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Drastic changes in protoplanets' orbits could occur in the early stages of planetary systems through interactions with other planets and their surrounding protoplanetary or debris discs. The resulting planetary system could exhibit orbits with moderate to high eccentricities and/or inclinations, causing planets to perturb one another as well as the disc significantly. The present work studies the evolution of systems composed of an initially inclined planet and a debris disc. We perform N-body simulations of a narrow, self-gravitating debris disc and a single interior Neptune-like planet. We simulate systems with various initial planetary inclinations, from coplanar to polar configurations considering different separations between the planet and the disc. We find that except when the planet is initially on a polar orbit, the planet-disc system tends to reach a quasi-coplanar configuration with low vertical dispersion in the disc. When present, the Zeipel--Kozai--Lidov oscillations induced by the disc pump the planet's eccentricity and, in turn, affect the disc structure. We also find that the resulting disc morphology in most of the simulations looks very similar in both radial and vertical directions once the simulations are converged. This contrasts strongly with massless disc simulations, where vertical disc dispersion is set by the initial disc-planet inclination and can be high for initially highly inclined planets. The results suggest caution in interpreting an unseen planet's dynamical history based only on the disc's appearance., Comment: 15 pages, 6 figures. Accepted for publication in MNRAS

We present ALMA band 6 images of the 12CO, 13CO and C18O J=2-1 line emissions for the circumstellar disc around HD 169142, at ~8 au spatial resolution. We resolve a central gas depleted cavity, along with two independent near-symmetric ring-like structures in line emission: a well-defined inner gas ring [~25 au] and a second relatively fainter and diffuse outer gas ring [~65 au]. We identify a localised super-Keplerian feature or vertical flow with a magnitude of ~75m/s in the 12CO map. This feature has the shape of an arc that spans azimuthally across a PA range of ~60 to 45 degrees and radially in between the B1[26au] and B2[59au] dust rings. Through reconstruction of the gas surface density profile, we find that the magnitude of the background perturbations by the pressure support and self-gravity terms are not significant enough to account for the kinematic excess. If of planetary origin, the relative depletion in the gas-density profile would suggest a 1 Mj planet. In contrast, the central cavity displays relatively smooth kinematics, suggesting either a low mass companion and/or a binary orbit with a minimal vertical velocity component.