Dental age assessment based on the radiographic visibility of the periodontal ligament in lower third molars in a Thai sample.

The objective of the present study was to analyze the radiographic visibility of the periodontal ligament in completed root formation lower third molars in a sample of lower northern Thai population. Digital panoramic images from 800 patients with ages ranging from 16 to 26 years were used in this study. The visibility status of the periodontal ligament of lower third molars with completed root formation including apical closure was assessed. For each stage, the minimum age, maximum age, median, mean, and standard deviation were calculated. The minimum age found in stage 0 was 16.17 years in males and 17.00 years in females. Stage 1 was first achieved at the age of 16.17 years in males and 17.08 years in females. The earliest onset of stage 2 was 17.00 years in males and 18.17 years in females. The incidence of stage 3 was first observed at 19.17 years in males and 18.83 years in females. It may be concluded that the radiographic visibility of the periodontal ligament in lower third molars may be a useful approach in the dental age assessment in a Thai population. In case the periodontal ligament visibility is found to be in stage 2, it may be confirmed that the individual is at least 18 years of age.

Severe Anti-epileptic Drug-induced Gingival Overgrowth in a Physically Disabled Patient.

Anti-epileptic drugs are considered to be the main drugs associated with gingival overgrowth. The co-administration of phenytoin and other anti-epileptic drugs, which increases the risk of phenytoin-induced gingival overgrowth, has been previously reported. However, no report has been done considering the new generation of anti-epileptic drug topiramate and its association with gingival overgrowth. High levels of dental plaque and calculus have also been reported as being a critical risk factor in the development and severity of drug-induced gingival overgrowth. Thus, this case report highlights the occurrence of severe gingival overgrowth and generalized periodontitis in a physically disabled patient with epilepsy who had been taking phenytoin and topiramate drugs for 10 years. It also emphasizes the importance for both medical and dental professionals to reduce the severity and impact of drug-induced gingival overgrowth.

Bifid mandibular canals: cone beam computed tomography evaluation.

OBJECTIVES: For surgical procedures involving the posterior mandible, it is important to be familiar with the details of the bifid mandibular canal. To our knowledge, there have been no systematic studies evaluating the bifid mandibular canal using sectional imaging. The purpose of this study is to evaluate the incidence and configuration of the bifid mandibular canal using cone beam CT. METHODS: 252 patients (301 mandible sides) underwent cone beam CT between October 2004 and September 2005 and were included in this study. The cone beam CT images were evaluated for the presence and configuration of the bifid mandibular canal. The patterns of bifurcation were classified into four types according to the classification of Nortjé et al (Variations in the normal anatomy of the inferior dental (mandibular) canal: a retrospective study of panoramic radiographs from 3612 routine dental patients. Br J Oral Surg 1977; 15: 55-63). The diameter of the accessory canal was classified into two categories: 50% or more and less than 50% of the diameter of the main mandibular canal. RESULTS: Of the 301 subjects, 47 (15.6%) demonstrated a bifid mandibular canal. They were Type I in 2, Type II in 40, Type III in 0, and Type IV in 5 cases. The diameter of the accessory canal was greater than or equal to 50% of the main canal in 23, and less than 50% in 24 cases. CONCLUSIONS: On the basis of the cone beam CT, a bifid mandibular canal was found in 15.6% of cases, a markedly higher proportion than found in previous reports using panoramic images. Cone beam CT is considered a suitable modality for detailed evaluation of bifid mandibular canals.

Correlation of darkening of impacted mandibular third molar root on digital panoramic images with cone beam computed tomography findings.

OBJECTIVES: Darkening of the lower third molar root on panoramic images is known to indicate an intimate relationship between the root and mandibular canal. The objective of this study was to investigate the anatomical relationship between the third molar root and its surrounding structures that leads to this panoramic finding. METHODS: Imaging findings of 253 impacted lower third molars examined by both digital panoramic radiography and cone beam CT were reviewed. Panoramic images were evaluated to detect the presence or absence of darkening of the root where the mandibular canal was superimposed. Cone beam CT images were evaluated for the presence or absence of the following two findings: (1) grooving of the root and (2) thinning or perforation of the cortical plate by the root. The correlation between the panoramic and cone beam CT findings was examined using logistic regression analysis. RESULTS: 80 (32%) third molars showed a panoramic finding of darkening of the root. Between cone beam CT findings, cortical thinning or perforation alone was significantly correlated with this panoramic finding (80%, P < 0.001). CONCLUSIONS: The panoramic finding of mandibular third molar root darkening was considered to reflect cortical thinning or perforation rather than grooving of the root.