The Twin Block appliance is a removable orthodontic appliance that is used to help correct a backward positioned lower jaw in growing children. This appliance works by guiding the lower jaw forward to a specific position over a certain period of time. After completing the treatment, patients often experience improvements in their appearance, such as an improved bite, a more balanced facial profile and improved lip posture.
The investigators' interest is to compare two types of Twin Block appliances; traditional (conventional) and 3D-printed, by examining several factors, including the amount of bacteria that stick to them, the surface roughness, and the overall effectiveness of each type.
Surface roughness refers to the texture of the appliance's surface, which could influence how much bacteria can accumulate. Rougher surfaces may trap more bacteria, potentially leading to oral health issues such as bad breath, tooth decay, and gum problems. The study will also assess the effectiveness of both the conventional and 3D-printed Twin Block appliances, focusing on factors like how well they perform in improving jaw position and achieving the desired treatment outcomes.
Additionally, the investigators want to assess how these appliances affect the quality of life related to oral health. Participants will answer questions about their experience to help understand how the type of appliance impacts their daily lives, comfort, and overall well-being during the course of treatment.
Patients with Class II Division 1 incisor relationship
Overjet of ≥ 7mm
Age range of children: 10-12 years in females, 12-14 years in males
All permanent incisors and molars erupted
Patients with craniofacial syndromes (example: cleft lip and palate)
Patients with previous history of orthodontic treatment
Patients with hyperdivergent facial type (MMPA > 40º)
Untreated gingival disease (e.g.: gingivitis, periodontitis)
Parallel
Conventional TBA
DeviceConventional TBA fabricated with polymethylmethacrylate
3D TBA
Device3D TBA made out of a 3D printing resin (Graphy TR07)
Microbial colony counts (CFU/ml) on the appliances.
Microbial colony count on the conventional Twin Block appliance \& 3D printed Twin Block appliance The conventional Twin Block appliance (TBA) and the 3D printed Twin Block 3D TBA appliance that are collected from the patients before issue of the appliance (T0), after 3 months (T1) and at 6 months (T2). The TBA will be placed in BHI media and then will undergo the process of sonication, which will produce the bacteria suspension. This bacteria suspension will then be cultured in an agar plate with BHI media and incubated for 18 - 24 hours. The total colony per count will then be counted and recorded.
Assessment of Oral health-related quality of life (OHRQoL): PIDAQ Scores
The Malaysian psychosocial impact of dental aesthetics (PIDAQ) questionnaire consists of 22 questions that measures the impact of malocclusion on the dental self-confidence (DSC), social impact (SI), psychological impact (PI) and aesthetic concern (AC). The responses to each question will be scored on a 5-point Likert scale and coded as follows: 0 = Not at all; 1 = A little; 2 = Somewhat; 3 = Strongly; 4 = Very strongly. The PIDAQ questionnaire will be distributed at T0 (at baseline- at issue appointment) T1 (at 3-months) TF (Final time-point).
Surface roughness (Ra) of the appliances
The surface roughness of both the conventional and 3D TBA appliances will be assessed using a profilometer (Mitutoyo Surf Test, Japan) at baseline and at T2 (6 months). Surface roughness will be assessed by measuring each specimen three times in three different directions. The three measurements performed for each specimen will be used to calculate the average surface roughness (Ra) and will be recorded in micrometres (µm).
Assessment of Oral health-related quality of life (OHRQoL): Child-ODIP (prevalence and scores)
The oral impacts on daily performances for children (Child-ODIP) questionnaire will evaluate oral impacts across eight performances i.e eating, speaking, cleaning teeth, relaxing, emotional stability, smiling, doing schoolwork and socialising. The Child-ODIP questionnaire will be distributed at T0 (at baseline- at issue appointment) T1 (at 3-months) TF3 (3-months after final time-point).
Treatment effectiveness: Treatment duration (in months)
The time (in months) required to reduce overjet to normal limits (\<4 mm). The overjet and other occlusal measurements (i.e canine relationships, molar relationships and overbite) will be recorded for the participants at the start of the study (T0) , and every month after the initial fitting of the Twin Block appliance until normal overjet (2-4mm) is achieved (T0-TFinal).
Treatment effectiveness: Linear measurements (in mm)
A lateral cephalogram will be taken at T0 and at the end of functional appliance treatment (TFinal), which is anticipated up to 12 months, to assess for skeletal and dental changes. Measurements of sagittal changes on the lateral cephalogram will be recorded in millimeters (mm).
Click on the lead sponsor to view all of their trials.
