Tiny Boumans - Academia.edu (original) (raw)

Papers by Tiny Boumans

Clinical Oral Implants Research, 2012

To design a relevant method to compare the virtual planned implant position to the ultimately ach... more To design a relevant method to compare the virtual planned implant position to the ultimately achieved implant position and to evaluate, in case of discrepancy, the cause for this. Materials and Methods: Five consecutive edentulous patients with retention problems of the upper denture received four implants in the maxilla. Preoperatively, first a cone-beam CT (CBCT) scan was acquired, followed by virtual implant planning. Then, a surgical template was designed and endosseous implants were flapless installed using the template as a guide. To inventory any differences in position, the postoperative CBCT scan was matched to the preoperative scan. The accuracy of implant placement was validated three-dimensionally (3D) and the Implant Position Orthogonal Projection (IPOP) validation method was applied to project the results to a buccolingual and mesio-distal plane. Subsequently, errors introduced by virtual planning, surgical instruments, and validation process were evaluated. Results: The bucco-lingual deviations were less obvious than mesio-distal deviations. A maximum linear tip deviation of 2.84 mm, shoulder deviation of 2.42 mm, and angular deviation of 3.41°w ere calculated in mesio-distal direction. Deviations included errors in planning software (maximum 0.15 mm), for surgical procedure (maximum 2.94°), and validation process (maximum 0.10 mm). Conclusions: This study provides the IPOP validation method as an accurate method to evaluate implant positions and to elucidate inaccuracies in virtual implant planning systems.

The Journal of prosthetic dentistry, Jan 25, 2015

Even though high-precision technologies have been used in computer-guided implant surgery, studie... more Even though high-precision technologies have been used in computer-guided implant surgery, studies have shown that linear and angular deviations between the planned and placed implants can be expected. The purpose of this study was to evaluate the effect of operator experience on the accuracy of implant placement with a computer-guided surgery protocol. Ten surgically experienced and 10 surgically inexperienced operators participated in this study. Each operator placed 1 dental implant (Replace Select) on the partially edentulous mandibular model that had been planned with software by following a computer-guided surgery (NobelGuide) protocol. Three-dimensional information of the planned and placed implants were then superimposed. The horizontal and vertical linear deviations at both the apex and platform levels and the angular deviation were measured and compared between the experienced and inexperienced groups with the independent t test with Bonferroni adjustment (α=.01). The magn...

Trends in Neurosciences, 2009

Manganese-enhanced magnetic resonance imaging (ME-MRI), blood oxygen-level-dependent functional M... more Manganese-enhanced magnetic resonance imaging (ME-MRI), blood oxygen-level-dependent functional MRI (BOLD fMRI) and diffusion tensor imaging (DTI) can now be applied to animal species as small as mice or songbirds. These techniques confirmed previous findings but are also beginning to reveal new phenomena that were difficult or impossible to study previously. These imaging techniques will lead to major technical and conceptual advances in systems neurosciences. We illustrate these new developments with studies of the song control and auditory systems in songbirds, a spatially organized neuronal circuitry that mediates the acquisition, production and perception of complex learned vocalizations. This neural system is an outstanding model for studying vocal learning, brain steroid hormone action, brain plasticity and lateralization of brain function.

Journal of Neuroscience, 2009

PLoS ONE, 2011

Background: Like human speech, birdsong is a learned behavior that supports species and individua... more Background: Like human speech, birdsong is a learned behavior that supports species and individual recognition. Norepinephrine is a catecholamine suspected to play a role in song learning. The goal of this study was to investigate the role of norepinephrine in bird's own song selectivity, a property thought to be important for auditory feedback processes required for song learning and maintenance.

PLoS ONE, 2008

Background: Male songbirds learn their songs from an adult tutor when they are young. A network o... more Background: Male songbirds learn their songs from an adult tutor when they are young. A network of brain nuclei known as the 'song system' is the likely neural substrate for sensorimotor learning and production of song, but the neural networks involved in processing the auditory feedback signals necessary for song learning and maintenance remain unknown. Determining which regions show preferential responsiveness to the bird's own song (BOS) is of great importance because neurons sensitive to self-generated vocalisations could mediate this auditory feedback process. Neurons in the song nuclei and in a secondary auditory area, the caudal medial mesopallium (CMM), show selective responses to the BOS. The aim of the present study is to investigate the emergence of BOS selectivity within the network of primary auditory sub-regions in the avian pallium.

NMR in Biomedicine, 2010

The advent of high-field MRI systems has allowed the implementation of blood oxygen level-depende... more The advent of high-field MRI systems has allowed the implementation of blood oxygen level-dependent functional MRI (BOLD fMRI) on small animals. An increased magnetic field improves the signal-to-noise ratio and thus allows an improvement in the spatial resolution. However, it also increases susceptibility artefacts in the commonly acquired gradient-echo images. This problem is particularly prominent in songbird MRI because of the presence of numerous air cavities in the skull of birds. These T 2 Ã -related image artefacts can be circumvented using spin-echo BOLD fMRI. In this article, we describe the implementation of spin-echo BOLD fMRI in zebra finches, a small songbird of 15-25 g, extensively studied in the behavioural neurosciences of birdsong. Because the main topics in this research domain are song perception and song learning, the protocol implemented used auditory stimuli. Despite the auditory nature of the stimuli and the weak contrast-to-noise ratio of spin-echo BOLD fMRI compared with gradient-echo BOLD fMRI, we succeeded in detecting statistically significant differences in BOLD responses triggered by different stimuli. This study shows that spin-echo BOLD fMRI is a viable approach for the investigation of auditory processing in the whole brain of small songbirds. It can also be applied to study auditory processing in other small animals, as well as other sensory modalities.

NMR in Biomedicine, 2006

Songbirds share with humans the capacity to produce learned vocalizations (song). Recently, two m... more Songbirds share with humans the capacity to produce learned vocalizations (song). Recently, two major regions within the songbird's neural substrate for song learning and production; nucleus robustus arcopallii (RA) and area X (X) are visualized in vivo using Manganese Enhanced MRI (MEMRI). The aim of this study is to extend this to all main interconnected forebrain Song Control Nuclei. The ipsilateral feedback circuits allow Mn 2þ to reach all main Song Control Nuclei after stereotaxic injection of very small doses of MnCl 2 (10 nl of 10 mM) into HVC of one and MAN (nucleus magnocellularis nidopallii anterioris) of the other hemisphere.

NeuroImage, 2005

Auditory fMRI in humans has recently received increasing attention from cognitive neuroscientists... more Auditory fMRI in humans has recently received increasing attention from cognitive neuroscientists as a tool to understand mental processing of learned acoustic sequences and analyzing speech recognition and development of musical skills. The present study introduces this tool in a well-documented animal model for vocal learning, the songbird, and provides fundamental insight in the main technical issues associated with auditory fMRI in these songbirds. Stimulation protocols with various listening tasks lead to appropriate activation of successive relays in the songbirds' auditory pathway. The elicited BOLD response is also region and stimulus specific, and its temporal aspects provide accurate measures of the changes in brain physiology induced by the acoustic stimuli. Extensive repetition of an identical stimulus does not lead to habituation of the response in the primary or secondary telencephalic auditory regions of anesthetized subjects. The BOLD signal intensity changes during a stimulation and subsequent rest period have a very specific time course which shows a remarkable resemblance to auditory evoked BOLD responses commonly observed in human subjects. This observation indicates that auditory fMRI in the songbird may establish a link between auditory related neuro-imaging studies done in humans and the large body of neuro-ethological research on song learning and neuro-plasticity performed in songbirds. D

Journal of Neurophysiology, 2008

European Journal of Neuroscience, 2007

Song perception in songbirds, just as music and speech perception in humans, requires processing ... more Song perception in songbirds, just as music and speech perception in humans, requires processing the spectral and temporal structure found in the succession of song-syllables. Using functional magnetic resonance imaging and synthetic songs that preserved exclusively either the temporal or the spectral structure of natural song, we investigated how vocalizations are processed in the avian forebrain. We found bilateral and equal activation of the primary auditory region, field L. The more ventral regions of field L showed depressed responses to the synthetic songs that lacked spectral structure. These ventral regions included subarea L3, medial-ventral subarea L and potentially the secondary auditory region caudal medial nidopallium. In addition, field L as a whole showed unexpected increased responses to the temporally filtered songs and this increase was the largest in the dorsal regions. These dorsal regions included L1 and the dorsal subareas L and L2b. Therefore, the ventral region of field L appears to be more sensitive to the preservation of both spectral and temporal information in the context of song processing. We did not find any differences in responses to playback of the bird's own song vs other familiar conspecific songs. We also investigated the effect of three commonly used anaesthetics on the blood oxygen level-dependent response: medetomidine, urethane and isoflurane. The extent of the area activated and the stimulus selectivity depended on the type of anaesthetic. We discuss these results in the context of what is known about the locus of action of the anaesthetics, and reports of neural activity measured in electrophysiological experiments.

Clinical Implant Dentistry and Related Research, 2013

Purpose: The purpose of the study is to determine the clinically relevant accuracy of implant pla... more Purpose: The purpose of the study is to determine the clinically relevant accuracy of implant placement in the edentulous maxilla using computer planning and a mucosa-supported surgical template.

Journal of Cerebral Blood Flow & Metabolism, 2005

Clinical Oral Implants Research, 2012

Purpose: To design a relevant method to compare the virtual planned implant position to the ultim... more Purpose: To design a relevant method to compare the virtual planned implant position to the ultimately achieved implant position and to evaluate, in case of discrepancy, the cause for this.

Clinical Oral Implants Research, 2012

To design a relevant method to compare the virtual planned implant position to the ultimately ach... more To design a relevant method to compare the virtual planned implant position to the ultimately achieved implant position and to evaluate, in case of discrepancy, the cause for this. Materials and Methods: Five consecutive edentulous patients with retention problems of the upper denture received four implants in the maxilla. Preoperatively, first a cone-beam CT (CBCT) scan was acquired, followed by virtual implant planning. Then, a surgical template was designed and endosseous implants were flapless installed using the template as a guide. To inventory any differences in position, the postoperative CBCT scan was matched to the preoperative scan. The accuracy of implant placement was validated three-dimensionally (3D) and the Implant Position Orthogonal Projection (IPOP) validation method was applied to project the results to a buccolingual and mesio-distal plane. Subsequently, errors introduced by virtual planning, surgical instruments, and validation process were evaluated. Results: The bucco-lingual deviations were less obvious than mesio-distal deviations. A maximum linear tip deviation of 2.84 mm, shoulder deviation of 2.42 mm, and angular deviation of 3.41°w ere calculated in mesio-distal direction. Deviations included errors in planning software (maximum 0.15 mm), for surgical procedure (maximum 2.94°), and validation process (maximum 0.10 mm). Conclusions: This study provides the IPOP validation method as an accurate method to evaluate implant positions and to elucidate inaccuracies in virtual implant planning systems.

The Journal of prosthetic dentistry, Jan 25, 2015

Even though high-precision technologies have been used in computer-guided implant surgery, studie... more Even though high-precision technologies have been used in computer-guided implant surgery, studies have shown that linear and angular deviations between the planned and placed implants can be expected. The purpose of this study was to evaluate the effect of operator experience on the accuracy of implant placement with a computer-guided surgery protocol. Ten surgically experienced and 10 surgically inexperienced operators participated in this study. Each operator placed 1 dental implant (Replace Select) on the partially edentulous mandibular model that had been planned with software by following a computer-guided surgery (NobelGuide) protocol. Three-dimensional information of the planned and placed implants were then superimposed. The horizontal and vertical linear deviations at both the apex and platform levels and the angular deviation were measured and compared between the experienced and inexperienced groups with the independent t test with Bonferroni adjustment (α=.01). The magn...

Trends in Neurosciences, 2009

Manganese-enhanced magnetic resonance imaging (ME-MRI), blood oxygen-level-dependent functional M... more Manganese-enhanced magnetic resonance imaging (ME-MRI), blood oxygen-level-dependent functional MRI (BOLD fMRI) and diffusion tensor imaging (DTI) can now be applied to animal species as small as mice or songbirds. These techniques confirmed previous findings but are also beginning to reveal new phenomena that were difficult or impossible to study previously. These imaging techniques will lead to major technical and conceptual advances in systems neurosciences. We illustrate these new developments with studies of the song control and auditory systems in songbirds, a spatially organized neuronal circuitry that mediates the acquisition, production and perception of complex learned vocalizations. This neural system is an outstanding model for studying vocal learning, brain steroid hormone action, brain plasticity and lateralization of brain function.

Journal of Neuroscience, 2009

PLoS ONE, 2011

Background: Like human speech, birdsong is a learned behavior that supports species and individua... more Background: Like human speech, birdsong is a learned behavior that supports species and individual recognition. Norepinephrine is a catecholamine suspected to play a role in song learning. The goal of this study was to investigate the role of norepinephrine in bird's own song selectivity, a property thought to be important for auditory feedback processes required for song learning and maintenance.

PLoS ONE, 2008

Background: Male songbirds learn their songs from an adult tutor when they are young. A network o... more Background: Male songbirds learn their songs from an adult tutor when they are young. A network of brain nuclei known as the 'song system' is the likely neural substrate for sensorimotor learning and production of song, but the neural networks involved in processing the auditory feedback signals necessary for song learning and maintenance remain unknown. Determining which regions show preferential responsiveness to the bird's own song (BOS) is of great importance because neurons sensitive to self-generated vocalisations could mediate this auditory feedback process. Neurons in the song nuclei and in a secondary auditory area, the caudal medial mesopallium (CMM), show selective responses to the BOS. The aim of the present study is to investigate the emergence of BOS selectivity within the network of primary auditory sub-regions in the avian pallium.

NMR in Biomedicine, 2010

The advent of high-field MRI systems has allowed the implementation of blood oxygen level-depende... more The advent of high-field MRI systems has allowed the implementation of blood oxygen level-dependent functional MRI (BOLD fMRI) on small animals. An increased magnetic field improves the signal-to-noise ratio and thus allows an improvement in the spatial resolution. However, it also increases susceptibility artefacts in the commonly acquired gradient-echo images. This problem is particularly prominent in songbird MRI because of the presence of numerous air cavities in the skull of birds. These T 2 Ã -related image artefacts can be circumvented using spin-echo BOLD fMRI. In this article, we describe the implementation of spin-echo BOLD fMRI in zebra finches, a small songbird of 15-25 g, extensively studied in the behavioural neurosciences of birdsong. Because the main topics in this research domain are song perception and song learning, the protocol implemented used auditory stimuli. Despite the auditory nature of the stimuli and the weak contrast-to-noise ratio of spin-echo BOLD fMRI compared with gradient-echo BOLD fMRI, we succeeded in detecting statistically significant differences in BOLD responses triggered by different stimuli. This study shows that spin-echo BOLD fMRI is a viable approach for the investigation of auditory processing in the whole brain of small songbirds. It can also be applied to study auditory processing in other small animals, as well as other sensory modalities.

NMR in Biomedicine, 2006

Songbirds share with humans the capacity to produce learned vocalizations (song). Recently, two m... more Songbirds share with humans the capacity to produce learned vocalizations (song). Recently, two major regions within the songbird's neural substrate for song learning and production; nucleus robustus arcopallii (RA) and area X (X) are visualized in vivo using Manganese Enhanced MRI (MEMRI). The aim of this study is to extend this to all main interconnected forebrain Song Control Nuclei. The ipsilateral feedback circuits allow Mn 2þ to reach all main Song Control Nuclei after stereotaxic injection of very small doses of MnCl 2 (10 nl of 10 mM) into HVC of one and MAN (nucleus magnocellularis nidopallii anterioris) of the other hemisphere.

NeuroImage, 2005

Auditory fMRI in humans has recently received increasing attention from cognitive neuroscientists... more Auditory fMRI in humans has recently received increasing attention from cognitive neuroscientists as a tool to understand mental processing of learned acoustic sequences and analyzing speech recognition and development of musical skills. The present study introduces this tool in a well-documented animal model for vocal learning, the songbird, and provides fundamental insight in the main technical issues associated with auditory fMRI in these songbirds. Stimulation protocols with various listening tasks lead to appropriate activation of successive relays in the songbirds' auditory pathway. The elicited BOLD response is also region and stimulus specific, and its temporal aspects provide accurate measures of the changes in brain physiology induced by the acoustic stimuli. Extensive repetition of an identical stimulus does not lead to habituation of the response in the primary or secondary telencephalic auditory regions of anesthetized subjects. The BOLD signal intensity changes during a stimulation and subsequent rest period have a very specific time course which shows a remarkable resemblance to auditory evoked BOLD responses commonly observed in human subjects. This observation indicates that auditory fMRI in the songbird may establish a link between auditory related neuro-imaging studies done in humans and the large body of neuro-ethological research on song learning and neuro-plasticity performed in songbirds. D

Journal of Neurophysiology, 2008

European Journal of Neuroscience, 2007

Song perception in songbirds, just as music and speech perception in humans, requires processing ... more Song perception in songbirds, just as music and speech perception in humans, requires processing the spectral and temporal structure found in the succession of song-syllables. Using functional magnetic resonance imaging and synthetic songs that preserved exclusively either the temporal or the spectral structure of natural song, we investigated how vocalizations are processed in the avian forebrain. We found bilateral and equal activation of the primary auditory region, field L. The more ventral regions of field L showed depressed responses to the synthetic songs that lacked spectral structure. These ventral regions included subarea L3, medial-ventral subarea L and potentially the secondary auditory region caudal medial nidopallium. In addition, field L as a whole showed unexpected increased responses to the temporally filtered songs and this increase was the largest in the dorsal regions. These dorsal regions included L1 and the dorsal subareas L and L2b. Therefore, the ventral region of field L appears to be more sensitive to the preservation of both spectral and temporal information in the context of song processing. We did not find any differences in responses to playback of the bird's own song vs other familiar conspecific songs. We also investigated the effect of three commonly used anaesthetics on the blood oxygen level-dependent response: medetomidine, urethane and isoflurane. The extent of the area activated and the stimulus selectivity depended on the type of anaesthetic. We discuss these results in the context of what is known about the locus of action of the anaesthetics, and reports of neural activity measured in electrophysiological experiments.

Clinical Implant Dentistry and Related Research, 2013

Purpose: The purpose of the study is to determine the clinically relevant accuracy of implant pla... more Purpose: The purpose of the study is to determine the clinically relevant accuracy of implant placement in the edentulous maxilla using computer planning and a mucosa-supported surgical template.

Journal of Cerebral Blood Flow & Metabolism, 2005

Clinical Oral Implants Research, 2012

Purpose: To design a relevant method to compare the virtual planned implant position to the ultim... more Purpose: To design a relevant method to compare the virtual planned implant position to the ultimately achieved implant position and to evaluate, in case of discrepancy, the cause for this.