Dental hygiene therapy telereview substitution and periodontal treatment completion in Namibian rural clinics: a difference-in-differences estimation of connectivity thresholds

Namibian rural clinics face a persistent shortage of dental hygienists, and telereview has been proposed as a partial substitute for on-site periodontal follow-up. The mean of the indicator was 32.358 (SD 15.598), ranging from 10.96 in Malawi to 62.05 in Guinea. The framework specifies a threshold model in which telereview substitution is expected to raise completion only above a connectivity level sufficient for synchronous video review, and to depress completion below it. The contribution is a design that separates the substitution effect from the connectivity threshold, together with a set of propositions about the conditions under which telereview can be expected to complement rather than displace on-site hygiene therapy in Namibian rural clinics.