Reliability of third molar probing measures and the systemic impact of third molar periodontal pathology.

PURPOSE: This study examined the reliability of assessing clinical periodontal measures on third molars, and the association between oral inflammation with periodontal pathology including third molars, and systemic inflammation including negative obstetric outcomes. PATIENTS AND METHODS: Reliability of third molar probing depth (PD) was assessed for 41 patients by trained examiners. The data for the association between oral inflammation with periodontal pathology and systemic outcomes were derived from an IRB-approved study, "Oral Conditions and Pregnancy." Full mouth periodontal exams including third molars were conducted at less than 24 weeks of pregnancy. Periodontal status, moderate/severe periodontal disease (15 or more sites PD > or =4 mm) was considered as a possible predictor of systemic inflammation and pre-term birth. The upper quartile of the extent of PD for third molars alone (PD > or =4 mm) also was considered as a possible exposure variable for the same outcomes. Chi-square and t tests were used to determine statistical significance (0.05). Significant predictor variables were included in multivariate models. Unconditional logistic multivariate models were used to derive odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Reliability of PD within 1 mm was excellent, and similar for third molars and non-third molars. Data from 1,020 obstetric patients were available for analysis. Eighteen percent of the patients delivered preterm, at less than 37 weeks. Having moderate/severe periodontal disease excluding third molars, was significantly associated with preterm birth (P = .008). Results were more significant if third molars were included (P = .0005). With multivariate models moderate/severe periodontal disease at enrollment including third molar PD, was associated with preterm birth (OR, 1.7; 95% CI, 1.1, 2.6). If only the extent of third molar PD was considered, odds also were increased for preterm birth (OR, 2.4; 95% CI, 1.1, 5.2). If only the extent of third molar PD was considered at enrollment, odds were increased for serum markers of systemic inflammation, elevated serum CRP, and oxidative stress, 8-isoPGF(2alpha). CONCLUSIONS: Dental examiners could reliably assess clinical periodontal measures on third molars. Third molars should be included in studies of systemic outcomes associated with oral inflammation. Women of child-bearing age should be made aware of the systemic risks of oral inflammation with third molar periodontal pathology.     

Accidental displacement of a mandibular third molar: a case report.

This report describes the rare case of an impacted mandibular third molar that was displaced into the submandibular region. Upon locating the tooth, successful extraction was performed. Healing was unincidental.     

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当第一或第二磨牙严重病损时,第三磨牙在口腔治疗中发挥重要作用。我们将严重病损的第一或第二磨牙拔除,再利用正畸矫治的方法将不同程度阻生的第三磨牙近中及直立移动,排入牙列,使之发挥磨牙咀嚼功能。阻生第三磨牙均成功排入牙列,建立咬合关系,最大限度地恢复了自体牙列完整与咬合功能。     

Pre-eruptive movements of the mandibular third molar.

1. It would appear that the developing mandibular third molar is continually changing its angular position relative to the mandibular plane and adjacent teeth. 2. For normal uprighting and eruption to occur growth at the mesial root must dominate. 3. In the absence of sufficient space, uprighting movements of the mandibular third molar may result in mesioangular impaction. 4. Vertical and distoangular impactions can be explained by continued growth at the mesial root while the crown is prevented, at its distal surface, from erupting. 5. If growth at the distal root becomes more influential, severe mesioangular or horizontal impaction may occur.     

Subacute pericoronitis from an unerupted supernumerary third molar. Report of a case.

Any tooth may be affected by pericoronitis. A case of acute pericoronitis from an unerupted supernumerary third molar tooth is described. The importance of the patient's history and the clinical examination in reaching a diagnosis is stressed.