Cephalometric evaluation of facial types in preschool children without sleep-related breathing disorder

Soft tissue airway dimensions and craniocervical posture in subjects with different growth patterns

OBJECTIVE

To compare the dimensions of the nasopharynx and oropharynx of subjects with different growth patterns and to determine whether any correlation exists with their craniocervical posture.

MATERIALS AND METHODS

Cephalometric radiograph of 60 subjects (16-25 years old), taken in natural head position, were divided into three groups according to the mandibular plane angle: hypodivergent (SN/MP <26°), normodivergent (SN/MP 26°-38°), and hyperdivergent (SN/MP <38°). Correlations were calculated between nasopharyngeal area, oropharyngeal area, and craniocervical posture. Continuous variables were compared by one-way analysis of variance, and the significance of mean difference between the groups was done by the Tukey post hoc test. A value of P < .05 was considered statistically significant.

RESULTS

Patients in the hyperdivergent group were found to have significantly smaller nasopharyngeal and oropharyngeal areas than the other groups (P < .001 and P < .05, respectively). Similarly, the oropharyngeal area in the normodivergent group was significantly smaller than that in the hypodivergent group (P < .05). However, no significant differences were found in the nasopharyngeal area between the hypodivergent and normodivergent groups and between the hyperdivergent and normodivergent groups (P > .05). Reduced pharyngeal airways were typically seen in patients with a large craniocervical angle and a large mandibular inclination.

CONCLUSIONS

Smaller nasopharyngeal and oropharyngeal airways were seen in connection with a large craniocervical and a large mandibular inclination. We therefore suggest that the vertical skeletal pattern may be one of the factors that contribute to nasopharyngeal and oropharyngeal obstruction.

Relationship between growth of facial morphology and chronologic age in preschool children with obstructive sleep apnea

BACKGROUND

The purpose of this study was to evaluate the relationship between facial morphology using cephalometry and chronologic age in preschool children with obstructive sleep apnea (OSA).

MATERIALS AND METHODS

From a group of lateral cephalometric radiographs taken of 35 children with OSA for diagnostic purposes, 15 were selected for the present investigation based on head position. The subjects consisted of preschool children with both OSA and primary dentition, all of them with a lowest documented SpO(2) <90% and a lowest 0 <AI. The control group included 15 preschool children with primary dentition and without enlarged tonsils or adenoids.

RESULTS

The present findings reveal that, compared to the controls, OSA children had a narrower pharyngeal airway space related to OSA. In addition, we found that, although there were direct correlations between heights, nasal floor and corpus length, with chronologic age in the controls, there was no significant correlation between height, nasal floor length or corpus length with age in the OSA children.

CONCLUSION

Obstructive sleep apnea in children may be associated with growth disturbances of the nasal floor and corpus length.

Dentofacial characteristics as indicator of obstructive sleep apnoea-hypopnoea syndrome in patients with severe obesity

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is a complex disease with a multifactor aetiology. OSAHS is strongly associated with obesity, but there are many other clinical risk factors, such as the dentofacial characteristics of hard and soft tissues, hyoid bone position, neck circumference, upper airway spaces and nasal respiration. A descriptive cross-sectional study was carried out involving 13 patients (one man and 12 women) with severe obesity in order to evaluate specific physical dentofacial characteristics through a cephalometric examination. Cephalometry was analysed using 29 measurements of the hard and soft tissues of the craniofacial structures and dimensions of the upper airways. The demographic data revealed a mean body mass index of 48 ± 6.26 kg m(-2) and cervical circumference of 43 ± 3.69 cm. No patient exhibited important facial asymmetry and facial types 1 (normal) and 3 (mandible forward) were the most prevalent. Septal deviation was observed in 46% of patients. The most prevalent modified Mallampati index score was between 3 and 4, while grade 1 was the most prevalent tonsillar hypertrophy index score (46%). Cephalometry revealed angular and linear measurements with normally acceptable values for the hard tissues. Obese patients seem to have a normal craniofacial structure and the risk of developing OSAHS is especially related to obesity.

Dimensões nasofaringeanas e faciais em diferentes padrões morfológicos

OBJETIVO: o presente estudo propõe-se a comparar as dimensões da nasofaringe e as características esqueléticas avaliadas por exame cefalométrico, em indivíduos com padrões morfológicos distintos. MÉTODOS: foram utilizadas 90 telerradiografias de pacientes de ambos os gêneros, de 12 a 16 anos de idade, as quais foram igualmente divididas em três grupos distintos, referentes aos padrões morfológicos - braquifacial, mesofacial e dolicofacial. Foram realizadas medições específicas da região nasofaringeana (ad1-Ptm, ad2-Ptm, ad1-Ba, ad2-S0, (ad1-ad2-S0-Ba-ad1/Ptm-S 0-Ba-Ptm) X 100, e Ptm-Ba) e relativas ao padrão esquelético da face. RESULTADOS: observou-se que os pacientes dolicofaciais apresentaram menor profundidade sagital óssea (Ptm-Ba) e da via aérea da nasofaringe (ad1-Ptm e ad2-Ptm). Sugere-se que essas diferenças estejam relacionadas a um posicionamento relativamente mais posterior da maxila, comum a esses pacientes. Todavia, não foram detectadas diferenças quanto à espessura de tecido mole na parede posterior nasofaringeana (ad1-Ba e ad2-S0), ou à sua proporção em relação a toda a área delimitada para a nasofaringe [(ad1-ad2-S0-Ba-ad1/Ptm-S 0-Ba-Ptm) X 100]. CONCLUSÃO: sugere-se, portanto, que as características faciais de excesso vertical encontradas em pacientes dolicofaciais podem ocorrer, dentre outros fatores, em virtude da obstrução da via aérea nasofaringeana, uma vez que tais dimensões se apresentaram menores para os dolicofaciais.

Can facial type be used to predict changes in hyoid bone position with age? A perspective based on longitudinal data

INTRODUCTION

Low positioning of the hyoid bone is associated with the unique human ability of speech, but it might also predispose the airway to collapse. The low position of the hyoid bone has been studied in adults with sleep apnea. However, information on age-related changes in hyoid bone position in the general adult population is sparse.

METHODS

We used pairs of lateral cephalometric radiographs taken 15 years apart to assess vertical changes over time in hyoid position in 163 normal white men (ages, 30-72 years).

RESULTS AND CONCLUSIONS

Significant changes in hyoid bone position were independent of age or obesity but were related to facial type, as classified by the steepness of the lower margin of the mandible. Changes in hyoid position over time were significant in dolichofacial subjects but not in brachyfacial subjects. This finding might be particularly important because a low hyoid bone with a brachial face appears to be a morphologic characteristic of nonobese patients with severe obstructive sleep apnea.

Positional changes of oropharyngeal structures due to gravity in the upright and supine positions

OBJECTIVES

To compare the responses of oropharyngeal structures to gravity while sitting upright or lying down in a supine position.

METHODS

Seven subjects were evaluated by cone beam CT (CBCT) while in the upright position and by a four-row multidetector helical CT (MDCT) while in the supine position. All of the voxel sizes were adjusted to be 0.3x0.3x0.3 mm3 in the x-y-z axis. The posterior nasal spine, basion and fourth cervical bone were used as references to measure positional changes in the oropharyngeal structures between the upright and supine positions. The smallest areas in the oropharynx were also evaluated.

RESULTS

The soft palate, epiglottis and entrance of the oesophagus moved caudally with the positional change from supine to sitting upright, and moved posteriorly when the position changed from an upright to a supine position. The hyoid bone moved caudally but not posteriorly in response to the same positional changes. The width and length of the smallest area present in the oropharynx was larger in the upright position than in the supine position.

CONCLUSIONS

Gravity can produce movements in oropharyngeal structures in response to postural changes between sitting upright and lying in the supine position.

Diagnostic studies in the assessment of pediatric sleep-disordered breathing: techniques and indications

In summary, SDB is a common condition in children that can have serious complications if left undiagnosed and untreated. OSA is the most commonly recognized form of SDB in children. The history and physical have limitations in their capacity to determine which children have SDB. Abbreviated or screening techniques, such as audio- or videotaping, oximetry studies, nap studies, or home studies, tend to be helpful if the results are positive but have a poor predictive value if the results are negative. Overnight polysomnography is the gold standard for the diagnosis of SDB in children. It is important that children are studied in laboratories that have expertise with children. Often, children with SDB have associated nonrespiratory or behavioral sleep disorders that also must be evaluated and addressed.

Absence of facial type differences among preschool children with sleep-related breathing disorder

The aim of this study was to find out whether there are specific facial types and a specific hyoid bone position in preschool children with sleep-related breathing disorder (SBD). A total of 69 children were divided into 4 groups based on the mandibular line/Frankfurt horizontal angle and apnea index. There were 19 children with hyperdivergent facial type and SBD and 19 children with neutral facial type and SBD, all of them with documented 0 < AI < 5. Ten children had hyperdivergent facial type and non-SBD, and 21 children neutral facial type and non-SBD. The present findings show that SBD may be associated with both hyperdivergent and neutral facial type. Furthermore, we could not find any specific hyoid bone position related to SBD, non-SBD, or to facial type. In conclusion, it is important to note that while evaluation based on facial type (mandibular shape or position) does not necessarily distinguish between children with SBD and children without SBD (non-SBD), important differences are found in the pharynx. Short nasal floor length, long soft palate, and particularly short upper pharyngeal width can be considered indicators of SBD.