A new factor involved during childbirth labor: the importance of having a good dental occlusion.

It is widely recognized that the physiology of childbirth labor largely depends on the interaction between three factors: a) the force generated by uterine contractions; b) the structure and characteristics of the birth canal and c) the fetus. Harmony between these three variables determines the initiation of maternal dynamic phenomena and the establishment of an optimal maternal-fetal balance in which both warrant for a correct delivery timing. The present study considered the above known factors and assessed if any other factor, still not recognized, could also play a role, and eventually modify the timing of delivery during the expulsive period. In particular, we focused our attention on the role played by the temporomandibular joint and dental occlusion on maternal body balance and on the stability of muscular reflected forces. The importance of assessing the temporomandibular function and the dental occlusion lies in the fact that any alteration in chewing or in temporomandibular joint (TMJ) mobility and occlusion brings to relevant modifications on the vertebral column and pelvic girdle. Our hypothesis is based on the evidence that those women who have any kind of alteration in their dental occlusion, can have an altered capability of pushing during the expulsive period, as the force applied on the pelvic floor is not expressed. Moreover, recent studies have highlighted a relationship between temporomandibular dysfunctions and sleep apnea syndrome and between sleep apnea syndromes and pregnancy. These relationships are explored in this study.