Lateral Cephalometry Research Articles

Acurácia da análise cefalométrica da faringe para o diagnóstico da síndrome da apnéia obstrutiva do sono (SAOS)

<span class="texto">Esta pesquisa teve por objetivo verificar a acurácia da cefalometria radiográfica das vias aéreas posteriores para o diagnóstico da SAOS. A amostra constou de 60 pacientes, todos com suspeita clínica de SAOS. Diagnóstico polissonográfico positivo: índice de apnéia-hipopnéia [I(A+H)] por hora de sono igual ou maior que 5 eventos. Diagnóstico cefalométrico positivo: EAPs (espaço aéreo posterior superior) < 26mm e (ou) EAPm (espaço aéreo posterior médio) < 9mm e/ou EAPi (espaço aéreo posterior inferior) < 11mm. O estudo estatístico verificou a acurácia da análise cefalométrica, comparada ao exame polissonográfico (padrãoouro). A comparação foi estabelecida através dos testes de McNemar e kappa de Cohen. A sensibilidade da análise cefalométrica foi de 91.5%. A especificidade foi de 38.5%. O valor preditivo positivo foi de 84.3%. O valor preditivo negativo foi de 55.6%. Falso negativo = 4 (quatro) situações. Falso positivo = 8 (oito) situações. O teste de McNemar mostrou não haver diferença estatisticamente significante entre os resultados auferidos pela cefalometria e pela polissonografia (p = 0.388), e o nível de concordância calculado por meio do coeficiente kappa de Cohen foi de 33.7% (p = 0.007), significante para valores de p < 0.05. A alta sensibilidade e o elevado valor preditivo positivo fazem da cefalometria radiográfica instrumento confiável, capaz de diagnosticar com alta acurácia pacientes portadores de SAOS, identificando o sítio obstrutivo relacionado à manifestação da condição. Entretanto, a baixa especificidade da cefalometria radiográfica e o seu valor preditivo negativo não permitem admiti-la como exame único.</span>

Models of management of velopharyngeal valve incompetence in developing countries. Tasks of the otolaryngologist and phoniatrician in multidisciplinary care

On the basis of the experience with 5300 various types of orofacial cleft operations, including 1130 velopharyngoplasties performed during 1959–2001, and of the 60–70 cases with velopharyngeal insufficiency (VPI) without cleft examined yearly, the author stresses that all functional consequences of velopharyngeal valve incompetence (respiratory, sucking, swallowing, speech, hearing and maxillofacial developmental disorders) should be properly assessed and managed by a multidisciplinary team. In cases with Robin-sequence, polysomnography is recommended to predict prognosis, risks and optimal time of palatoplasty which may increase respiratory problems. For assessment of oropharyngeal dysphagia due to facial clefts and VPI, cinefluoroscopy and videonasopharyngoscopy are appropriate. In the diagnosis of speech disorders, the auditive–perceptive evaluation, articulatory, speech intelligibility and teachability tests with five-point rating scale are fundamental. Among the instrumental procedures, endoscopic and radiological methods and nasometry are the most informative; to detect neuromyogen causes, electrophysiological examinations are indicated. The development of the maxillofacial complex may be followed by lateral cephalometry. Hearing disorders should be revealed continuously with subjective and objective methods (ERA, OAE, tympanometry). The management of VPI depends on the etiology. Phoniatric/logopedic and phonosurgical therapy is indicated only when neuromyogen processes are undoubtedly excluded. Regarding ear and hearing disorders, grommet and adenoidectomy may be considered as alternative methods. In developing countries, the assessment and management of VPI are recommended on three levels. On the first level basic diagnostic methods; on the second level nasopharyngo-endoscopy, X-ray methods and speech therapy; on the third level nasometry, genetic evaluation and phonosurgical interventions could be performed.

Differences in cephalometric and occlusal outcome of cleft palate patients regarding different surgical techniques

Introduction: The purpose of this study was to assess differences of the long-term results following surgical treatment in patients with cleft palate treated by two different surgical concepts. Patients: Fifty-nine adult patients operated on for cleft palate were examined. Thirty palates were closed by a two stage (Widmaier and Veau) and 29 by a single-stage procedure (Veau's pedicled flap). Methods: Lateral cephalometric and model analysis was performed. In the cephalometric analysis, the vertical and horizontal parameters of the position of maxilla and midface and transverse and sagittal dimensions of the models were compared between the two groups. Results: Model analysis: According to the Bolton analysis the maxillary dental arch was too large in 22 patients in each group. The other patients had mandibular arches that were too large. In 18 patients with two-stage closure and in 9 patients with one-stage closure, a space deficit in the lateral part of the maxilla was observed. Persisting transverse deficits were seen in all patients with two-stage repairs and in 11 patients with one-stage repairs. The deficit was more severe in the molar area in the first group and almost equally severe in the premolar and the molar regions of the second group. A sagittal deficiency was found more often in patients with two-stage repairs while Angle's class I occlusion was seen more often in patients with one-stage surgery. Lateral cephalometry: Similar SNA-angles were seen in both groups whereas the ANB-angle was greater following two-stage repair. In both patient groups a low inclination of the midface was seen. The vertical dimension of the midface in comparison with the lower face was normal in the one-stage group; in the other group a deficiency of the anterior midface height was registered. Conclusion: There was a more severe growth impairment of the midface in patients with this type of two-stage palatal repair. The horizontal deficiency was similar in both groups. The long-term occlusal result revealed smaller sagittal and transverse deficiencies in patients with this type of single-stage closure.

Contribution of body habitus and craniofacial characteristics to segmental closing pressures of the passive pharynx in patients with sleep-disordered breathing.

Obesity and craniofacial abnormalities may contribute to the pathogenesis of obstructive sleep apnea. The purpose of this study was to evaluate the influence of body habitus and craniofacial characteristics on types of pharyngeal closure. The types of pharyngeal closure were determined by endoscopic evaluations of closing pressures of the passive pharynx in 54 paralyzed and anesthetized patients with sleep-disordered breathing (SDB). Assessment of craniofacial characteristics of the SDB patients and 24 normal subjects were made by lateral cephalometry. As compared with normal subjects, SDB patients demonstrated receded mandibles and long lower faces with downward mandible development. SDB patients with positive closing pressures at both the velopharynx and oropharynx (VP + OP group) demonstrated smaller maxillas and mandibles than those with positive closing pressures at the velopharynx only (VP-only group). Obesity was more prominent in the VP-only group than in the VP + OP group. Our results suggest that obesity and craniofacial abnormalities contribute synergistically to increases in collapsibility of the passive pharyngeal airway in patients with SDB. Furthermore, the relative contribution of obesity and craniofacial anomaly appears to determine the type of pharyngeal closure in SDB.

Frontal and lateral cephalometry in patients with sleep-disordered breathing.

The traditional lateral-view cephalometric analysis is limited because it provides only two-dimensional analysis of the three-dimensional craniofacial structure. The objectives were to analyze lateral and frontal cephalometric radiographs in a series of normal patients and those with varying degrees of sleep-disordered breathing and to define the degrees of narrowing or other unfavorable anatomical changes that might differentiate the patients with sleep-disordered breathing from normal subjects. A prospective study of 100 adult patients with sleep-disordered breathing and 60 age-matched normal subjects. An analysis of the lateral and frontal cephalometric measurements was performed to assess velopharyngeal anatomical features. A comparison was made between the patients' polysomnographic and cephalometric analyses. The compromised cephalometric parameters that may be found in patients with sleep-disordered breathing include acute skull-base and bony nasopharynx angles, inferior hyoid position, thickening of the velum, reduced retrovelar posterior air space along with thickening of the velum, thickening of the posterior pharyngeal wall, and narrowing of the velopharyngeal lumen. Worsening of sleep-disordered breathing was generally associated with increased numbers of compromised cephalometric parameters. As body mass index increases, there is reduced velopharyngeal width, the velum thickness is increased, and the posterior pharyngeal wall thickness is increased. Sleep-disordered breathing is associated with statistically significant changes in a number of cephalometric measurements. Frontal cephalometric analysis adds further information regarding the anatomical assessment of patients with upper airway obstruction, enhancing the traditional lateral cephalometric view.

The Influence of Cephalometric Parameters on Resonance of Speech in Cleft Lip and Palate Patients An Interdisciplinary Study

There are only few studies concerning the correlation between craniofacial morphology and resonance of speech in cleft palate patients. Moreover, these investigations show a considerable inhomogeneity in material and method, their basic approach was predominantly retrospective, and the statistical methods were restricted to univariate procedures. Thus, the aim of the present study was twofold: firstly to clarify the extent to which correlations exist between craniofacial morphology and resonance of speech in cleft palate patients, subject to a sufficiently large number of patients being available to ensure differentiation with regard to age and cleft type, and secondly, within a prospective longitudinal study in juvenile cleft palate patients, to investigate whether pubertal craniofacial growth changes result in changes of resonance. The collective comprised 137 cleft palate patients. The following investigations were performed: lateral cephalometry, nasometry, and standardized speech recording. Additionally, these investigations were repeated in 51 juvenile patients after a minimum time interval of 2 years. In order to analyze the complex relations between craniofacial morphology and degree of hypernasality, multivariate statistical procedures were applied. The results of the present study indicate complex correlations between cephalometric parameters and resonance of speech, requiring age-specific differentiation. In this regard, the ratios between the length of the soft palate and the sagittal depth of the nasopharyngeal airway were of prime importance. Beyond this, significant correlations were found between craniofacial growth changes and changes of resonance during puberty which might be influenced both by dentofacial orthopedics and by maxillofacial surgery.

Comparison of three facebow/semi-adjustable articulator systems for planning orthognathic surgery

Our aim was to measure the steepness of the occlusal plane produced by three different semi-adjustable articulators: the Dentatus Type ARL, Denar MkII, and the Whipmix Quickmount 8800, and to assess the influence of possible systematic errors in positioning of study casts on articulators that are used to plan orthognathic surgery. Twenty patients (10 skeletal class II, and 10 skeletal class III) who were having pre-surgical orthodontics at Liverpool University Dental Hospital were studied. The measurement of the steepness of the occlusal plane was taken as the angle between the facebow bite-fork and the horizontal arm of the articulator. This was compared with the angle of the maxillary occlusal plane to the Frankfort plane as measured on lateral cephalometry (the gold standard). The Whipmix was closest to the gold standard as it flattened the occlusal plane by only 2 ° (P<0.05). The results of the Denar and Dentatus differed significantly from those of the cephalogram as they flattened the occlusal plane by 5 ° and 6.5 ° (P<0.01), respectively. Clinicians are encouraged to verify the steepness of the occlusal plane on mounted study casts before the technician makes the model.

Cephalometric characteristics of nonobese patients with severe OSA.

The purpose of this study was to determine the facial characteristics of nonobese patients with obstructive sleep apnea (OSA). Observational data on a cohort of patients was analyzed retrospectively. The subjects were classified into four groups: nonobese mild, obese mild, nonobese severe, and obese severe. The nonobese mild group included patients with a body mass index (BMI = kilogram/meter2) <25 and an apnea-hypopnea index (AHI) >5 and <15; the obese mild patients had a BMI >35 and an AHI >5 and <15; the nonobese severe patients had a BMI <25 and an AHI >40; the obese severe group had a BMI >35 and AHI >40. Thirty-three male patients referred for overnight polysomnography and lateral cephalometry who met the selection criteria were included. Between-group differences were examined pairwise by analysis of variance (ANOVA) with Bonferroni correction. Only two variables--lower facial height and overbite--were significantly different at p<0.05 between the nonobese severe group and the obese mild group. A discriminant analysis on the cephalometric measurements revealed that patients in the nonobese severe group could be distinguished from patients in other groups by their facial characteristics. OSA patients do not have a homogenous bony structure of the face. In particular, OSA severity in nonobese severe patients may be associated with a vertical skeletal disharmony.

Effect of obesity and erect/supine posture on lateral cephalometry: relationship to sleep-disordered breathing.

Craniofacial and upper airway anatomy, obesity and posture may all play a role in compromising upper airway patency in patients with the sleep apnoea/hypopnoea syndrome. The aim of this study was to investigate the relationship between obesity, facial structure and severity of sleep-disordered breathing using lateral cephalometric measurements and to assess the effect of body posture on cephalometric measurements of upper airway calibre variables in obese and non-obese subjects. Lateral cephalometry was carried out in erect and supine postures in 73 awake male subjects randomly selected from patients referred for polysomnography who had a wide range of apnoea/hypopnoea frequencies (1-131 events x h sleep(-1)). Subjects were divided into non-obese (body mass index (BMI) < 30 kg x m(-2); n=42) and obese (BMI > or = 30 kg x m(-2); n=31) groups. Significant but weak correlations were found between apnoea/hypopnoea index (AHI) and measurements reflecting upper airway dimensions: uvular protrusion-posterior pharyngeal wall (r=-0.26, p<0.05) and hyoid-posterior pharyngeal wall (r=0.26, p<0.05). Multiple regression using both upper airway dimensions improved the correlation to AHI (r=0.34, p=0.01). Obese subjects had greater hyoid-posterior pharyngeal wall distances than non-obese subjects, both erect (42+/-5 versus 39+/-4 mm, respectively (mean+/-SD) p<0.01) and supine (43+/-5 versus 40+/-4 mm, p<0.05). Skeletal craniofacial structure was similar in obese and non-obese subjects. In conclusion, measurements reflecting upper airway size were correlated with the severity of sleep-disordered breathing. Differences in upper airway size measurements between obese and non-obese subjects were independent of bony craniofacial structure.

Shape of the face and tongue in obstructive sleep apnea patients--statistical analysis of coordinate data.

To determine the shape difference of the face and tongue of obstructive sleep apnea (OSA) patients, in comparison to those of non-apneic patients. Retrospective analysis of observational data on a cohort of patients. A university teaching hospital and sleep referral center. SAMPLE POPULATION AND METHOD: Eighty patients referred for overnight polysomnography and lateral cephalometry and who met the selection criteria were included. Upright and supine cephalograms were obtained and subgrouped based on the severity of clinical symptoms. Shape differences between the groups were assessed by a multiple analysis of variance and a Hotelling's T2. A set of anatomical landmarks were selected for outlines of the face and the tongue on cephalograms. X and Y coordinates of each landmark were utilized as variables. As symptoms become severe, the hyoid bone and the submental area positioned inferiorly and the fourth vertebra relocated posteriorly with respect to the lower mandibular border. When subjects changed their body position from the upright to the supine, the posterior part of the tongue appeared to sink down. The hyoid bone position to epiglottis-retrognathion line in the supine position distinguishes OSA patients from non-apneic subjects. Despite many limitations, we demonstrate that the supine cepahlometrics during wakefulness can be a useful adjunctive diagnostic tool for OSA, when cephalograms are analyzed in a coordinate data form.

Longitudinal Study on Cranio-Maxillofacial Growth and Development in Children with Cleft Lip and Palate. Analysis with Lateral Cephalometry.

Longitudinal Study on Cranio-Maxillofacial Growth and Development in Children with Cleft Lip and Palate. Analysis with Lateral Cephalometry.

Relationship between difficult tracheal intubation and obstructive sleep apnoea

The upper airway abnormalities predisposing to difficult tracheal intubation may also predispose to obstructive sleep apnoea (OSA). The potential association is important as both conditions increase perioperative risk and patients with a trachea that is difficult to intubate may need assessment for OSA. We determined if patients with difficult intubation are at greater risk of OSA and, if so, whether or not they have characteristic clinical or radiographic upper airway changes. We studied 15 patients in whom the trachea was difficult to intubate and 15 control patients. Each was evaluated clinically (Mallampati score, thyromental distance, neck circumference, head extension), polysomnographically (apnoea-hypoponea index (AHI)) and radiographically (lateral cephalometry). AHI was greater in the difficult intubation group (mean 28.4 (SD 31.7)) compared with controls (5.9 (8.9)) (P < 0.02); eight of 15 patients in the difficult intubation group and two of 15 in the control group had an AHI > 10 (P < 0.03). Difficult intubation, but not OSA, was associated (P < 0.05) with a smaller thyromental distance and mandibular length, and greater soft palate length. Both difficult intubation and OSA were associated (P < 0.05) with a greater Mallampati score, anterior mandibular depth, and smaller mandibular and cervical angles. OSA, but not difficult intubation, was associated (P < 0.05) with increased neck circumference, tongue area and craniocervical angle, and decreased head extension, mandibular ramus length and atlantooccipital distance. We conclude that difficult intubation and OSA are related significantly. They share anatomical features which act to reduce the skeletal confines of the tongue. Patients with OSA may compensate, when awake, by increasing craniocervical angulation, which increases the space between the mandible and cervical spine and elongates the tongue and soft tissues of the neck.

Prediction of liability to orofacial clefting using genetic and craniofacial data from parents.

BACKGROUND: Cleft lip with or without cleft palate (CL(P)) and isolated cleft palate (CP) are separate clinical entities and for both polygenic multifactorial aetiology has been proposed. Parents of children...

Obstructive sleep apnoea syndrome: results and conclusions of a principal component analysis

A cephalometric analysis according to Hasund, supplemented by special obstructive sleep apnoea syndrome (OSAS) parameters, was performed on 169 patients who had been referred from the sleep laboratory. Statistical analysis showed a correlation between specific cephalometric landmarks including posterior airway space (PAS), a soft palate length, hyoid position and posterior growth development of the mandible and OSAS severity. A principal component analysis differentiated between four subgroups of OSAS patients: (1) orthognathic obese subjects; (2) patients with a long soft palate and low-positioned hyoid; (3) retrognathic patients with narrow PAS; and (4) prognathic ones. Lateral cephalometry is an important contribution to OSAS diagnostics and oral and maxillofacial therapy procedures.

Sex Determination by Discriminant Function Analysis of Lateral Radiographic Cephalometry

The present work is an attempt to develop a new method to determine sex from the skull with lateral radiographic cephalometry and discriminant function analysis. The superciliary ridges, frontal sinuses, external occipital protuberance, and mastoid processes were adopted as objects of lateral radiographic cephalometric measurements. With discriminant functions created from 18 established cephalometric variables, a total of 100 cases were classified into two sexual groups with 100% accuracy in a random sample of Taiwanese adults. Therefore, we may obtain a much greater reliability of sex determination from skulls according to this newly developed technique.

Effect of chronic continuous positive airway pressure (CPAP) therapy on upper airway size in patients with sleep apnoea/hypopnoea syndrome.

There is evidence to suggest that chronic continuous positive airway pressure (CPAP) therapy may produce reversible changes in upper airway morphology and function in patients with sleep apnoea/hypopnoea. This study was designed to examine the effect of chronic CPAP therapy on upper airway calibre. Twenty four men with the sleep apnoea/hypopnoea syndrome (mean (SE) apnoea/hypopnoea index 37 (5)) underwent lateral cephalometry with measurement of posterior airway space performed before and at least three months after initiation of CPAP therapy. There was no weight change between the two assessments and mean CPAP use was 4.8 (0.4) hours per night. Posterior airway space (PAS) was measured in erect and supine postures. PAS supine increased with CPAP therapy from a mean (SE) of 11.8 (0.8) mm to 13.4 (0.8) mm, but PAS erect did not. Correlation of the change in PAS (dPAS) before and after CPAP therapy showed an increase with increasing CPAP compliance measured as machine run time both for dPAS supine (r = 0.68) and dPAS erect (r = 0.47). Patients with the sleep apnoea/hypopnoea syndrome regularly using CPAP for more than four hours per night all showed an increase in dPAS supine. The use of chronic CPAP increases PAS supine probably by a reduction in upper airway oedema, and the change in size is dependent on CPAP use.

Velopharyngeal incompetence and persistent hypernasality after adenoidectomy in children without palatal defect.

Persistent hypernasal speech after adenoidectomy has been reported in children with palatal deficiency. Hypernasality after adenoidectomy can also occur in children with normal palatal function. The aim of the present study was to identify the cause of velopharyngeal incompetence and hypernasality after adenoidectomy in children who did not have palatal defect as a predisposing factor. Sixteen children who developed hypernasality after adenoidectomy were included in the present study. Standard lateral cephalometry, videofluoroscopy, and nasopharyngoscopy were performed to visualize the velopharynx and its function during speech. The results showed that enlarged tonsils and prominent remaining adenoid tissue on the posterior pharyngeal wall were the causes of hypernasality in these children. Incomplete removal of the adenoid tissue should be avoided and enlarged tonsils should be removed at the time of adenoidectomy to prevent the risk for postoperative hypernasality.

The Relationship Between Obesity and Craniofacial Structure in Obstructive Sleep Apnea

To evaluate the interaction between craniofacial structure and obesity in male patients with obstructive sleep apnea (OSA). 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). A university teaching hospital and tertiary sleep referral center. A consecutive series of patients with OSA who underwent polysomnography and lateral cephalometry. 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. 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.

Cephalometric and computed tomographic predictors of obstructive sleep apnea severity

The interaction between craniofacial structure assessed by lateral cephalometry, and tongue, soft palate, and upper airway size determined from computed tomography (CT) scans was examined in 25 control subjects and 80 patients with obstructive sleep apnea (OSA). On the basis of the cephalometric analyses, the patients with OSA had retruded mandibles with large ANB angle differences, elongated maxillary and mandibular incisors and mandibular molars, and high total upper and lower face heights The computed tomographic evaluations revealed that patients with OSA also had larger tongue, soft palate, and upper airway volumes. Men with OSA and skeletal Class I malocclusions had significantly larger soft palates than comparable controls. Both tongue and soft palate volumes were positively correlated with body mass index. A principal component analysis reduced the database, and one significant correlation was identified. Subjects with high total, upper and lower face heights, elongated maxillary and mandibular teeth, and proclined lower incisors were observed to have large tongue, soft palate, and upper airway volumes, to have a higher apnea index and to be obese. Linear regression analysis indicated that a high apnea index was seen in association with large tongue and soft palate volumes, a retrognathic mandible, an anteroposterior discrepancy between the maxilla and mandible, an open bite tendency between the incisors, and obesity. (A M J O RTHOD D ENTOFAC O RTHOP 1995;107:589-95.)

三次元的な下顎枝外側骨片復位・固定システムによる下顎後退術後の後戻りに関する研究

We have previously reported an exact three-dimensional repositioning technique for external ramus fragments in sagittal split ramus osteotomy using screw fixation. Eighteen patients with mandibular prognathism who underwent sagittal split ramus osteotomy were studied. In one-half of these cases, a circumferential wire fixation (circum group) was performed, and in the other half a screw fixation with this repositioning technique (screw group) was used. These cases were studied with regard to preoperative, postoperative and one-year postoperative changes in lateral roentogenographic cephalometry. The following results were obtained: 1. There was no clockwise rotation of external fragments in the screw group. 2. Internal fragments relapsed anteriorly in the circum, group. 3. At one-year postoperative follow-up, the mandibular length relapsed 15% in the circum group and 4 % in the screw group.It was suggested that this repositioning technique is effective for preventing postoperative relapse.