Third molar impaction in extraction cases treated with the Begg technique

Abstract

SUMMARY The aim of this study was to investigate the differences between two groups of patients with either erupted or impacted mandibular third molars before and after orthodontic treatment. All patients were treated with Begg appliances following extraction of the four first premolars. The erupted group consisted of 14 subjects and the impacted group 13 subjects.Lateral cephalometric films, peri-apical radiographs, orthopantomographs and orthodontic casts of each subject were taken before and after treatment. Thirteen measurements were carried out on the lateral cephalometric radiographs.The results revealed slightly more vertical growth and a smaller mandibular arc angle in the erupted group at pre-treatment, and also a more upright lower third molar position and slightly greater distance between the distal point of the lower second molars and the centre of ramus (Xi) in the same group. In the course of treatment, mandibular third molars seemed less likely to erupt when the condyle grew vertically. The lesser resorption on the anterior border of the ramus might have played a part in this finding. In addition, a greater mesial inclination of the mandibular third molars might be an indication of the tendency for these teeth to be impacted in the present study.

Influence of First Premolar Extraction on Mandibular Third Molar Angulation

“…Measurements of third molar angulation on lateral cephalograms, as seen in previous studies, 18,21,24,26,27 may be biased because of differences in angulation between the superimposed images. Similar problems are present in any cephalometric study of changes in posterior tooth positions and can only be overcome if measurements are made on 60-degree head films of the left and right sides, as shown by Richardson.…”

“…Extraction of premolars to allow mesial drifting of the buccal segment has been the subject of many investigations. 6,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] The intent of the present study was to determine whether extraction of the first premolars results in more mesial movement of the mandibular buccal segment and causes favorable rotational changes in the mandibular third molar tilt. This study evaluated the changes in the mandibular third molar angulations relative to a reference plane and to the second molar long axis.…”

Effects of first premolar extraction on maxillary and mandibular third molar angulation after orthodontic therapy

“…Measurements of third molar angulation on lateral cephalograms, as seen in previous studies 4,17,18,21,22 may be biased because of differences in angulation between the superimposed images. Similar problems are present in any cephalometric study of changes in posterior tooth positions and can only be overcome if measurements are made on 60- 24,25 and palatal plane 29 as the horizontal plane of reference to measure treatment changes.…”

Teeth position, eruption and temporomandibular joint ankylosis

“…It has been established that vertical direction of condylar growth leads to lesser resorption of anterior border of ramus contributing to less space. Furthermore, reduced growth in mandibular length, vertical direction of mandibular growth and a distal pattern of eruption of mandibular eruption would lead to impaction of 3rd molar [3]. In our present case series, contralateral side to TMJ ankylosis, in 2 cases, third molars were more abnormal as compared to normal sides.…”