Pathologic tooth migration (PTM) is a common complication of advanced periodontitis and often motivation for patients to seek orthodontic therapy. An interdisciplinary approach is required to control the periodontal infection, reconstruct the defects and realign the migrated teeth. The optimal timing of active orthodontics after regenerative therapy is a topic of ongoing debate.

There are no data available from RCTs that have compared the effect of the timing of orthodontic tooth movement (early vs. late) on the outcomes of regenerative periodontal surgery in these patients.

It is the aim of the present randomized clinical multicenter trial to compare 2 different treatment protocols of a combined perio-regenerative and orthodontic therapy in advanced periodontitis patients with intrabony defects and pathologic tooth migration in order to establish whether one treatment modality is superior to the other with regard to clinical outcomes. A total of 46 patients will be enrolled and randomized into 2 treatment groups that differ by the time point of initiation of orthodontic therapy (early: 4 weeks vs. late: 6 months following regenerative periodontal surgery).

Primary outcome measure will be the change in clinical attachment level (CAL gain) at 12 months after regenerative therapy. Secondary outcomes will include changes in probing depth BOP, gingival recession, radiographic bone height and patient-centered outcomes.

Inclusion Criteria:

• Advanced periodontitis
• Presence of intrabony defects at a minimum of 2 and a maximum of 7 adjacent teeth (positions 15-25 or 35-45) in either the maxilla or the mandible with PPD of ≥6 mm at a minimum on one site
• Pathologic tooth migration
• Full mouth plaque index (PI) <25% at baseline (after initial non-surgical periodontal therapy)
• Full mouth bleeding on probing (FMBP) <25% at baseline (i.e., following initial non-surgical periodontal therapy)
• Committed to the study and the required follow-up visits

Exclusion Criteria:

Any contraindications for oral surgical procedures

• Uncontrolled diabetes or other uncontrolled systemic diseases
• Disorders or treatments that compromise wound healing
• Medical conditions requiring chronic high dose steroid therapy
• Bone metabolic diseases
• Radiation or other immuno-suppressive therapy
• Infections or vascular impairment at the surgical site
• Presence of oral lesions (such as ulceration, malignancy) or mucosal diseases
• History of malignant disease in the oral cavity or previous radiotherapy to the head
• Inadequate oral hygiene or unmotivated for adequate home care
• Current smokers > 6Cig