Prediction of mandibular third molar impaction in the orthodontic patient from a panoramic radiograph

Abstract

In this study we explored the predictability of mandibular third molar impactions. Serial panoramic radiographs from 50 non‐extraction and 15 extraction patients were traced for various angular and linear measurements. A linear discriminant function analysis was performed for each stage of third molar development. The results indicate that the earliest stages of development have very little predictive value. Accordingly, a justification for the oft‐practiced enucleation procedure cannot be made. Although the more the tooth is developed, the higher is the accuracy of prediction, two earlier stages where the crown is fully formed or the roots 1/3 formed possess high predictive values. Based on our data, impaction of third molars in the mandible is a predictable event both in extraction and non‐extraction patients.

Comparison between two radiographic methods used for the prediction of mandibular third molar impaction

“…13,16,[25][26][27] However, panoramic radiography yielded one of the most accurate estimations in this field 19,27 and it is the most popular dental record for the clinician, since it has been a common research tool for assessing lower third molars for extraction. 8,26 In this study, were selected panoramic radiographs because they are the usual radiological exploration modality for dental screening in dental clinic.…”

“…[10][11][12][13][14][15] The different methods included measurement of the available space, 10,11 mandibular size and growth 10,12 and third molar angulation. 14,16 Prediction in the patient during growth could be of great interest and help planning future dental treatments (orthodontic, prosthesis or surgical exodontia). Because when most dental treatments start, third molars often show a limited amount of calcification and just start to develop.…”

Orthodontic Space Closure without Contralateral Extraction through Mesial Movement of Lower Molars in Patients with Aplastic Lower Second Premolars

“…To ascertain whether mesialization led to a gain in space for the third molars, the distance between the second molar and the anterior bony margin of the mandibular ramus was measured by drawing a line of reference on the panoramic radiograph along the two cranial tips of the cusps for each lower second molar with reference to Castella et al [3]. On this line of reference, a point was obtained by taking a perpendicular tangent at the distal edge of the second lower molar.…”

“…Zu diesem Zweck wurde in Anlehnung an Castella et al [3] im Orthopantomogramm für jeden unteren zweiten Molaren eine Bezugslinie entlang der beiden kranialen Höckerspitzen konstruiert. Zu diesem Zweck wurde in Anlehnung an Castella et al [3] im Orthopantomogramm für jeden unteren zweiten Molaren eine Bezugslinie entlang der beiden kranialen Höckerspitzen konstruiert.…”

Influence of First Premolar Extraction on Mandibular Third Molar Angulation

“…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.…”