Frequency of unerupted mandibular third molar in mandibular angle fractures

Fractures of the mandibular angle are common and comprise 31% of all mandibular fractures. Multiple recent studies report a 2-3 fold increased risk for mandibular angle fractures when un-erupted mandibular third molars are present. The objective of this study was to assess the frequency of un-erupted mandibular third molar in mandibular angle fractures. This crosssectional study was conducted at the Department of Oral and Maxillofacial Surgery, Ayub Medical College, Abbottabad from April to October 2009. One hundred and two patients were included both from the outdoor and ward on consecutive non-probability sampling base. Data were recorded on a structured Performa and analysed using SPSS-16. A hemi-mandible containing un-erupted mandibular third molar was seen to have a 1.41 times the risk of mandibular angle fracture then a hemi-mandible containing an erupted mandibular third molar. The presence of unerupted mandibular third molar is associated with an increased risk for mandibular angle fracture.

Evaluation of tooth size discrepancy in different malocclusion groups

Orthodontic diagnosis and treatment planning requires the patient's thorough history, extra and intra oral examination, analysis of diagnostic records comprising of orthodontic photographs, necessary radiographs and properly trimmed study casts. Tooth-size is the sum of mesio distal widths of the maxillary and mandibular teeth. For ideal occlusion, teeth in both arches should be proportional in size. If larger teeth in one jaw are occluded with smaller teeth in the other jaw, ideal occlusion is not achieved. Tooth size analysis was presented by Bolton in 1958. The ratio for anterior segment was derived to be 77.2 +/- 0.22% and 91.3 +/- 0.26% for the whole arch. A quantitative study was carried out at the Armed Forces Institute of Dentistry [AFID], Rawalpindi, Pakistan, a tertiary care facility. Cross sectional data was gathered from the study casts of patients undergoing orthodontic treatment at AFID, after obtaining informed written consent from them. 135 out of 200 study casts were filtered based upon the inclusion and exclusion criteria. ANB angle and witt's appraisal were traced on corresponding lateral cephalograms. The mesio distal widths of all maxillary and mandibular teeth from right first molar to left first molar were calibrated with the use of a manual caliper. The readings were then used to compute the anterior and total Bolton ratios. Significantly higher mean anterior tooth ratios were found for Class II [p<0.01] patients. All other ratios were within close range of Bolton's norms. Skeletal Class II patients showed a tendency towards higher mesiodistal widths of teeth in the mandibular anterior region