Rhinometry and open-mouth posture in young children

Prevalence of an incompetent lip seal during growth periods throughout Japan: a large-scale, survey-based, cross-sectional study

BACKGROUND

Systemic and local factors may lead to disruption of craniofacial growth and development, causing an imbalance between the orofacial skeleton, muscle and soft tissue, dental occlusion, and the dental arch during growth periods. We aimed to reveal whether the prevalence of incompetent lip seal (ILS) varies with age and region, as well as to clarify the factors related to an ILS, in a national, large-scale epidemiological study.

METHODS

We surveyed 3399 children, from 3 to 12 years of age, visiting 66 pediatric dental clinics throughout Japan. For this survey, we employed a questionnaire consisting of 44 questions regarding daily health conditions and lifestyle habits. We evaluated the differences in ILS prevalence by age and region (using a Cochran-Armitage test for trend and a Kruskal-Wallis test), and the relationship between ILS and factors investigated in the questionnaire (using Spearman's rank correlation coefficient).

RESULTS

We observed that 30.7% of Japanese children exhibited an ILS and that the ILS rate increased with age (p < 0.001). There were no regional differences in the rate of ILS in Japanese children (p = 0.506). We revealed that 12 of 44 survey items exhibited a statistically significant correlation with ILS (p < 0.001), using Spearman's rank correlation coefficient. These items involved orofacial morphology, mouth breathing, and possibly, allergic rhinitis.

CONCLUSION

The rate of ILS seems to increase with age in children, throughout Japan. Therefore, this disorder may not self-correct during the growth periods in these children. Guidelines are required for pediatric dentists to recognize ILS among children aged 3-12 years.

Volumetric, planar, and linear analyses of pharyngeal airway change on computed tomography and cephalometry after mandibular setback surgery

INTRODUCTION

The purpose of this study was to use lateral cephalometry and computed tomography (CT) to examine the volumetric, planar, and linear changes in the pharyngeal airway after mandibular setback surgery.

METHODS

The pharyngeal airways of 12 subjects who underwent mandibular setback surgery at Seoul National University Dental Hospital were assessed linearly and volumetrically on lateral cephalometric radiographs and CT before surgery and 6 months after surgery. The pharynx, nasopharynx, and oropharynx were evaluated by volumetric analysis. Pharyngeal depth, airway space, pharyngeal soft-tissue thickness, and hyoid bone position were measured by linear analysis. The axial section area of the airway was measured by area analysis.

RESULTS

From the linear analysis, a significant decrease in pharyngeal depth and a significant posterior movement of the hyoid bone (P <0.05) were noted. Volumetric analysis by CT showed that the oropharynx decreased after mandibular setback surgery. However, the volume and the axial section area of the airway in the CT images did not change significantly after mandibular setback surgery (P >0.05).

CONCLUSIONS

Although the structures around the mandible inevitably moved backward after mandibular setback surgery on linear analysis, physiologic deformation could occur to preserve the airway capacity after sagittal compression.

Long-Term Effects of Rapid Maxillary Expansion on Nasal Area and Nasal Airway Resistance

Background

Rapid maxillary expansion (RME) may improve the nasal respiratory pattern. This study was performed to evaluate the effect of RME on the nasal cavity by acoustic rhinometry and computed rhinomanometry and to determine nasal and maxillary width by posteroanterior cephalometric radiography, up to 30 months after the orthodontic procedure.

Methods

Twenty-seven children with oral breathing, ranging in age from 7 to 10 years, and with mixed dentition were selected. The children had unior bilateral posterior crossbite involving deciduous canines and the first permanent molars. All subjects were submitted to nasofibroscopy, acoustic rhinometry, and computed rhinomanometry and posteroanterior cephalometric radiography at four different times, i.e., before expansion, immediately, 90 days and 30 months after expansion.

Results

The mean linear left-to-right nasal cavity lateral prominence and left-to-right jugal points cephalometric measures increased considerably after expansion and this increase was maintained throughout the period of evaluation. There was an immediate significant decrease in nasal resistance, up to 90 days after RME, but the nasal resistance increased 30 months after the procedure. The acoustic rhinometry results did not show any difference in values throughout time.

Conclusion

RME significantly increased nasal and maxillary width as measured by frontal cephalometry, but the nasal mucosal effects were more subtle. Also, the influence of RME on nasal resistance was not stable, and nasal resistance values returned to close to the initial ones after 30 months.

Orientation and position of head posture, scapula and thoracic spine in mouth-breathing children

OBJECTIVE

Mouth-breathing is a common clinical condition among school-age children and some studies have correlated this condition with quality of life and postural alterations. Therefore, the objective of this study was to investigate the orientation and position of the scapula, thoracic spine and head posture among mouth-breathing (MB) children and nasal-breathing (NB) children.

METHODS

Twenty-one male MB children and 21 male NB children between 8 and 12 years of age participated in the study. Data were obtained through a stereophotogrammetry system that uses passive markers over anatomical landmarks to capture the position of the segments. Internal rotation, upward rotation, anterior tilt, scapular elevation and abduction were measured bilaterally as well as thoracic kyphosis, forward head position and shoulder protrusion.

RESULTS

The MB children showed increased scapular superior position in relation to the NB group. No statistically significant differences were found between groups regarding the angular and linear measurements of the scapula. To verify reliability, three measurements were taken for each variable in the study. The intraclass correlation coefficient (ICC) showed results above 0.8 for all the variables except for the internal rotation angle (I-Rot), below 0.5, probably due to uncertainty in the palpation of the inferior angle of the scapula. Ninety-five percent of the NB children and 58% among the MB children had been breastfed, this difference was statistically significant. There were statistically significant differences between groups regarding the domains of the Autoquestionnaire Qualité de Vie Enfant Imagé (AUQEI) scale and body mass index, which was higher among the NB children.

CONCLUSIONS

MB children increased scapular superior position in comparison to NB children due probably to the position of forward head, leading to an alteration in the positioning of the mandible. The absence of significantly difference in posture pattern between groups in the present study could attributed to height-weight development in this age, as the posture of children changes in order to adapt to new body proportions, regardless of health status. The results observed in this study demonstrate the importance of using reliable measurements in the postural assessment of MB and NB children helping physical therapists to focus their strategies during rehabilitation in more specific conditions.

Electromyographic activity evaluation and comparison of the orbicularis oris (lower fascicle) and mentalis muscles in predominantly nose- or mouth-breathing subjects

INTRODUCTION

The objective of this study was to evaluate and compare the electromyographic (EMG) activity of the orbicularis oris--lower fascicle (LOO) muscle and the mentalis muscle (MT)--in predominantly nose-breathing (PNB) and mouth-breathing (PMB) subjects.

METHODS

Thirty-four subjects, 22 PNB and 12 PMB, with Class II Division 1 malocclusions were evaluated in 2001 (T1) and again in 2004 (T2), 2 years 5 months later. The age ranges of the sample were 11 years to 14 years 11 months at T1, and 13 years 4 months to 16 years 6 months at T2. EMG activity was recorded with bipolar surface electrodes at rest and during 12 movements; data were processed and normalized by the EMG highest value. The Student t test and the Mann-Whitney nonparametric test were used to compare the mean values and the variables between the observation times.

RESULTS

Greater EMG activity of the MT was observed in the PMB group at rest and swallowing at T1 and T2. At T2, increased EMG activity of the LOO at blowing and pronunciation of the phoneme \b\ was observed as well as a greater increment of EMG activity of this muscle at blowing, pronunciation of the phoneme \m\, and chewing in the PMB group. In addition, greater EMG activity of the MT at chewing in the PMB group was observed at T2.

CONCLUSIONS

These results suggest that mouth breathing influences EMG activity of the LOO and MT muscles.

Acoustic rhinometric measurements in children undergoing rapid maxillary expansion

OBJECTIVE

To evaluate geometric changes of nasal cavities in children undergoing rapid maxillary expansion and to assess the effect of this procedure on nasal airway size by means of acoustic rhinometry.

METHOD

We recruited 14 mouth-breather children (mean age 8.2 years) presenting constricted maxillary arches and scheduled for rapid maxillary expansion in the orthodontics department of our hospital. Clinical history did not reveal any allergic diseases and ENT examination was completely normal with a well-aligned nasal septum. Nasal measurements were obtained using acoustic rhinometry, which was performed before the expansion treatment and after 1-year follow-up. A postero-anterior radiograph of the skull was also performed in all patients for cephalometric analysis before and 3 months after the treatment.

RESULTS

We observed a satisfactory increment in the transverse dimension of the maxilla in all patients but one who manifested a relapse after 4 months from the treatment and required a second procedure. Similarly, acoustic rhinometric measurements and cephalometric tracings showed a statistically significant increase respectively in decongested total nasal volumes (p=0.047) and in binasal cavity width (p=0.001). However, only eight children switched their respiration from oral to nasal breathing mode.

CONCLUSIONS

Rapid maxillary expansion is an effective method for increasing the width of narrow maxillary vault and it is also associated with a significant increment in nasal volumes and in the transverse diameter of the maxilla. With regard to breathing posture, the role of this procedure still remains debatable. To date this is the first study aimed at analysing the effects of rapid maxillary expansion on nasal dimensions by means of acoustic rhinometry.

Infant oral health and oral habits

Many oral diseases and conditions, including dental caries (cavities) and malocclusions, have their origins early in life. Prudent anticipatory guidance by the medical and dental professions can help prevent many of the more common oral health problems. This article provides information on the rationale for early dental examination and instructions for pediatric and family practitioners in scheduling and conducting an early oral intervention appointment. In addition, feeding practices, non-nutritive sucking, mouth breathing, and bruxing are discussed, including their effects on orofacial growth and development.

Long-term follow-up of early treatment of unilateral forced posterior cross-bite. Orofacial status

Twenty-nine subjects, 20 years old on average and all treated at 4 years of age for unilateral forced posterior dento-alveolar cross-bite by grinding or by expansion of the upper dental arch, were clinically examined to evaluate the long-term effects of their treatment. The frequency of successful treatment-indicated as stable correction of the cross-bite-by means of only 1 treatment sequence was 59%; by grinding, 57%; and by expansion, 60%. The 18 subjects that had only been treated at the age of 4 years formed the 'early group' in our study. Eleven of our subjects had been retreated later in the mixed or permanent dentition because of a relapse of the unilateral forced posterior cross-bite and formed the 'late group'. A significantly higher frequency of mouth breathing, breathing obstacles, and snoring was found in this group. According to our clinical investigation, 2 of the subjects in our cohort still had a unilateral forced posterior cross-bite. Our findings regarding masticatory performance, bite force, and endurance showed no significant differences between the initial cross-bite and the healthy sides or between the early and the late group subjects, which showed that the masticatory function of the treated subjects was symmetrical. Grinding and expansion treatments seem to display similar success rates in the long-term regarding correction of unilateral posterior forced cross-bite.

Urinary catecholamine levels and gingivitis in children

This study investigated the relationship between gingivitis and emotionally stressful states measured by the urinary catecholamines in children. Three-hundred and fourteen (314) children, boys and girls, aged 6 to 8 years were included in the study. Gingivitis was recorded by the gingival bleeding index and dental plaque by the plaque control record index. Proximal decayed surfaces, faulty restorations, and stainless steel crowns were diagnosed clinically and radiographically. Information concerning systemic and socioeconomic factors was collected by a questionnaire. A 24-hour urine sample was collected for each subject and analyzed by the HPLC technique to assay the catecholamine content. The multiple-regression analysis was carried out to test whether gingivitis was affected by the studied variables. The 95% probability was used. The results showed that epinephrine, norepinephrine, and dopamine did not have a significant association with gingival index. Dental plaque and proximal decayed surfaces significantly affected gingivitis. Of the socioeconomic factors, mother's education had a significant association with gingivitis when all factors were included in the analysis. The data suggest that emotionally stressful states may not increase the probability of developing gingivitis in children of this age.

A comparison of nasal resistance in white Caucasians and blacks

Total nasal resistance was measured in 42 white caucasian and 32 black healthy adults by both anterior and posterior rhinomanometry after using a nasal decongestant. The nasal airway resistance was found to be lower in the blacks compared to the caucasians by both anterior and posterior methods. The mean total nasal airway resistance was 0.136 Pa/ cm3/s in the blacks and 0.179 Pa/cm3/s in the caucasians by the anterior method, and 0.134 Pa/cm3/s and 0.161 Pa/cm3/s, respectively, by the posterior method. These differences were highly statistically significant.

Open-mouth posture and maxillary arch width in young children: a three-year evaluation

A large biracial sample of children were assessed for open mouth posture and maxillary arch width once a year for 3 years. Analyses revealed that although the youngsters exhibited open-mouth posture at high levels, over time, there was a significant decrease in this behavior. Racial and gender differences, as well as a race-by-time interaction, were also evidenced. The children displayed a significant increase in maxillary arch width across time, with gender and racial differences seen in this growth pattern. Finally, when the youngsters were classified as exhibiting primarily open-mouth or closed-mouth posture, it was observed that children with open-mouth posture displayed a significantly slower pattern of maxillary growth compared with children who display anterior lip seal posture. The implications of the findings were discussed.