Extraction of Lower Third Molars: Risk indication for Postoperative Complications

Kazuhiko Nakaue DDS, Department of Oral and Maxillofacial Surgery, Nara Medical University, Nara-Kashihara, Japan
Kumiko Aoki DDS, PhD, Department of Oral and Maxillofacial Surgery, Nara Medical University, Nara-Kashihara, Japan
Yoshihiro Ueyama DDS, Department of Oral and Maxillofacial Surgery, Nara Medical University, Nara-Kashihara, Japan
Souta Ihoki DDS, Department of Oral and Maxillofacial Surgery, Nara Medical University, Nara-Kashihara, Japan
Tadaaki Kirita DDS, DMSc, Department of Oral and Maxillofacial Surgery, Nara Medical University, Nara-Kashihara, Japan
Extraction of lower third molars is one of the most frequently operation among the procedures in oral surgery. In addition, postoperative inflammatory conditions, including alveolar osteitis, surgical site infections, and abscess, are frequent complications after the surgically removal of impacted lower third molars and multiple accompanied risk factors have been identified. In this study, we have evaluated the complications in the extraction of lower third molars and the risk factor of it statistically.

 A retrospective analytic study had been performed of 492 patients, 227 males (46%) and 265 females (54%), who was executed surgically removal of 586 lower third molars from September 1, 2011, to August 31, 2013, in the Department of Oral and Maxillofacial Surgery, Nara Medical University. The patients’ ages are ranged from 13 to 90 years (median 29). This study has been enforced only for the patient who has provided the written informed consent for this studies, reviewed and approved by the institutional review board. Patients with missing the second lower molars were excluded from this study. All data of this study were collected from the case histories and the orthopanoramic radiographic evaluations of the each patient. The case histories shows the clinician-completed questionnaire and an examination, including questions about the patient’s smoking history, medical history and the medication history. The medication history shows especially included the medications that could have an effect on oral wound healing and/or alveolar osteitis formation, and these included the drugs used for mental illness, diabetic medications, bisphosphonates, antibiotics at extraction, antiplatelet and anticoagulation drugs, and steroids. All mandibular third molars were classified by the classifications of G.B Winter. The position of the mandibular third molar was evaluated by the using a series of parameters of 3 categorical position variables: inclination of the longitudinal axis of the molar, the depth of impaction, and the available space with respect to the ascending mandibular ramus. The longitudinal axis forms an angle with the occlusal plane, providing objective classification of its angulation as follows: horizontal (0°-30°),mesioangular (31°-60°), vertical (61°-90°), and distoangular (-90°).

 The computer database using a personal computer was applied by the data on a spreadsheet. Statistical analysis was performed using Stat Flex, version 6.  To assess the independent risk factors, logistic regression analysis was used for the multivariate analysis.

 Neurosensory deficits of inferior alveolar nerve had developed in 17 patients. Preoperative infection, the distance from mandibular ramus, an operative time were also significant risk factors of the inferior alveolar nerve disorder. The dosage period of the antibiotic is between 3 to 60 days and the median was 7 days. It was 100 cases that the additional dosage was necessary at the one week after the extraction of lower third molars. Smoking, diabetes, premeditation, an operative time were also significant factors of the dosage period of the antibiotic. The periodical dosage of the analgesics was between 0 to 60 days and the median was 7 days. It was 90 cases that the additional dosage was necessary after extraction of lower third molars at one week. Smoking, premeditation, degree of depth, the year of experience of the operator, an operative time were also significant factors of the dosage period of the analgesics.

 Several indicators were found to increase the risk of postoperative complications.

References.

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