Eruption pattern of the maxillary canines: features indicating treatment needs as seen in PTG at the late mixed stage-Part II.

AIM: To describe features of maxillary permanent canines in the late mixed stage as seen in panoramic radiograph (PTG) that later needed treatment to erupt into the oral cavity and to compare them with naturally erupted canines. METHODS: The cross-sectional part of this retrospective register-based study consisted of 1454 PTGs of children (mean age 9.3 years) living in Eastern Finland, while the longitudinal part involved patient data on 184 treated maxillary canines. The variables examined were treatment needs, overlapping and inclination of the maxillary canines, the development stage of the canines and lateral incisors and dental age. RESULTS: Only 11.6% of the maxillary canines needed treatment, including interceptive procedures. The treated canines significantly more often had overlapping (p < 0.001), larger inclination (p = 0.001) and incomplete lateral incisors (p = 0.002) than did the naturally erupted canines. The children treated significantly more often had a delayed dental age (p = 0.035). Clear overlapping was closely associated with all treatment modalities, whereas some overlapping and a large inclination angle (≥ 25°) were associated especially in cases of late treatment. An incomplete lateral incisor and delayed dental age were associated with treatment. CONCLUSION: An association with treatment needs was found especially in the case of overlapping and a large inclination angle of the maxillary canine a couple of years before eruption into the oral cavity. These features can be early signs and indications for instant or later treatment of a maxillary canine and underline the importance of monitoring space conditions and erupting canines.

Eruption pattern of the maxillary canines: features of natural eruption seen in PTG at the late mixed stage-Part I.

AIM: To describe the variation of eruption pattern of maxillary canines in the late mixed stage of dentition seen in PTG when eruption was later natural. METHODS: Material for this longitudinal and retrospective register-based study consisted of 1454 PTGs of children living in Eastern Finland (mean age 9.3 years, SD 0.6). Natural eruption of a canine consisted of 744 PTGs (336 girls and 408 boys) including 1488 maxillary canines. The variables examined were treatment/natural eruption, overlapping, inclination, dental age, developmental stage of the canine and lateral incisor. RESULTS: Only 2.0% of maxillary canines had clear overlapping and 56.2% no overlapping was detected at the age of 8.5-10.5 years. Large inclination angle (≥ 25°) was found for 5.5% of examined canines. Overlapping of canine with lateral incisor root decreased as the development of canine root exceeded 1/3. Larger inclinations occurred at earlier stages but decreased significantly as the root developed from 1/3 to 1/2. Mean inclination was significantly larger at children with normal dental age and/or incomplete lateral incisors when overlapping occurred. Regardless overlapping mean inclination was larger if dental age was delayed and/or lateral incisors incomplete. CONCLUSION: Some overlapping and larger inclination in maxillary canine are features of normal eruption pattern at an earlier stage of canine development and while lateral incisor is incomplete in PTG (8.5-10.5 years). In addition to the overlapping and inclination, stages of canine and lateral incisor root as well as dental age should be observed radiologically when evaluating erupting maxillary canine in children of this age.

Reliability and Validity of The Finnish Version of The Boston Carpal Tunnel Questionnaire among Surgically Treated Carpal Tunnel Syndrome Patients.

BACKGROUND AND AIMS: The Boston Carpal Tunnel Questionnaire is the most commonly used outcome measure in the assessment of carpal tunnel syndrome. The purpose of this study was to translate the original Boston Carpal Tunnel Questionnaire into Finnish and validate its psychometric properties. MATERIALS AND METHODS: We translated and culturally adapted the Boston Carpal Tunnel Questionnaire into Finnish. Subsequently, 193 patients completed the Finnish version of the Boston Carpal Tunnel Questionnaire, 6-Item CTS Symptoms Scale, and EuroQol 5 Dimensions 12 months after carpal tunnel release. The Boston Carpal Tunnel Questionnaire was re-administered after a 2-week interval. We calculated construct validity, internal consistency, test-retest reliability, and coefficient of repeatability. We also examined floor and ceiling effects. RESULTS: The cross-cultural adaptation required only minor modifications to the questions. Both subscales of the Boston Carpal Tunnel Questionnaire (Symptom Severity Scale and Functional Status Scale) correlated significantly with the CTS-6 and EuroQol 5 Dimensions, indicating good construct validity. The Cronbach's alpha was 0.93 for both the Symptom Severity Scale and Functional Status Scale, indicating high internal consistency. Test-retest reliability was excellent, with an intraclass correlation coefficient greater than 0.8 for both scales. The coefficient of repeatability was 0.80 for the Symptom Severity Scale and 0.68 for the Functional Status Scale. We observed a floor effect in the Functional Status Scale in 28% of participants. CONCLUSION: Our study shows that the present Finnish version of the Boston Carpal Tunnel Questionnaire is reliable and valid for the evaluation of symptom severity and functional status among surgically treated carpal tunnel syndrome patients. However, owing to the floor effect, the Functional Status Score may have limited ability to detect differences in patients with good post-operative outcomes.

Flap Related Complications Requiring Secondary Surgery in a Series of 851 Local Flaps Used for Fingertip Reconstruction.

BACKGROUND: Local flaps are widely used to cover fingertip defects. Errors in design or technical execution of the flap may lead to morbidity and additional surgical procedure. The purpose of this study was to review flap related complications requiring unplanned secondary surgery to characterize preventable issues. METHODS: 851 local flaps were used to reconstruct fingertip defects during a 9-year period. Patients requiring unplanned secondary surgery to address flap related complications were subjected to analysis. RESULTS: 31 of 851 flaps (3.6%) required unplanned secondary surgery because of flap related complications. The most reliable flap was VY advancement flap with only one (0.3%) re-operation. The reverse vascular island flap, cross finger flap, and neurovascular island flap were associated with the comparable number of complications (8.0%; 6.3%; and 3.8% respectively). Total or partial necrosis was the cause for re-operation in 6 patients (0.7%). The typical reason for secondary surgery was inadequate soft tissue cover of the tip with homodigital neurovascular island flap and flexion contracture with reverse vascular island flap. Cross finger flaps were revised because of poor graft take at the donor site, bulky flap or flap necrosis. CONCLUSIONS: Local flaps are reliable operations to cover fingertip defects. Each flap has potential pitfalls, which may be avoided if the surgeon is aware of them.

Epidemiology of Flexor Tendon Injuries of the Hand in a Northern Finnish Population.

BACKGROUND: Flexor tendon injuries cause significant morbidity in working-age population. The epidemiology of these injuries in adult population is not well known. The aim of this study was to describe the epidemiology of flexor tendon injuries in a Northern Finnish population. MATERIAL AND METHODS: Data on flexor tendon injuries, from 2004 to 2010, were retrieved from patient records from four hospitals, which offer surgical repair of the flexor tendon injuries in a well-defined area in Northern Finland. The incidence of flexor tendon injury as well as the gender-specific incidence rates was calculated. Mechanism of injury, concomitant nerve injuries, and re-operations were also recorded. RESULTS: The incidence rate of flexor tendon injury was 7.0/100,000 person-years. The incidence was higher in men and inversely related to age. The most common finger to be affected was the fifth digit. In 37% of injuries also digital nerve was affected. The most common finger to have simultaneous digital nerve injury was the thumb. CONCLUSION: Flexor tendon laceration is a relatively rare injury. It predominantly affects working-aged young males and frequently includes a nerve injury, which requires microsurgical skills from the surgeon performing the repair. This study describes epidemiology of flexor tendon injuries and therefore helps planning the surgical and rehabilitation services needed to address this entity.

A comparison of the reliability of make versus break testing in measuring palmar abduction strength of the thumb.

Previous studies have established the role of quantitative measurements of palmar abduction strength of the thumb (PAST). This study compares the reliability of the 'make' versus the 'break' test in measuring PAST in healthy volunteers. In a 'make' test, the body part being tested is positioned at the start of its range of motion and the participant is asked to exert his/her maximal force. In a 'break' test, increasing force is applied to a body part after it has completed its range of motion, until the joint being tested gives way. PAST was measured in both hands in 100 healthy volunteers using a handheld device. Two examiners measured PAST using both the 'make' and 'break' test to determine inter-rater reliability. The tests were repeated in 30 volunteers 6 weeks after the initial testing to determine intra-rater reliability. Our results showed that the 'make' test has better inter and intra-rater reliability.

An analysis of the pull-out strength of 6 suture loop configurations in flexor tendons.

PURPOSE: New, stronger suture materials have been introduced for flexor tendon surgery. The advantage of these materials can be lost if the suture loop pulls out from the tendon. The aim of this study was to compare the ability of various locking loops to grip the tendon. METHODS: We inserted 4 different standard and 2 experimental locking loops with 200-µm nitinol wire into human cadaveric flexor digitorum profundus tendons. The standard loops were: group 1, cruciate; group 2, Pennington modified Kessler; group 3, cross-stitch; and group 4, Lim-Tsai. The experimental loops were: group 5, a composition of Pennington modified Kessler with a cross-stitch loop; and group 6, a locking Kessler type of loop with a superficial transverse component. We loaded the loops until failure. We recorded the pull-out strength and stiffness and documented failure mechanisms during the pull-out test. RESULTS: The cruciate loop had the weakest holding capacity, 20 N, which was significantly less than in groups 2 to 6. The cross-stitch loop, Lim-Tsai loop, and modified Kessler loop performed similarly (36 N, 37 N, and 39 N, respectively). The experimental loops had the highest pull-out strength (group 5, 59 N; and group 6, 60 N, both significantly greater than groups 1 to 4). The mode of failure was pull-out for all of the standard loops and 7 of the experimental loops. Of 20 experimental loops, 13 failed by suture rupture. CONCLUSIONS: The 2 experimental loop configurations demonstrated higher pull-out strength and may have advantages when used with newer and stronger suture materials. The number of the locking components in the loops and the way the tension is transmitted to the tendon fibrils explain the results. CLINICAL RELEVANCE: The loops presented in this study and that grip the tendon better may be useful with new materials that have high tensile strength.

Comparison of the holding capacity of round monofilament, round multifilament, and flat multifilament nitinol suture loops in human cadaveric flexor tendon.

Tendon repairs done with strong suture materials fail by suture pull out. To avoid pull out, suture loop needs to have a strong grip on the tendon. The aim of this study was to determine whether a single suture loop has a better grip of the tendon when multifilament or flat sutures are used compared with a conventional monofilament round suture. A cross-locking or simple grasping suture loop was placed into the distal end of a human cadaveric tendon using nitinol wire sutures in the following configurations: round monofilament (200 µm), round multifilament (4 × 100 µm), and flat multifilament (4 × 30 µm × 445 µm). The mean pull-out strength of the round multifilament (49.4 N) and flat multifilament sutures (50.7 N) were significantly higher than that of the round monofilament nitinol suture (36.5 N) when a locking loop was used. Suture grip can be improved by using a multifilament suture and a locking type of suture configuration.

The effect of blocking radial abduction on palmar abduction strength of the thumb.

The measurement of palmar abduction strength of the thumb (PAST) is often used as a research tool to provide an objective assessment of thenar muscle function in patients with carpal tunnel syndrome (CTS). The purpose of this study is to determine the effect of blocking radial abduction on PAST in a normal population. PAST was measured for both hands of 100 healthy volunteers in two positions. In the first position a vertical board was placed perpendicular to the radial border of the hand to block radial abduction, and in the second position PAST was measured without the board. Men had greater PAST. There was no difference in PAST between the dominant and non-dominant hand for both men and women, when a vertical board was used. Without the board, the values were significantly greater in the dominant hand. Radial abduction should be blocked during measurement of PAST.

Nickel-titanium wire in circumferential suture of a flexor tendon repair: a comparison to polypropylene.

PURPOSE: Nickel-titanium (NiTi) has been proposed as an alternative material for flexor tendon core suture. To our knowledge, its suitability as a circumferential suture of flexor tendon repair has not been investigated before. The purpose of this ex vivo study was to investigate the biomechanical properties of NiTi circumferential repairs and to compare them with commonly used polypropylene. METHODS: Forty porcine flexor tendons were cut and repaired by simple running or interlocking mattress technique using 100 microm NiTi wire or 6-0 polypropylene. RESULTS: The NiTi circumferential repairs showed superior stiffness, gap resistance, and load to failure when compared to polypropylene repairs with both techniques. CONCLUSIONS: Nickel-titanium wire seems to be a potential material for circumferential repair of flexor tendons.

Nickel-titanium wire as a flexor tendon suture material: an ex vivo study.

Nickel-titanium shape memory alloy (NiTi) is a new suture material that is easy to handle, is strong, and biocompatible. The purpose of this study was to evaluate the material properties and biomechanical behaviour of 150 microm and 200 microm NiTi wires in flexor tendon repair. Braided polyester (4-0 Ethibond) was used as control. Fifty fresh-frozen porcine flexor tendons were repaired using the Pennington modification of the Kessler repair or a double Kessler technique. NiTi wires were stiffer and reached higher tensile strength compared to braided polyester suture. Repairs with 200 microm NiTi wire had a higher yield force, ultimate force and better resistance to gapping than 4-0 braided polyester repairs. Repairs made with 200 microm NiTi wire achieved higher stiffness and ultimate force than repairs made with 150 microm NiTi wire.

Oscillatory cortical drive to isometrically contracting muscle in Unverricht-Lundborg type progressive myoclonus epilepsy (ULD).

OBJECTIVE: We investigated with whole-scalp magnetoencephalography (MEG) oscillatory cortical drive to isometrically contracting muscle in 8 genetically verified, and thus etiologically homogeneous, Unverricht-Lundborg type progressive myoclonus epilepsy (ULD) patients suffering from cortical myoclonus and generalized tonic-clonic seizures. The results were compared with those of 8 healthy control subjects. METHODS: Cortical MEG signals were measured simultaneously with surface electromyography (EMG) during isometric contraction of the left and right first dorsal interosseus muscles. Cortex-muscle coherence and cross-correlograms between MEG and EMG signals were calculated as indicators of oscillatory cortical drive to muscle. The cortical areas involved in the maximum cortex-muscle coherence were also identified. RESULTS: In patients, the strengths of the dominant coherent peaks were 2-4 fold compared with the healthy controls. Whereas the coherence was found strictly in the contralateral primary motor cortex in controls, additional coherent activity was observed ipsilaterally in 5 out of 8 patients. CONCLUSIONS: The remarkably increased MEG-EMG coherence in ULD patients suggests altered oscillatory cortical drive to the muscle during isometric contraction. We suggest that the enhanced cortex-muscle coherence in ULD patients reflects reduced inhibition in the motor cortex, and may contribute to disturbed voluntary movements.

Role of FliC and FliD flagellar proteins of Clostridium difficile in adherence and gut colonization.

In vitro and in vivo adhesive properties of flagella and recombinant flagellin FliC and flagellar cap FliD proteins of Clostridium difficile were analyzed. FliC, FliD, and crude flagella adhered in vitro to axenic mouse cecal mucus. Radiolabeled cultured cells bound to a high degree to FliD and weakly to flagella deposited on a membrane. The tissue association in the mouse cecum of a nonflagellated strain was 10-fold lower than that of a flagellated strain belonging to the same serogroup, confirming the role of flagella in adherence.

Analysis of expression of GroEL (Hsp60) of Clostridium difficile in response to stress.

Our laboratory has previously shown that adherence of Clostridium difficile to tissue culture cells is augmented by various stresses and that GroEL, a heat shock protein, serves an adhesive function in this bacterium. In this communication, RT-PCR, SDS-PAGE and immunoblotting were used to study the stress response in C. difficile following heat, acid or osmotic shock, iron deprivation or presence of a subinhibitory concentration of ampicillin in the culture medium. All these stresses increased transcription of groEL and production of GroEL to various degrees. Furthermore, the protein was found in membrane fractions and in the extracellular space after heat stress.

Molecular and genomic analysis of genes encoding surface-anchored proteins from Clostridium difficile.

The gene slpA, encoding the S-layer precursor protein in the virulent Clostridium difficile strains C253 and 79--685, was identified. The precursor protein carries a C-terminal highly conserved anchoring domain, similar to the one found in the Cwp66 adhesin (previously characterized in strain 79--685), an SLH domain, and a variable N-terminal domain mediating cell adherence. The genes encoding the S-layer precursor proteins and the Cwp66 adhesin are present in a genetic locus carrying 17 open reading frames, 11 of which encode a similar two-domain architecture, likely to include surface-anchored proteins.

Characterization of a cell surface protein of Clostridium difficile with adhesive properties.

Our laboratory has previously shown that Clostridium difficile adherence to cultured cells is enhanced after heat shock at 60 degrees C and that it is mediated by a proteinaceous surface component. The present study was undertaken to identify the surface molecules of this bacterium that could play a role in its adherence to the intestine. The cwp66 gene, encoding a cell surface-associated protein of C. difficile 79-685, was isolated by immunoscreening of a C. difficile gene library with polyclonal antibodies against C. difficile heated at 60 degrees C. The Cwp66 protein (66 kDa) contains two domains, each carrying three imperfect repeats and one presenting homologies to the autolysin CwlB of Bacillus subtilis. A survey of 36 strains of C. difficile representing 11 serogroups showed that the 3' portion of the cwp66 gene is variable; this was confirmed by sequencing of cwp66 from another strain, C-253. Two recombinant protein fragments corresponding to the two domains of Cwp66 were expressed in fusion with glutathione S-transferase in Escherichia coli and purified by affinity chromatography using gluthatione-Sepharose 4B. Antibodies raised against the two domains recognized Cwp66 in bacterial surface extracts. By immunoelectron microscopy, the C-terminal domain was found to be cell surface exposed. When used as inhibitors in cell binding studies, the antibodies and protein fragments partially inhibited adherence of C. difficile to cultured cells, confirming that Cwp66 is an adhesin, the first to be identified in clostridia.

Molecular characterization of fliD gene encoding flagellar cap and its expression among Clostridium difficile isolates from different serogroups.

The fliD gene encoding the flagellar cap protein (FliD) of Clostridium difficile was studied in 46 isolates belonging to serogroups A, B, C, D, F, G, H, I, K, X, and S3, including 30 flagellated strains and 16 nonflagellated strains. In all but three isolates, amplification by PCR and reverse transcription-PCR demonstrated that the fliD gene is present and transcribed in both flagellated and nonflagellated strains. PCR-restriction fragment length polymorphism (RFLP) analysis of amplified fliD gene products revealed interstrain homogeneity, with one of two major patterns (a and b) found in all but one of the strains, which had pattern c. A polyclonal monospecific antiserum raised to the recombinant FliD protein reacted in immunoblots with crude flagellar preparations from 28 of 30 flagellated strains but did not recognize FliD from nonflagellated strains. The fliD genes from five strains representative of the three different RFLP groups were sequenced, and sequencing revealed 100% identity between the strains with the same pattern and 88% identity among strains with different patterns. Our results show that even though FliD is a structure exposed to the outer environment, the flagellar cap protein is very well conserved, and this high degree of conservation suggests that it has a very specific function in attachment to cell or mucus receptors.

GroEL (Hsp60) of Clostridium difficile is involved in cell adherence.

Previous results have demonstrated that adherence of Clostridium difficile to tissue culture cells is augmented by various stresses; this study focussed on whether the GroEL heat shock protein is implicated in this process. The 1940 bp groESL operon of C. difficile was isolated by PCR. The 1623 bp groEL gene is highly conserved between various C. difficile isolates as determined by RFLP-PCR and DNA sequencing, and the operon is present in one copy on the bacterial chromosome. The 58 kDa GroEL protein was expressed in Escherichia coli in fusion with glutathione S:-transferase and the fusion protein was purified from IPTG-induced bacterial lysates by affinity chromatography on glutathione-Sepharose. A polyclonal, monospecific antiserum was obtained for GroEL which established by immunoelectron microscopy, indirect immunofluorescence and immunoblot analysis that GroEL is released extracellularly after heat shock and can be surface associated. Cell fractionation experiments suggest that GroEL is predominantly cytoplasmic and membrane bound. GroEL-specific antibodies as well as the purified protein partially inhibited C. difficile cell attachment and expression of the protein was induced by cell contact, suggesting a role for GroEL in cell adherence.

Lack of activation of human secondary somatosensory cortex in Unverricht-Lundborg type of progressive myoclonus epilepsy.

Previous electroencephalographic and magnetoencephalographic studies have demonstrated giant early somatosensory cortical responses in patients with cortical myoclonus. We applied whole-scalp magnetoencephalography to study activation sequences of the somatosensory cortical network in 7 patients with Unverricht-Lundborg-type progressive myoclonus epilepsy diagnostically verified by DNA analysis. Responses to electric median nerve stimuli displayed 30-msec peaks at the contralateral primary somatosensory cortex that were four times stronger in patients than in control subjects. The amplitudes of 20-msec responses did not significantly differ between the groups. In contrast to control subjects, 5 patients displayed ipsilateral primary somatosensory cortex activity at 48 to 61 msec in response to both left- and right-sided median nerve stimuli. Furthermore, their secondary somatosensory cortex was not significantly activated. These abnormalities indicate altered responsiveness of the entire somatosensory cortical network outside the contralateral primary somatosensory cortex in patients with Unverricht-Lundborg-type progressive myoclonus epilepsy. The deficient activation of the secondary somatosensory cortex in Unverricht-Lundborg patients may reflect disturbed sensorimotor integration, probably related to impaired movement coordination.

Phenotypic and genotypic diversity of the flagellin gene (fliC) among Clostridium difficile isolates from different serogroups.

Phenotypic and genotypic diversity of the flagellin gene (fliC) of Clostridium difficile was studied in 47 isolates from various origins belonging to the serogroups A, B, C, D, F, G, H, I, K, X, and S3. Electron microscopy revealed 17 nonflagellated strains and 30 flagellated strains. PCR and reverse transcription-PCR demonstrated that the flagellin gene was present in all strains and that the fliC gene was expressed in both flagellated and nonflagellated strains. Southern blotting showed the presence of only one copy of the gene and three different hybridization patterns. DNA sequence analysis of fliC from the strains belonging to serogroups C, D, and X, representative of each profile, disclosed great variability in the central domain, whereas the N- and C-terminal domains were conserved. The variability of the flagellin gene fliC was further studied in the isolates by PCR-restriction fragment length polymorphism (RFLP) analysis. Nine different RFLP groups were identified (I to IX), among which three (I, VII, and VIII) corresponded to numerous serogroups whereas the six others (II, III, IV, V, VI, and IX) belonged to a single serogroup. Flagellin gene RFLP analysis could constitute an additional typing method employable in conjunction with other typing methods currently available.