Detection and characterization of the accessory mental foramen using cone-beam computed tomography.

OBJECTIVE: This study aimed to investigate the frequency and characteristics of accessory mental foramina (AMFs) and their bony canals in a selected Chinese population using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Reconstructed CBCT images of the mandible in 784 Chinese patients (305 males and 479 females) were retrospectively analysed to identify the AMF. The presence, dimension and location of the AMF as well as the origin and course of the associated bony canal were evaluated and classified. Variations in these characteristics were analysed according to gender, side and age. RESULTS: A total of 66 AMFs were found in 57 (7.3%) of the 784 patients. The frequency of AMFs was significantly influenced by gender and side of the mandible (p < .05). Most AMFs were located apically between apices of the first and second premolars. The high-position AMFs (above the mental foramen) accounted for 54.5% of the total. The mean horizontal and vertical diameters of the AMF were 1.38 ± 0.47 and 1.23 ± 0.37 mm, respectively. Two typical types of the bony canal leading to the AMF were identified according to their bifurcation site from the mandibular canal. Most bony canals originated from the anterior loop of the mental canal (56.1%) and coursed posterosuperiorly (36.3%). The mean length of the bony canals was 5.78 ± 2.31 mm. CONCLUSIONS: This study presents a considerable frequency of AMFs in a Chinese population. The high-position AMF and the associated bony canal coursing in the oblique upward direction appear frequently. Thus, clinicians should be alert to the presence of the AMF to avoid neurovascular complications especially when dental procedures require periosteum detachment and implant insertion in the mental region.

[Investigation of subjective well-being and influence factors among residents living in old districts in Wuhan, China].

OBJECTIVE: To investigate the subjective well-being and its influence factors among residents living in old districts in Wuhan. METHODS: In June, 2011, a total of 500 residents living in Shanghai Street in Wuhan were recruited as subjects for this study by two-stage stratified random sampling method. The information of demographic features, health status, spare time, family status, interpersonal relationship and social environment were collected by self-made questionnaires naming "survey of satisfaction of residents living in old districts". The results were analyzed by single-factor and multi-factors analysis method. RESULTS: In this study, 448 samples of questionnaire were answered qualified (89.6%, 448/500). The subjects aged (51.3 ± 16.1) years old. The single-factor analysis showed that male and female influence the subjective happiness got 5.43 ± 1.66, 5.77 ± 1.65 (U = -2.32, P < 0.05);the age of 0 - 45, 46 - 59, 60 and above group got 5.12 ± 1.68, 5.47 ± 1.81, 6.29 ± 1.23, respectively (H = 43.07, P < 0.01); the unmarried, married, divorced, loss of spouse and remarriage groups got 5.18 ± 1.94, 5.74 ± 1.54, 4.00 ± 2.04, 5.68 ± 1.91, 6.63 ± 0.92, respectively (H = 17.41, P < 0.01); education background were primary school and blow, junior middle school, senior high school, bachelor degree, master degree and above got 6.30 ± 1.42, 5.55 ± 1.82, 5.90 ± 1.46, 5.07 ± 1.74, 4.75 ± 2.22 (H = 26.99, P < 0.01); monthly household income was ¥0 - 2000, ¥2001 - 4000, ¥4001 - 8000, ¥8001 - 10 000, ¥10 000 and above got 5.34 ± 1.87, 5.68 ± 1.53, 6.20 ± 1.07, 7.33 ± 0.58, 6.00 ± 0.00, respectively (H = 13.85, P < 0.01). The subjective satisfaction of social environment ranked from high to low were: city public security (56.0%, 248/448), traffic environment (44.9%, 199/448), community environment (14.9%, 66/448), housing conditions (13.8%, 61/448) and medical environment (8.2%, 36/448). Multiple regression model suggested that the determinant coefficient was 0.53(P < 0.01), with a good degree of fitting. The model showed that the factors influencing the residents' happiness were ranked: social environment (ß' = 0.34), family status (ß' = 0.32), health status (ß' = 0.21), education background (ß'(0-6) school year = 0.00, ß'(7-9) school year = -0.12, ß'(9-12) school year = 0.04, ß'(>12) school year = -0.14), monthly household income (ß' = 0.07) and marital status (ß'(unmarried) = 0.00, ß'(married) = 0.03, ß'(divorced) = -0.03, ß'(widowed) = 0.01, ß'(remarried) = 0.02). CONCLUSION: The factors that social environment, family status, health status, education background, monthly household income and marital status could influence the subjective happiness of residents living in old districts in Wuhan. A perfect social security system could improve the subjective happiness of residents in old districts in Wuhan.