The seven-year outcome of an early orthodontic treatment strategy.

The benefits of early orthodontic treatment are continuously discussed, but studies are few. We examined whether definite need for orthodontic treatment could be eliminated in public health care by systematically focusing on early intervention. One age cohort living in a rural Finnish municipality (N = 85) was regularly followed from ages 8 to 15 years, and persons with malocclusions were treated according to a pre-planned protocol. Treatment need was assessed according to the Dental Health Component (DHC) of the Index of Orthodontic Treatment Need, and treatment outcome by the Peer Assessment Rating Index (PAR). Fifty-two percent of the cohort received treatment, and definite treatment need decreased from 33% to 9%. In the treated group, the mean PAR score reduction was 63%, and 51% showed more than 70% improvement. The results suggest that an early treatment strategy may considerably reduce the need for orthodontic treatment in public health care with limited specialist resources.

Exposure to airborne methacrylates and natural rubber latex allergens in dental clinics.

The exposure of dental personnel to airborne methacrylates and natural rubber latex (NRL) allergens was studied during placing of composite resin restorations in six dental clinics in Finland. Both area and personal sampling were performed, and special attention was paid to measurement of short-term emissions from the patient's mouth. Methacrylates were collected onto thermal desorption tubes filled with Tenax TA and NRL allergens onto membrane filters. The methacrylate samples were thermally desorbed and analysed by gas chromatography with mass selective detection. The NRL allergen concentrations were determined by the allergen-specific IgE-ELISA-inhibition method. The median concentration of 2-hydroxyethylmethacrylate (2-HEMA) was 0.004 mg m-3 close to the dental nurse's work-desk and 0.003 mg m-3 in the breathing zone of the nurse with a maximum concentration of 0.033 mg m-3. Above the patient's mouth the concentration of 2-HEMA was about 0.01 mg m-3 during both working stages, i.e., during application of adhesive and composite resins and during finishing and polishing of the fillings. Maximum concentrations of 3-5 times higher than median concentrations were also measured. Triethyleneglycol dimethacrylate was released into the air mainly during the removal of old composite resin restorations (0.05 mg m-3) and only to a minor extent during finishing and polishing procedures. The median concentration of the NRL allergen was 0.12 au m-3 (au = arbitrary unit) with a maximum concentration of 1.1 au m-3. The results show that, except for short-term emissions from the patient's mouth, the exposure of dental personnel to methacrylates and NRL allergens is very low. Measures to reduce exposure are discussed, as the airborne concentrations of methacrylates should be kept as low as possible in order to reduce the risk of hypersensitivity.

The need for treatment and satisfaction with dental appearance among young Finnish adults with and without a history of orthodontic treatment.

The aim of this investigation was to evaluate orthodontic treatment need and patient satisfaction among young adults living in a city where free-of-charge orthodontic treatment was provided. A total of 281 18- to 19-year-old subjects randomly selected from the population register of the city of Vantaa took part in the study. The drop-out rate was 30%. Treatment need was clinically assessed according to the Index of Orthodontic Treatment Need (IOTN), consisting of a Dental Health Component (DHC) and an Aesthetic Component (AC). Information on previous orthodontic treatment was based on the patient records. Satisfaction of the subjects with their dental appearance and with the orthodontic treatment received was obtained using a questionnaire. The rate of orthodontic treatment among the subjects was 46% (54% for the females and 37% for the males, p < 0.05). 4% had discontinued treatment. A definite need for treatment (DHC 4 to 5/AC 8 to 10) was assessed in 15% of the subjects, and borderline/moderate need (DHC 3/AC 5 to 7) in 36%. No difference in IOTN scores between the treated and untreated subjects was found. Females had significantly more often no treatment need (DHC 1 to 2/AC 1 to 4) compared with males (p < 0.05). The majority of subjects (89%) reported that they were very or quite satisfied with their dental appearance. The odds of being satisfied were significantly higher for the treated subjects (OR = 2.71, p < 0.05) and lower for those at the non-attractive end of the AC scale (OR = 0.14, p < 0.01). Neither gender nor DHC grade significantly affected the odds of being satisfied among the subjects. The results indicate that the majority of young adults in this study were satisfied with their dental appearance regardless of objective treatment need of various degrees. The high treatment rate in relation to unnoticed treatment need calls for reevaluation of priorities in patient selection.

Self-reported health complaints among general dental practitioners, orthodontists, and office employees.

Studies in the Scandinavian countries have shown that orthodontists run an equal or even greater risk of contracting dermatitis compared to other dental personnel. The aim of the study was to find out whether the self-reported occupation-related health problems of general dental practitioners and orthodontists differ from those of office employees in Finland. The subjects were 147 general dentists, 81 orthodontists and 99 office employees (77% women and 23% men). The data were collected using a mailed questionnaire. Within the past year, 42% of the subjects had had occupational health problems, while 51% had experienced symptoms in the previous year or earlier. The complaints of hand dermatoses, musculoskeletal, as well as respiratory symptoms were significantly more common among women than among men. Musculoskeletal complaints were the most common symptoms in all occupational groups, but the odds ratio of having them were significantly higher for dental professionals compared to office employees. The frequency of self-reported hand dermatoses was 42% for dental professionals and 26% for office employees, but the difference did not reach statistical significance. The odds of having hand dermatoses were higher for atopic subjects and for women. Orthodontists did not differ from general practitioners in respect of any of the complaints reported. Materials used in dentistry were mentioned as the cause of symptoms by 49 (21.5%) of the dental professionals. The present results show an increased risk of self-reported musculoskeletal symptoms for the dental professionals. Also, a tendency towards increased occurrence of skin symptoms was noted for the dental professionals compared to office employees of this study.

Salivary nickel and chromium in subjects with different types of fixed orthodontic appliances.

The aim was to investigate nickel and chromium concentrations in saliva of patients with different types of fixed appliances. Saliva samples were collected from 47 orthodontic patients, ages 8 to 30 years. Four samples from each subject were collected: (1) before insertion of the appliance, (2) 1 to 2 days after, (3) 1 week after, and (4) 1 month after insertion of the appliance. A considerable variation in the concentrations of both nickel and chromium was observed. No significant differences were found between the no-appliance samples and the samples obtained after insertion of the appliances. The results suggest that nickel and chromium concentrations of saliva are not significantly affected by fixed orthodontic appliances during the first month of treatment.

Nickel allergy in adolescents in relation to orthodontic treatment and piercing of ears.

The aim of this study was to investigate the frequency of nickel hypersensitivity in adolescents in relation to sex, onset, duration and type of orthodontic treatment, and the age at which ears were pierced. The subjects were 700 Finnish adolescents, from 14 to 18 years of age, of which 476 (68%) had a history of orthodontic treatment with metallic appliances. The study consisted of patch-testing for a nickel allergy and a patient history obtained by a questionnaire and from patient record. The frequency of nickel sensitization in the whole group was 19%. Nickel allergy was significantly more often found in girls (30%) than in boys (3%) and in subjects with pierced ears (31%) than in those with no piercing of ears (2%). Orthodontic treatment did not seem to affect the prevalence of nickel sensitization. None of the girls who were treated with fixed orthodontic appliances before ear piercing showed hypersensitivity to nickel, whereas 35% of the girls who had experienced ear piercing before the onset of orthodontic treatment were sensitized to nickel. The results suggest that orthodontic treatment does not seem to increase the risk for nickel hypersensitivity. Rather, the data suggests that treatment with nickel-containing metallic orthodontic appliances before sensitization to nickel (ear piercing) may have reduced the frequency of nickel hypersensitivity.

Allergic patch test reactions to palladium chloride in schoolchildren.

A study of the prevalence of allergic patch test reactions to palladium chloride compared to nickel sulfate was performed in a group of Finnish schoolchildren. All adolescents 14-18 years of age in a Finnish town with 40,000 inhabitants, who had received orthodontic treatment with metallic appliances at a municipal dental clinic, were included in the study. The selection of patients was based on patient records. A non-treatment control group was randomly selected from the same age groups of the town population. A total of 700 subjects (77% of those invited), 417 (60%) girls and 283 (40%) boys, participated. The majority (91%) of the girls had pierced ears. Orthodontic treatment was equally common (67-70%) in the boys and the girls. The girls had a much higher frequency of allergic patch test reactions to both nickel sulfate and palladium chloride. Of the 700 adolescents tested, 48 (7%) had an allergic patch test reaction to palladium chloride. Of the 417 girls, 44 (11%) were palladium-chloride-positive, whereas only 4 of the 283 boys tested (1%) had an allergic patch test reaction to palladium chloride. 3 patients reacted to palladium chloride only, whereas all other patients with allergic patch test reactions to palladium chloride also had an allergic patch test reaction to nickel sulfate. The results support the concept of cross-reactivity between nickel sulfate and palladium chloride. The clinical significance of the allergic patch test reactions caused by palladium chloride remains unclear.

The influence of incisal malocclusion on the social attractiveness of young adults in Finland.

The aim of this study was to investigate the importance of dentofacial appearance on the perceived social attractiveness of young adults in Finland. The dental arrangements studied were incisal crowding, median diastema, protruding incisors, and ideal incisal occlusion. Facial photographs of six young adults were obtained and modified, so that for each face, four different dental arrangements could be portrayed. The photographs were shown to 1007 Finnish students to estimate social and personal characteristics of the person in the photograph. Dental arrangement had a significant influence on the perceived beauty and success of the persons. Test faces with incisal crowding and median diastema were ranked as significantly less intelligent, beautiful and sexually attractive, and judged to belong to lower social class than the same faces with ideal occlusion. Protruded incisors did not affect the ratings compared to ideal occlusion. On the average, female test faces were judged more favourably than the male ones. The results indicate that among Finnish students conspicuous incisal crowding or spacing represent a social disadvantage compared to normal or protruded incisors.

In vitro release of nickel and chromium from different types of simulated orthodontic appliances.

Five identical samples, each consisting of a fixed appliance, a headgear and a quad-helix for one-half of a dental arch, were immersed in 0.9% sodium chloride for 2 hours, 24 hours and 7 days. A control appliance was subjected to dynamic test conditions in a specially built "oral simulator" under similar test conditions. A significant release of nickel was detected from the quad-helix during the first two hours in static conditions, whereas during the following two periods significantly less nickel was released from the quad-helix than from the other appliances. The fixed appliance with simulated function showed a significantly higher cumulative release of nickel than the similar appliance in static conditions, 44.2 micrograms (SD 22.8) and 17.1 micrograms (SD 3.4). The total amounts of chromium released from the fixed appliance were significantly lower than those of nickel. No difference in the release of chromium was seen between the static and dynamic conditions. The results indicate certain differences in the amount and pattern of nickel release from different stainless steel orthodontic appliances in vitro. The release rate of nickel from dynamically loaded fixed appliances was found to be accelerated compared with that released under static conditions. Caution should be exercised when applying the results to the in vivo situation.

Caries experience in the primary dentition of Tanzanian and Finnish 3-7-year-old children.

Caries experience of primary teeth in relation to age, sex, ethnic group, socioeconomic status and frequency of consuming sweet snacks and drinks was studied among groups of Tanzanian and Finnish 3-7-yr-olds, a total of 1118 children. In all age groups the Tanzanian children had higher mean dmft scores than Finnish children did. In the Finnish group the mean dmft score was higher at age 7 than at age 3, while in the Tanzanian group no statistically significant difference in dmft scores was found between age groups. In both groups maxillary incisors and molars were the main teeth affected by caries. Frequent consumption of sweet snacks and drinks increased the risk for caries in Tanzanian but not in Finnish children. High socioeconomic status decreased the risk for caries in Finnish children but among Tanzanian children high SES was not associated significantly with the risk of developing caries. According to these results, caries experience in Tanzanian urban nursery school children was significantly higher than in Finnish children of the same age, the differences being especially high among the youngest age groups.

Occlusal characteristics in groups of Tanzanian and Finnish urban schoolchildren.

The occurrence of different occlusal and space anomalies was studied in groups of 642 Tanzanian and 458 Finnish school-children. Similar diagnostic criteria and methods were used in both countries. The Finnish children had significantly higher prevalences of distal occlusion and crowding and a lower prevalence of anterior openbite than the Tanzanian children. The proportion of subjects with no occlusal or space anomalies was considerably higher among the Tanzanians than among the Finns, 55% and 12% to 22%, respectively. The distinct differences found in occlusion of Tanzanian and Finnish children in this study seem to reflect differences in hereditary or environmental factors, which are expressed as craniofacial or dentoalveolar differences between these ethnic groups.

Occlusion in the primary and early mixed dentitions in a group of Tanzanian and Finnish children.

Two high and two low socioeconomic areas were selected for the Tanzanian portion of this study, with all nursery schools located in those areas included, for a subtotal of 580 children. The Finnish group was comprised of a total of 575 Caucasian children examined. The Tanzanian children (83 percent Black African, 10 percent Asian, 7 percent Arab) had fewer occlusal anomalies than the Finnish children did. Finnish children had a 13-percent incidence rate of lateral cross-bite; among African children, 8 percent showed anterior crossbite; and among the combined Asian/Arab group of children, 10 percent had an anterior open bite. African children had significantly fewer prevalences of distal bite, lateral crossbite and crowding than Finnish children did.

Occlusion among a group of Tanzanian urban schoolchildren.

Occlusion and its variations were studied in a group of primary schoolchildren (n = 642, age 11-18 yr) in Dar es Salaam. Most children (96%) had Angle's Class I occlusion. Distal and mesial bite were rare in the sample, representing 3% and 1%, respectively. Crowding was found to be the most common dental disorder (16%) and the frequency of moderate and severe crowding decreased with age. No clear differences in occlusion were found between boys and girls. The results of this study show smaller occlusal variation compared with Caucasian children, and also some differences compared with previous African studies.

Oral health status among teenage schoolchildren in Dar es Salaam, Tanzania.

In the developing countries, the main dental problem has traditionally been periodontal disease, but recently dental caries has been reported to be increasing. There are some findings showing the same pattern in Tanzania. The aim of the present study was to explore the prevalence of caries and the periodontal status among schoolchildren in Dar es Salaam. The series consisted of pupils of classes 6 and 7 in five primary schools (n = 640, ages 12-18 yr). Two-thirds of the children examined were caries-free. Boys had significantly lower DMF scores than girls, 0.7 and 1.2, respectively. Almost all the children showed early signs of gingivitis and assessment by the Community Periodontal Index of Treatment Needs (CPITN) showed that in over 50% all sextants of the mouth were affected. In the older age group (15-18 yr) girls had a significantly higher number of periodontally healthy sextants than boys. The results confirm the high prevalence of periodontal problems but show a very low prevalence of caries. Thus, there are no signs of an alarming caries problem in Dar es Salaam, but oral hygiene education should be promoted.