Therapeutic approach to Class II, Division 1 malocclusion with maxillary functional orthopedics

Electromyography: Processing, Muscles' Electric Signal Analysis, and Use in Myofunctional Orthodontics

Electromyography, commonly known as EMG, utilizes superficial or needle electrodes to record and analyze the fundamental electrical characteristics of skeletal muscles, determining whether the muscles are contracting. The motor unit, which consists of a collection of group muscle fibers and the motor neurons that govern them, is the structural basis of EMG. Three types of electrode are used in EMG which are needle electrode, fine wire electrode, and surface electrode. A significant amount of literature indicates that the correction of muscle function affects the relationships between teeth within the same jaw and between the jaws on opposing sides. The mechanism of action in myofunctional appliance therapy is linked to neuromuscular and skeletal adaptations resulting from altered function in the orofacial region. Both myofunctional therapy and orthodontics aim to address abnormal muscular behavior, restore abnormal muscle activity, and maintain proper alignment in various areas, including the lips, lower jaw, and tongue. This knowledge is essential for functions such as swallowing, speaking, chewing, and respiration as well as for minimizing incorrect movements and positioning. This article aims to describe the application of surface EMG as a diagnosis tool for assessing muscle activities in various orthodontic disorders, such as class II malocclusion open bite, crossbite, maxillary constriction, cleft lip and palate (CLP), and temporomandibular dysfunction, in patients. The electrodes used in EMG can be utilized to detect bioelectric activity in the muscles of the jaws and abnormalities in jaw movement. Analyzing EMG data is vital for obtaining a comprehensive understanding of the masticatory muscle system.

Treatment of Skeletal Class II Division 1 Using Twin Block Myofunctional Appliance

Myofunctional appliances are customarily used to treat Class II malocclusions in growing children to alter their growth. Functional appliances are widely accepted to enhance skeletal relationships in the short term efficiently. It utilizes muscular forces by muscles to make dental and skeleton modifications. The myofunctional appliance might be removable or fixed. The variation of mode and method of action depends on the design, but the forces created by the muscles' stretching provide their effect. According to research, the effectiveness of functional appliances as a therapy for Class II malocclusion might be influenced by mandibular growth patterns. Their low skeletal maturation influence outweighs the primary dentoalveolar impact of the twin block myofunctional orthodontic appliances. Class II malocclusions can benefit by using myofunctional appliances in specific clinical situations, such as when the patient is still developing. These devices make the fixed appliance phase easier to use, but their effectiveness depends heavily on the patient's compliance. In this case, an 11-year-old female expressed concern about the forward positioning of her upper front teeth when she visited the department of orthodontics. Twin block, a myofunctional appliance, was used to manage it, and then fixed orthodontic treatment was used to fine-tune the occlusion. This case report illustrates the design and treatment effects.

Oral cavity morphology among children at risk of sleep disordered breathing

PURPOSE

The aim of this study was to evaluate oral cavity morphology in children at risk of sleep disordered breathing (SDB).

METHODS

The study included children 3-17 years of age. The risk of SDB was evaluated using the paediatric sleep questionnaire (PSQ); afterwards, children at risk of SDB were enrolled in the study group. A control group was randomly established from patients with negative PSQ results. The oral cavity morphology evaluation included assessment of the oropharynx using Mallampati classification (MC), palatine tonsil size using the Pirquet scale, occlusion and the presence of a high-arched palate and lingual frenulum.

RESULTS

A total of 131 children were evaluated, 65 in the study and 66 in the control group. The mean ages were 9.5 ± 3.0 and 9.4 ± 3.1 years, respectively. The presence of higher scores on the MC, higher scores in the Pirquet scale, a crossbite, a high-arched palate and a short frenulum were significantly more frequent in the study group than the control group.

CONCLUSION

The evaluation of oral morphology is an important part of paediatric examination. Enlarged palatine tonsils; higher scores on the MC; and the presence of a crossbite, short lingual frenulum and high-arched palate may suggest abnormal breathing during sleep in children.

CBCT Evaluation of Condylar Changes in Class II Hyperdivergent Adult Patients Following Posterior Maxillary Intrusion Using Miniscrews/Miniplates—A Prospective Study

Aim & Objectives: To evaluate using CBCT, the condylar changes taking place in retrognathic, hyperdivergent Class II adult patients following maxillary intrusion using miniscrew assembly. Materials and methods: In this prospective study design, 20 class II div I high angle cases in the age group of 20-25 years with Class II molar and canine relationship; Overjet > 5mm; ANB angle > 4°; FMA angle >25°; SNGoGn > 35°; Jaraback ratio< 60° and Lower Gonial angle>75° were taken. Each patient had a miniscrew assembly in the maxilla through which intrusive force was applied to the maxilla. Two additional miniscrews were placed between the first mandibular molars and second premolars to prevent extrusion of lower molars. CBCT images were taken at the beginning of the treatment (T1) and at the end of 6-9 months of molar intrusion (T2). Statistical analysis was carried out using student T- test. Results: Prior to treatment, the patients showed significant mandibular retrusion associated with increased maxillary posterior heights. Following maxillary intrusion with miniscrew assembly, CBCT evaluation revealed that the distance from the centre of condyle to the posterior border of the external auditory meatus was 19.2±1.67 mm on right side and 18.1±1.54mm on left side in T1 which increased to 19.6±1.45mm on right side and 18.5±1.36mm on left side in T2. The average forward displacement of condyle was .5mm which was statistically significant. The distance from the centre of condyle to superior border of external acoustic meatus was 3.1±1.7 mm on right side and 3.5 ±1.8 mm on left side in T 1 which increased to 3.8±1.9 mm on right side and 4.1 ±1.3mm on left side in T 2. The average downward displacement was .7mm which was statistically significant. Conclusion: Significant Maxillary intrusion can be achieved using miniscrews/ miniplate in adult hyperdivergent skeletal class II patients.