Does the quality of residual alveolar bone apical to a periodontal lesion beneath the maxillary sinus play a vital role in preventing the extension of periodontal disease to maxillary sinus? A CBCT-assisted retrospective study.

BACKGROUND: The mucous membrane of the maxillary sinus is sensitivis susceptible to infection or inflammation adjacent to it, which may contribute to mucous membrane thickening (MMT). Residual alveolar bone quality (RABQ) is considered a quality of the remaining bone apical to periodontal defect adjoining to the floor of the maxillary sinus. OBJECTIVE: The current study aimed to analyze the minimum RABQ to prevent the extension of periodontal pathology from reaching maxillary sinus using cone-beam computed tomography (CBCT). METHODS: In this retrospective observational study, 240 sinus exposure CBCT records of 146 patients were evaluated. Patients with at least one sinus exposure were included. RABQ and MMT were calculated using CBCT inbuilt tools. RABQ was divided into four groups based on gray scale values (GSV). Statistical analysis was performed using one way ANOVA and independent sample t-tests. Correlation was completed applying Pearson's correlation coefficient. RESULTS: A significant difference (p< 0.05) was observed between the MMT values of the four RABQ groups. Inverse correlation was observed between mean MMT and GSV values. Mean MMT was higher than pathological MMT range (> 2 mm), with significant differences in groups A and B, where mean GSV values are less than 500. Mean GSV greater than 500 in groups C and D show non-pathological MMT. Prevalence of MMT is 91.4% if GSV is < 500 and 7.5% if GSV is > 500. CONCLUSIONS: Our study suggests that MMT is present if RABQ has GSV values < 500. Maxillary sinusitis and its etiology from periodontal pathology can be excluded based on RABQ adjoining periodontal lesion. Early detection and prompt treatment along with appropriate regenerative protocols can be performed to increase the RABQ. Further microbiological investigation is required to support the present results.

Does residual bone thickness apical to periodontal defect play a major role in maxillary sinus mucous membrane thickness?: A cone-beam computed tomography-assisted retrospective study.

BACKGROUND: The mucous membrane of the maxillary sinus is very sensitive to foreign bodies and infections. Any triggering may lead to mucous membrane thickening (MMT). Residual bone thickness (RBT) is the remaining bone apical to the periodontal defect until the floor of the maxillary sinus acts as a barrier for the periodontal infections to reach the sinus. The aim of our current study was to evaluate the minimal RBT to prevent periodontal infection to reach Schneiderian membrane using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: In this descriptive study, 144 maxillary sinus exposure records of 100 patients were collected retrospectively. Patients with minimum one sinus exposure were considered. MMT and RBT were calculated with the CBCT assistance. Statistical analysis was done using Mann-Whitney U-test, Kruskal-Wallis and Chi-square test. (P < 0.05) was considered as statistically significant. RESULTS: Significant difference (P < 0.001) was observed in MMT among three RBT groups. Significantly, higher mean MMT was observed with <2 mm and 2-4 mm RBT groups. The prevalence of MMT with >4 mm group is less (7%) compared to <2 mm group and 2-4 mm RBT groups (91.2% and 90.2%, respectively). Furthermore, there is no significant difference in MMT between angular and furcation defects (P = 0.890). CONCLUSION: Probability of MMT was increased if RBT is <4 mm. Early detection and prompt periodontal treatments associated with regenerative procedures can be instituted wherever possible to improve RBT and to reduce MMT. Further, microbiological studies are required to confirm the analysis.

Incidence of distal caries in mandibular second molars due to impacted third molars: Nonintervention strategy of asymptomatic third molars causes harm? A retrospective study.

BACKGROUND: Removal of impacted third molars is the most common oral surgical procedure. Many investigators have questioned the necessity of removal in patients who are free of symptoms or associated pathologies. AIM: The aim of this retrospective study was to evaluate the incidence of caries on distal aspect of mandibular second molars in patients referred for corresponding third molar assessment and to identify its association with angular position and depth of the impacted mandibular third molars based on the classification of Pell and Gregory. METHODOLOGY: Records of 150 patients with impacted third molar presenting to the Department of Oral and Maxillofacial Surgery, Sri Rajiv Gandhi College of Dental Sciences and Hospital, were assessed retrospectively. The radiographic angulation and depth of mandibular third molar impaction were determined and compared to determine the relationship with incidence of caries on the distal surface of the second molar. RESULTS: According to this study results, 37.5% cases show caries on the distal aspect of mandibular second molars. The incidence of caries with mesioangular impacted third molars was 55%. A majority of these mesioangular cases were Level B and Class I as per the Pell and Gregory classification. CONCLUSION: The prophylactic extraction of mandibular third molars is indicated if the angulation is between 30° and 70° and is justified by incidence of distal caries in the second molars.