How Similar are the Dentoskeletal Characteristics of Class III Double-Jaw Surgery Patients with Ideal Post-Treatment Profiles and Class I Subjects?

Objective: To define the dental and skeletal characteristics of Class III surgery patients with ideal final soft-tissue profiles, and to compare them with those of Class I subjects. Also, to show how soft-tissues respond to surgical jaw movements and contribute to the outcome. Methods: This short-term, retrospective study was conducted using pre-treatment (T0), pre-surgery (T1), and post-treatment (T2) records of 50 double-jaw Class III surgery patients who presented with ideal cephalometric characteristics in sagittal (Holdaway and soft-tissue convexity angles) and vertical dimensions (GoGn. SN angle and upper-to-lower face harmony) at the end of treatment, and 50 control subjects. Results: At T2, the horizontal distance between the vertical reference plane (a perpendicular plane to the horizontal reference plane that is angulated 7° clockwise to the SN plane) and hard-tissue A, B and Pog points, lower lip, soft-tissue B, and pogonion points were greater, Wits appraisal was more negative, U1.PP was higher, IMPA was lower, and soft-tissue chin (Pog-Pog') was thicker in Group 1 when compared to Group 2 (p<0.05). Moreover, upper lip and subnasal (A-A') thicknesses were decreased, and chin thickness (Pog-Pog') was increased significantly (p<0.05). Conclusion: Dentoskeletal characteristics of an ideally-treated Class III surgery patient differed from a Class I subject concerning a protrusive maxilla and soft-tissue pogonion, and incisors that were not fully-decompensated. Soft-tissues hindered the actual surgical correction to 66% and 73% in the mid- and lower-faces, respectively.

Machine learning based orthodontic treatment planning for mixed dentition borderline cases suffering from moderate to severe crowding: An experimental research study.

BACKGROUND: Pedodontists and general practitioners may need support in planning the early orthodontic treatment of patients with mixed dentition, especially in borderline cases. The use of machine learning algorithms is required to be able to consistently make treatment decisions for such cases. OBJECTIVE: This study aimed to use machine learning algorithms to facilitate the process of deciding whether to choose serial extraction or expansion of maxillary and mandibular dental arches for early treatment of borderline patients suffering from moderate to severe crowding. METHODS: The dataset of 116 patients who were previously treated by senior orthodontists and divided into two groups according to their treatment modalities were examined. Machine Learning algorithms including Multilayer Perceptron, Linear Logistic Regression, k-nearest Neighbors, Naïve Bayes, and Random Forest were trained on this dataset. Several metrics were used for the evaluation of accuracy, precision, recall, and kappa statistic. RESULTS: The most important 12 features were determined with the feature selection algorithm. While all algorithms achieved over 90% accuracy, Random Forest yielded 95% accuracy, with high reliability values (kappa = 0.90). CONCLUSION: The employment of machine learning methods for the treatment decision with or without extraction in the early treatment of patients in the mixed dentition can be particularly useful for pedodontists and general practitioners.

Pharyngeal airway and hyoid bone position changes of skeletal anchored Forsus Fatigue Resistant Device and activator appliances.

OBJECTIVES: To evaluate the effects of miniplate anchored Forsus Fatigue Resistant Device (MAF) and activator treatments in the pharyngeal airway dimensions and hyoid bone position. MATERIALS AND METHODS: Thirty-eight patients with mandibular retrusion who were treated with either MAF or activator were selected retrospectively and compared with an untreated control group. The data of 114 lateral cephalograms, comprising those taken before treatment (T1) and at the end of functional treatment (T2), were evaluated with regard to their linear, angular, and area measurements. RESULTS: The mandibular length increased and the hyoid bone moved forward with both treatments (P < 0.05). The horizontal change in the hyoid bone position with MAF treatment was correlated with changes in the point B and ANB angle. Increases of 1.8 mm, 1.4 mm, and 1.8 mm in the pharyngeal airway dimensions were obtained at the levels of the second, third, and fourth cervical vertebra, respectively, with the MAF treatment. On the other hand, an increase of 1.9 mm was found at the level of the fourth cervical vertebra with the activator treatment. The greatest vertical movement in the Menton and the highest increase in the oropharyngeal area were observed in the MAF group (P < 0.05). CONCLUSION: Both the MAF and activator treatments caused favorable maxillomandibular changes; however, the MAF treatment provided a greater increase in the oropharyngeal area according to both the increase in mandibular length and the change in the vertical position of the mandible. CLINICAL RELEVANCE: Functional appliances were found to be useful in increasing the pharyngeal airway dimensions in the short-term. The skeletal anchored fixed functional appliance caused a greater increase in the oropharyngeal airway area that may be beneficial for Class II patients who carry a risk of having respiratory problems.

Treatment efficiency of activator and skeletal anchored Forsus Fatigue Resistant Device appliances.

OBJECTIVES: The aim of the study was to investigate the treatment efficiency of miniplate anchored Forsus Fatigue Resistant Device (MAF) as compared with the activator appliance. MATERIALS AND METHODS: Mandibular retrognathia was treated with two methods, the MAF group (8 girls, 11 boys, mean age 13.03 ± 0.69 years) and the activator group (7 girls, 12 boys, mean age 12.68 ± 0.73 years). An untreated control group (9 girls, 10 boys, mean age 12.95 ± 0.73 years) was constructed to eliminate growth-related changes through the American Association of Orthodontists Foundation Legacy Collection. Data of 114 lateral cephalograms were analyzed. RESULTS: The inhibition of the maxillary growth was greater in the MAF group, whereas forward displacement of the mandible was higher in the activator group (P < 0.05). Sagittal maxillomandibular relation was improved similarly in both treatment groups (P < 0.05). Mandibular length was increased in both treatment groups with the highest increase in the activator group (P < 0.05). Retroclination of the incisors was observed in the MAF group (P < 0.05). The upper lip was retruded in the MAF group and lower lip was protruded in the activator group (P < 0.05). CONCLUSION: The activator created greater mandibular changes, whereas the MAF provides somewhat smaller mandibular changes due to the restriction caused by retroclined maxillary incisors. CLINICAL RELEVANCE: Although both MAF and activator treatments caused favorable maxillomandibular changes, new treatment alternatives that reduce dentoalveolar side effects and eliminate patient cooperation are still required to achieve skeletal correction in class II malocclusion treatment in growing patients.

Treatment of an adult skeletal class II patient with a modified surgery-first approach.

This case report presents an 18-year-old female patient who had skeletal Class II relationship due to a mandibular retrognathia, decreased lower anterior facial height and proclined incisors with increased overjet and overbite. Her main complaints were protruding upper incisors and decreased distance between the tip of the nose and chin. A modified surgery-first approach was performed with two months of presurgical orthodontics to achieve 8mm mandibular advancement. The total treatment time was 11 months. Improved aesthetics, a balanced facial profile and a stable and functional occlusion were obtained in less treatment time due to accelerated tooth movement.