Patients with characteristic CII/2 malocclusion always show a prognathic
maxilla, retroclined maxillary central incisors, a retrusive mandible, and a deep curve of Spee .
, pear-shaped dorsoventrally, defined cervical region absent, total length 1.01-1.15 mm ([bar.x] = 1.10 [+ or -] 0.06 mm), width 0.80-0.91 mm ([bar.x] = 0.87 [+ or -] 0.05 mm) with a prominent occipital suture.
Skeletal bi-maxillary protrusion or prognathic jaws is usually associated with prominent everted lips, convex facial profile, accentuated ANB angle, short posterior cranial base, anterior positioned glenoid fossa and divergent facial planes.2
The major contri- bution to skeletal class two malocclusion was due to a prognathic maxilla as evident from the pre-treatment mean SNA value of 87o.
Distortion coordinate analysis (Cartesian Transformation) of mature larvae crania for certain members of Dytiscidae (Matus bicarinatus (Say), Coptotomus lenticus Hilsenhoff, and Thermonectus basillaris Harris were employed to evaluate and compare prognathic
, hypoprognathic and hyperprognathic patterns of orientation.
Skeletal bi-max- illary protrusion or prognathic
jaws is usually associ- ated with increased skeletal lower facial height, accen- tuated ANB angle, short posterior cranial base, ante- rior positioned glenoid fossa and divergent facial planes.2
Cephalometric analysis [COGS] showed skeletal class II pattern with prognathic
maxilla with anterior vertical excess between 4 to 18 mm and a posterior excess between 3 to 5 mm.Three patients had increased lower facial height between 6 to 10 mm and a retrognathic chin.
Anterior Crossbite incidence was about 3%-5% in Scandinavia (Guyer et al.25) This may be found in all facial types - prognathic
, orthognathic, and retrognathic - in combination with varying degrees of hypoor hyperplasia of the jaws.
In contrary, a few investigations does not agree with present study results and indicated prognathic
maxilla in class II/2 malocclusions.11,12
Some studies revealed that class II/1 malocclu-sion is associated with prognathic
maxilla and mandible was found out to be retrognathic and in dental parameters, bimaxillary proclination is demon-strated.10,11,12 Other studies demonstrated that the max-illa was in a normal position while the mandible was retrusive.13,14 In Class II/2 malocclusion, most of the studies stated a normally positioned maxilla in sagittal plane and retroclined upper incisors.15,16
Extra oral examination revealed concave profile with hypoplastic maxilla and a relative prognathic