Condylar response to functional therapy with Twin-Block as shown by cone-beam computed tomography

Abstract

Objective: To evaluate the condylar changes through cone-beam computed tomography (CBCT) images in patients treated with Twin-Block functional appliance. Materials and Methods: In this retrospective study, CBCT images of 30 patients who were treated with the Twin-Block appliance were used. Mandible was segmented and pretreatment and posttreatment (T0 and T1) condylar volume was compared. The angle between sella-nasion-Point A (SNA), angle between sella-nasion-Point B (SNB), angle between Point A-nasion-Point B (ANB), midfacial length (Co-A), mandibular length (Co-Gn), and the distances from right condylion to left condylion (Co R -Co L ) were also measured on three-dimensional images. Differences were analyzed with Wilcoxon signed rank tests, and Mann-Whitney U-tests were used to compare the scores of male and female participants. Significance was set at P , .05. Results: In this study, a decrease in SNA and ANB (P , .05 and P , .01, respectively) and an increase in SNB (P , .01) were found. Additionally, Co R -Co L , Co-Gn, and condylar volume increased at both the left and right sides (P , .01). However, increase at Co-A was not statistically significant (P . .05). Comparison of differences by sex was not statistically significant for all measurements (P . .05). Conclusion: Twin-Block appliance increases condylar volume, mandibular length, and intercondylar distance by stimulating growth of condyle in an upward and backward direction.

Impact of functional mandibular advancement appliances on the temporomandibular joint - a systematic review

“…Also, no great differences were found in the mandibular body and the growth of the ramus, in condyle flexibility or in changes in gonial angle. In contrast, Yildirim et al (23) observed that treatment with the Twin Block increased the volume of the condyle, the length of the mandible and the inter-condyle distance due to stimulation of condyle growth upwards and backwards.…”

Evaluation of Changes in TMJ Position for Angle Class I Malocclusion After Orthodontic Treatment by Using Cephalometric Radiograph

“…Some of these studies showed a significant relation in changes of condyle position after orthodontic treatment. 16,21,28 For the mean difference in Condylion to TC line before and after orthodontic treatment, Angle class I type 1 is 9.8%, Angle class I type 2 is 11.9%, Angle class I type 3 is 9.3%, Angle class I type 4 is 9.2% and for Angle class I type 5 is 8.2%. The p-value of this five groups of sample were less than 0.05 which showed that that was a statistically significant effect observed in the condylar osition for five types of Angle class I malocclusion before and after orthodontic treatment.…”

“…20 Cephalometric radiograph also considered as a common approach in radiographic to evaluate TMJ due to its availability, low radiation requirement, and affordable cost. 21 In this study, we attempted to determine if there was any difference in TMJ position in Angle class I malocclusion before and after fixed appliances orthodontic treatment. Position changes were evaluated by lateral cephalometric analysis.…”

Evaluation the Treatment Effects of Functional Appliances Used in Class II Malocclusions

“…Twin-blok apareyi ile tedavi ettikleri 30 hastada TME'yi tedavi başı ve sonunda aldıkları CBCT ile değerlendirdikleri araş-tırmalarında; kondilin yukarı ve arka yönde uyarılması ile kondil hacminde, inter kondiller mesafede ve mandibular uzunlukta artış meydana geldiğini bildirmişlerdir. 28 Chavan ve ark. Twin-blok ve Bionator apareylerini birbirleri ve kontrol grubuyla karşılaştır-dıkları 30 hastada yaptıkları araştırmalarında kondil, disk ve fossa ilişkisini manyetik rezonans görüntüleme ile değerlendirmişlerdir.…”