- [Show abstract] [Hide abstract] ABSTRACT: The aim of this study was to compare the reliability of cone-beam computerized tomography (CBCT) with that of other radiographic methods in preoperative radiographic determination of the number of roots of lower third molars and their relationship to the inferior alveolar canal (IAC). Forty-two teeth were clinically studied and imaged using CBCT and other imaging methods-panoramic radiography, multiprojection narrow-beam radiography (MNBR), and cross-sectional tomography. Statistical analysis (kappa values) was used to compare the diagnoses of 2 trained oral radiologists and the radiologic diagnoses with the findings at operation. Cone-beam CT revealed the number of roots of teeth more reliably than panoramic radiographs. CBCT examination was highly reliable in locating the IAC, whereas MNBR was unreliable and cross-sectional tomography fell between the two. With cross-sectional tomography, the IAC was noninterpretable in one-third of the cases. We recommend CBCT examination for preoperative radiographic evaluation of complicated impacted lower third molars.
- [Show abstract] [Hide abstract] ABSTRACT: This study is part of a larger research program, at the Finnish Student Health Service in Helsinki, in which changes in the dental and oral health of first-year university students (born in Helsinki) in the years 1982 and 2002 were compared. Panoramic radiographs were taken of 176 students in 1982, mean age 19.8 years (SD+/-0.7), and of 231 in 2002, mean age 20.2 (SD+/-0.7). DMFT index, caries and periapical changes, alveolar bone resorption, wisdom teeth, supernumerary, missing, and persisting deciduous teeth were evaluated from the radiographs. The chi-squared test and non-parametric tests were used to analyze the statistical significance of differences between the study groups and between genders. The DMFT index diminished from 11.0 (SD +/- 4.2) to 2.9 (SD +/- 3.3) (p < 0.0001). In 2002, 27.9% of the students had a DMFT index of zero (in 1982, 0%, p < 0.000). The mean number of endodontically treated teeth diminished from 0.1 to 0.03 (p < 0.05). The number of impacted wisdom teeth increased in males from mean 0.41 to 0.69 (p < 0.05). An improvement in dental health was obvious in the year 2002. The favorable change in DMFT index is a trend that has been going on for several decades in Finland, probably as a result of the use of fluorides and better education in dental hygiene. The change might also be connected with improved general health.
- [Show abstract] [Hide abstract] ABSTRACT: The aim of the study was to examine oral piercings among first-year university students. First-year university students in 2002 were invited to a dental examination (n = 234; 49 men and 185 women). Students with piercings formed the study group and the rest served as controls. The methods included decayed, missing, and filled teeth (DMF) index, stimulated salivary flow rates, panoramic tomograms, and questionnaires including the Depression Inventory of Beck. Fisher's 2-sided exact test was used for statistical analysis. The prevalence of oral piercings was 3.4%. In the DMF indices, no statistically significant differences existed between the groups. Increased salivary flow rates were noted among students with piercings (63% vs 26%, P < .05). Use of tobacco and illicit drugs, and also depression, were more prevalent in the study group than in the controls. Because of the possibility of oral implications, follow-up of oral piercings is essential.
- [Show abstract] [Hide abstract] ABSTRACT: The aim of the present study was to follow the clinical changes in third molar status during an 18-year period in patients aged 20 to 38 years. The series consisted of 118 subjects (37 men and 81 women). In the beginning of the study, the mean age was 20.2 years (SD, +/-0.6 year), and at the end, it was 38.6 years (SD, +/-0.6 year). Panoramic radiographs were taken at baseline and at age 38. All of the subjects were clinically examined at baseline and at the end of the study. A portion of the subjects (n = 69) were also examined at age 32. Most of the initially unerupted third molars were removed during the follow-up period (73%, maxilla and mandible together). More than half of the initially partially erupted third molars were removed during the follow-up period (64%, maxilla and mandible together). The percentage of erupted third molars found in the mouth at age 38 increased significantly depending on the initial status. Of the initially unerupted, partially erupted, or erupted third molars, 10%, 33%, and 50%, respectively, were erupted at age 38 (maxilla and mandible together). Changes in the status of third molars continued from age 32 to age 38, although to a lesser extent (8%). The 3 third molars with advanced eruption were all maxillary teeth in men. Third molars undergo continuous clinical change on a reduced scale at least up to the age of 38 years.
- [Show abstract] [Hide abstract] ABSTRACT: Short-root anomaly (SRA), occurring mostly in maxillary incisors, is defined as developmentally very short, blunt dental roots. The condition has a genetic background and is related to hypodontia. Earlier population studies have been based on schoolchildren with developing dentitions and have indicated prevalence figures between 1% and 10%. We studied a random sample of existing panoramic radiographs of 2000 university students for SRA. Roots as long as or shorter than the crowns in the incisors and visually evaluated as very short, blunt roots bilaterally in the posterior teeth were classified as SRA. The prevalence was 1.3%. According to anamnestic information, half the SRA patients had undergone orthodontic therapy, but pre-treatment radiographs were unavailable. In 70% of the SRA patients the short-rooted tooth pairs were upper incisors, but also involved were maxillary premolars, lateral incisors, and lower second premolars. Women were significantly more often affected. We discuss other factors known to cause short-rooted teeth and conclude that the population prevalence for genetic SRA in fully developed dentitions is close to our 1.3%.
- [Show abstract] [Hide abstract] ABSTRACT: Nineteen patients (13 male, six female) with 34 impacted third molars, 21 in the mandible and 13 in the maxilla were radiographically followed from age 20 to 32. All were examined clinically and panoramic radiographs were taken at baseline and at the end of the study. Radiographic analysis included resorption of teeth, enlargement of the follicle, development of the root, change in inclination of the third molar, state of impaction, relative depth of the third molar in bone and relation to the ramus of the mandible and to the second molar tooth. In the mandible, the mean change in inclination was 19 degrees and the percentage of teeth with changed angulation was 76%. In the maxilla, only 23% of the teeth changed their inclination. The state of impaction (soft tissue, partially in bone, completely in bone) had changed for 44% of the teeth. According to the questionnaire, no pain or symptoms in the region of the third molars were reported by 74% of the students during the 12-year period. It is concluded that considerable radiographic changes, without notable symptoms, may occur involving inclination of the tooth and state of impaction in impacted third molars after the usual age of eruption.
- [Show abstract] [Hide abstract] ABSTRACT: The aim of this study was to evaluate the estimates on need for third molar removals made at age 20 after 12 years. The series consisted of 81 university students followed from age 20 to 32 years. At baseline and at study end, these students were clinically examined, and panoramic radiographs were taken. At baseline in 1982, a qualified oral surgeon had made estimates on need for removal of third molars within 5 years; 75% of students needed removals. Actual treatment performed was evaluated after 12 years. A questionnaire served to determine symptoms related to third molars during the 12-year period. During the follow-up, one or more third molars had been removed from 67% of the former students. A total of 155 third molar removals had been estimated, but by age 32 years the percentage actually removed was only 59%. Of the 79 third molars taken out at the Finnish Student Health Service, 77% were initially estimated to need a surgical procedure, but actually 66% were simply extracted. Most were removed at around age 27 years. According to the questionnaire, 67% of the students were asymptomatic in the third molar region during 12 years. Because need for surgical removal decreases during early adulthood, routine prophylactic extraction of asymptomatic third molars in young adults cannot be recommended. Well-defined indications for prophylactic removals are needed.
- [Show abstract] [Hide abstract] ABSTRACT: The aim of the study was to follow the clinical changes in third molar status during a 12-year period in patients aged 20 to 32 years. The study was based on a follow-up of 81 university students (32 men, 49 women). They were clinically examined and panoramic radiographs were taken at baseline (mean age, 20.7+/-0.5 years) and at the end of the study (mean age, 32.6+/-0.6 years). The students had 285 unerupted, partially erupted, or fully erupted third molars at the beginning of the study, and 150 at the end. On final examination, 115 teeth were erupted. During the first 6 years from age 20 to 26, various clinical changes took place in the status of the third molars. In the second 6 years, until age 32, the two main changes were either removal or eruption. During the 12-year follow-up, 22% of third molars erupted, a few even after 26 years of age; the percentage of third molars removed was 42%. Third molars undergo continuous clinical change at least up to the age of 32 years.
- [Show abstract] [Hide abstract] ABSTRACT: A questionnaire dealing with the incidence of traumatic injuries was sent to 1,000 randomly selected 3rd-year university students in Finland; 617 students responded adequately. Of those, 177 (28.7%) reported a combined total of 281 accidents and 323 separate injuries requiring medical or dental treatment during the preceding 3 years. The accidents resulted in 1,061 days of official sick leave, and one third of the accidents caused permanent sequelae to the affected students. Almost half of all accidents had been sustained during sports activities and 14% in traffic. Only 0.5% of the accidents were classified as having occurred in the university environment or during activities directly related to studies. Alcohol was involved in 10.1% of the accidents; 45% of the injuries affected the lower extremities, and 22% the upper extremities. Most of the injuries were related to the students' active lifestyles and keen interest in sports.
- [Show abstract] [Hide abstract] ABSTRACT: The study was carried out to determine the risk of acute disease of third molars in young adult patients. The subjects in this case-control study were 100 consecutive university students who complained of third molar problems when making an appointment. The third molars were mostly mandibular, partly erupted, and distoangularly oriented. Severity of discomfort and interference with daily activities were graded by the patients on average as 5.0 (SD +/- 2.7) and 3.6 (SD +/- 2.9), on a scale from 0 through 10. Distoangular lower third molars caused the most discomfort and interfered most with activities of patients. The risk of acute disease in patients with distoangularly oriented third molars was 3.6 times that in other patients. Bivariate analysis showed that if the follicle of a distoangular third molar were enlarged, the risk of acquiring acute disease was 44 times that in other patients. It was concluded that early removal of partially erupted and distoangularly oriented lower third molars is recommended, especially when they are associated with an enlarged follicle.
- [Show abstract] [Hide abstract] ABSTRACT: The purpose of this study was to assess how the eruptive status of third molars relates to gingival and dental health and, in particular, to the status of the adjacent second molar. One hundred and twenty-three young adults were followed up over a 6-year period, from age 20 to age 26. The status of the second and third molars, and DMF, DMFS, DS, MS, and FS indices, periodontal condition, and salivary acidogenic bacterial counts were assessed. The 6-year DFS increase in relation to second molars was greatest in sextants with unerupted third molars. The percentage of erupting third molars that became carious or had been filled during the study period was 30%. Most new caries lesions or filled surfaces were on mesial surfaces of second molars and occlusal surfaces of third molars. The periodontal condition was best in mandibular sextants in which the third molar was missing. It is concluded that the most favourable situation for upper second molars is if the neighbouring third molar is missing by age 20.
- [Show abstract] [Hide abstract] ABSTRACT: The beneficial effects of xylitol, a noncariogenic sweetening agent, on oral health have been conclusively demonstrated in international trials, its therapeutic mechanisms have been thoroughly investigated. A four-week trial was conducted to study university students' conceptions of xylitol and their willingness to use xylitol chewing gum to improve their oral health. The trial was carried out in a large student's refectory operated by the State Catering Centre in Turku. During the first test period every student eating in the refectory was given one packet of xylitol gum free and during the second period only on request. Students' use of the gum after meals was monitored, and their opinions were surveyed One thousand two hundred and twenty-one students returned completed questionnaires. Virtually every student was either chewing or about to chew when separately monitored on leaving the refectory. Students' attitudes towards use of xylitol chewing gum in the refectory diet were favourable: 66% recommended it unconditionally and 31% accepted it. The students were aware of the properties and benefit to oral health of xylitol. Thirty-eight per cent of the students studied considered xylitol chewing gum to be of considerable benefit to dental health. Fifty-seven per cent considered it to be moderate benefit to dental health. Most students considered their teeth to be in good condition; only 2% felt they were not. Two thirds of the students stated that they used chewing gum at least once a week Fifteen per cent of students regularly used chewing gum after meals. The results of the trial demonstrated that university students reacted favourably to provision of xylitol chewing gum in connection with refectory meals. There would seem to be potential for the promotion of post prandial use of xylixol chewing gum.
- [Show abstract] [Hide abstract] ABSTRACT: This follow-up study was carried out to survey the utilization of dental services among university students, together with treatment modalities received during their six years of university studies. Initially 20-year-old students were followed during six years, starting from their first year at the University of Helsinki. Results of the questionnaire showed that during the previous 12 months 59% of the students had had a dental appointment, mostly on their own initiative. According to the patient register, 83% of the students, during their studies, had received dental care financially subsidized at the Finnish Student Health Service (FSHS) in Helsinki. During the six years of follow-up, the mean number of appointments was 9.3 per patient (SD 6.8). Female students made dental appointments relatively more often than did male students (p < 0.01). The main treatment modality was restorative care. Patients did not show up for 3.5% of all appointments reserved. One sixth of all visits were made by a group representing 5% of the study group. In conclusion, as the utilization of FSHS dental services was very common, and as restorative dentistry continues to be the main treatment modality among Finnish university students, prophylaxis of caries in systematic dental health care programmes at FSHS is of prime importance and thus has a good possibility to reach each student.
- [Show abstract] [Hide abstract] ABSTRACT: To determine radiographic features by which one could estimate whether lower third molars are likely to erupt after the age of 20 years, university students with a total of 84 unerupted or partially erupted lower third molars were followed up. Five radiographic features of each third molar were measured from the panoramic tomogram taken at age 20 years, and the status of third molars was examined for a second time at age 26 years. The results showed that the lower third molars that did erupt after the age of 20 years were initially: 1) root formation complete; 2) impacted in soft tissue; 3) vertical; 4) placed at the same occlusal level as the neighbouring second molar; 5) showed sufficient space between the ramus and the second molar. In contrast, the teeth that remained impacted at the age of 26 years showed such initial features as: 1) incomplete root formation; 2) embedding in bone; 3) mesioangularity; 4) situated at the cervical level of the neighbouring second molar. It was concluded that a panoramic tomogram taken at age 20 years revealed radiographic features on which an estimation of future eruption of mandibular third molars could be based.
- [Show abstract] [Hide abstract] ABSTRACT: The development of 412 upper and lower third molars was clinically followed up for 6 years in 120 students, starting at the age of 20 years. Clinical and radiographic examinations carried out at baseline and 6 years later showed that during the follow-up period almost half the third molars originally recorded as partially erupted had erupted. When the lower third molars were initially invisible, only 9% of them had erupted by age 26 years whereas 29% remained invisible. When third molars had been already erupted at baseline, only a few were extracted during the 6-year follow-up period. It was concluded that a certain proportion of third molars erupt relatively late, and therefore the need for surgical interventions may decrease with age during early adulthood.
- [Show abstract] [Hide abstract] ABSTRACT: The periodontal status of 217 5th-year students (aged 25-26 years and born in Helsinki) at the University of Helsinki was assessed. The students had been eligible for community-based dental care free of charge until the age of 18 years, after which they could obtain low-cost dental care from the Helsinki Student Health Service. Their periodontal status was determined according the community periodontal index of treatment needs; gingival retraction was recorded when 1 mm or more of the cementum was exposed. Code 0 sextant was found for 67% of the women and 57% of the men. 20% of the students examined had sextant scoring of code 3; no-one had code 4 sextants. 69% of the women and 49% of the men had gingival retraction, in average 1.5 +/- 0.5 mm. No correlation was found between the frequency of toothbrushing or the hand used for brushing and the number of retractions, nor did the number of healthy sextants correlate with the frequency of retractions. The findings emphasize the importance of better guidance regarding qualitative aspects of oral hygiene at home.
University of Helsinki
Helsinki, Province of Southern Finland, Finland
- Department of Oral and Maxillofacial Surgery