Changes in cranial base and craniocervical junction during growth in healthy individuals and in patients with Osteogenesis imperfecta

Cranial base and craniocervical junction anatomy can be evaluated from CT and MR scans, and lateral skull radiographs. Cranial base anatomy changes during growth, as the form of the anatomic structures and their relative positions alter. In disorders of compromised bone quality, abnormal changes in the craniocervical junction can lead to pathological conditions with possibly life-threatening neurological complications. In this investigation these issues have first been addressed by making skull base measurements of healthy growing individuals to determine the age-specific normative values used to evaluate cranial base structures. These normative values were then employed in the following analysis of growing patients suffering from osteogenesis imperfecta (OI), a disorder of bone fragility due to abnormal collagen composition. In healthy individuals cranial base measurements, young children demonstrated significantly different results from those of older growing individuals and adults. Thus studies on patients younger than 9 years should include age-appropriate controls. Significant individual variation in skull base measurements during growth may appear, as revealed by longitudinal observation. The observed wide ranges, and the fact that the position of the odontoid process in relation to skull base structures may individually display alternating up- and downward movements, are important to consider when conducting follow-up examinations. Nevertheless, a notable deviation from the documented normal values is suggestive of pathological development in the craniocervical junction. When comparing the age-specific normal values, skull base abnormalities were found to be present in approximately one fifth of OI patients; platybasia was the most frequent finding. Patients with haploinsufficiency mutations (which lead to a relatively mild phenotype) were less likely to have skull base abnormalities than patients with helical glycine substitutions. However, the strongest predictor of skull base abnormality was not the type of collagen mutation underlying OI but the clinical severity of the disorder, as expressed by the height Z-score. No evidence was found for a protective effect of bisphosphonate treatment, nor for the progression of craniocervical junction pathology with age. Based on this normative data and the observations made in patients with OI, age-appropriate screening limits for skull base pathology are proposed here, in addition to a recommendation for timing of radiological screening in patients with OI.Kallonpohjan ja kaularangan välisen liitoksen anatomiaa voidaan tarkastella magneetti- ja tietokonetomografiakuvista, sekä kallosta sivusuunnassa otetuista röntgenkuvista. Kallonpohjan ja kaularangan rakenteiden muoto, ja niiden väliset suhteet muuttuvat kasvun myötä. Sellaisissa tautitiloissa, joissa esiintyy luukudoksen poikkeavuutta, kallonpohjan ja kaularangan suhde voi muuttua siten, että syntyy henkeä uhkaava ydinjatkoksen puristustila. Tutkimuksessa tarkasteltiin ensin terveiden lasten kallon ja kaularangan välisen liitoksen mittasuhteita kasvun aikana. Näin muodostettiin viitearvot, joihin luuston haurautta aiheuttavaa osteogenesis imperfectaa (OI) sairastavien lasten vastaavia arvoja voitiin verrata. Terveiden lasten kohdalla havaittiin, että kallonpohjan ja kaularangan välisten mittasuhteiden kasvun aikaiset muutokset vaihtelivat huomattavasti eri yksilöillä ja että alle kouluikäisten mitta-arvot poikkesivat merkitsevästi vanhempien lasten ja aikuisten vastaavista arvoista. Tulosten perusteella suositellaankin, että alle 9-vuotiaiden lapsipotilaiden kallokuvia tulkittaessa tulisi käyttää iänmukaisia viitearvoja. Huomattava poikkeama viitearvoista on aihe potilaan jatkotutkimuksille mahdollisen patologisen tilan kehittymisen arvioimiseksi. Työssä havaittiin jokin kallonpohjan anomalia noin viidesosalla kasvuikäisistä OI-potilaista. Platybasia (eli kallonpohjan litistyminen) oli yleisin anomalia. Niillä potilailla, joilla OI:ta aiheuttava kollageenivirhe aiheutuu toisen alleelin toimimattomuudesta ja ilmiasuna on lievä oireyhtymämuoto, oli pienempi riski kallonpohjan anomalioihin kuin niillä potilailla, joilla oireyhtymä aiheutuu glysiinin korvautumisesta toisella aminohapolla johtaen vaikeaan oireyhtymän ilmiasuun. Potilaan suhteellinen pituus oireyhtymän vaikeusasteen ilmentäjänä oli merkittävin kallonpohjan anomalian kehittymistä ennustava tekijä. Bisfosfonaattilääkityksen ei havaittu estävän anomalioiden syntyä. Lääkitsemättömillä potilailla todettujen kallonpohjan anomalioiden ei havaittu vaikeutuvan iän myötä. Tutkimuksen pohjalta laadittiin kliiniseen käyttöön lasten viitearvojen lisäksi ehdotus toimintamalliksi OI:aa sairastavien lasten kallonpohjan radiologisten seulontatutkimusten ajoituksesta

Craniofacial and Craniocervical Features in Cartilage-Hair Hypoplasia : A Radiological Study of 17 Patients and 34 Controls

BackgroundBiallelic mutations in the non-coding RNA gene RMRP cause Cartilage-hair hypoplasia (CHH), a rare skeletal dysplasia in which the main phenotypic characteristic is severe progressive growth retardation. ObjectiveThis study compared the cranial dimensions of individuals with CHH to healthy subjects. MethodsLateral skull radiographs of 17 patients with CHH (age range 10 to 59 years) and 34 healthy individuals (age range 10 to 54 years) were analyzed for relative position of the jaws to skull base, craniofacial height and depth, as well as vertical growth pattern of the lower jaw, anterior cranial base angle, and the relationship between the cervical spine and skull base. ResultsWe found that the length of the upper and lower jaws, and clivus were significantly decreased in patients with CHH as compared to the controls. Anterior cranial base angle was large in patients with CHH. Basilar invagination was not found. ConclusionThis study found no severe craniofacial involvement of patients with CHH, except for the short jaws. Unexpectedly, mandibular deficiency did not lead to skeletal class II malocclusion. Clinical ImpactAlthough the jaws were shorter in patients with CHH, they were proportional to each other. A short posterior cranial base was not associated with craniocervical junction pathology.Peer reviewe

Examination performance of dentistry students during the COVID-19 pandemic

Publisher Copyright: © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Acta Odontologica Scandinavica Society.Objective: The global COVID-19 pandemic has led to an increase in remote teaching and online assessment in higher education. The examination performance of undergraduate students of dentistry was evaluated to assess any possible association between the altered learning environment and learners’ performance. Materials and methods: Using administrative data from the University of Helsinki, the examination performance during the years 2018 and 2019 was compared with that of 2020. Results: In 16 out of 22 courses (73%) taught remotely during the pandemic, a statistically significant difference (p <.05) between the awarded grades was observed, as compared to the two previous years. Annual variation in examination grades was common even before the onset of remote teaching, but more so after it. The grade variation during the pandemic was nearly as prevalent towards falling grades (26%) as towards rising grades (36%), implying a multifactorial cause possibly unrelated to remote teaching. Conclusions: Our results imply that online teaching did not systematically improve or worsen the examination performance of undergraduate students of dentistry. Our findings have important policy implications for educational practices in the future. The observed annual grade variation might reflect the effectiveness of remote teaching, changes in students’ performance, or non-systematic grading.Peer reviewe

Longitudinal analysis of the quality of orthodontic treatment outcome and stability of occlusal traits

Objectives To assess the quality and stability of orthodontic treatment outcome relative to the initial malocclusion. Material and methods The study was performed in one public health care clinic in Finland. Study subjects comprised 51 orthodontic patients (age range 12.7-18.7 years). Pre-treatment medical records and lateral skull radiographs were analysed for malocclusion type. The main reasons for orthodontic treatment were mandibular retrognathia, Class II distal bite, deep bite and crowding. At the end of a retention phase (Examination 1), the quality of treatment outcome was assessed using the occlusal morphology and function index (OMFI) and patients were asked about treatment satisfaction. Stability of occlusal traits and patient satisfaction were re-evaluated after a two-year follow-up (Examination 2). Occlusal characteristics descriptive statistics were performed. Results At Examination 1, all six morphological criteria for acceptability were fulfilled by 76% and all functional criteria by 82% of the patients. All OMFI criteria were met by 67% of the patients. At Examination 2, 68% of the patients fulfilled all morphological and 82% all functional criteria of acceptability. At Examination 2, all the OMFI criteria were still met by 64% of the patients and 92% expressed satisfaction with own occlusion. The main reasons for unacceptability were deficiencies in canine relationship and overbite, in addition to functional protrusion interferences. Conclusions In the evaluated health care clinic, patient satisfaction and the quality of treatment outcome were high. However, deep bite showed a tendency for relapse.Peer reviewe

Fatigue and disturbances of sleep in patients with osteogenesis imperfecta - a cross-sectional questionnaire study

Background: Persisting fatigue has been reported to be a common complaint by individuals with connective tissue disorders, including Osteogenesis imperfecta (OI). This controlled study evaluated in an adult OI population the subjective experience of fatigue, affecting daily life. Sleep disturbances and chronic pain were examined as hypothesized underlying factors. Methods: This cross-sectional study analyzed the answers of 56 OI patients and 56 matched healthy controls to a questionnaire, designed to evaluate levels of experienced fatigue and bodily pain, as well as the presence or absence of symptoms related to sleep disturbances or sleep apnea. The relationships between fatigue, pain, and sleep disturbances were evaluated with correlation analysis and regression analysis. Results: Fatigue was reported by 96%, and daily pain by 87% of the individuals with OI. Notably, the level of fatigue was similarly experienced by patient respondents and controls. In total, 95% of the patients and 77% of the controls reported one to several sleep disturbance symptoms. These symptoms as well as previously diagnosed sleep apnea were statistically significantly more prevalent in the patient group than in the controls (p <0.05). Likewise, the experienced bodily pain was statistically highly significantly more severe among the respondents with OI (p <0.001), and correlated with the reported fatigue. Conclusions: In comparison with age-matched controls, adults with OI do not differ in experienced fatigue, unlike hypothesized. Therefore, sleep disturbances, which based on the frequency of reported related symptoms and previous sleep apnea diagnoses appear to be common in OI patients, may remain undiagnosed.Peer reviewe

Association between joint hypermobility, scoliosis, and cranial base anomalies in paediatric Osteogenesis imperfecta patients : a retrospective cross-sectional study

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Is sleep apnea underdiagnosed in adult patients with osteogenesis imperfecta? -a single-center cross-sectional study

BackgroundPatients with Osteogenesis imperfecta (OI) suffer from increased bone fracture tendency generally caused by a mutation in genes coding for type I collagen. OI is also characterized by numerous co-morbidities, and recent data from questionnaire studies suggest that these may include increased risk for sleep apnea, a finding that lacks clinical evidence from cohort studies. In this cross-sectional study, 25 adults with OI underwent clinical otorhinolaryngology examination as well as overnight polysomnography to address the question. The participants were aged between 19 and 77years, and ten of them had mild clinical OI phenotype, seven had a moderately severe phenotype, and eight had a severe phenotype.ResultsWe found obstructive sleep apnea (apnea hypopnea index 5/h) in as many as 52% of the OI patients in the cohort. Unexpectedly, however, no correlation was present between sleep apnea and daytime sleepiness, experienced bodily pain, severity of OI, Mallampati score, or neck circumference.ConclusionsSeeing that the usual predictors showed no association with occurrence of sleep apnea, we conclude that obstructive sleep apnea may easily be left as an undetected disorder in individuals with OI. Recurrent nocturnal hypoxia due to episodes of apneas can even affect bone metabolism, thereby further aggravating bone fragility in patients with OI.Peer reviewe

Timing of dental development in osteogenesis imperfecta patients with and without bisphosphonate treatment

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Positive airway pressure therapy for obstructive sleep apnea in patients with Osteogenesis imperfecta: a prospective pilot study

BackgroundObstructive sleep apnea (OSA) is prevalent in individuals with Osteogenesis imperfecta (OI). To date, no study has investigated treatment of OSA in adult individuals with OI using positive airway pressure (PAP). This observational pilot study examined the adherence of adults with OI to treatment of OSA with PAP therapy, and the evolution of self-experienced sleepiness and depression symptoms before and after treatment.MethodsWe included 20 patients, with a mean age of 51 years, who represented varying severity of OI and displayed an apnea and hypopnea index ≥ 5 /sleeping hour as recorded by an overnight polysomnography. PAP therapy was proposed to all patients. Epworth Sleepiness Scale (ESS) questionnaire to evaluate daytime sleepiness, and a validated self-rating depression questionnaire to identify possible depression, were completed prior to PAP therapy and repeated after a minimum of one year. The datasets supporting the conclusions of this article are included within the article.ResultsFrom the 20 patients, 15 initiated PAP therapy, and two patients later interrupted it. The mean PAP follow-up period was 1230 days. At baseline, an abnormally high ESS score was reported by 29% of the respondents, and an abnormally high number of symptoms suggesting depression by 29%. Follow-up questionnaires were completed by 60% of the patients, of whom 83% were adherent to PAP treatment. ESS score and depression symptoms did not decrease significantly with PAP therapy.ConclusionsPatients with OI accepted well PAP therapy and remained compliant. Sleepiness and depression persisted unaltered despite good PAP adherence. These unexpectedly poor improvements in symptoms by PAP therapy may be due to subjective depression symptoms and the complexity of factors underlying persisting sleepiness in OI. Further research is needed to confirm this novel finding.</p