## 4 Discussion
Therefore, most studies and case reports in the scientific dental literature investigate and describe intrusion and retraction of extruded and protruded incisors as the most common orthodontic intervention strategy [17, 18, 22, 23, 24, 25]. In such cases, it is critical to minimize the extrusion and mesial movement of posterior teeth [16]. For appropriate anchorage reinforcement, previous studies have described the use of heathy posterior teeth, headgear, bite blocks, rigid TPAs, Nance buttons and TADs [23, 25, 26, 27, 28]. However, such an approach is not applicable to our case given the case findings, etiology and treatment objectives. In their systematic review, [PERSON] and colleagues (2023) highlighted the scarcity of studies that have investigated extrusive mechanics [29]. They only included one randomized clinical trial that recommended orthodontic extrusion as an effective strategy for patients with infra-bony defects to improve periodontal health parameters such as probing depth, bleeding index and clinical attachment level [30]. Previous reports have shown predictable treatment outcomes with regenerative periodontal treatment of teeth with significant attachment loss before orthodontists moved the teeth towards an infra-bony defect [31]. However, our patient did not present with infra-bony defects. Others have also shown the benefit of extrusive movement to modify the gingival margin position [32], which was not indicated in our case. The only comparable study to our case is a case report described by [PERSON] and colleagues in 2013 [33]. Their adult female patient presented with hopeless maxillary central incisors due to severe bone loss. She was treated by slow forced extrusion for implant site development [33]. Such an approach was presented to our patient as an alternative option, but she rejected it due to psychological and financial constraints, as mentioned previously. Regardless of the type of movement (extrusion or intrusion), there is a clear consensus that orthodontic forces in periodontally compromised patients should be targeted, light, controlled and continuous [29]. Extrusion force should allow movement of \(\geq\)2 mm per month [34], and intrusion force should be between 5 and 10 g per tooth [23]. Previous studies also warned against the use of forces with a deleterious effect, such as the use of continuous arch mechanics for intrusion and retraction movements or the application of tooth-born inter-arch elastics for sagittal correction [16]. In line with our approach, previous authors have shown the benefit and applicability of segmental targeted mechanics along with the use of TADs for inter-arch elastics [15; 35]. The fifth step includes black triangles and gingival recession. Black triangles, as sites of food debris accumulation, are another complicating factor from esthetic, phonetic and health perspectives [16]. Black triangles can be improved with orthodontic teeth repositioning, especially intrusion movement, interproximal stripping and closure of diastema and other spaces [36]. Despite performing interproximal reduction in our patient, the black triangles were not notably reduced. Such a lack of notable improvement is to be expected given the significant distance between the bone crest and the base of the contact point [16]. Although challenging and unpredictable, one multidisciplinary approach to reconstructing the interdential papilla includes the use of composite resins and/or a subepithelial connective tissue graft [37; 38]. Patients with a sensitive receded periodontitis could benefit from desensitizing gel and/or a coronal advanced flap with a connective tissue graft, depending on the severity of the problem [39]. Pre-orthodontic periodontal treatment for our patient included the use of desensitizing gel and fluoride application only. In periodontally involved patients, dental expansion and advancement may cause recession and dehiscence and will worsen a preexisting gingival recession, especially in patients with a thin gingival biotype [40].