Cephalometric evaluation of pharyngeal airway and tongue space following treatment with Herbst and AdvanSync appliances : A prospective randomized clinical trial.

OBJECTIVES: To evaluate and compare pharyngeal airway and tongue space changes after treatment with fixed functional appliances-Herbst and AdvanSync™ (Ormco, Orange, CA, USA) appliances-in skeletal class II patients in pre- and posttreatment lateral cephalograms. METHODS: For this randomized, controlled trial, 40 patients (21 male, 19 female) were divided into two groups-a Herbst group (mean age 12.6 ± 0.67 years) and an AdvanSync group (mean age 12.8 ± 0.66 years). Pre- and posttreatment (appliance therapy duration-8 months) lateral cephalograms were traced using a software program to evaluate pharyngeal airway and tongue space changes. RESULTS: Nasopharyngeal airway, velopharyngeal airway, glossopharyngeal airway, and hypopharyngeal airway increased in the Herbst group by 2.12 mm (p ≤ 0.001), 2.33 mm (p ≤ 0.001), 2.40 mm (p ≤ 0.01), and 1.57 mm (p ≤ 0.05), while in the AdvanSync group the increases were 1.89 mm (p ≤ 0.001), 1.21 mm (p ≤ 0.001), 1.18 mm (p ≤ 0.001), and 1.53 mm (p ≤ 0.001), respectively. In the Herbst group, tongue length and height increases were 2.04 mm (p ≤ 0.01) and 3.74 mm (p ≤ 0.001), while the values in the AdvanSync group were 2.41 mm (p ≤ 0.05) and 2.69 mm (p ≤ 0.001). The change of the tongue tip from the lower occlusal plane was 0.69 mm (p ≤ 0.001) in the Herbst group and 0.77 mm (p ≤ 0.001) in the AdvanSync group. The velopharyngeal airway dimension was correlated positively with that of the retroglossal oropharyngeal airway, which in-turn positively correlated with the laryngopharyngeal airway which correlated well with the distance of the tongue tip from the lower occlusal plane. CONCLUSIONS: The airway dimensions and tongue parameters increased significantly in both treatment groups in the present study. These changes were higher in the Herbst appliance than in the AdvanSync group, except for the distance of the tongue tip from the lower occlusal plane. A significant difference between the pharyngeal airways was found only for the retropalatal oropharyngeal airway.

Three-Dimensional Evaluation of Condyle-Glenoid Fossa Complex Following Treatment with Herbst Appliance.

The purpose of the present retrospective observational study was to compare the effects of treatment with Herbst appliance and fixed therapy with elastics on the condyle and glenoid fossa complex. Thirty patients aged between twelve and sixteen years with skeletal Class II malocclusion who met the inclusion criteria were included in the study: fifteen patients treated with Herbst appliance (Group 1), and fifteen patients treated with orthodontic camouflage using MBT prescription (MBTTM Versatile+ Appliance System) (Group 2). For Group 2, patients had CBCT scans taken before treatment either after Herbst appliance removal or at the end of treatment. CBCT scans were evaluated for changes in condyle-glenoid fossa complex using the In Vivo Dental 5.1 software. Statistical significance was set at p ≤ 0.05. On inter-group comparison, the Herbst group showed statistically significant increases in the condylar height of 1.35 mm (p ≤ 0.001) on the right and 1.21 mm (p ≤ 0.01) on the left side, and a condylar volume of 111.03 mm3 (p ≤ 0.01) on the right and 127.80 mm3 (p ≤ 0.001) on the left side. The Herbst group showed anterior remodelling on the postero-superior aspect of glenoid fossa. Herbst appliance treatment induced growth at the condylar head and anterior remodelling of glenoid fossa, thereby improving the maxilla-mandibular relationship in growing skeletal Class II patients.

Three-Dimensional Evaluation of the Tongue Volume in Different Dentoskeletal Patterns - A Cone Beam Computed Tomographic Study.

AIM: The aim of this study is to evaluate tongue volume using cone-beam computed tomographic (CBCT) and its correlation to different growth patterns in patients. MATERIALS AND METHODS: Sixty preorthodontic records of CBCT scans of subjects ranging from 14 to 25 age group from retrospective data of department were selected for the study. Patients were classified into three groups based on angle FMA; Group I (n = 20) with average growth pattern (FMA 22°-28°); Group II (n = 20) vertical growth pattern (FMA >28°); Group III (n = 25) horizontal growth pattern (FMA <20°). Tongue volume evaluation was done using Myrian® Software. Dentoskeletal features and parameters related to archform such as palatal vault depth, interpremolar, and intermolar distance were evaluated in all the subjects. ANOVA test was used for intergroup comparison of tongue volume and dentoskeletal parameters in all three groups. Correlation of the tongue volume to dentoskeletal parameters was done using Pearson's correlation test. RESULTS: Mean tongue volume in Group I was 66.10 cm3, Group II, 66.04 cm3 and Group III was 66.72 cm3. There was a statistically significant correlation (P < 0.5) of tongue volume with palatal vault width, maxillary length, and mandibular interpremolar and intermolar distance among dentoskeletal parameters. CONCLUSION: Tongue volume was found equal in all groups despite the variation in growth patterns. Skeletal differences leading to different growth patterns were found to be related to mandibular morphology. The results indicate the indirect role of the tongue in causing malocclusion in orthodontic patients.

Effects of miniplate anchored Herbst appliance on skeletal, dental and masticatory structures of the craniomandibular apparatus: A finite element study.

OBJECTIVE: To analyze the stress distribution in the hard and soft tissue structures of craniomandibular complex during mandibular advancement with miniplate anchored rigid fixed functional appliance (FFA) using Finite Element Analysis (FEA). MATERIAL AND METHODS: The virtual model consisting of all the maxillofacial bones (up to calvaria), the mandible and temporomandibular joint (TMJ) was generated using the volumetric data from pre-treatment CBCT-scan of a growing patient. The masticatory muscles, other soft tissues, Herbst appliance and plate geometry were modelled mathematically. Force vectors simulating muscle contraction at rest and advanced mandibular positions, with protraction force of 8N were applied. The final model was imported into ANSYS for analysis after assigning material properties. RESULTS: The maximum von Mises stress of 11.69MPa and 11.96MPa magnitude was observed in the region of pterygoid plates and at the bone-miniplate interface respectively, with the mandibular advancement of 7mm. Stress patterns were also noted at the condylar neck. The stress values observed in the medial and lateral pterygoid muscles were of 10.42MPa and 4.16MPa magnitude, respectively. Stress was noted in the bucco-cervical region of the upper posterior teeth, but negligible change was seen on the lower anterior teeth and periodontal ligament. CONCLUSION: Miniplate Anchored Herbst Appliance brought about Class II skeletal correction in growing children as it was accompanied by minimal changes in the inclination of the lower incisors. Soft tissue structures like pterygoid muscles and discal ligaments exhibited increased stress whereas masseter muscle displayed reduction in stresses.

Hybrid Coronary Revascularization - Current State of the Art.

Hybrid coronary revascularization (HCR) seeks to combine the benefit of surgical and nonsurgical techniques for optimum management for selective patients with multivessel obstructive coronary artery disease. The goal of HCR is to combine the benefit of surgical anastomosis of the left internal mammary artery to the left anterior descending coronary artery (LAD) graft along with stenting of non-LAD lesions with percutaneous coronary intervention (PCI). HCR usually involves the use of minimally invasive surgical techniques like robotically assisted coronary artery bypass graft (CABG), with the objective to produce a rapid recovery in the postoperative period, lower complications, and decreased length of stay in the hospital. In this review the authors seek to define the role of HCR in current practice including patient selection, techniques, logistics, outcome data and the challenges it faces in comparison to conventional CABG and PCI.