Walking distance to a metro station

Joukkoliikenteen suunnitteluohjeissa ja muussa joukkoliikennettä käsittelevässä kirjallisuudessa mainitaan usein maksimikävelymatkoja joukkoliikennepysäkeille. Ohjeissa ei kuitenkaan yleensä kerrota, millä perusteella mikäkin matka on määritelty. Tämän tutkimuksen tavoitteena oli selvittää metron liityntämatkojen osalta, kuinka pitkiä matkoja matkustajat ovat todellisuudessa valmiita kävelemään. Yleisesti on tiedossa, että luotettavalle ja tiheästi liikennöivälle joukkoliikennevälineelle – esimerkiksi metrolle – ollaan valmiita kävelemään pidempiä matkoja kuin harvemmin liikennöiville tai vähemmän luotettaville joukkoliikennevälineille. Tutkimus keskittyykin ainoastaan Helsingin metroon, mutta tulokset ovat jossain määrin yleistettävissä esimerkiksi Helsingin seudun lähijunaliikenteeseen ja runkobussilinjoille. Periaatteellisella tasolla tutkimus tuotti arvokasta tietoa myös kävelymatkojen tutkimisesta yleisesti. Tutkimuksessa selvitettiin matkustajien kävelemiä matkoja Helsingin seudun liikkumistutkimusten aineistosta sekä toteutettiin erillinen kyselytutkimus viidellä helsinkiläisellä metroasemalla. Myös aihetta käsittelevään kirjallisuuteen tutustuttiin perusteellisesti. Tutkimusprosessin edetessä kävi ilmi, etteivät toteutuneet kävelymatkat kerro juurikaan matkustajien kävelyvalmiudesta, vaan ne kuvastavat todennäköisesti enimmäkseen metron ympäristön maankäyttöä ja alueen muuta liikennetarjontaa. Eräänä tutkimuskysymyksenä oli selvittää se, mitä tilastollista tunnuslukua tarkastelemalla toteutuneista kävelymatkoista saadaan selvitettyä se, kuinka pitkiä matkoja jokin sopiva osa matkustajista on valmiita kävelemään. Koska toteutuneilla kävelymatkoilla ja matkustajien kävelyvalmiudella ei havaittu olevan suoraa yhteyttä, ei tilastollisen tunnusluvun määrittämistä pidetty lopulta tarkoituksenmukaisena. Helsingin seudun liikkumistutkimuksen aineistossa metron liityntäkävelymatkoissa kuitenkin havaittiin nopea määrän väheneminen noin 600–700 metrin linnuntie-etäisyydellä kaikista metroasemista, ja taitteen oletettiin johtuvan siitä, että kyseisellä etäisyydellä matkustajat joko siirtyvät muiden liityntäliikennemuotojen käyttöön tai korvaavat koko metromatkansa jollakin muulla kulkumuodolla. Tämän tutkimuksen yhteydessä tehdyssä kyselytutkimuksessa metromatkustajia pyydettiin muun muassa arvioimaan oma maksimikävelymatkansa metroasemalle. Vastausten mediaani oli 1000 metriä. Kirjallisuustutkimuksen, asiantuntijahaastatteluiden, teoreettisten laskelmien ja edellä mainitun aineiston pohjalta voidaan arvioida, että keskivertometromatkustaja on valmis kävelemään noin 900–1000 metrin matkan metroasemalle.Transit planning guidelines and other literature often state distances that passengers are willing to walk to a transit stop. However, the grounds of these distances are rarely described. The objective of this thesis was to find out what the acceptable walking distance would be to a metro station. It is widely recognized that passengers accept longer walking distances when they are using rapid transit instead of regional buses, reasons for that being for example shorter headways and better reliability. This research concentrates on the metro in Helsinki, but the results are likely to be useful among other transit modes and in other cities as well. Some of the discoveries can even be useful among the research of walking distances in general. The main research methods in this thesis were the Helsinki region transportation survey from 2008 and 2012 and a tailor-made survey that was conducted on 5 metro stations in Helsinki in spring 2014. A broad literature study was also carried out. During the research process it became clear that studying the distances of the revealed walking trips does not really provide information on how far the passengers are willing to walk, but rather describes the land use and other transportation possibilities around the metro station. One research question was to find out which statistical variable of the revealed walking distances would best represent the acceptable walking distance. As no direct connection between the revealed and the acceptable distances was detected, naming the statistical variable was found insignificant. However, in the Helsinki region transport survey data a dramatic decrease in the amount of walking distances was found on 600–700 meter bee line distance from the station. The phenomenon was reasoned to be a sign of passengers finding another transportation method either to the metro station or for the whole trip. In the tailor-made survey the passengers were asked to evaluate the longest acceptable walking distance to the metro station. The mean answer was 1000 meters. Based on the literature study, interviewing of experts, theoretical calculations and the data described above, it can be estimated that an average passenger is ready to walk 900–1000 meters to a metro station

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

Malpractice claims related to tooth extractions

The aim of this study was to analyze malpractice claims related to tooth extractions in order to identify areas requiring emphasis and eventually to reduce the number of complications. We compiled a file of all malpractice claims related to tooth extractions (EBA code) between 1997 and 2010 from the Finnish Patient Insurance Centre. We then examined the data with respect to date, tooth, surgery, injury diagnosis, and the authority's decision on the case. The material consisted of 852 completed patient cases. Most of the teeth were third molars (66 %), followed by first molars (8 %), and second molars (7 %). The majority of claims were related to operative extraction (71 %) followed by ordinary extraction (17 %) and apicoectomy of a single-rooted tooth (7 %) or multi-rooted tooth (2 %). The most common diagnosis was injury of the lingual or inferior alveolar nerve. According to the authority's decision, the patient received compensation more often in cases involving a third molar than other teeth (56 vs. 46 %, P <0.05). The removal of a mandibular third molar was the basis for the majority of malpractice claims. To reduce the numbers of lingual and inferior alveolar nerve injuries, the removal of mandibular third molars necessitates recent and high-quality panoramic radiograph, preoperative assessment of the difficulty of removal, and consciousness of the variable anatomical course of the lingual nerve.Peer reviewe

Rapid prototyped patient specific guiding implants in critical mandibular reconstruction

Large tumours of the mandible need immediate reconstruction to provide continuity of the mandible, satisfactory function of the jaw, as well as an acceptable aesthetic outcome. In this prospective study we described the immediate reconstruction of the mandible using computer aided design and 15 rapid prototyped patient specific implants (PSI) in 14 patients suffering from benign or malignant tumours demanding continuity resection of the mandible. The scaffold PSI was filled with beta-tricalcium phosphate granules and autologous bone. Microvascular reconstruction was additionally needed in 12/15 cases. The clinical follow up was on average 33 months and the radiological follow up was on average 21 months. In nine cases the healing was uneventful. One patient lost the microvascular flap during the first postoperative week and one patient needed a revision due to perforation of the mucosa at the site of the PSI. Four patients had a major complication due to perforation of the mucosa leading to infection, which resulted in the total or partial removal of the PSI. The PSI seems to be a promising solution for treatment of patients demanding large reconstruction after mandible resection. The benefits are decreased rate of donor site complications and more accurate and prompt surgical procedure. (C) 2016 Published by Elsevier Ltd on behalf of European Association for Cranio-Maxillo-Facial Surgery.Peer reviewe

Rapid prototyping modelling in oral and maxillofacial surgery: a two year retrospective study

Background: The use of rapid prototyping (RP) models in medicine to construct bony models is increasing. Material and Methods: The aim of the study was to evaluate retrospectively the indication for the use of RP models in oral and maxillofacial surgery at Helsinki University Central Hospital during 2009-2010. Also, the used computed tomography (CT) examination – multislice CT (MSCT) or cone beam CT (CBCT) - method was evaluated. Results: In total 114 RP models were fabricated for 102 patients. The mean age of the patients at the time of the production of the model was 50.4 years. The indications for the modelling included malignant lesions (29%), secondary reconstruction (25%), prosthodontic treatment (22%), orthognathic surgery or asymmetry (13%), benign lesions (8%), and TMJ disorders (4%). MSCT examination was used in 92 and CBCT examination in 22 cases. Most of the models (75%) were conventional hard tissue models. Models with colored tumour or other structure(s) of interest were ordered in 24%. Two out of the 114 models were soft tissue models. Conclusions: The main benefit of the models was in treatment planning and in connection with the production of pre-bent plates or custom made implants. The RP models both facilitate and improve treatment planning and intraoperative efficiency

Odontogenic causes complicating the chronic rhinosinusitis diagnosis

Objectives Chronic rhinosinusitis (CRS) frequently stems from a dental origin, although odontogenic sinusitis (OS) remains underdiagnosed amongst different professionals. This study aimed to explore how often odontogenic causes are considered when diagnosing CRS. Materials and methods Patient records from 374 new CRS patients treated at a tertiary-level ear, nose, and throat (ENT) clinic were selected. Entries and radiological reports were assessed exploring how often dentition was mentioned and OS was suspected, how often radiologists reported maxillary teeth, and how commonly typical OS microbial findings and unilateral symptoms occurred. Results Although 10.1% of the CRS diagnoses were connected to possible dental issues, teeth were not mentioned for 73.8% of patients. Radiological reports were available from 267 computed or cone beam computed tomographies, of which 25.1% did not mention the maxillary teeth. The reported maxillary teeth pathology was not considered in 31/64 (48.4%) cases. Unilateral symptoms associated with apical periodontitis (OR = 2.49, 95% CI 1.27-4.89, p = 0.008). Microbial samples were available from 88 patients, for whom Staphylococcus aureus was the most common finding (17% of samples). Conclusions Odontogenic causes are often overlooked when diagnosing CRS. To provide adequate treatment, routine assessment of patient's dental history and status, careful radiograph evaluation, and utilization of microbial findings should be performed. Close cooperation with dentists is mandatory.Peer reviewe

Surgical Management of Mandibular Odontogenic Myxoma Utilizing CAD/CAM Technology: A Case Report

Peer reviewe

Dental health in patients with and without HPV-positive oropharyngeal and tongue cancer

BackgroundHuman papilloma virus is associated with oral and oropharyngeal cancer. Our aim was to examine oral health in patients with oropharyngeal (OPSCC) and oral tongue cancer (OTSCC), expecting better oral health among OPSCC patients.Material and methodsFifty-five OPSCC patients with known HPV status and 59 OTSCC patients were randomly selected from a list of consecutive patients of the Helsinki University Hospital, Finland. Oral health was assessed from panoramic jaw radiographs. Total Dental Index (TDI) summarizing the dental health status was calculated and Finnish population study data were used for comparison. Descriptive statistics were used for analyses.ResultsPatients with HPV-positive OPSCC had higher periapical lesion index compared with HPV-negative OPSCC patients or with OTSCC patients. Residual roots were more common among OPSCC patients compared with OTSCC patients, because of their higher occurrence among HPV-negative OPSCC patients compared with OTSCC patients. Similarly, modified TDI score was significantly higher among OPSCC patients than among OTSCC patients, because of higher TDI score among HPV-negative OPSCC patients compared with OTSCC patients. OPSCC patients more often used a removable prosthesis than OTSCC patients. Dental health of the cancer patients was poorer when compared with the population data.ConclusionsOur study hypothesis was only partly confirmed. Periapical lesions were more prevalent among HPV-positive OPSCC patients, compared with the other groups. The number of residual roots was higher among HPV-negative subgroup. Thus, OPSCC patients had worse oral health parameters than OTSCC patients.Peer reviewe

Dentomaxillofacial imaging with panoramic views and cone beam CT

Panoramic and intraoral radiographs are the basic imaging modalities used in dentistry. Often they are the only imaging techniques required for delineation of dental anatomy or pathology. Panoramic radiography produces a single image of the maxilla, mandible, teeth, temporomandibular joints and maxillary sinuses. During the exposure the x-ray source and detector rotate synchronously around the patient producing a curved surface tomography. It can be supplemented with intraoral radiographs. However, these techniques give only a two-dimensional view of complicated three-dimensional (3D) structures. As in the other fields of imaging also dentomaxillofacial imaging has moved towards 3D imaging. Since the late 1990s cone beam computed tomography (CBCT) devices have been designed specifically for dentomaxillofacial imaging, allowing accurate 3D imaging of hard tissues with a lower radiation dose, lower cost and easier availability for dentists when compared with multislice CT. Panoramic and intraoral radiographies are still the basic imaging methods in dentistry. CBCT should be used in more demanding cases. In this review the anatomy with the panoramic view will be presented as well as the benefits of the CBCT technique in comparison to the panoramic technique with some examples. Also the basics as well as common errors and pitfalls of these techniques will be discussed. Teaching Points • Panoramic and intraoral radiographs are the basic imaging methods in dentomaxillofacial radiology.• CBCT imaging allows accurate 3D imaging of hard tissues.• CBCT offers lower costs and a smaller size and radiation dose compared with MSCT.• The disadvantages of CBCT imaging are poor soft tissue contrast and artefacts.• The Sedentexct project has developed evidence-based guidelines on the use of CBCT in dentistry.Peer reviewe

Sähköisen viestinnän salaus- ja suojausmenetelmät

Osana digitaalisen liiketoiminnan kasvuympäristön rakentamista koskevaa hallituksen kärkihanketta parannetaan kansalaisten luottamusta digitaalisiin palveluihin. Tämän kärkihankeen yhtenä keskeisenä toimenpiteenä on laadittu kansallinen tietoturvastrategia, jolla pyritään lisäämään kaupallisten tiedon salaus- ja suojausmenetelmien tarjontaa ja käyttöä sisämarkkinoilla. Salaus- ja suojausmenetelmien merkitys on kasvanut digitalisaatiokehityksen myötä. Salausmenetelmien käytöllä voidaan kasvattaa kuluttajien luottamusta digitaalisiin palveluihin. Markkinoilla saatavilla olevien salausteknologioita hyödyntävien tieto- ja viestintäpalveluiden määrä jatkuvasti kasvanut. Tässä raportissa esitetään katsaus sähköisen viestinnän salaus- ja suojausmenetelmistä, niihin liittyvistä mahdollisuuksista sekä riskeistä. Selvityksessä kuvataan myös salaus- ja suojausteknologioiden kehittymisen tulevaisuuden näkymiä. Raportin keskeisimmät johtopäätökset ovat, että salausteknologioilla on suuri merkitys sähköisen viestinnän suojaamiseksi. Viestinnän suojaamiseksi on suositeltavaa käyttää päästä päähän salattuja ja tiedon eheyden varmentavia viestintämenetelmiä. Takaporttien eli tahallisesti heikennettyjen salausmenetelmien vaatimista voidaan pitää ykistyiselämän suojalle sekä tietoturvallisuudelle haitallisen