Duration of Second Stage of Labor Wearing a Dental Occlusion Device

The increased use of epidural anesthesia during labor has lead to an increased incidence of prolonged second stage as an indication for cesarean section or instrumental delivery. The use of oxytocin has proven to be an effective method of augmentation of labor in such prolonged labor cases. However, despite oxytocin augmentation, there has been an increase in the number of cases that require cesarean section or instrumental delivery to effect delivery.

McRobert's maneuver, which is often used in to relieve shoulder dystocia, has recently been shown to increase intrauterine pressure approximately two-fold. However; it is an arduous position for the pregnant woman to maintain over a long period of time. Developing alternative methods to maximize expulsive forces, both uterine contractions and maternal expulsive effort, may be of great value in reducing the number of cesarean sections or instrumental deliveries.

Various researchers have investigated the effect of an occlusal support device (OSD) on the isometric strength of different muscle groups, e.g., neck, back, and extremities. The natural condition of dental occlusion, also known as the index of physical performance, has an affect on both muscle strength and body balance. When occlusal support is given to edentulous individuals they show improved physical exercise ability after the re-establishment of mandibular support. Patients whose dentition is in proper occlusion demonstrate greater endurance of isometric muscle strength than those who are in malocclusion. We hypothesize that optimization of dental occlusion by an OSD may improve muscle strength, leading to increased intrauterine pressure during the second stage in labor.

The aim of our study is to investigate whether the use of the OSD results in a shortened duration of the second stage of labor.

Inclusion criteria

• Primipara
• Term
• Singleton
• Cephalic presentation
• Reactive fetal heart rate pattern
• Functioning epidural anesthesia

Exclusion criteria

• Medical or obstetrical complications including intrauterine growth restriction
• Large for gestational age
• Uterine anomaly
• Uterine myomata
• Pre-eclampsia
• Diabetes mellitus
• Fetal anomaly
• Maternal heart disease