Is it possible to reveal a typical swallowing pattern for specific skeletal malocclusion types using M-mode sonographic imaging of tongue movements?

PURPOSE: The present study aims to compare the M­mode ultrasound findings of different skeletal malocclusions and to evaluate whether sonographic parameters can be used for the diagnosis of malocclusions. METHODS: Tongue movements of 36 adolescents aged between 10.37 and 17.29 years (mean 14.25 ± 1.78 years) were assessed using simultaneous two-dimensional real-time B­mode and M­mode sonography. The swallowing patterns of the subjects were visualized recording the motion of the tongue surface in the ultrasound images utilizing a fixed scan line through the middle of the tongue. M­mode scans of tongue motion during empty deglutition were recorded. The parameters range, duration, and speed were computed for the entirety of the swallowing process using M­mode examination. Findings were evaluated and statistically analyzed. RESULTS: No clear intraindividual repeatability in the M­mode imaging of the subjects' swallowing process could be observed. Considering the setup used in the study, it was not always possible to distinguish individual swallowing stages in the M­mode images with regard to the chosen reference points. The average duration, range of motion, and speed of swallowing were found to be 2.43 s, 24.06 mm, and 10.34 mm/s, respectively. The findings showed both intra- and intersubject variability during empty swallowing. CONCLUSION: With the help of the metrics that could be calculated based on the M­mode images, it was not possible to differentiate the swallowing acts of different skeletal malocclusion types. It remains unclear whether M­mode imaging can accurately visualize the swallowing pattern. Therefore, further progress in technology and multidisciplinary work is needed in order to establish diagnostic references regarding swallowing.

Inconsistencies in the differential diagnosis of open bite.

OBJECTIVE: To examine inconsistencies in the differential diagnosis of open bite. MATERIALS AND METHODS: Using visual judgments, a total of 77 anterior open-bite cases in the postpubertal growth period were grouped as either morphogenetic, functional, or combination. The same sample was also grouped as either hyperdivergent, normodivergent, or hypodivergent using mandibular-plane angle and conventional cephalometry. Kappa analysis was used to test the agreement between the 2 methods of evaluation, and chi2 tests were used to analyze the distribution of cephalometrically grouped hyperdivergent, normodivergent, and hypodivergent cases among the visually assessed morphogenetic, functional and combination groups and vice versa. A kappa score of 0.343 indicated a weak agreement between visual judgment and cephalometric methods of evaluation (P < .001). RESULTS: Despite the expectation that cases evaluated as hyperdivergent using cephalometry would be visually evaluated as morphogenetic, more than half of the cases assessed as hyperdivergent were in fact classified as functional. CONCLUSIONS: These findings highlight the inadequacy of relying solely on cephalometric evaluation to classify open bite.

Hemisection of a fused tooth.

Fusion is a developmental anomaly which occurs due to a union of 1 or more adjacent teeth during morphodifferentiation of the dental germs. The present case report presents the hemisection of a maxillary central incisor fused with a supernumerary tooth. A 10-year-old boy was referred to clinic with the chief complaint of the presence of a large anterior tooth. Intraoral and radiographic investigations indicated fusion between the left central incisor and a supernumerary tooth. The fused tooth was separated with a diamond bur, and the supernumerary tooth was extracted. The left central incisor was restored with composite resin and the diastema between the maxillary central incisors was closed with orthodontic treatment. The left central incisor was still healthy after a follow-up examination period of 24 months. An ideal overjet and overbite relation was achieved at the end of the orthodontic treatment. Hemisection can be considered as an appropriate treatment alternative for a permanent tooth fused with a supernumerary tooth.

Investigation of natural head posture in different head types.

The aim of this study was to investigate natural head posture (NHP) in different head types. Lateral cephalograms of 99 adults (Mean age, 21.8 years +/- SD, 2.2 yrs, range between 19 and 29 yrs) were examined. Head types were determined as Hyperbrachycephal, Brachycephal, Mesocephal or Dolichocephal according to the cephalic index. Analysis of variance and the Duncan's test were performed to assess inter-group differences for the parameters. The findings revealed that, NHP was statistically not different between the head type groups. Thus, it was suggested that environmental factors during growth may alter NHP, as well as craniofacial morphology but in a different manner (i.e. degree and direction) in each head type.