Distance between mandibular canal and third molar root among 20-year-old subjects

The aim of the study was to evaluate the proximity of the mandibular third molar (M3) and the inferior alveolar canal (IAC) in a panoramic radiograph of 20-year-old subjects. The specific aim was to assess differences in this proximity over time. Two similar samples of panoramic radiographs taken in a routine oral health examination with 20-year time interval were examined retrospectively and images with both mandibular M3s were included. The material consisted of 300 subjects (25% men, mean age 20.5 +/- 0.6 years). The radiographic relationship between the mandibular M3 root and the IAC was assessed as follows: the M3 root was either apart from, tangential to, superimposed with, or inferior to the IAC. Differences between frequencies were tested using the chi-squared test. In the combined samples, only 16% of the M3s located apart from the IAC, 15% located tangential to, 61% superimposed with, and 8% inferior to the IAC. The proportion of the intimate locations had increased during the 20-year time interval from 79 to 88% (P <0.01) and especially in females (P <0.05). The vast majority of the mandibular M3s situated very close to the mandibular canal. Our results suggest that in the cohort of 20-year-old non-extraction subjects, most of the M3s are possibly at risk for inferior alveolar nerve injury at removal, as judged from the panoramic radiograph, and also the number of such teeth has increased over the 20-year period.Peer reviewe

Are women more susceptible than men to iatrogenic inferior alveolar nerve injury in dental implant surgery?

An over-representation of women in dental implant-related inferior alveolar nerve injuries (IANIs) is recognized in the literature but has not been investigated. Therefore, a nationwide retrospective register study was conducted to analyse how IANIs compare with other implant-related complications (infection, implant malposition, lack of bone at implant site, mechanical damage, or failed osseointegration) separately in women and men. Financially compensated malpractice claims related to dental implant surgery were collected from the Finnish Patient Insurance Centre for the years 1997-2013, while the total number of nationally placed implants was ascertained from the implant register held by the Finnish Institute for Health and Welfare. In the 242 complications, the following were analysed: age of subject, absolute risk for complication, and aetiological factor of IANI. Statistical tests applied include Mann-Whitney U-test, Chi-squared test, and Fisher's exact test. Women sustaining IANI were more likely older than those having infection, mechanical damage, or failed osseointegration (P < 0.05), while no significant differences emerged in men. Women were more likely at risk for IANI (P < 0.01) or implant malposition (P < 0.05) than men. The results support earlier propositions that women are more vulnerable than men to iatrogenic IANI.Peer reviewe

What kind of third molars are disease-free in a population aged 30 to 93 years?

ObjectivesThe aim of the study was to characterize third molars that have remained disease-free in a representative sample of the Finnish population aged 30years and older.Materials and methodsTwo-staged stratified cluster sampling (N=8028) was used, and 6005 subjects participated in a clinical oral examination and panoramic radiography. Disease-free third molars were characterized as follows: no dentinal caries, no filling, periodontal pocket depths of neighboring second molars less than 4mm, and no radiographic pathological findings. Logistic regression analyses served for assessment of the strength of characteristics of third molars for disease-free status.ResultsOf the subjects, 2653 (44%) had at least one third molar. Of them, the majority (62%) had only diseased third molars, 16% had only disease-free ones, and 22% had both. Participants had in total 5665 third molars; 29% of them were disease-free. Female gender, higher level of education, and younger age were related to disease-free status (PPeer reviewe

Signs of disease occur in the majority of third molars in an adult population

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Is dental panoramic tomography appropriate for all young adults because of third molars?

Objective:The purpose of this study was to determine, if a dental panoramic tomograph (DPT) is appropriate for every young adult due to third molars. Materials and methods:The study sample consisted of 217 university students (20% men and 80% women; mean age 20.7 years; SD +/- 0.6 years) and included a questionnaire about symptoms caused by third molars, clinical oral examination of third molars, and a DPT. Subjects were divided into the following groups: subjects with a clinical indication for a DPT and subjects without such indication. The DPTs were then examined for findings regarding third molars. Results:Clinical indication for a DPT was observed in 64% of the subjects. Radiography revealed an additional 1.4% of the subjects with >= 1 radiographic signs of disease in relation to their third molars. Also, an additional 27% of the subjects had >= 1 other radiographic findings in relation to third molars that may have affected the clinical decision making. Conclusions:In our study population, clinically undetectable pathology cannot be considered as an indication for a DPT. However, if prevailing clinical practice supports preventive removals and detecting or monitoring of unerupted third molars, a referral to DPT can be considered as good clinical practice.Peer reviewe

Level of difficulty of tooth extractions among roughly 100,000 procedures in primary care

ObjectivesThe study examined treatment codes of extracted teeth and aimed to assess degree of difficulty concerning all tooth extractions.Materials and methodsRetrospective data on treatment codes of all tooth extractions during a two-year period were obtained from the patient register in primary oral healthcare of the City of Helsinki, Finland. Prevalence, indication, and method of extraction appeared in the treatment codes (EBA-codes). Degree of difficulty was determined from the method and classified as non-operative or operative and as routine or demanding. Statistics included frequencies, percentages, and chi(2) test.ResultsTotal number of extraction procedures was 97,276, including 121,342 extracted teeth. The most frequent procedure was a routine extraction of a tooth with forceps (55%, n = 53,642). The main reason for extraction was caries (27%, n = 20,889). Of the extractions, 79% (n = 76,435) were non-operative, 13% (n = 12,819) operative, and 8% (n = 8,022) multiple extractions in one visit. Level of difficulty was distributed as routine non-operative (63%), demanding non-operative (15%), routine operative (12%), demanding operative (2%), and multiple extractions (8%).ConclusionsTwo-thirds of all tooth extractions in primary care were relatively simple. However, 29% of procedures were classified as demanding.Peer reviewe