Abstract:

Objective To study the relationship between the position of mandibular wisdom tooth and pericoronitis.
Methods 450 mandibular wisdom teeth of 434 patients were collected and studied. 450 mandibular wisdom teeth were divided into two groups. One was pericoronitis group（groupⅠ）, the other was no pericoronitis group（groupⅡ）. Impacted type of mandibular wisdom tooth, the depth of pericoronal pockets and the size of gingival flaps, the height and gradient of retromolar pads were recorded. The data in the two groups was analysis statistically. Results Compared with the mandibular wisdom tooth in the no pericoronitis group, the retromolar pad was higher and more oblique, pericoronal pocket was deeper and size of gingival flap was bigger in the pericoronitis
group. But no difference was observed in type of impaction between two groups.
Conclusion It was the danger factors of pericoronitis occurrence that deeper pericoronal pocket and bigger gingival flap surrounding mandibular wisdom tooth, heighter and more oblique retromolar pad, which was served as the criterion of prophylactic wisdom tooth extraction.