Radiological risk indicators for persistent postoperative morbidity after third molar removal

Pathologic conditions associated with impacted third molars: A retrospective study of panoramic radiographs in a Southern Brazilian population

Purpose

This study investigated the prevalence of developmental and acquired pathologic conditions associated with impacted third molars (3Ms) in a Southern Brazilian population and evaluated whether demographic and tooth characteristics were correlated with the presence of bone or tooth lesions.

Materials and Methods

Panoramic radiographs were assessed for developmental (bone-related) or acquired (tooth-related) pathoses associated with impacted upper or lower 3Ms. Data on tooth positioning, tooth development, and patient demographics were collected. A trained, calibrated postgraduate student evaluated all images. Binary and multivariate logistic regression models were used to assess associations between outcomes and the demographic and radiographic variables. The threshold for statistical significance was set at 5% (P<0.05).

Results

The sample comprised panoramic radiographs from 2054 patients, predominantly female (59.2%), with a mean age of 27.2 ± 11.5 years. Overall, 4066 impacted 3Ms were evaluated, revealing 471 (11.6%) developmental and 710 (17.5%) acquired pathoses. Among the developmental pathoses, 460 (95.2%) were indicative of dentigerous cysts. Male sex, lower 3M location, vertical or distoangular positioning, and incomplete root formation were associated with an elevated likelihood of developmental pathology. Lower tooth position, complete root formation, and partial eruption were linked to an increased probability of an acquired pathology in the third or second molar.

Conclusion

The prevalence of pathologic conditions associated with impacted 3Ms was low. Male sex, lower 3M placement, horizontal or distoangular positioning, and incomplete root formation were associated with developmental pathoses, while lower tooth position, complete root formation, and partial eruption were related to acquired pathoses.

Risk factors observed in 2-dimensional radiographs for permanent injury of the inferior alveolar nerve after removal of mandibular third molars: a case-control study

OBJECTIVE

To assess whether differences exist in signs observed in 2D radiographs of mandibular third molars between a case group of patients with and a control group without permanent sensory disturbance of the inferior alveolar nerve (IAN) after removal.

STUDY DESIGN

Three observers blinded to patient status assessed radiographs from the case group (n=162) and the control group (n=172). Two new signs, craniocaudal relation of the roots and the mandibular canal and position of the canal over the roots; and 4 "classic" signs, interruption of the white borders of the canal, darkening of the roots, narrowing of the canal lumen, and diversion of the canal over the roots were registered. Chi-square tests assessed differences in distribution of radiographic signs between the groups. Odds ratios expressed the association between radiographic signs and permanent sensory disturbance. Inter- and intraobserver reliability values were calculated.

RESULTS

We found significantly more teeth with roots positioned inferiorly to the canal borders (P<0.001; OR 4.1-5.3) and with the canal superimposed over the upper or middle third of the roots (P<0.001; OR 2.6-3.9) in the case group than in the control group. Inter- and intraobserver reproducibility was excellent for roots inferior to the canal borders and fair to good for canal superimposition.

CONCLUSIONS

Two radiographic signs are valid predictors of permanent sensory disturbance of the IAN in 2D radiographs.

Surgical experience and patient morbidity after third molar removal

OBJECTIVES

The present study aimed to assess differences in patients' postoperative morbidity after third molar removal in relation to the surgeon's level of experience and other intraoperative factors.

MATERIAL AND METHODS

Patients admitted for prophylactic removal of asymptomatic third molars were prospectively followed up on day 3 and 10 after surgery in the context of the M3BE-study. Uni- and multivariable logistic regression was performed to assess the associations between surgeon's (in)experience and postoperative discomfort. Other contributing factors were gender, age, extraction method (osteotomy or not), and number of extractions and involved jaws.

RESULTS

In total, 7 senior surgeons and 28 surgical residents operated 2560 patients (8672 third molars). Differences in postoperative morbidity on day 3 and 10 after surgery were small. The results showed no significant associations between surgeon's inexperience and postoperative discomfort (pain, trismus, swelling), except for persistent pain (day 10; OR 1.468; p = 0.0016). No effect was observed on the occurrence of postoperative nerve complications. It was shown that postoperative morbidity was more dependent on factors like age, gender, number of extractions and intraoperative osteotomy.

CONCLUSION

We may conclude that patient recovery following third molar removal is affected by other factors than surgical experience. However, surgical residents seemed to cause significantly more persisting pain problems 10 days after surgery.