Bilateral treatment of the masseter with botulinum toxin: Consequences for mastication, muscle force and the mandibular condyle.

Background: Clinical use of botulinum neurotoxins (BoNTs) in masticatory muscles is usually bilateral, but most studies on the functional consequences of BoNT treatment have used unilaterally treated animals.

Objectives: To test the hypothesis that bilateral BoNT treatment of the rabbit masseter hampers mastication and to assess its effects on bone density of the mandibular condyles.

Methods: Ten 5-month-old female rabbits received injections of BoNT into both masseter muscles and nine sham animals received saline.

Repeated botulinum treatment of rabbit masseter causes cumulative tissue damage.

Objective: Botulinum neurotoxins (BoNT) are used in masticatory muscles for pain relief, unloading of the mandible, and cosmetic facial contouring. Treatment is often repeated every few months as function returns. This study assessed masticatory function and musculoskeletal structure after multiple BoNT treatment of the rabbit masseter.

Selection on crop-derived traits and QTL in sunflower (Helianthus annuus) crop-wild hybrids under water stress.

Locally relevant conditions, such as water stress in irrigated agricultural regions, should be considered when assessing the risk of crop allele introgression into wild populations following hybridization. Although research in cultivars has suggested that domestication traits may reduce fecundity under water stress as compared to wild-like phenotypes, this has not been investigated in crop-wild hybrids. In this study, we examine phenotypic selection acting on, as well as the genetic architecture of vegetative, reproductive, and physiological characteristics in an experimental population of sunflower crop-wild hybrids grown under wild-like low water conditions.