Muhammad Adil Khan, Ulfat Bashir, Hanna Jalil, Umar Hussain.
Relationship between maxillary and mandibular effective lengths and dental crowding in class II malocclusions.
Pak Oral Dental J Jan ;37(2):252-6.

The objective of this study was to determine the frequency of crowding in patients with class II malocclusions and to compare the mean maxillary and mandibular apical base lengths in patients with more than 3mm and less than 3mm of crowding in class II malocclusion patients This study was a descriptive case series carried out at Islamic International Dental Hospital Islamabad. A total of 95 patients were selected according to the inclusion criteria of a complete (full cusp) bilateral class II molar relationship and presence of all permanent teeth up to the first molars. Patients with an open bite, cross bite, presence of caries or restored teeth were excluded. Measurements were performed on pre-treatment dental casts and lateral cephalograms. Pre-treatment dental casts were used to calculate crowding. The radiographs were traced manually with an acetate paper attached on top and used to calculate the apical base lengths of the maxilla and mandible. The sample was divided into two groups according to severity of mandibular crowding. Group 1 consisted of patients with crowding more than or equal to 3mm. Group 2 consisted of patients with crowding less than 3mm. Data analysis was carried out using Statistical Package for the Social Sciences (IBM SPSS version 20, Chicago, Ill). Mean mandible length was 124 (7.208) and mean maxilla length was 91.60( 6.772) while mean mandible ALD -2.92 (2.866). A comparison of the means with a one sample T-test revealed a P value of 0.000, showing that both the variables were highly significant. The results of this study demonstrate a significant inverse correlation between maxillary and mandibular effective lengths and the severity of dental crowding.

PakMediNet -Pakistan's largest Database of Pakistani Medical Journals - http://www.pakmedinet.com