[Investigation of tongue movements during swallowing with M-mode ultrasonography].

AIM: Evaluation of tongue movements during swallowing with a computer-aided, M-mode ultrasonography system in combination with a cushioning device. SUBJECTS AND METHOD: Motion pattern and activity duration of the tongue dorsum during swallowing were investigated in 55 volunteers. RESULTS: The duration, amplitude and pattern of tongue movements during swallowing differed interindividually, whereas they were reproduced well intra-individually. We thus observed three characteristic variations in phases I and IIIb and two in phases IIb and IIIa. The movement pattern in phase IIa and in the rest phase was uniform. CONCLUSIONS: M-mode ultrasonography provides valid information on tongue movements without any side-effects and is thus a useful tool in the diagnosis and research of tongue functions in orthodontics and dentistry.

Unilateral horizontally impacted maxillary canine and first premolar treated with a double archwire technique.

A patient with a unilateral horizontally impacted upper left canine and first premolar was treated orthodontically. The use of a double archwire technique achieved the desired treatment goals. We discuss the problems associated with impacted maxillary canines and first premolars and the biomechanical interventions used for this patient.

Comparison of tongue functions between mature and tongue-thrust swallowing--an ultrasound investigation.

Many studies have proved that tongue thrusting plays a significant role in the etiology of some orofacial deformities. To learn more about the relationship between tongue function and the form of orofacial structures, it is important to recognize patients with abnormal swallowing patterns. A cushion scanning technique in combination with M-mode ultrasound was applied to measure and compare tongue movements between mature swallowing and tongue-thrust swallowing. Forty subjects with a mature swallowing pattern (23 female, 17 male, aged 21.8 +/- 6.1 years) and 15 subjects with a tongue-thrust swallowing pattern (8 female, 7 male, aged 13.6 +/- 6.6 years) were included in this study. Duration, range, speed, and reproducibility for each of the swallowing subphases were calculated and compared. Tongue-thrust swallowers had a longer late transport phase than mature swallowers (P <.0009), and the tongue speed was faster in the early final phase (P <.05) compared with mature swallowers. Distinctly different movements can be positively differentiated with the method used.

Differential diagnosis between infantile and mature swallowing with ultrasonography.

In order to investigate the difference in tongue movement between visceral (infantile) and somatic (mature) swallowing patterns, 12 visceral (seven females, five males) and 14 somatic (eight females, six males) swallowers were examined with the B+M-mode ultrasound technique. Movements of the tongue tip and submental musculature during swallowing were recorded on video cassette and evaluated with a personal computer. The results demonstrated that the tongue dorsal surface, which was thought to be ideal for observing tongue function, was not suitable for differentiating between visceral and somatic swallowing patterns. Conversely, the movements of the genioglossus muscle were found to be identical within groups but significantly different (P < 0.01) from each other between the two swallowing patterns. Therefore, the genioglossus muscle can serve as a reliable means for differentiating between visceral and somatic swallowers.

Measurement of tongue movement during vowels production with computer-assisted B-mode and M-mode ultrasonography.

OBJECTIVES: We sought to apply B- + M-mode ultrasonography in combination with the cushion-scanning technique (CST) in quantitative analysis of tongue movement during vowel articulation. STUDY DESIGN AND SETTING: Twenty normal persons (10 women and 10 men) were enrolled in this study. Each individual was asked to enunciate 5 vowels:/e/, /i/, /aI/, /o/, and /ju/. A noninvasive diagnostic technique, computer-assisted B-mode plus M-mode ultrasonography, was used in combination with the CST to assess their tongue movement. The sonographic signals were recorded on a video recorder and then transferred to a personal computer via a frame grabber for digital assessment. RESULTS: M-mode images show an amplitude-time diagram, whereas B-mode images reveal midsagittal tongue configuration. The ranges of tongue movement in midsagittal plane in male speakers during production of the vowels /e/, /i/, /aI/, /o/, and /ju/ were 8.29 +/- 1.76, 4.00 +/- 0.78, 13.82 +/- 2.86, 14.05 +/- 1.63, and 6.72 +/- 1.66 mm, respectively; for female speakers, the averages were 7.19 +/- 0.92, 3.36 +/- 1.31, 12.74 +/- 2.16, 12.86 +/- 2.18, and 7.11 +/- 2.09 mm, respectively. CONCLUSIONS: The computer-assisted B-mode plus M-mode ultrasonography in combination with the CST provides a standardized and quantifiable ultrasonographic examination for the clinical investigation of tongue movement during vowel articulation. In our study group, there was no difference in the thickness of tongue or the range of tongue movement in midsagittal plane during articulation of the selected vowels between males and females. Further exploration can be extended in the field of speech research by this valuable tool.

Dentofacial morphology and tongue function during swallowing.

To understand the role of the tongue in the development of occlusion, we examined the relationship between tongue movements during swallowing and dentofacial morphology with ultrasonography, cephalometric radiography, and dental casts. Duration, magnitude, and speed of tongue movements were measured in 112 healthy adult volunteers and compared with their dentofacial morphology with a simple correlation analysis. The results showed that the movements of tongue during swallowing are related to dentofacial morphology, especially in the motion magnitude of the early final phase (phase IIIa), but that few correlations are found when analyzing the duration and the speed of swallowing. The results also showed that the intermaxillary vertical dimension is significantly and positively correlated with the motion magnitude of the tongue movements. Furthermore, we found that arch length increased with prolonged duration of swallowing. This study showed that the computer-aided B+M mode of ultrasonography combined with the cushion-scanning technique is a valuable tool for investigating the relationship between tongue movements during swallowing and dentofacial morphology.