Discussion

Soft-tissue embedding of orthodontic appliances is an uncommon but clinically significant complication that may necessitate surgical intervention and multidisciplinary management. The pathogenesis is multifactorial and may involve appliance design, placement technique, tissue characteristics, oral hygiene status, and patient compliance with follow-up visits. TADs placed in non-keratinized mucosa are particularly susceptible to soft-tissue overgrowth because of the reduced resistance of alveolar mucosa to mechanical irritation and tissue remodeling. In addition, excessive insertion depth and inadequate monitoring may predispose mini-implants to progressive mucosal coverage and eventual soft-tissue embedding [8-10].

Orthodontic mini-implants are commonly classified according to their design (cylindrical or tapered), dimensions, insertion method (self-drilling or self-tapping), and placement site, including interradicular and extra-alveolar locations. The choice of mini-implant should be individualized according to the available bone, soft-tissue characteristics, and the intended orthodontic mechanics [11]. Primary stability is a major factor influencing treatment success and depends on factors such as cortical bone quality, implant size, insertion technique, and maintenance of good oral hygiene.

In the first case, complete soft-tissue overgrowth around the orthodontic mini-implant led to pain and functional discomfort. A mini-implant measuring 1.4 mm in diameter and 8 mm in length had been placed in the attached gingiva adjacent to the maxillary second premolar. Although orthodontic mini-implants are associated with high clinical success rates, biological and mechanical complications may occur during treatment. Common complications include peri-implant soft-tissue inflammation, infection, implant loosening, root contact, and screw fracture, whereas injury to adjacent anatomical structures is relatively uncommon. Gingival overgrowth or soft-tissue embedding is a less frequent complication and is often associated with inadequate transmucosal collar height, prolonged treatment duration, plaque accumulation, poor oral hygiene, or placement in non-keratinized mucosa [1,2,8]. In the present case, continuous mechanical irritation combined with plaque retention likely contributed to the inflammatory response and progressive soft-tissue coverage of the implant. Surgical exposure followed by thorough debridement restored access to the mini-implant while preserving the surrounding tissues, and primary wound closure resulted in satisfactory healing with complete resolution of symptoms [12-14].

Orthodontic mini-implants have a high success rate (80-90%); however, complications occur in approximately 13-30% of cases. Soft-tissue inflammation is the most common biological complication (5-22%), while gingival overgrowth and mucosal embedding are reported in 2-15% of patients. These complications are often associated with poor oral hygiene, placement in non-keratinized mucosa, increased soft-tissue thickness, and prolonged implant use [15,16].

The second case involved partial embedding of the TPA loop within the palatal mucosa. The TPA is commonly used to reinforce maxillary anchorage, maintain transverse arch width, correct molar rotation, and stabilize maxillary molars during orthodontic treatment. Although it is a simple and effective appliance, prolonged intraoral use may be associated with complications such as palatal mucosal irritation, plaque accumulation, tissue overgrowth, appliance distortion, and, rarely, soft-tissue embedding. These complications are more likely when the appliance is positioned too close to the palatal mucosa, oral hygiene is inadequate, or regular follow-up is lacking [17,18]. In the present case, continuous mechanical irritation from the closely adapted TPA loop likely promoted localized inflammation and gradual mucosal overgrowth, resulting in partial embedment of the appliance. Surgical retrieval was performed with minimal tissue trauma, and healing by secondary intention was uneventful.

Various techniques have been described for the management of embedded TPA appliances, including conventional surgical exposure and soft-tissue laser-assisted retrieval. Regardless of the method employed, prevention remains the cornerstone of management. Appropriate appliance design, including maintaining adequate clearance between the TPA and palatal tissues, is essential to minimize tissue impingement [18]. Additional modifications, such as repositioning the palatal loop or incorporating a protective sleeve over the loop, have been proposed to reduce chronic mucosal irritation and decrease the likelihood of soft-tissue overgrowth. These preventive measures may contribute to improved patient comfort and reduce the risk of appliance embedment during orthodontic treatment [19].

Both cases highlight the important role of the periodontist in the management of orthodontic complications involving soft tissues. Surgical exposure or retrieval of soft tissue-embedded appliances requires careful tissue handling, effective debridement, and appropriate postoperative care to achieve predictable healing outcomes [13,14]. Furthermore, these cases emphasize the importance of regular clinical monitoring, patient education regarding oral hygiene maintenance, and timely intervention when early signs of tissue impingement or overgrowth are detected.