Surgical Removal of an Orthodontic Mini-Screw Displaced Into the Lateral Pharyngeal Space: A Case Report and Review of Pertinent Literature

Abstract

Oral and maxillofacial surgeons are often faced with the clinical challenge of foreign body displacement into the perioral tissues and soft tissues of the head and neck. This mainly occurs either because of trauma or inadvertently during dental treatment. In addition to the maxillary sinus, iatrogenic foreign body displacement during dental treatment could happen into one of the 16 distinct fascial spaces of the head and neck region. Commonly displaced foreign bodies related to dental treatment include tooth roots or fragments, local anesthetic needles, implants and restorations. The clinical sequelae of a displaced foreign body depend on its size, shape, anatomic location and proximity to vital structures. Although patients may remain asymptomatic for a considerable amount of time, retained foreign bodies result in persistent pain, recurrent infection and scarring of soft tissue due to inflammation, all of which may complicate delayed retrieval. In addition to the history, imaging modalities such as plain radiographs and computed tomography (CT) help in locating the displaced foreign body and its subsequent retrieval. Surgical retrieval may be attempted through intraoral, transcervical and endoscopic approaches. Additionally, surgery may be aided by real-time imaging such as fluoroscopy. The present report aims to detail a case of inadvertent displacement of an orthodontic mini-screw, commonly used as a temporary anchorage device (TAD), into the lateral pharyngeal space, while attempting placement in the mandibular retromolar area. The case report also describes the surgical retrieval procedure of the TAD screw using an intraoral approach and with fluoroscopy guidance using C-Arm radiographic imaging. This case is reported along with the pertinent review of literature, as it not only explains a rare complication of orthodontic mini-screw placement but also details a modality to remove displaced foreign bodies from fascial spaces of the head and neck, which are otherwise directly inaccessible.

Keywords: fluoroscopy; foreign body displacement; lateral pharyngeal space; orthodontic mini-screw; parapharyngeal space; temporary anchorage device.