Changes in soft tissue facial profile of class II skeletal malocclusion patients with retrognathic mandible treated with twin block appliance

Abstract

Introduction: The soft tissue aspect in orthodontics treatment has gained attention in the last few years. The soft tissue profile is said to reflect the underlying skeletal profile, which causes a convex profile in patients with class II skeletal malocclusion. This research was aimed to determine the changes in the soft tissue facial profile of class II skeletal malocclusion patients with retrognathic mandible after twin block treatment. Methods: The type of research used in this study was retrospective descriptive research with paired t-test. The population was children aged 10-13 years old with class II skeletal malocclusion that were treated with twin block appliance in the Faculty of Dentistry Universitas Padjadjaran, Indonesia. The results of soft tissue changes before and after twin block treatment were compared. Results: There was an insignificant increase in soft tissue profile angle and Holdaway’s soft tissue angle after twin block treatment (p > 0.05). Whereas, Holdaway’s H-angle was decreasing and Merrifield’s Z-angle was increasing after twin block treatment, with statistically significant difference (p < 0.05). Conclusion: There was a decrease of H-angle, indicates a reduction in facial convexity and improvement of the facial profile after twin block treatment, but no difference in soft tissue profile angle and Holdaway’s soft tissue angle after twin block treatment. Keywords: Facial soft tissue profile, class II skeletal malocclusion, retrognathic mandible, twin block appliance

Myobrace versus twin block in the treatment of class II malocclusion in Children: A systematic review

“…It consists of acrylic bite blocks on the upper and lower jaw that interlock at a 70-degree angle to guide the mandible downward and forward. ( Lin et al, 2019 , Zhang et al, 2020 ) Children with a considerable overjet and class II malocclusion benefit the most from it, even at an early stage of development, as functional devices like twin blocks can be utilized. ( Chen et al, 2022 , Golfeshan et al, 2018 , DiBiase and Qureshi, 2020 ) Ajami S et al stated that twin blocks have the potential to impact the class II malocclusion patients' facial aesthetics by causing modifications to the skeletal and dentoalveolar structures.…”

The Effectiveness of Using Twin Block Functional Appliances and Activators in Class II Malocclusion

“…The ideal indication for a skeletal Class II malocclusion with a retrognathic mandible is a functional appliance. (18) Functional appliances have been used for many years in the treatment of Class II malocclusions with the aim of obtaining bone correction of the malocclusion. The use of these appliances should support an increase in the position and growth of the mandible along with changes in the tooth-muscle relationship.…”

“…The design that is separated into two parts, the top and bottom on this appliance provides convenience in speaking and chewing. (16,18) A clinical trial has shown that class II malocclusion can be corrected with an activator device. It has been reported that maxillary growth can be limited by the use of an activator.…”

Degree of facial profile convexity using Subtelny’s analysis in patients aged 6 to 12 years

“…7 For example, class II skeletal malocclusion with a protrusive maxilla may produce a convex facial profile, while class III skeletal malocclusion with a protrusive mandible may result in a concave facial profile. 8,9 Convex, concave, and straight soft tissue profiles can help determine the underlying skeletal relationship and position of the jaws from the sagittal plane. 10 According to Kasai, the relationship between facial soft tissue and skeletal structures may vary because soft tissues can be affected by thickness, function, and length.…”