Samaneh Sadeghi; Zohreh Hedayati
Abstract
Background: Reverse chin cap appliance consists of a removable plate that is attached to a vertical projection hooks via elastics. This appliance is preferred for treatment of combination of maxillary retrognathia and mandibular prognathism malocclusion.
Objectives: The aim of this study was to assess ...
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Background: Reverse chin cap appliance consists of a removable plate that is attached to a vertical projection hooks via elastics. This appliance is preferred for treatment of combination of maxillary retrognathia and mandibular prognathism malocclusion.
Objectives: The aim of this study was to assess the effects of the reverse chin cap appliance to hard and soft tissues.
Methods: In this retrospective study 16 consecutive Class III patients (6 females, 10 males) with mean age of 9.3 ± 2 (Mean ± SD) years, who were treated with reverse chin cap appliance were selected. Pre- and post- treatment lateral cephalograms were analyzed. The overall changes were compared with growth changes in 20 control samples of Class I (10 females and 10 males) with Cl I occlusion and average age of 9.9 ± 3 (Mean ± SD) years. Independent Samples t-test was used to compare mean differences between the two of them. Differences were considered significant at P < 0.05. Results: At the end of treatment in treatment group, SNB angle decreased 3.7º and ANB angle increased by 2.9º both (P = 0.005). Mandibular length decreased 0.18 mm (P = 0.009). Lower incisors retroclined 10.03º (P = 0.001). Linear distance of the upper lip and lower lip to the E-line significantly decreased 2.3 mm (P = 0.04) 1.1 mm (P = 0.05) respectively. Nasolabial angle decreased significantly 4.1º (P = 0.005).
Conclusions: Reverse chin cap appliance therapy has a skeletal and dental effects. This treatment is effective in correction of the Cl III malocclusion by retroclination of the lower incisors, and retardation of mandibular growth. At the end of treatment, soft tissue profile
Azita Tehranchi; Hossein Behnia; Sepideh Soheilifar
Abstract
Background and aim: Bilateral mandibular distraction osteogenesis (BMDO) has been suggested as a suitable method for correcting severe mandibular deficiencies. The purpose of this study was to evaluate the cephalometric changes of patients undergoing BMDO.Materials and methods: Seven patients were selected ...
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Background and aim: Bilateral mandibular distraction osteogenesis (BMDO) has been suggested as a suitable method for correcting severe mandibular deficiencies. The purpose of this study was to evaluate the cephalometric changes of patients undergoing BMDO.Materials and methods: Seven patients were selected for BMDO, all suffering from severe mandibular retrognathia as a result of previous trauma. Pre-treatment (T1), post-treatment (T2) and follow up (T3) cephalograms were obtained. The changes in skeletal and soft tissue parameters were assessed by paired t-test within two time intervals (T1-T2 and T2-T3). Results with a P value <0.05 were considered statistically significant. Results: In patients treated by extra-oral distractor, BMDO improved jaw relationships by increasing SNB (12.1˚) and mandibular length (22.5mm) and decreasing ANB (10.3˚) and Wits (17.2mm). Lower facial height increased significantly (4.5mm). Dental relationships were changed by increasing interincisal angle (24.8˚) and decreasing IMPA (23.2˚) and overjet (8.8mm). Reduction in the distance between upper and lower lip to E-line led to changes in the soft tissue profile. Airway space analysis revealed an increase in the nasopharyngeal space (Nph2) (4.7 mm), the oropharyngeal space (Oph2) (5.4mm) and the posterior airway space (PAS) (9mm). The available cases remained stable during the follow up period.
Conclusion: BMDO improved maxillomandibular discrepancy by lengthening mandibular body. Lower anterior facial height was increased significantly. Lip prominency relative to the nose and the chin was decreased and dental relationships were corrected by the treatment. DO procedure significantly improves the pharyngeal spaces.