years, who completed questionnaires about their orthodontic treatment experiences and were available for clinical examination.

RESULTS

Complete dentitions in both jaws were present in 52.8% of the women and 45.3% of the men at the examinations. Significantly higher percentages of the women had received orthodontic treatment of some kind (24.3% compared with 16.9% for the men) and treatment with fixed appliances (16.0% compared with 9.5% for the men). Malocclusion traits were recorded with a standardized method, describing sagittal and vertical incisor relationships, sagittal and transverse molar relationships, and mandibular and maxillary space conditions. The results showed that 45.5% of the subjects had no malocclusions, 33.9% had 1 malocclusion trait, and 20.5% had 2 to 4 traits. The most frequent malocclusion traits were distal molar occlusion (27.7%), mandibular anterior crowding (13.4%), molar crossbite (11.9%), excessive overbite (11.8%), maxillary anterior crowding (7.1%), mesial molar occlusion (6.9%), and excessive overjet (5.3%). The prevalences of mandibular overjet, mesial occlusion, and scissors-bite were significantly higher in the men than in the women.

CONCLUSIONS

The prevalences of malocclusion traits were similar in treated and untreated subjects, except for a significantly lower prevalence of overjet and a higher prevalence of molar crossbite in the treated group. Comparison with other studies showed low prevalences of overjet, overbite, open bite, and maxillary and mandibular spacing and crowding; other variables fell within the ranges of prevalence in previous surveys.

Prevalence and severity of malocclusion in adolescent Kuwaitis

OBJECTIVES

Our aim was to evaluate prevalence and severity of malocclusion in an adolescent Kuwaiti population.

SUBJECTS AND METHODS

Using a stratified cluster sampling method and excluding non-Kuwaitis, subjects with mesial migration and/or loss of first molars, and subjects with orthodontic treatment experience without availability of initial study models, we examined 1,299 Kuwaitis (674 boys and 625 girls) of mean age 13.2 +/- 0.4 years in a regular well lit classroom. We scored molar and canine relationship, overjet, overbite, anterior and posterior cross bite as well as spacing and irregularity of the incisors using gloves, mirrors, rulers, and spatulas.

RESULTS

Fourteen, 15, and 71% met the criteria for almost ideal, mild, and moderate to severe malocclusion, respectively. Of the 86% with malocclusion, occurrence of class 1, half step class 2, full step class 2, half step class 3, and full step class 3 was 57.8, 24.9, 6.3, 8.8, and 2.2% for the first molars, and 36.1, 50.0, 6.2, 5.4, and 2.3% for the canines, respectively. Incisor malalignment was the most prevalent malocclusion trait (73.2%). Overjet > or = 9.5 mm occurred in less than 1.5%, open bite in less than 3.5%, deep bite with gingival contact in less than 2.0%, complete posterior cross bite in less than 1.5%, and complete anterior crossbite in less than 2.0%. Median diastema was present in about 2/3 of the cases with maxillary anterior spacing as opposed to only about 1/3 of those with mandibular spacing.

CONCLUSION

Our findings suggest that more than 70% of young adolescent Kuwaitis have moderate to severe malocclusion, with incisor malalignment as the most prevalent malocclusion trait.

Autotransplantation of premolars to premolar sites. A long-term follow-up study of 40 consecutive patients

This article describes the long-term outcome of 40 consecutive patients having transplanted premolars. The objective of this ongoing study is to investigate survival rate, pulp survival rate, periodontal condition, and root development of autotransplanted premolars in orthodontic patients. This report covers 17 years; 32 orthodontic patients had 40 premolars transplanted into contralateral or opposing jaw quadrants where a premolar was missing. The teeth were examined systematically with clinical and radiographic measures at 1, 2, 6, 12, and 60 months or more after autotransplantation. The observation time varied from 2 years 5 months to 22 years 3 months, with a mean of 10 years 4 months. Bonded.018-in edgewise appliances were used, subjecting 87.5% of the transplanted teeth to normal orthodontic forces. One tooth was removed because of root fracture during the observation period, and 2 more had complications possibly related to the transplantation. The remaining 37 teeth and their supporting structures were all healthy at the last examination--a 92.5% success rate. Transplants with closed apices received endodontic therapy, but, in those with open or half-open apices, a 66% pulp survival rate was observed. No teeth in the sample had signs of replacement resorption or developed periodontal attachment loss. Inflammatory resorption in 2 teeth was arrested after endodontic treatment. Root formation, when not complete, continued on transplanted teeth, giving normal root form and adequate root length for normal function. It is concluded that autotransplantation of premolars combined with orthodontic treatment should be the first treatment alternative in cases of missing premolars, when a suitable donor tooth is available.

A maxillary protracting bow appliance for Class III treatment in the primary dentition

The design of a simple facial mask type appliance for the treatment of Class III with anterior crossbite in the primary dentition, is described. Its clinical effect is illustrated in two cases. The appliance is easy to make, cheap, well tolerated and efficient.

Class III malocclusion: a cephalometric study of Saudi Arabians

The records of 500 consecutive Saudi Arabian patients referred for orthodontic treatment were examined clinically and cephalometrically for Class III malocclusion. A control group was drawn at random from the same sample. The incidence of Class III was 9.4 per cent, with mandibular prognathism being the commonest presentation of the malocclusion. The upper and lower incisors exhibited a marked degree of dentoalveolar compensation, on dental bases having mean values of SNA--78.77 degrees and SNB--81.17 degrees. The maxillary length was reduced, as were the saddle and maxillary-mandibular plane angles. The gonial angle (ArGoMe), anterior and posterior facial heights, and mandibular lengths (ArGo, ArPo) were all significantly larger than the control group. The cephalometric values of the control group showed the increased tendency to bimaxillary protrusion in the Saudi Arabian sample.

Overjet and overbite distribution and correlation: a comparative epidemiological English-Iraqi study

There have been no widely used criteria and methods of measurement for evaluating the incisor relationship in terms of overjet and overbite and, therefore, no widely accepted definition of their normal values. A simple, efficient, metric overbite and overjet gauge has been developed and used on 236 English and 250 Iraqi samples. The normal range of overjet and overbite is considered as 2-4 mm. The English variation tends towards increased overjet and overbite, while the Iraqi variation tends towards lower values for both parameters. Significant correlation is seen between overjet and overbite at 1 per cent level in both samples.

Skeletal maturation of the hand in Iceland

The mean time at onset of the stages of skeletal maturation of the hand, PP2=, MP3=, S, MP3cap, DP3u, PP3u, and MP3u, in a cross-sectional sample of Icelandic school chidren in Reykjavík, a total of 1426 (690 boys and 736 girls), was assessed on radiographs of the hand and compared with results published from Denmark and Greenland. On the whole, the Icelandic children were most ahead, while S appeared at about the same time in all three nations. Otherwise, the mutual relationship between the skeletal stages was very similar. Girls reached all stages significantly sooner than boys, and this agrees with the findings in Denmark and in Greenland. The sex difference was most marked in the Icelandic material. The accidental error due to method in assessing the differences in skeletal maturation proved to be less than 5%, similar to that reported by others.

Prevalence and awareness of malocclusion in Swedish men

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.

An epidemiologic study of dental space anomalies in Icelandic schoolchildren

This study was performed mainly to determine the prevalence of space anomalies with regard to the various stages of dental development in Icelandic schoolchildren. The sample consisted of 1,641 randomly selected children (791 boys and 850 girls), making up 9.5% of the children attending all primary and secondary schools in Reykjavík during the school year 1972--73. In most of the frequencies of the different space anomalies boys showed a higher prevalence than girls. In both sexes there was often a significant difference from one stage of dental development to another. The results were compared with those reported for other ethnic groups.

Prevalence of hypodontia and malformations of permanent teeth in Iceland

This study was performed to elucidate the prevalence of hypodontia and congenital malformations of permanent teeth in Iceland. Computer analysis was done on the basis of results from examining 1,116 children (521 boys and 595 girls), or about 9.5% of all schoolchildren in Reykjavík in stages DS 3 (canines and premolars erupting) and DS 4 (canines and premolars fully erupted) of dental development at the time of the study. The age range was mainly from 8-16 years. The prevalence of congenitally missing teeth (second and third molars excluded) was 6.7% in boys and somewhat higher, 8.9%, in girls, 7.9% for both sexes combined. On the average, each child was missing 1.9 teeth. In the girls, the most commonly absent teeth were the mandibular second premolar (55%), the maxillary second premolar (19%), and the maxillary lateral incisors (18%). In the boys the figures were 51%, 18%, and 10%, respectively. Malformation of permanent teeth, mainly in the form of pegshaped maxillary laterals, was also less common in the boys, 1.3% against 3.0% in the girls, and 2.2% for both sexes combined. Among Icelandic children hypodontia and/or congenital malformation of permanent teeth were found in 9.1%.

Intra-examiner reliability of epidemiologic registrations of malocclusion

Intra-examiner consistency in the recording of single traits of malocclusion according to a previously described method was assessed by duplicate registrations on study models of 292 children. The level of agreement was expressed by the consistency ratio and the phi coefficient. A high level of consistency was obtained for most of the malocclusion traits, and it was concluded that the method employed is appropriate also for analyses of interrelations between these traits.