Outcome and long-term stability of an early orthodontic treatment strategy in public health care.

Our aim was to evaluate the long-term treatment outcome of a systematically applied orthodontic screening and early treatment strategy in a public dental health care system, with special reference to occlusal stability at least 5 years post-retention. The subjects (N = 68) belonged to one age cohort born in a Finnish rural municipality (N = 85), and they were regularly followed from 8 to 20 years. Persons with malocclusions were screened and treated according to pre-planned protocol. Treatment need was assessed according to the Dental Health Component of the Index of Orthodontic Treatment Need, and treatment outcome using the peer assessment rating (PAR) Index and Little's Index of Irregularity. Eighty-two per cent of the treated participants were out of retention (mean 6.9 years post-retention) at age 20. Definite treatment need in the study population decreased from 37% to 3 %. In the treated group, the mean PAR improvement decreased from 65 % to 63% from age 15 to 20 years. The mean irregularity score for the mandibular incisors was 4.0 [standard deviation (SD) 2.4] and for maxillary incisors 3.7 (SD 2.1) with no significant difference between treated and not treated subjects. The results suggest that definite need for orthodontic treatment may be predominantly eliminated from the target population with a systematically implemented treatment strategy focusing on early treatment with simple appliances. Emphasis on early timing of treatments may have contributed to the good long-term stability of treatment results.

Dental age in patients with neurofibromatosis 1.

Neurofibromatosis type 1 (NF1) is a common, hereditary, neurocutaneous skeletal condition with a variety of osseous manifestations. Although NF1 also affects craniofacial structures, the literature has only limited information related to the effect of NF1 on dental development. In this study the dental age of 34 Finnish NF1 patients, 8-17 yr of age, was estimated using the Demirjian & Goldstein method. The dental age of children with NF1 was similar to that of a Finnish control population. The findings suggest that NF1 does not affect the timing of tooth development.

Dental arch width, overbite, and overjet in a Finnish population with normal occlusion between the ages of 7 and 32 years.

The aims of the present study were to provide data on growth changes in the dental arches from age 7 to 32 in Finns with untreated normal Angle Class I occlusions. The material consisted of 33 series of dental casts of 18 women and 15 men. The subjects had been examined and study models taken at the ages of 7, 10, 12, 15, and 32. Dental arch width, overbite, and overjet were measured. Our longitudinal findings show that both the dental arches of young adults are slightly narrowed from adolescence to 32 years of age. All increases in width dimensions took place before 15 years of age. The means of the changes were mostly small, in the order of 0.5 to a few millimetres. Variability in age changes was considerable. In both genders, each variable increased in some subjects and decreased in others during every age interval. Differences between growth changes in the mesial, distal, and gingival intermolar widths indicate that both the maxillary and the mandibular first molars rotate mesiolingually and that the maxillary first molars also become more upright during late occlusal development. We expect the present findings of the changes occurring in the arch dimensions of subjects with untreated normal occlusions to help clinicians in following up occlusal development, choosing an optimal treatment time, and making orthodontic treatment and retention plans. However, because of the wide variability, accurate prediction of future development cannot be made on the individual level.

Dental age in 6-year-old children with submucous cleft palate and cleft of the soft palate.

OBJECTIVE: To evaluate dental age in 6-year-old children with submucous cleft palate (SMCP) and to compare this in age-matched and sex-matched children with clefts of the soft palate (CPs). MATERIAL AND METHODS: The dental maturity of 73 children (39 girls) with SMCP was evaluated from panoramic radiographs and compared in age-matched and sex-matched controls with CPs. Mean biological age of the children was 6.1, ranging from 5.5 to 6.8 (boys 6.2 years, range 5.7-6.8; girls 6.1 years, range 5.5-6.7). Dental stages were assessed following the method of Demirjian, and dental age was calculated in accordance with the Finnish dental maturity reference values. Student's paired t-test was used in the statistical analysis. RESULTS: There were no significant differences in dental age between the sexes, such that boys and girls were combined in the further analyses. Dental age of the children with SMCP (6.2 years, range 4.9-7.4) was similar to their biological age (NS). Dental age of those with CPs was 0.2 years delayed (dental age 5.9 years, range 4.6-7.5; p<0.001) compared to their biological age. Children with CPs had a lower dental age than children with SMCP (p<0.001). CONCLUSION: Dental maturation in 6-year-old children with submucous cleft palate is not delayed, whereas in children with clefts of the soft palate dental age is slightly delayed.

Dental arches in submucous cleft palate: comparison of six-year-old boys with unoperated submucous cleft palate, with operated cleft of the soft palate, and without a cleft.

OBJECTIVE: To evaluate the dental arch dimensions in 6-year-old boys with unoperated submucous cleft palate (SMCP), and to compare their dental arch dimensions with those of boys without clefts and boys with clefts of the soft palate (CP). MATERIAL AND METHODS: The sizes of dental arches in 97 boys were compared retrospectively from dental casts taken at a mean age of 6.4 years (range 5.2-8.4). The material included 34 boys without clefts, 30 with unoperated SMCP, and 33 with CP. In children with CP, palatal closure had been done by the pushback technique at a mean age of 1.5 years. RESULTS: The dental arch dimensions of the boys with SMCP were similar to those of boys without clefts, except for a decreased maxillary arch length. There was no difference in maxillary arch length between the boys with SMCP and those with CP. The boys with CP had smaller maxillary and mandibular dental arch widths than the boys without clefts and with SMCP. There were no differences in the number of boys with permanent incisors between the three groups. CONCLUSION: Six-year-old boys with unoperated SMCP have similar dental arch dimensions as boys without clefts, except for a decreased maxillary arch length.

Timing of developmental stages in permanent mandibular teeth of Finns from birth to age 25.

OBJECTIVE: The aim was to provide radiographic data on postnatal development of the 8 mandibular teeth to serve as reference norms in clinical dentistry, forensic dentistry, anthropology, and research. MATERIAL AND METHODS: Developmental stages of teeth were assessed from a total of 2795 radiographs, mostly panoramic, of 1970 Finns (966 M and 1004 F) from birth to age 25. The grading was based on Demirjian's 8 mineralization stages and the crypt stage. RESULTS: Timing of development in individual mandibular teeth is presented in two ways: as age at attainment of each developmental stage and as age of subjects in a developmental stage. Initiation of mineralization was visible in 1st molars at 0.20 years, in central incisors at 0.22 years, lateral incisors at 0.37 years, and canines at 0.56 years of age. Timing was usually earlier in girls than in boys. Differences were greatest in canines, where females were advanced by 1.74 years at the closure of the apex. Root development in 3rd molars showed an opposite trend, where apical closure was 1.19 years earlier in men. In 3rd molars, age at apical closure in females was 21.50 years, among the highest reported. In general, the early developmental stages had the shortest duration and the last stages the longest. CONCLUSION: Timing of postnatal development of individual mandibular teeth in Finns resembled developmental schedules reported for other Caucasian population groups. Any differences were mostly small and inconsequential.

Tooth wear in maxillary anterior teeth from 14 to 23 years of age.

Using a planimetric method, the size of horizontal wear facets on maxillary anterior teeth was studied longitudinally in the permanent dentition of 35 subjects at ages 14, 18, and 23?years. The study subjects had not previously undergone any orthodontic treatment and had Class I occlusion. We studied the association between the amount of wear and reported parafunctions and maximal bite force. Total wear areas in age groups 14, 18, and 23 years were 29.5 mm2 (SD 11.4), 39.1 mm2 (SD 12.7), and 45.0 mm2 (SD 13.0), respectively. The total wear area increased significantly both from 14 to 18 years of age and from 18 to 23 years of age (p <0.0001). Between 18 and 23?years of age, the maxillary canines showed strongest wear, although the central incisors had largest wear facets. It can be concluded that wear of permanent anterior teeth is a continuous phenomenon in adolescence and young adulthood.

Comparison of dental maturity in children of different ethnic origins: international maturity curves for clinicians.

Dental maturity was studied with 9577 dental panoramic tomograms of healthy subjects from 8 countries, aged between 2 and 25 years of age. Demirjian's method based on 7 teeth was used for determining dental maturity scores, establishing gender-specific tables of maturity scores and development graphs. The aim of this study was to give dental maturity standards when the ethnic origin is unknown and to compare the efficiency and applicability of this method to forensic sciences and dental clinicians. The second aim was to compare the dental maturity of these different populations. We noted an high efficiency for International Demirjian's method at 99% CI (0.85% of misclassified and a mean accuracy between 2 to 18 years +/- 2.15 years), which makes it useful for forensic purposes. Nevertheless, this international method is less accurate than Demirjian's method developed for a specific country, because of the inter-ethnic variability obtained by the addition of 8 countries in the dental database. There are inter-ethnic differences classified in three major groups. Australians have the fastest dental maturation and Koreans have the slowest.

Orthodontic treatment need from eight to 12 years of age in an early treatment oriented public health care system: a prospective study.

The aim of this study was to investigate the effects of an early treatment oriented orthodontic program on treatment need at age 12 years in a public health care system. The subjects consisted of one whole age cohort in a municipality in Finland, 87 children in total. All children were examined at ages eight, 10, and 12 years. Treatment need was assessed on casts using a modified Dental Health Component of the Index of Orthodontic Treatment Need and a 10-Grade Scale based on the Treatment Priority Index. Early treatment was started on children having definite treatment need according to both indices. The agreement between indices was good at ages eight and 12 years and moderate at age 10 years. Treatment need changed significantly from eight to 12 years. Of the 29 children with definite treatment need at age eight years, only two had treatment need at age 12 years. Of the 38 children with no treatment need at age eight years, 28 remained in this category and only two children had definite need for treatment at age 12 years. The duration of treatment ranged from one to 61 months, although 59% of the treatments lasted two years or less. We conclude that systematically planned early orthodontic treatment may have contributed to the significant reduction in treatment need from eight to 12 years of age.

Dental maturity curves in Finnish children: Demirjian's method revisited and polynomial functions for age estimation.

Dental maturity was studied from 2213 dental panoramic radiographs of healthy ethnic Finns from southern Finland, aged between 2 and 19 years. The aim was to provide new Finnish maturity tables and curves and to compare the efficiency of Demirjian's method when differently weighted scores and polynomial regressions are used. The inter-ethnic variations lead us to calculate specific Finnish weighted scores. Demirjian's method gives maturity score as a function of age and seems better adapted for clinicians because, in their case, the maturity score is unknown. Polynomial functions give age as a function of maturity score and are statically adapted for age estimation studies. Finnish dental maturity tables and development curves are given for Demirjian's method and for polynomial functions. Sexual dimorphism is established for the same weighted score for girls and boys, and girls present a greater maturity than boys for all of age groups. Polynomial functions are highly reliable (0.19% of misclassifies) and the percentile method, using Finnish weighted scores, is very accurate (+/- 1.95 years on average, between 2 and 18 years of age). This suggests that polynomial functions are most useful in forensic sciences, while Demirjian's method is most useful for dental health clinicians.

An 8-year follow-up study of temporomandibular disorder and psychosomatic symptoms from adolescence to young adulthood.

AIMS: To assess the prevalence of subjective symptoms of pain and/or temporomandibular disorder (TMD) dysfunction and their association with psychosomatic (PS) symptoms in a longitudinal follow-up study of Finnish young adults over an 8-year period. METHODS: One hundred twenty-eight Finnish young adults (60 men and 68 women) were assessed longitudinally at the ages of 15, 18, and 23 years using routine stomatognathic methods and a standardized questionnaire. RESULTS: The prevalence of reported TMD symptoms ranged from 6% to 12% for pain symptoms, from 12% to 28% for dysfunctional symptoms, and from 4% to 7% for a combination of these 2 types of symptoms. The prevalence of PS symptoms, which were constantly present in many of the patients who reported them, ranged from 7% to 11%. A significant correlation (P < .05) was found between TMD pain and PS symptoms at the ages of 15 and 18 years. PS symptoms were not significantly correlated to TMD dysfunction symptoms or to experiencing no symptoms at any age. The majority of subjects in all age groups with both TMD and PS symptoms were female, in a ratio of approximately 2 to 1. CONCLUSION: The prevalence of TMD and PS symptoms was low in adolescence and young adulthood, and there was a significant association, although relatively weak, between PS symptoms and reports of either TMD pain or a combination of TMD pain and dysfunction symptoms.

Tooth formation and the mandibular symphysis during the first five postnatal months.

Schedules based on tooth development are useful in age assessments of children, but in early infancy they are based on only a few studies. The radiographic appearance of the mandibular symphysis during the first postnatal months has not gained attention. The present study describes the formation of teeth and the development of fusion between the mandibular halves during the first five postnatal months, as seen in panoramic tomograms taken in medicolegal autopsies of 29 ethnic Finns, 19 boys and 10 girls, at the Department of Forensic Medicine, University of Helsinki. In the majority of the infants, the criteria of sudden infant death (SID) were fulfilled. The stages of tooth formation used were those applied by Moorrees et al. with one modification (Nyström et al.). Mineralization of all primary teeth proceeded rapidly during the first postnatal months, the change being on average two developmental stages in four months. Considerable variation in tooth development existed in infancy. The mandibular halves were separated at birth. Complete fusion had occurred in the majority of infants aged four months, and the tomograms of the remaining infants showed a thin vertical line in a part of the symphysis. The marked changes, which during the first postnatal months occur in the radiographical appearance of the mandibular symphysis, and in the formation of primary teeth, provide valuable information for age assessments of infants.