The ability of orthodontists and maxillofacial surgeons in predicting spontaneous eruption of mandibular third molar using panoramic serial radiographs

Abstract

Objective: To evaluate the skill of orthodontists and oral/maxillofacial surgeons (OMFS) in providing a prognosis of mandibular third molars spontaneously erupted, through follow-up panoramic analysis. Methods: 22 orthodontic patients treated without extraction, presenting spontaneously erupted mandibular third molars (n = 44) were analyzed through panoramic serial radiographs. The first panoramic radiograph was obtained just after orthodontic treatment (PR1), in patients aging from 13 to 19 years. A second panoramic radiograph (PR2), was obtained in average two years later. The radiographs were randomly analyzed by 54 specialists, 27 orthodontists and 27 OMFS, to obtain the opinion about the approach to be adopted to these teeth in PR1. Then, another opinion was collected by adding a serial radiograph (PR1+2). Results: The concordance of the answers was moderate for OMFS (Kappa 0.44; p< 0.0001) and significant for orthodontists (Kappa 0.39; p< 0.0001). In the analysis of the first radiograph (PR1) of the spontaneously erupted molars, OMFS indicated extraction in 44.5% of cases, while orthodontists indicated in 42%, with no difference between groups (p= 0.22). In PR1+2 analysis, orthodontists maintained the same level of extraction indication (45.6%, p= 0.08), while surgeons indicated more extractions (63.2%, p< 0.0001). Conclusions: Orthodontists and OMFS were not able to predict the eruption of the third molars that have erupted spontaneously. Both indicated extractions around half of the third molars. A follow-up analysis, including one more radiograph, did not improve the accuracy of prognosis among orthodontists and worsened for OMFS.

Factors associated with indication of prophylactic extraction of the lower third molar in orthodontic practice

“…who found that impaction of the third molar is one of the factors more important that influences to a possible extraction of a lower third molar ( 2 , 5 , 8 ). The published literature indicates that a complex location of the third molar would affect the decision due to a positive correlation between the decision to extract a third molar and the probability of producing collateral damage ( 21 ), added to the fact that the professional’s ability to predict a risk or spontaneous eruption in cases of impaction has limitations ( 3 , 4 , 9 ).…”

“…The third molar is a tooth characterized by certain variability in its presence or absence, in time of its conformation and calcification, its coronal and root morphology, as well as its eruption course and final position ( 1 ). Added to the above, in approximately 73% of people the lower third molar erupts in the third decade of life with an impaction rate that varies between 9.5% and 39% ( 2 , 3 ).…”

Midfacial development and the wisdom of teeth: A case series

“…They noted that severe impactions were associated with postoperative pain, trismus, and swelling with a need for pain medication. However, when the ability to identify the risk of third molar non‐eruption using panoramic radiographic analysis was evaluated, Libdy et al 8 found that both orthodontists and oral maxillofacial surgeons were unable to predict which third molars would become impacted; both groups of specialists indicated extractions in approx. 50% of cases, being unable to distinguish those in which the third molars would erupt normally.…”

The prediction of impacted versus spontaneously erupted mandibular third molars

“…Monitoring should be performed every 2 years up to at least the age of 18. The serial analysis of panoramic radiographs, a method widely used for clinical monitoring of orthodontic patients, might be able to increase the accuracy of this prediction [12].…”

“…Whenever indicating extraction of third molars, dentists, should have a justifiable reason, taking into account future treatment planning from an orthodontic, surgical, periodontal, and/or prosthetic point of view [12].…”