Table 1

The schedule of enrolment, interventions and assessments

	Study period
	Enrolment	Allocation		Postallocation				Close-out
Timepoint	−T₁	T_0a	T_0b	T₁	T₂	T₃	T₄	T₅
Enrolment:
Eligibility screen		√
Informed consent		√
Allocation		√
Interventions:
Tunnel technique		√/×
Orthodontics			√	√	√	√	√	√
Assessments:
Patients’ characteristics		√
Height of the gingival margin		√	√	√	√	√	√	√
Probing depth		√	√	√	√	√	√	√
Gingival phenotype		√	√	√	√	√	√	√
Gingival thickness		√		√	√		√	√
Clinical attachment level		√	√	√	√	√	√	√
Width of keratinised gingiva		√	√	√	√	√	√	√
Gingival recession class		√	√	√	√	√	√	√
Frequency of complete root coverage		√	√	√	√	√	√	√
Full-mouth plaque score		√	√	√	√	√	√	√
Alveolar bone thickness		√		√	√		√	√
Lower incisor inclination		√		√	√		√	√
Subjective symptoms		√	√	√	√	√	√	√