Effects of unilateral posterior missing-teeth on the temporomandibular joint and the alignment of cervical atlas.

Cervical atlas alignment changes are associated with craniofacial development. Disturbance of craniofacial development may be associated with temporal mandibular joint function. Therefore, we examined the possibility of a correlation between unilateral missing teeth and morphologic changes of the spine and posture. We collected eighty-nine patients (38 men and 51 women) with unilateral posterior missing teeth and twenty patients without previous orthodontic treatment or missing posterior teeth by tracing and analyzing their panoramic and cephalometric film. We measured the angulations of articular eminence, cranio-cervical angle, and the percentage of the occlusal plane passing through the first and second cervical vertebrae with other morphologic geometric data. The angle of articular eminence inclination was higher in the non-missing teeth group than the missing teeth group (46.66° and 42.28°, respectively). The cranio-cervical angle was smaller in the missing posterior teeth group than the non-missing posterior teeth group (99.81° and 103.27°, respectively). The missing teeth group also showed fewer occlusal planes passing through the intersection of the first and second cervical vertebrae compared to the non-missing teeth group (28.9% and 65%, respectively). Individuals with unilateral missing teeth had lower articular eminence inclination, smaller cranio-cervical angle, and a lower percentage of the occlusal plane passing through the intersection of the first and second cervical vertebrae.

The association of betel quid, alcohol, and cigarettes with salivary gland tumor-A case-control study.

BACKGROUND/PURPOSE: Salivary gland tumor (SGT) is a rare disease with a largely unknown etiology. The risks of betel quid chewing, alcohol drinking, and cigarette smoking have been well documented in oral cancer but not in SGT. We aimed to investigate the independent and combined effects of betel quid chewing, cigarette smoking, and alcohol consumption on the incidence of SGT. MATERIALS AND METHODS: We conducted a case-control study of 1845 patients aged 35-65 years, including 239 patients with pathologically proven SGT and 1606 controls from the health examination clinics of the same hospital during 2005-2014 to examine the association of these three risk factors with SGT in Taiwan. Adjusted odds ratio (aOR) and their 95% confidence interval for the association of risk factors to SGT were analyzed. RESULTS: After adjusting for covariates, aOR of cigarette smoking, alcohol drinking, and betel quid chewing were 2.50, 1.27, and 3.38, respectively for SGT. The significantly increased risk for SGT was observed in cigarette smoking (P < 0.001). Cigarette smoking was also found to increase risks in subgroups of SGT (aOR = 5.24, 2.41, 2.63, and 2.04 in minor, major, benign, and malignant SGT, respectively). CONCLUSION: Our study provided the first evidence to show the independent and combined impact of betel quid chewing with cigarette smoking and alcohol drinking on the SGT, and support the concept that cigarette smoking may associate with SGT carcinogenesis.