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PubMedDate not supplied

[Cystine-amino-peptidase (C.A.P.) and D.B.P. in "at risk" pregnancy with "poor intrauterine fetale growth" (P.I.F.G.) (author's transl)].

The normal range of serum cystine-amino-peptidase (C.A.P.) in 54 cases of uncomplicated pregnancies was established. 21 patients whose pregnancies were though to be "at risk" were serially monitored by sonar biparietal cephalometry and serum cystine-amino-peptidase determination. The results show that exists a correlation between C.A.P. and biparietal cephalometry values. Furthermore the "predictive power" towards neonatal conditions (by birth weight and Apgar score determination) was of 77,55% for the biparietal cephalometry and 76,10% for C.A.P.

Aminopeptidases↗

PubMed1999

Mandibular contouring: a surgical technique for the asymmetrical lower face.

Correcting facial asymmetry is a difficult problem for plastic surgeons. From 1991 to 1996, the authors treated 53 cases of mandibular angle resection, 13 of which were of patients with an asymmetrical lower face. On the basis of these experiences, the authors highlight two important points in dealing with the asymmetrical lower face. The first is accurate resection of each side of the face. A cloth pattern was used to improve the accuracy of the procedure and to make the final result match the preoperative design regarding amount and shape. The second concerns soft-tissue change after the operation. Satisfactory results are obtained by the accurate resection of the bone coupled with the correct management of the surrounding soft tissue. The amount of bone to be resected was determined not simply by cephalometry, but by both cephalometry and external appearance. Postoperative cephalometry is not always symmetrical, and it is important that the final external appearance be harmonious and symmetrical. Using the above method, results have been satisfactory to both the surgeons and the patients, with the exception of three patients who had residual asymmetry. No permanent sensory loss or motor nerve palsy was observed, and no infections occurred.

Adult↗

PubMed2001

Teleradiographic method for determining the position of 1:6, 1:4, 1:3, 2:3, 2:4, 2:6 in complete denture.

UNLABELLED: The existing methods for determining the position of 1:3; 2:3 teeth make possible subjective decisions in the construction of complete dentures. The use of objective auxiliary methods and devices that ensure metric determination of the position of 1:6; 1:4; 1:3; 2:3; 2:4; 2:6 haven't been cited in the known literature. PURPOSE: We have set as a purpose to create a methodology that eliminates the subjective determination of the position of 1:3; 2:3 in complete denture construction. METHODOLOGY: With the help of teleradiographic analysis of frontal cephalometry we created a methodology that avoids subjectivity in 1:3; 2:3 preparation. We applied well-known dependencies in orthodontics. - The correlation between the dental arch and the sum of the incisors. - The first law of Izard. The intermolar distance is equal to half the distance measured between the points Z : Z. - The method for graphic depiction of the dental arch of the maxilla created by Hawley and Herbert and refined by Herbst. CONCLUSIONS: The prostheses fabricated according to our methodology with the help of frontal cephalometry provide the possibility to avoid subjectivity in the work of both the dentist and the dental technician. When the frontal teeth are arranged the cutting tooth must lie on the graphic and the side teeth are inscribed in the graphic. The application of frontal cephalometry is an auxiliary method for the arrangement of the teeth in complete dentures, that with its metric values introduces a new aspect in the exactness and the positioning of the teeth in the prostheses.

Dental Arch↗

PubMed1990

Variability of measurements of cranial growth in the rabbit.

This study concerns techniques used in experimental cranial growth research: roentgen cephalometry, roentgen stereophotogrammetry, and gross measurements (osteometry). A comparison of the precision of these methods has not been found in the literature. Computation of technical errors is fundamental to the sound evaluation of registered findings, and such a presentation must be obligatory in all biometric reports. We compared the measurement error of roentgen cephalometric and osteometric data with that obtained by roentgen stereophotogrammetry (RSA). RSA demonstrates a superior replicability, and this technique gives possibilities for kinematic and volumetric determinations simultaneously with distance evaluation. Roentgen cephalometry has the advantage of enabling distance and angular measurements between any well-defined skeletal points or lines. This technique, preferably after implantation of bone markers, is a reliable alternative, but optimal results necessitates calculations of the magnification factor for each bone segment involved. Direct osteometry does not contribute additional information, but problems of image magnification are omitted. Preferably, one individual should perform all measurements regardless of the method used. Growth rates and values calculated by one technique cannot be directly transformed to some other approach. In all probability, assessments of distance changes would gain substantially by using one technical approach consistently throughout actual age intervals. The least variable measurements of sutural growth are made for sutures growing primarily in one plane and with substantial growth rates. One must realize that differences among studies may be due to the limitations of, in particular, the cephalometric and osteometric techniques.

Animals↗

PubMed1985

Cephalometric radiography and computed tomography in infants undergoing craniofacial surgery.

A program for preoperative workup and post-operative follow-up in children with craniofacial anomalies is described. Objective measurements were made with cephalometry and computed axial tomography. Improvement in length of the anterior cranial base and shape of the calvaria after surgery and growth was demonstrated in this manner in serial follow-ups. It was concluded that both cephalometry and computed tomography were essential for the diagnosis, surgical planning and follow-up for this group of patients.

Cephalometry↗

PubMed2001

Cephalometric image analysis and measurement for orthognathic surgery.

Automatic identification of landmarks in cephalometry is very important and useful for orthognathic surgery. A computerised automatic cephalometric analysis system (CACAS), based on image processing, is presented. For an original X-ray image, median filtering and histogram equalisation are used to improve image quality. The edge of an X-ray image is detected by a wavelet transform and Canny filter. Seventeen landmarks in cephalometry are successfully identified by knowledge-based edge tracing and changeable templates. Seventy-three measurements based on distances, angles and ratios between landmarks are computed automatically. The reliability of the landmarks and the validity of the measurements are compared for automatic and manual operation. The values of measurements obtained by CACAS are more precise and reliable: the mean error for linear measurements is less than 0.9mm; the mean error for angular measurements is less than 1.2 degrees. The rate of validity is over 80%, even if the image quality is poor. For an image with a high signal-to-noise ratio, the rate of validity of landmarking and measurements using the CACAS system is over 90%.

Cephalometry↗

PubMed2004

Craniofacial differences according to AHI scores of children with obstructive sleep apnoea syndrome: cephalometric study in 39 patients.

BACKGROUND: Cephalometry is useful as a screening test for anatomical abnormalities in patients with obstructive sleep apnoea syndrome (OSAS). OBJECTIVE: To evaluate comprehensively the cephalometric features of children with OSAS, with or without adenotonsillar hypertrophy, and to elucidate the relationship between cephalometric variables and apnoea-hypopnoea index (AHI) severity. MATERIALS AND METHODS: The study population consisted of 39 children, aged 4-12 years, with OSAS. Cephalometry was analysed using 11 measurements of the bony structures, their relationships and the size of the airways. Additionally, adenoid and tonsillar hypertrophy were graded. RESULTS: Cranial base angles (BaSN and BaSPNS) were found to correlate with increasing levels of AHI scores (P<0.001). Protrusion of the maxilla (SNA) and mandible (SNB) did not correlate with AHI scores (P>0.05). The length of the mandibular plane (GnGo) and the minimal posterior airway space (MPAS) were inversely correlated with AHI scores (P<0.001). There was positive correlation between MPAS and GnGo (r=0.740, P<0.001), and negative correlation between MPAS and gonial angle (ArGoGn) (r=-0.541, P<0.001). There was significant correlation between cephalometric data and adenotonsillar hypertrophy concerning BaSN, BaSPNS, ArGoGn, GnGoH, BaN-GnGo, MPAS, GnGO and MPH (P<0.001). CONCLUSIONS: There is significant correlation between cephalometric data and AHI score severity in children with OSAS. Adenotonsillar hypertrophy affects the cephalometric measurements adversely. The study clearly mandates the institution of early and effective therapy of adenotonsillar hypertrophy in children with OSAS.

Adenoids↗

PubMed1985

Finite element method modeling of craniofacial growth.

The application of the concepts of continuum mechanics and of the numerical techniques of the finite element method permits the development of a new and potentially clinically useful method of describing craniofacial skeletal growth. This new method differs from those associated with customary roentgenographic cephalometry in that its descriptions and analyses are invariant; that is, they are independent of any method of registration and superimposition. Such invariance avoids the principal geometric constraint explicit in all analytical methods associated with conventional roentgenographic cephalometry. The conceptual and mathematical bases of the finite element method (FEM) are presented and illustrated by the numerical and graphic descriptions of the two-dimensional growth of the rat skull, for which two sets of longitudinal growth data are used. In practice, the FEM permits analysis of the skull at a scale significantly finer than previously possible, by considering cranial structure as consisting of a relatively large number of contiguous finite elements. For each such element, independently, it is then possible to describe and depict both the magnitude and the direction of temporal size and shape changes occurring in that element relative to itself at some initial time. It is emphasized that such descriptions are completely independent of any local reference frame.

Aging↗

PubMed2004

Effects of an anteriorly titrated mandibular position on awake airway and obstructive sleep apnea severity.

The objective of this study was to investigate whether a reduction of obstructive sleep apnea (OSA) severity was associated with significant upper airway (UA) changes after an anterior titration of the mandibular position. Eighteen OSA patients with a mean (SD) apnea hypopnea index (AHI) of 32.5 (12.3) were recruited. Baseline supine cephalometry was obtained before the initial insertion, and follow-up supine cephalometry was undertaken after titration with a titratable oral appliance in place. The mean AHI before treatment was significantly reduced to 9.7 (7.4) (P <.001) after titration. In 13 responders with AHI reduced to < or =15/h, a significant forward displacement of the anterior wall of the velopharynx (P <.05) was observed. In addition, there was a significant forward displacement of the posterior wall of the oropharynx and the hypopharynx (P <.05). In the 5 nonresponders, no significant changes in the position of the anterior and posterior wall were observed. There was no significant difference in the total amount of mandibular advancement between responders and nonresponders. We conclude that treatment success with oral appliance therapy appears to depend not only on anterior titration of the mandibular position to enlarge the UA, but also on the amount of change in the size of the UA in response to mandibular advancement.

Adult↗

PubMed2005

Anatomic changes after hyoid suspension for obstructive sleep apnea: an MRI study.

OBJECTIVE: To assess the effects of isolated hyoid suspension on subjective and objective parameters of obstructive sleep apnea and to evaluate changes in upper airway anatomy with the help of standardized magnetic resonance imaging. STUDY DESIGN AND SETTING: Fifteen patients received isolated hyoid suspension. Changes in respiratory disturbance index were assessed with polysomnography, and anatomical changes with standardized magnetic resonance imaging. Snoring, daytime sleepiness, and functional parameters were assessed with questionnaires. Lateral x-ray cephalometry was performed preoperatively. RESULTS: Mean respiratory disturbance index was reduced from 35.2 +/- 19.1 to 27.4 +/- 26.2. Forty percent of the patients were classified as responders. Daytime sleepiness improved significantly. Relevant changes in upper airway anatomy could not be detected. There were no remarkable differences between responders and nonresponders in regard to imaging. CONCLUSIONS: Hyoid suspension is effective only in a subgroup of patients and does not lead to relevant changes in airway diameters in the awake patient. Magnetic resonance imaging and x-ray cephalometry do not add additional information for patient selection. SIGNIFICANCE: The reported clinical effects of hyoid suspension are more likely due to functional changes in airway collapsibility than to an enlargement of the upper airway.

Adult↗

PubMed1993

Effect of head posture on cephalometric sagittal angular measures.

The definitions of cephalometric landmarks include relative terms that are dependent on the orientation of the head (e.g., lowest, most posterior) and head orientation differ widely during cephalometry (e.g., Frankfort plane horizontal, natural head posture). The purpose of this study was to quantify the effect of head posture changes on the commonly used sagittal angular measures SNA, SNB, and SNPogonion (SNPg). The sample comprised 30 Chinese skulls. Cephalograms were taken in a purpose designed skull holder with the Frankfort plane horizontal and at +10 degrees, +20 degrees, +30 degrees, -10 degrees, -20 degrees, and -30 degrees. A geometric grid was used to locate the deepest landmarks, and the landmarks were digitized followed by computer superimposition on the S-N line. To compare the values of the SNA, SNB, and SNPg angles in the different head postures, t tests were used. Head (skull) posture changes produced significant effects on the cephalometric values even at +/- 10 degrees of tilting. Overall, the angles were underestimated by approximately 1 degrees. In general, the angular differences and their standard deviations increased as the skull rotation increased with most of the differences for the SNB and the SNPg angles being clinically significant and also statistically significant at the 0.1% level. It was concluded that head posture needs to be standardized during cephalometry. Changes in posture significantly affect the location of some landmarks and the subsequent data obtained.

Asian People↗

PubMed2002

Morphospatial analysis of soft-tissue profile in patients with Class II Division 1 malocclusion treated using twin block appliances: geometric morphometrics.

OBJECTIVES: To study soft-tissue profile changes in patients treated with twin block appliances (TBA) for the correction of Class II division 1 malocclusion. The null hypothesis is that soft-tissue profiles do not show any significant improvements associated with TBA treatment. DESIGN: Longitudinal, retrospective. SETTING AND SAMPLE POPULATION: Scotland, UK, using lateral cephalographs of 46 consecutive, prepubertal children (aged 9-11 years) and 55 adolescents (aged 12-14 years) obtained from an orthodontic practice. EXPERIMENTAL VARIABLE: The prepubertal children underwent = 13 months of TBA treatment, while the adolescents underwent = 22 months of treatment. OUTCOME MEASURES: Configurations of 13 digitized homologous landmarks of pre- and post-treatment soft-tissue facial profiles were compared using cephalometry, Euclidean distance matrix analysis (EDMA) and thin plate spline (TPS) analysis. RESULTS: Cephalometry showed that height increases associated with the TBA were in the labiomental areas, and the most significant height decreases were seen in the lip regions. The results of EDMA also indicated significant changes (P < 0.05). The distance between the lips decreased by >5%, with increases in length in the labiomental region. The TPS analysis showed the soft-tissues of the mandibular complex being displaced anteroinferiorly, with anterior displacement of the landmarks of the lip region. These changes showed that the lips were brought into closer proximity with each other, permitting a functional oral seal. Moreover, the labiomental groove became less pronounced, reflecting the underlying dento-alveolar correction. CONCLUSION: Demonstrable improvements in soft-tissue facial profile may be associated with TBA treatment.

Adolescent↗

PubMed2003

Effects of the headgear-activator Teuscher appliance in the treatment of Class II Division 1 malocclusion: a geometric morphometric study.

OBJECTIVES: To test the hypothesis that there are no gender differences in the outcomes of patients with class II malocclusion treated with the headgear-activator Teuscher appliance (HATA). DESIGN: Retrospective, longitudinal SETTING AND SAMPLE POPULATION: Puerto Rico and Scotland, UK. Thirty-one patients requiring correction of class II division 1 malocclusions. EXPERIMENTAL VARIABLE: Male and female patients treated using HATA. OUTCOME MEASURES: Mean pre- and post-treatment parameters derived from cephalometry subjected to t-tests, and finite-element scaling analysis (FESA), which localizes and quantifies differences between mean pre- and post-treatment configurations. RESULTS: Post-treatment, cephalometry showed that for both males and females, angle SNA decreased, SNB increased, and lower facial heights increased significantly (p < 0.01). For the female post-treatment configuration, FESA revealed large size increases (approximately 20%) located in the inter-maxillary region, the ramus and mandibular body, and around the nasal and mental regions. Conversely, the lip region was diminished (approximately 20%). Similarly, male post-treatment showed size increases located in the inter-maxillary region that extended into the nasal region and the mandibular body (approximately 10-15%), and around the chin (15%). The lip region was diminished (approximately 5%). CONCLUSION: In the attainment of a normal occlusion, both male and female patients treated for class II malocclusions using HATA exhibit antero-posterior restraint of the maxilla, improvements in the mandible maintaining facial height, and lip changes commensurate with improvements in the soft tissue profile.

Activator Appliances↗

PubMed2001

Dose reduction by direct-digital cephalometric radiography.

Patient radiation exposure was determined for conventional and direct-digital cephalometric radiography. An anthropomorphic phantom was positioned to expose lateral cephalographs from the patient's left side. The conventional radiographs were exposed with a Siemens Orthophos C unit (77 kV, 14 mA, 0.5 s) and a film-screen system of a relative speed of 400. The direct-digital radiographs were exposed with a Siemens Orthophos DS Ceph (73 kV, 15 mA, 15.8 s). A set of 108 thermoluminescence detectors (TLDs; Bicron STI/Harshaw, Solon, Ohio) was used for dose measurements. For each measurement, 84 TLDs were placed at the surface of the head and neck, as well as inside the phantom, at anatomically relevant positions. The remaining detectors were employed for calibration purposes and quality control. The highest absorbed doses were recorded for the conventional technique at the skin of the left parotid region (132 microGy), in the left parotid gland (103 microGy), and in the ocular lens of the left eye (81 microGy). Digital cephalometry resulted in an absorbed dose about 2 times lower than the dose received by the conventional technique. The effective doses had the same relation (conventional 2.3 microSv; digital 1.1 microSv). The results demonstrate that direct-digital cephalometric radiography cuts the patient's dose in half compared with the conventional screen-film technique. Direct-digital cephalometry is more advantageous than the conventional technique from the perspective of radiation protection.

Cephalometry↗

PubMed2001

Optimal continuous positive airway pressure in patients with obstructive sleep apnoea: role of craniofacial structure.

Although nasal continuous positive airway pressure (CPAP) is effective in improving nocturnal obstructive apnoea, daytime sleepiness and well-being in patients with obstructive sleep apnoea syndrome (OSAS), not all patients tolerate this treatment. Since optimal CPAP titration is essential to maintain compliance, it is important to elucidate the factors that help to determine the optimal pressure. However, the determinants of the optimal CPAP level are controversial. The subjects comprised 27 Japanese male patients with OSAS who underwent standard polysomnography (PSG), pulmonary function tests, arterial blood gas analysis, cephalometry and CPAP titration. Twenty normal controls also underwent cephalometric analysis. The apnoea-hypopnoea index (AHI), mean oxygen saturation (mean SaO2) and the lowest SaO2 during sleep were found to be 54.7+/-22.6, 89.0+/-5.6%, and 69.7+/-9.0%, respectively by PSG. The mean optimal CPAP was 9.6+/-1.8 cmH2O. The cephalometric angles (SNA, SNB and NSBa) were similar to those found in the control subjects. but MP-H, and PNS-P were significantly longer than those in the control subjects as shown by cephalometry. The optimal CPAP was correlated with the mean SaO2 (P<0.0001), neck circumference (P<0.05) and three cephalometric variables (NSBa: P<0.01, MP-H: P<0.05, PNS-P: P<0.05). Multiple, step-wise, regression analysis showed that the mean SaO2 and NSBa were independent variables that best predicted the optimal CPAP. These variables accounted for 57.5% of the total variance (R2=0.575, P<0.001). Optimal CPAP was closely correlated with oxygen desaturation during sleep. However, the craniofacial structure had additional effects such as an independent factor in determining the optimal CPAP level.

Adult↗

PubMed2001

Cephalometric and physiologic predictors of the efficacy of an adjustable oral appliance for treating obstructive sleep apnea.

The purpose of this study was to investigate whether any physiologic or cephalometric parameters could be used to predict the efficacy of an adjustable mandibular advancement appliance for treating obstructive sleep apnea (OSA). Forty-two male and 5 female patients with OSA were recruited on the basis of baseline polysomnography with a documented Apnea and Hypopnea Index (AHI) greater than 15 per hour. Repeat polysomnography was performed with the appliance in place. Baseline cephalometry was performed for each patient, and follow-up cephalometry was completed for 19 of the subjects. The subjects were divided into 3 groups on the basis of the degree of change in the AHI with oral appliance therapy: good response (> 75% decrease in AHI), moderate response (25% to 75% decrease in AHI), and poor response (< 25% decrease in AHI). Patients with a good response were younger and had smaller upper airways. In a linear regression analysis, the change in AHI (%) was associated with physiologic (age and body mass index), cephalometric (overjet, height of the maxillary molars, vertical height of the hyoid bone), and airway variables. However, changes in either overbite or overjet were not related to changes in any of the polysomnographic variables for the 19 subjects. A stepwise regression analysis revealed a better treatment response with the adjustable mandibular advancement appliance in patients who were younger and had a lower body mass index, a longer maxilla, a smaller oropharynx, a smaller overjet, less erupted maxillary molars, and a larger ratio of vertical airway length to the cross-sectional area of the soft palate.

Adult↗

PubMed1995

The relationship between obesity and craniofacial structure in obstructive sleep apnea.

STUDY OBJECTIVE: To evaluate the interaction between craniofacial structure and obesity in male patients with obstructive sleep apnea (OSA). DESIGN: Retrospective analysis of a cohort of OSA patients. The relationships between neck circumference (NC), body mass index, apnea severity, and craniofacial and upper airway soft-tissue measurements from upright lateral cephalometry were examined. Patients were divided into groups; small to normal NC (group A), intermediate NC (group B), or large NC (group C). SETTING: A university teaching hospital and tertiary sleep referral center. PATIENTS: A consecutive series of patients with OSA who underwent polysomnography and lateral cephalometry. MEASUREMENTS AND RESULTS: Group A patients were less obese and had more craniofacial abnormalities such as a smaller mandible and maxilla and a more retrognathic mandible. Group B patients had both upper airway soft-tissue and craniofacial abnormalities. Group C patients were more obese with larger tongues and soft palates, and an inferiorly placed hyoid. Group C patients also had fewer craniofacial abnormalities than group A or B patients. There was no difference in airway size among the three groups. CONCLUSIONS: We conclude that there is a spectrum of upper airway soft-tissue and craniofacial abnormalities among OSA patients: obese patients with increased upper airway soft-tissue structures, nonobese patients with abnormal craniofacial structure, and an intermediate group of patients with abnormalities in both craniofacial structure and upper airway soft-tissue structures.

Adult↗

PubMed2000

Simple predictors of uvulopalatopharyngoplasty outcome in the treatment of obstructive sleep apnea.

STUDY OBJECTIVE: Our objective was to determine whether baseline polysomnography, cephalometry, and anthropometry data could predict uvulopalatopharyngoplasty (UPPP) success or failure. DESIGN: We retrospectively reviewed polysomnography, cephalometry, and anthropometry data from patients who underwent UPPP for obstructive sleep apnea (OSA). SETTING: A university medical center. PATIENTS: OSA was diagnosed by polysomnography in 46 patients who underwent UPPP surgery for their sleep disorder. INTERVENTIONS: UPPP surgery with/or without tonsillectomy. MEASUREMENTS AND RESULTS: The mean patient age was 43 years, and the mean body mass index was 32.5 kg/m(2). The mean presurgical apnea-hypopnea index (AHI) was 45, and the mean baseline nadir oxygen saturation was 81%. Successful surgery was defined as a reduction in AHI to < 10 or to < 20 with a 50% reduction from the patient's baseline AHI. Of the 46 patients, 16 were successfully treated and 30 did not respond to surgical treatment. A mandibular-hyoid distance (MP-H) > 20 mm was found to be significantly (p = 0.05) predictive of failure of UPPP. When stepwise regression analysis was performed utilizing postsurgical AHI as the dependent variable and presurgical AHI, age, body mass index, baseline nadir O(2) saturation, and five cephalometric measurements as independent variables, MP-H distance significantly (r = 0.524; p = 0.01) correlated positively with postsurgical AHI. The distance between the superior point of a line-constructed plane of the sphenoidale (parallel to Frankfort horizontal) and a point at the intersection of the palatal plane perpendicular to the hyoid correlated negatively with postsurgical AHI (r = 0.586; p = 0.05). By creating a logistic model of this data, an MP-H distance < 21 mm, an angle created by point A to the nasion to point B < 3 degrees, and the presence of a baseline AHI < 38 enhanced the predictability of UPPP success. CONCLUSIONS: The presence of a baseline AHI < 38 and an MP-H < or = 20 mm, and the absence of retrognathia are predictors of improvement after UPPP. Based on these findings, we would advocate the continued evaluation of cephalometric measurements and careful consideration of surgical treatment options for OSA.

Adult↗