Recent trends in placenta accreta in the United States and its impact on maternal–fetal morbidity and healthcare-associated costs, 1998–2011

Objective: To describe the prevalence, trends, adverse maternal-fetal morbidities and healthcare costs associated with placenta accreta (PA) in the United States (US) between 1998 and 2011.

Methods: A retrospective, cross-sectional analysis of inpatient hospital discharges was conducted using the National Inpatient Sample (NIS). We used International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) codes to identify both cases of PA and of selected comorbidities. Survey logistic regression was used to assess the association between PA and various maternal–fetal outcomes. Joinpoint regression modeling was used to estimate annual percent changes (APCs) in PA prevalence during the study period.

Results: The prevalence of PA from 1998 to 2011 was 3.7 per 1000 delivery-related discharges. After adjusting for known or suspected confounders, PA conferred between a 20% to over a 19-fold increased odds of experiencing an adverse outcome. This resulted in a higher mean, per-hospitalization, cost of inpatient care after adjustment for inflation ($5561 versus $4989), translating into over $115 million dollars in additional inpatient expenditures relative to non-PA affected deliveries from 2001 to 2011.

Conclusions: This study updates recent trends in the prevalence of PA, which is valuable to clinicians and policymakers as they formulate targeted strategies to address factors related to PA.     

Vectorial analysis of the equilibrium of forces transmitted to TMJ and Occlusal biteplane splints

SUMMARY A mechanical model (link quadrilateral bell crank) is used to demonstrate the equilibrium of normal force vectors transmitted to the masticatory system and maxillary occlusal biteplane splints with different designs. Occlusal contacts were imposed on the proposed models under the action of a masticatory force vector with an arbitrary value of 40 kgf. The consequence of this force action created different responses within the joint and at the level of the dentition. When compared to the intercuspal position in centric occlusion, intra-oral appliances with either smooth contacting surfaces or indentations, both with increased vertical dimension, forced the mandible to assume an anterior position with a con- current increase of joint forces. The bite-splint that produced the least amount of joint force was the stabilization type with minimal increase of vertical dimension.