Caries and periodontal disease are chronic diseases of the oral cavity. The incidence of caries and periodontal disease can vary depending on the position of the third molar, The aim of this study was to verify possible associations between oral health-related quality of life (QoL), periodontal disease, caries lesions and the position of the lower third molar.

Caries and periodontal disease are chronic diseases of the oral cavity. The presence of third molar teeth can lead to periodontal disease in the region, and often can lead to injuries and damage to the oral health, having a significant impact on the quality of life. The incidence of caries and periodontal disease can vary depending on the position of the third molar. Purpose: The aim of this study was to verify possible associations between oral health-related quality of life (QoL), periodontal disease, caries lesions and the position of the lower third molar. Materials and Methods: The investigators performed a clinical, observational cross-sectional study within 116 patients that were screened attending to evaluate the need for extraction of third molars at of the specialization course of Oral and Maxillofacial Surgery of Dental School Foundation of University of São Paulo (FFO-USP). Caries, periodontal disease and quality of life are the outcomes that were evaluated by the main researcher. Caries lesions were assessed by visual tactile examination and periodontal disease through two probing sites around third molar, considering the presence of periodontal pathology when at least one periodontal probing depth was greater than 4 mm, and both were evaluated by radiograph diagnostic methods. The assessment of oral health related quality of life by Oral Health impact Profile questionary (OHIP-14), applied as an interview. The evaluation of the position of the third molars was made by clinical and panoramic radiographs according to the classification of Pell and Gregory and Winter. Data was treated and analyzed according to STATA 13.0, software with descriptive and inferential statistics. The level of significance used was 95%. The study had the approval of ethics committee from University of Sao Paulo Dental School (number 280084).

Inclusion Criteria:

• American society of anesthesiology (ASA) I patients (negative medical history)
• with at least one third molar erupted or partially erupted

Exclusion Criteria:

• systemically compromised
• allergic
• pregnants
• patients who had the four third molars included
• patients who have already undergone the extraction of one of the third molars

All participants with at least one third molar erupted or partially erupted. , regardless of age, gender, cultural level or socioeconomic status could participate in the study.