Changes In Head Position Research Articles

Impact of change in head and neck position on ultrasound localisation of the cricothyroid membrane: an observational study.

The ideal position for performing surgical cricothyroidotomy is with full neck extension. Some authors have recommended marking the cricothyroid membrane before general anaesthesia, typically with the patient's head and neck in a neutral position. The primary aim of this observational study was to determine whether skin marks made over the centre of the cricothyroid membrane with the head and neck in the neutral position moved outside the boundaries of the membrane when the neck was subsequently extended. The secondary aim was to assess changes in the height of the cricothyroid membrane between the neutral and extended positions. Twenty-two volunteers completed the study. With the head and neck in the neutral position, the distance between the upper and lower borders ('height') of the cricothyroid membrane was measured by a radiologist using ultrasound. The skin was marked over the mid-point of the membrane. The subject then maximally extended the neck, and the measurements and marking were repeated. The skin marking over the centre point of the cricothyroid membrane moved by median (IQR [range]) 5 (4-6 [0-10]) mm when the head and neck were moved from a neutral to a fully extended position. The initial skin mark moved to lie outside the boundary of the cricothyroid membrane in 12 of 22 subjects after extending the neck. The height of the cricothyroid membrane increased by 30% with the neck extended. We recommend that marking the skin in preparation for cricothyroidotomy should be performed with the neck extended, not with the head and neck in the neutral position as previously suggested.

Abstract: Volumetric Changes of the Mid and Lower Face with Animation and the Standardization of 3D Facial Imaging

GOALS: 3D photography provides volumetric data and surface topography with sub-millimeter precision, but current methods lack standardization for facial expression and position. For example, smiling can mimic the desired outcomes of a facelift and fat grafting by increasing malar volume while decreasing volume in the jowls. Our goal was to quantify volumetric changes of the mid and lower face caused by facial expression so that we can accurately assess volumetric changes after surgery. Secondarily, we aimed to identify soft tissue landmarks that can be used to detect these changes in facial expression or head position to ensure the standardization of 3D images. METHODS: 3D facial images of 16 subjects performing 22 facial expressions or changes in head position were captured. Variable degrees of animation during smiling and frowning were also evaluated. Volumetric changes of the malar and jowl regions with facial expressions were quantified using a 3D superimposed image subtraction technique. Translation (movement >1 mm) of 14 standard soft tissue surface landmarks was assessed during various facial animations to determine which landmarks can be utilized to standardize 3D images. RESULTS: Sixteen of the 22 facial expression studied had a significant effect on malar and/or jowl volume. Significant volume changes were noted with subtle animation during smiling and frowning. During maximal smile, mean excursion of oral commissures was 13.7mm +/- 3.0 and the malar region demonstrated a 17.2mL +/- 5.7 increase in volume, whereas the jowl region demonstrated a 1.7mL+/- 0.9 decrease in volume. During maximal frowning, mean excursion of oral commissures was 7.4mm +/- 2.3. The malar region demonstrated a 3.7mL +/- 2.3 decrease in volume, whereas the jowl region demonstrated a 5.4mL +/- 0.9 increase in volume. In the act of smiling, there was significant volume augmentation of the malar region with small degrees of oral commissure excursion, such that a quarter smile (excursion = 25% of excursion with maximal smile) could induce a volume change equivalent to 75% of maximum smile. The jowl decreases in volume with smiling, but in a linear fashion (a quarter smile yields a volume change equivalent to 25% of a maximum smile). Frowning exhibited the opposite, but similarly significant changes in mid and lower facial volume. A 1mm commissure excursion during smiling can produce 5-10mL of malar augmentation or 2-4mL of jowl augmentation with frowning. We believe these results are related to isometric contraction of mimetic muscles and their influence on fat compartments. A combination of 5 landmarks (glabella, bilateral cheilion, pogonion and laryngeal prominence) was found to indicate all tested facial expressions which effect mid and facial volumes, with the exception of platysmal straining. CONCLUSION: Most facial expressions will lead to translation of the oral commissures, with even a subtle (1mm) excursion leading to 5-10mL of malar augmentation during smiling or 2-4mL of jowl augmentation during frowning. We identified that the glabella, pogonion, laryngeal prominence, and bilateral cheilion can be used as a referencing system to allow identification of subtle changes in head position and facial expression for standardization of 3D images.

Docking of the Femoral Head Following Closed Reduction for DDH: Does it Really Occur?

It has been suggested that the femoral head can "dock" deeper into the acetabulum after initial closed reduction (CR) for developmental dysplasia of the hip (DDH). The purpose of this study was to quantify the interval change in femoral head position between immediate postoperative magnetic resonance imaging (MRI) and follow-up imaging at ~3 weeks. A retrospective review of 29 patients (30 hips) who underwent CR and spica casting for DDH was conducted. Immediate postoperative and average 3-week follow-up MRI scans in spica were performed on all patients. On both scans, 2 blinded reviewers measured the following indices: the distance between the femoral head and the acetabulum on midcoronal and midaxial images, the displacement of the center of femoral head from Hilgenreiner's line in the coronal and axial plane, and the left-right displacement of the center of femoral head from Perkins line. Measurements were averaged between the 2 reviewers and the interval change in femoral head position between the immediate postoperative and follow-up scans were compared. There were 26 female individuals and 3 male individuals in our series with a mean age of 7.6 months (range, 4 to 13 mo). Follow-up MRI scans were performed at an average of 23.8 days (range, 13 to 46 d). On the basis of the averaged measurements from both readers, the distance between the femoral head and the acetabulum decreased significantly on coronal measurement and on all 3 axial measurements between initial and follow-up MRI. In addition, the position of the femoral head became significantly more medial, more anterior, and more cranial relative to the acetabulum. The interrater correlation coefficient between both readers across all measurements was 0.731. These findings provide evidence that femoral head position within the acetabulum improves even over a short time period following initial CR for DDH, suggesting that the "docking" phenomenon may in fact occur. Level IV-therapeutic study.

Changes in Cervical Lordosis After Orthognathic Surgery in Skeletal Class III Patients.

The purpose of this study was to evaluate cervical lordosis and head posture changes using lateral cephalographs after bimaxillary orthognathic surgery for mandibular prognatism by null hypothesis. Twenty-five patients with skeletal class III dentofacial deformities (10 men, 15 women; mean age, 29.28 ± 8.23 years; range 18-48 years) were included in this prospective clinical study. Lateral cephalographs were taken in natural head position (NHP) 2 weeks before and 6 months after orthognathic surgery. The reproducibility of the radiographer's technique of taking radiographs in NHP was investigated using a photographic method and found to be acceptable. All measurements for cervical lordosis (CV1/CV2; CV3/CV7; CV1/CV7), head posture (NSL/OPT; NSL/VER), and other cephalometric values (NSL/Go-Gn; NSL/OCL; Overjet) were repeated 3 times by the same blinded investigator at 2-week intervals and the average values of the 3 measurements were calculated to use in statistical analysis. Intraclass correlation coefficients (ICC) ranged between 0.996 and 1.000, demonstrating a high reliability of the measures. Statistically significant differences were found for CV3/CV7 (P = 0.006) and CV1/CV7 (P = 0.005) and no significant differences were identified in head posture for both cranio-cervical and cranio-vertical angles. The null hypothesis was rejected. Orthognathic surgery resulted in significant cervical lordosis extension, and a tendency for head extension could also be observed.

Analysis of sensory system aspects of postural stability during quiet standing in adolescent idiopathic scoliosis patients

BackgroundThe aim of this study was to quantitatively analyze quite standing postural stability of adolescent idiopathic scoliosis (AIS) patients in respect to three sensory systems (visual, vestibular, and somatosensory).MethodIn this study, we analyzed the anterior-posterior center of pressure (CoP) signal using discrete wavelet transform (DWT) between AIS patients (n = 32) and normal controls (n = 25) during quiet standing.ResultThe energy rate (∆EEYE%) of the CoP signal was significantly higher in the AIS group than that in the control group at levels corresponding to vestibular and somatosensory systems (p < 0.01).ConclusionsThis implies that AIS patients use strategies to compensate for possible head position changes and spinal asymmetry caused by morphological deformations of the spine through vestibular and somatosensory systems. This could be interpreted that such compensation could help them maintain postural stability during quiet standing. The interpretation of CoP signal during quiet standing in AIS patients will improve our understanding of changes in physical exercise ability due to morphological deformity of the spine. This result is useful for evaluating postural stability before and after treatments (spinal fusion, bracing, rehabilitation, and so on).

Effect of different head and neck positions on kinematics of elite dressage horses ridden at walk on treadmill

The debate on proper head and neck positions (HNP) in horse training is lively, but little is known about the biomechanical effects of various HNPs in horses ridden at walk. The aim was to quantify the influence of different HNPs on the kinematics of horses ridden at walk. The standard competition position (HNP2) was compared to a free, unrestrained position (HNP1), more flexed positions (HNP3, HNP4), a raised extended position (HNP5) and a forward-downward extended position (HNP6). An experimental study in seven high-level dressage horses ridden at walk on a treadmill was designed. Kinetic and kinematic measurements were obtained with different HNPs. HNP2 was used as a speed-matched reference. Kinematics were measured from skin-fixed markers recorded by high-speed video cameras. The kinetics of the limbs were measured by the force-measuring instrumentation of the treadmill. In HNP1, compared to HNP2, the lumbar back and the pelvis were more horizontally positioned (more extended), and fore- and hindlimb pro- and retraction increased, with increased caudal rotation of the femur during the second half of hindlimb stance. HNP6 induced similar changes as HNP1, but caused larger increases in forelimb pro- and retraction. In HNP3, HNP4 and HNP5 the pelvis was more angled (less extended) compared to HNP2 at hindlimb midstance, and in HNP3 and HNP4 also in early hindlimb stance. All three HNPs caused increased maximum flexion of the tarsus, stifle and metatarsophalangeal joint during the swing phase. HNP3 and HNP5, but not HNP4, had a decreasing influence on fore- and hindlimb pro- and retraction, and decreased caudal rotation of the femur during the second half of hindlimb stance.The main limitation was that horses were not ridden overground and the number of horses was small. Our conclusion was that changes in head and neck position can markedly affect the horse’s movement pattern at walk.

Eye gaze direction shows a positive serial dependency.

Recent work from several groups has shown that perception of various visual attributes in human observers at a given moment is biased towards what was recently seen. This positive serial dependency is a kind of temporal averaging which exploits short-term correlations in visual scenes to reduce noise and stabilize perception. Here we test for serial dependencies in perception of head and eye direction using a simple reproduction method to measure perceived head/eye gaze direction in rapid sequences of briefly presented face stimuli. In a series of three experiments, our results reveal that perceived eye gaze direction shows a positive serial dependency for changes in eye direction, along both the vertical and horizontal dimensions, although more strongly for horizontal gaze shifts. By contrast, we found no serial dependency at all for horizontal changes in head position. These findings show that a perception-stabilizing 'continuity field' operates on eye position-well known to be quite variable over short timescales-while the more inherently stable signal from head position does not.

Head tracking extends local active control of broadband sound to higher frequencies

Local active sound control systems provide useful reductions in noise within a zone of quiet which only extends to about one tenth of an acoustic wavelength. If active control is required above a few hundred hertz, this generally limits the movement of a listener to unrealistically small changes in head position. We describe a local active sound control system using a fixed array of monitoring microphones, in which the pressures at the ear positions are estimated from these microphone signals using head position information from an optical head tracker. These signals are then actively controlled to give robust attenuation at the ear positions, even as the listener moves their head. Feedforward control provides selective attenuation of noise and broadband attenuation of around 20 dB is measured up to excitation frequencies of 1 kHz under favourable conditions, with head tracking achieved in a few seconds. The active control performance is thus comparable with that achieved with active headphones, but without the listener having anything attached to their head.

Morphological evaluation of temporo-mandibular joint in indian population

The temporomandibular joint (TMJ) is one of the most complex joints in the body and its harmonious functioning is very important to maintain a normal masticatory system. The morphologic alterations and the asymmetrical position of the TMJ structures may lead the various clinicalsigns &amp; symptoms. Morphology of the temporomandibular joint may be influenced by gender of patients, environmental factor and also food habits at various places. Objective: To evaluate the morphology of the temporomandibular joint using computed tomography, in order to determine the condyle shape, joint space and glenoid fossa roof thickness. Material and Methods: One hundred and six healthy patients (212 TMJs) who visited a private hospital (or the University’s Hospital) for CT brain scan were included to this cross-sectional study sample.The patients were aged between 20–50 years with an average age of 35.46 years. All the images were taken by positioning patients in supine position with 120kvp , 50ma,2.33minute exposure with 0.7mm thick slicesby computed topography machine in all three projection that is Axial, Coronal and Saggital view. Results: For all variables, the mean and standard deviation were calculated, based on gender, and TMJ sides. The Paired t-test was used and P&lt;0.05 will be considered to be significant. Conclusion: Present study showed that thereis positive evidence of temporomandibular joint involvement in elderly patients. Change in morphology and position of condylar head with glenoid fossa and roof thickness are one of the most common cause of degenerative diseases.KeywordsTemporomandibular joint; Morphology; Condyle; Joint space.KeywordsTemporomandibular joint; Morphology; Condyle; Joint space

Early motor signs of autism spectrum disorder in spontaneous position and movement of the head.

We examined the characteristics of spontaneous movements at 9-20weeks postterm age in very low birth-weight infants who later developed autism spectrum disorder (ASD). We analyzed video recordings of spontaneous movements of 39 children who had no clinical issues [typically developing (TD) group], 21 children who showed developmental delay, and 14 children who were diagnosed with ASD (ASD group) at 6years of age. Head position in each video frame was classified by visual inspection. The percentage of midline head position (PMHP) and number of changes in head position were calculated. Spontaneous limb movements were quantified using six indices. The values of PMHP were significantly lower in the ASD group than in the TD group. The lower PMHP during early infancy is associated with later development of ASD. Poorer performance in maintaining midline position of the head at this period may distinguish infants who later develop ASD from those who show TD.

Comparison of the effectiveness of Brandt-Daroff Vestibular training and Epley Canalith repositioning maneuver in benign Paroxysmal positional vertigo long term result: A randomized prospective clinical trial.

Objective:Benign paroxysmal positional vertigo (BPPV) is the most common peripheral cause of vertigo. It can be defined as transient vertigo induced by rapid change in head position, associated with a characteristic paroxysmal positional nystagmus. Posterior canal benign paroxysmal positional vertigo is the most frequent form of BPPV. The aim of our study was to investigate and compare the effectiveness of Epley maneuver and Brand-Daroff home exercises for the treatment of posterior canal BPPV.Methods:A total of 50 patients between 27 and 76 years of age who were diagnosed with unilateral posterior canal into BPPV were randomized prospectively into two groups. In Group-1, modified particle repositioning maneuver and in Group-2 Brandt-Daroff exercises were utilized as treatment. Patients were followed weekly. Cure weeks were recorded. The patients were followed for 12 to 24 months for recurrence.Results:The recovery rates at the first, second and third week controls were 76%, 96% and 100% for Group-1 (modified Epley maneuver) and 64%, 88% and 100% for Group-2 (Brandt-Daroff exercises) respectively. The recovery rates were similar for both groups. The average follow-up duration was 18 months. In Group 1, 7 patients (28%) and in Group 2, 5 patients (20%) had recurrence, which was also similar with no statistical difference.Conclusion:It was concluded that both Brandt-Daroff Exercises and Modified Epley maneuvers were almost equally effective in the treatment of BPPV.

Chiari type 1 malformation presenting as an atypical benign paroxysmal positional vertigo in a 16 year old patient

&lt;p&gt;Dizziness and vertigo are very common symptoms and can be difficult to distinguish clinically. Vertigo is a specific subtype of dizziness in which a patient experiences the illusion of motion (often rotatory) of either themselves or their surroundings. Vertigo can be either peripheral (arising within the labyrinth) or central (brain). It is important to identify central aetiologies as they can be fatal if missed. This case report narrates a 16-year-old male who presented complaining of vertigo related to changes in head position which was initially misdiagnosed as a benign paroxysmal positional vertigo (BPPV). It was several years before he was correctly diagnosed as having Chiari type 1 malformation on MRI scan. He underwent a surgical decompression with complete alleviation of his symptoms. All cases of atypical vertigo should be evaluated in detail. Patients with failure of initial management should undergo imaging to identify any central pathology. &lt;/p&gt;

Changes in head posture after rapid maxillary expansion in patients with nasopharyngeal obstruction

Introduction: Nasopharyngeal obstruction is an important etiologic factor in the development of an extreme vertical growth facialpattern, and insufficient transversal growth of the maxilla. The treatment outcomes associated with rapid maxillary expansion in theliterature are mainly discussed in terms of changes in dentofacial morphology, without special reference to changes in the pharyngealairway, the position of the mandible, hyoid bone and the tongue.Aim: The aim of this study was to evaluate the effects of rapid maxillary expansion (RME), on changes in head posture and airway dimension.Materials and methods: The cephalometric evaluation was conducted on thirty lateral cephalograms of patients with nasopharyngeal obstruction (mean age 9.11 years; standard deviation (SD) ± 2.0; range 8-14 years) treated with appliance for rapid maxillary expansion. Patients were randomly divided into two groups: 1) study group comprised of 15 patients treated with RME immediately after the first visit; 2) a control group comprised of 15 subjects monitored for approximately 12 months prior to commencing therapy, who became untreated controls. Lateral cephalograms, taken in the natural head position, were obtained at the first visitand 6 months later for all subjects. Six angular measurements were measured to describe craniocervical angulation, and five linear measurements were measured to describe airway dimension.Results: The investigated group treated with RME shows a statistically significant decrease in craniocervical angulation, especially at the angleof interaction between palatal plane and the tangent odontoid processus (4.07 degrees, for PP/OPT angle) and angle interaction between palatal plane and the tangent of cervical vertebra (4.95 degrees for PP/CVT angle). Airway dimension in the treated group increased, especially at the levels PNS-ad1 (2.52 mm), ve-pve (2.97 mm), and uv-puv (2.88 mm). No significant changes were observed in the control group.Conclusions: RME is a treatment procedure capable of providing increased nasopharyngeal airway adequacy, changing the head posture as well as position of the mandible and tongue, creating the conditions for myofunctional balance and proper development of craniofacial complex and changing mode of respiration.

Effects of head tilt on visual field testing with a head-mounted perimeter imo.

PurposeA newly developed head-mounted perimeter termed “imo” enables visual field (VF) testing without a fixed head position. Because the positional relationship between the subject’s head and the imo is fixed, the effects of head position changes on the test results are small compared with those obtained using a stationary perimeter. However, only ocular counter-roll (OCR) induced by head tilt might affect VF testing. To quantitatively reveal the effects of head tilt and OCR on the VF test results, we investigated the associations among the head-tilt angle, OCR amplitude and VF testing results.Subjects and methodsFor 20 healthy subjects, we binocularly recorded static OCR (s-OCR) while tilting the subject’s head at an arbitrary angle ranging from 0° to 60° rightward or leftward in 10° increments. By monitoring iris patterns, we evaluated the s-OCR amplitude. We also performed blind spot detection while tilting the subject’s head by an arbitrary angle ranging from 0° to 50° rightward or leftward in 10° increments to calculate the angle by which the blind spot rotates because of head tilt.ResultsThe association between s-OCR amplitude and head-tilt angle showed a sinusoidal relationship. In blind spot detection, the blind spot rotated to the opposite direction of the head tilt, and the association between the rotation angle of the blind spot and the head-tilt angle also showed a sinusoidal relationship. The rotation angle of the blind spot was strongly correlated with the s-OCR amplitude (R2≥0.94, p<0.0001). A head tilt greater than 20° with imo causes interference between adjacent test areas.ConclusionsBoth the s-OCR amplitude and the rotation angle of the blind spot were correlated with the head-tilt angle by sinusoidal regression. The rotated VF was correlated with the s-OCR amplitude. During perimetry using imo, the change in the subject’s head tilt should be limited to 20°.

Relationship between vertebral artery blood flow in different head positions and vertigo

Objective: To identify the vertebral artery blood flow in different head positions in patients with positional vertigo with no specific diagnosis.Methods: Patients with history of vestibular symptoms associated with changes in head position were enrolled into the study. Healthy volunteers were evaluated as control group. Doppler ultrasonography examination of the cervical segment of the vertebral arteries was performed under three different head positions: (i) supine position, (ii) head hyperextended and rotated to the right side and (iii) head hyperextended and rotated to the left side.Results: In the study group, right and left vertebral artery blood flow was significantly lower in the ipsilateral hyperextended position compared to standard supine position (respectively p = .014; p = .001), but did not differ significantly when compared between the standard supine and contralateral hyperextended positions (respectively = .959; p = .669). In the control group, left and right vertebral artery blood flow did not differ significantly when the head was hyperextended to the right or left sides compared to standard supine position (p > .05).Conclusions: Our data demonstrated that the etiology of vestibular complaints in patients with undiagnosed positional vertigo might be related to impairment in vertebral artery blood flow according to head positions.

Nasal patency and craniocervical posture in scholar children

ABSTRACT Changes in head posture have been observed as a compensatory mechanism for the nasal airflow impairment. This study aimed to compare the craniocervical posture between children with normal and decreased nasal patency and correlate nasal patency with craniocervical posture. Children aging from six to twelve years went through nasal patency and craniocervical assessments. The biophotogrammetric measures of craniocervical posture used were Cervical Distance (CD), Head Horizontal Alignment (HHA) and Flexion-Extension Head Position (FE), evaluated by SAPO software (v.0.68). Nasal patency was measured using Peak Nasal Inspiratory Flow meter (PNIF) and Nasal Obstruction Symptom Evaluation (NOSE) scale. One hundred thirty-three children were distributed into two groups: G1 (normal nasal patency - PNIF higher than 80% of predicted value) with 90 children; G2 (decreased nasal patency - PNIF lower than 80% of predicted value) with 43 children. Differences between groups were not found in CD and HHA measures. FE was significantly higher in G2 than G1 (p=0.023). Negative weak correlation between FE and %PNIF (r=-0.266; p=0.002) and positive weak correlation between CD and PNIF (r=0.209; p=0.016) were found. NOSE scores negatively correlated with PNIF (r=-0.179; p=0.039). Children with decreased nasal patency presented greater head extension. This postural deviation is prone to increase as nasal airflow decreases, thus indicating the relationship between craniocervical posture and nasal patency. Lower values of PNIF reflected on additional problems caused by nasal obstruction symptoms.

P13.04: The role of ultrasound in prediction of successful induction of labour

The aim of this study was to evaluate the potential value of cervical length and posterior cervical angle measurement by transvaginal ultrasound and determination of the fetal head position by transabdominal ultrasound before induction of labour in prediction of successful induction of labour. In a prospective study of 298 singleton pregnancies who admitted for induction of labour, after informed consent maternal characteristics were recorded. Fetal head position assessed by TAS, cervical length and posterior cervical angle measured by TVS. We examined the value of pre induction ultrasound parameters in prediction of labour induction outcomes. The cervical length measured by TVS was significantly shorter in patients who delivered vaginally in comparison with patients who delivered by Caesarean section due to the failure to progress.(18±5.7) versus (29.5±11) mm, respectively (p〈0.001). The odds ratio for successful induction for occiput anterior was 1.75(CI 95%=1.064-2.878) and for OP was 0.455 ,(CI 95%=0.272-0.763). And risk ratio for OA was 1.243(1.033-1.4950); and for OP was0.701 (CI 95%=0.541-0.908). The mean of posterior cervical angle in patients delivered vaginally was 124±18; and in patients with failed induction was 100±20.5 (P〈0.001). Using pre-induction ultrasound to determine fetal head position and cervical changes provides more precise information in comparison with Bishop score to predict the outcome of induction of labour, and enable clinicians to improve further management of pregnancy.

Effect of Head Position on the Success Rate of Blind Intubation through Air Q Laryngeal Mask in Morbidly Obese Patients

Aim: To evaluate the effect of head positioning whether neutral or sniffing position on the conduct of intubation through air Q in morbidly obese patients. Patients and method: This study was conducted on 90 patients with body mass index equal or above 40 who were scheduled for surgery under GA and were randomly divided into 2 equal groups: Group N (Gn) in which blind intubation through air Q was done in neutral position. Group S (Gs) in which blind intubation was done in sniffing position. Proper airway assessment of the patients was done. Basic monitoring was attached; Induction of anaesthesia was achieved by Fentanyl 2 ug/kg, Propofol 1.5 - 2.5 mg/kg and Atracurium 0.5 mg/kg. Maintenance of anaesthesia was achieved by Sevoflurane, Atracurium, oxygen and air. When neuromuscular blockade was complete, the head of the patient was adjusted according to their group. The supraglottic device was inserted and connected to capnography, thereafter a well lubricated proper sized ETT was passed through the air Q. We recorded a baseline reading of HR, SBP, DBP, MBP, and oxygen saturation. A second reading was taken after induction of anesthesia, just before intubation. The third reading was recorded after intubation while further readings were measured 1, 3, 5, 10, 15 min after intubation. After ETT removal, we observed the patients in the recovery room at 0, 3 & 24 hours for possible postoperative complications. Results: There was no statistical difference between the two groups regarding the demographic data. Although the intubation in sniffing position has a higher success rate from the first time than the neutral position, the results were statistically insignificant, regarding the mean duration of blind intubation trials through the Air Q and postoperative complications. Conclusion: Although the sniffing position improves glottic visualization, the change of head position had no effect on the success rate of blind intubation through air Q in obese patients.

Advances in the diagnosis and treatment of benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) (otolith disease) is the most common neurological and position change related vertigo, accounting for 17–20% of peripheral vertigo. BPPV occur in the elderly. The high incidence age for BPPC was 50 to 70 years and mostly in female. According to the different parts of the lesions, it is divided into anterior canal BPPV (AC-BPPV), posterior canal BPPV (PC-BPPV), horizontal canal BPPV (HC-BPPV). Studies have shown that the incidence of PC-BPPV was 86.36%, the incidence of HC-BPPV was 11.37%, the incidence rate of AC-BPPV was 2.27%. Treatment for PC-BPPV includes manual reduction, drug treatment, psychological treatment, and surgical treatment. Repositioning is the preferred method for the treatment of PC-BPPV with high effective rate and low risk. The mechanism is through the different changes of head position to make the otolith back to utricle. Many manual reduction methods have been reported in clinical treatment of PC-BPPV. With the increasing emphasis on the BPPV, a variety of new methods are being developed and designed.

Effect of changing the head position on accuracy of transverse measurements of the maxillofacial region made on cone beam computed tomography and conventional posterior-anterior cephalograms.

This study aimed to assess the effect of head position on the accuracy of transverse measurements of the maxillofacial region on CBCT and conventional posteroanterior (PA) cephalograms. The second objective of this study was to find skull positions with the greatest and smallest effect on transverse measurements in the maxillofacial region. PA cephalograms and CBCT scans were obtained from 10 dry human skulls in 7 positions, namely the central position, 10° and 20° rotations, 10° and 20° tilts and 10° and 20° tips. The CBCT scans were converted to PA cephalograms on which distances from six landmarks, namely the nasal cavity, zygomatic arch, jugale, antegonion, condylion and zygomaticofrontal suture to the mid-sagittal plane, were measured on both sides using Dolphin two-dimensional software. The paired t-test was used to compare the mean values separately in each position (for each landmark) with the gold standard (central skull position). The interclass correlation coefficient and the Bland-Altman plot were used to compare the mean values measured by two observers. The mean values of the distances measured on CBCT PA cephalograms were greater than those measured on conventional PA cephalograms; this difference was statistically significant for some landmarks (p < 0.005). The rotated position (as compared with the central position) caused the greatest change in values for most landmarks on both sides (p < 0.005). The CBCT PA cephalogram was more accurate than the conventional PA cephalogram, and landmarks farther from the midline exhibited greater changes on cephalograms compared with those closer to the midline. Patients are at risk of improper positioning when undergoing extraoral radiography such as PA cephalograms. Changes in head position may affect the transverse measurements and thus the treatment plan.