No abstract

NK, a 12-year-old male patient, presented with a Class II division 1 incisor relation on a Class II skeletal base with a decreased maxillomandibular plane angle and decreased face-height ratio. He had a convex profile, incompetent lips, lip trap, deep mentolabial sulcus, everted lower lip and a positive VTO (Visual Treatment Objective). Intraorally, he presented with bilaterally Angle’s Class II molar relation and canine relation, scissor bite in the region of first premolars bilaterally, a closed bite and a 13 mm overjet. He presented with mild spacing in the upper arch and mild crowding in the lower arch with a pronounced curve of Spee. This was further complicated as the LR6 was endodontically treated and temporarily restored; also, enamel hypoplasia was seen in all permanent first molar region. The treatment was carried out in two phases, Phase I involved growth modulation done with a twin block appliance, and Phase II was the postfunctional orthodontic phase for dental corrections and finishing and detailing of occlusion, which was done with a preadjusted edgewise appliance (0.022 × 0.028˝ slot) with MBT (McLaughlin, Bennett, Trevisi) prescription. The posttreatment results were highly satisfactory, showing improvement in facial esthetics and occlusal traits as well as good long-term stability as was evident in the 3-year retention records.

Frictionless mechanics for extraction space closure is one of the commonly used method in orthodontic practice. The ‘Mouse” loop is a new design for efficient and low friction space closure. The 'Mouse' loop has biomechanical advantages of increased range of activation and low load deflection rate. A case report is presented for the application of the loop. In the case report, a deciduous canine was extracted and its space was closed with the help of the 'Mouse' loop. The space of the deciduous canine was closed within five months without any clinical disadvantage.

The vertical and horizontal growth influences the height of mandibular ramus and length of the mandibular body. The soft tissue chin thickness, the lower airway space and the chin throat length can vary in different growth patterns and different skeletal patterns. Lateral cephalograms of non-growing patients seeking orthodontic treatment (n=120) were included in the study. The samples were divided into two subgroups based on skeletal pattern (Cl I & Cl II) according to ANB angle and Wit’s appraisal. Further sub divided into four groups based on cephalometric mandibular plane inclination to anterior cranial base (SN-GoGn) and Frankfort’s mandibular plane (FMA) angle in hypodivergent and hyperdivergent patterns. The parameters lower airway space, mandibular body, mandibular ramus, chin thickness and chin throat length were measured. Results showed maximum lower airway space, mandibular body, mandibular ramus, chin thickness, and chin throat length in the hypodivergent skeletal Class I group. The minimum lower airway space, mandibular body, mandibular ramus, chin thickness, and chin throat length observed in the hyperdivergent skeletal Class II group. The inter-group comparison of all samples indicates that there was a statistically significant difference between various groups and the measures of the hypodivergent samples are more than the hyperdivergent samples irrespective of the skeletal pattern. The study concludes that the lower airway, mandibular ramus, mandibular body, soft tissue chin thickness, chin throat length was less in hyperdivergent skeletal Class I and skeletal Class II samples than the skeletal Class I and skeletal Class II hypodivergent.