# Submental Abscess Following Peri-Implantitis: Case Report and Comprehensive Literature Review
Cases of implant migration into maxillary sinus are frequently reported; however, implant displacement into other anatomical spaces like the nasal cavity is uncommon [18]. Generally, these types of complications result from planning errors or surgical inexperience. When implants migrate into the sinus, there may or may not be signs or symptoms of infection, but there will likely be an oral-antral communication. If infection occurs, it may involve the adjacent sinuses. Therefore, the removal of displaced implants is recommended. Implants that are displaced into the maxillary sinus can be removed with a Caudwell-Luc procedure or by a trans nasal approach with functional endoscopic sinus surgery. One case report described the displacement of a dental implant into the anterior cranial fossa and its endoscopic removal. A dural repair was necessary for treating a subsequent leak of cerebral spinal fluid. The authors did not describe the placement of this implant [19]. A retrospective analysis of 244 cases of complications after the placement of zygomatic implants found 2 cases of subcutaneous malar emphysema caused by dislocation of the tip of the implant burs in the zygomatic-facial region. The subcutaneous emphysema resolved naturally by resorption of the air [20]. The sublingual salivary gland can be injured when an implant is placed in the posterior mandible [21]. The contiguity of the sublingual gland to the lingual cortex of the mandible, which lies directly below the phylohyoid muscle, makes it susceptible to injury if penetration occurs in this area. Cases of development of neck and mediastinal abscesses with serious compromise of the patient's health conditions have been found in the literature [22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33]. Some cases described severe complications like descending necrotizing mediastinitis following osseointegrated dental implant placement [22; 23; 24]. Chest and neck CT images can reveal detailed information regarding the extent of the necrotizing process, and suggest, within the surgical treatment, the best approach for an effective drainage. The most common CT findings included increased attenuation of mediastinal fat, localized mediastinal fluid collections, free gas bubbles in the mediastum, pleural effusions and sternal dehiscence [34]. Submandibular space infections are potentially lethal infections. Airway obstruction and spread of infection to the mediastum are the most troublesome complications. Therefore, the maintenance of a secure airway is paramount and aggressive treatment is justified. Patients with cellulitis and small abscesses can respond to antibiotics alone. A surgical drainage should be performed in patients with larger abscesses, [PERSON]'s angina, anterior visceral space involvement, and in those who do not respond to antibiotic treatment [25]. The literature reports some cases of [PERSON]'s angina as a complication of odontogenic infections. [PERSON]'s angina is a condition that could be fatal, causing severe diffuse cellulitis bilaterally that affects the submandibular, sublingual, and submental areas. It has an acute onset and progresses rapidly. A common and potentially deadly complication is airway impairment. Most cases of [PERSON]'s angina are odontogenic in etiology, primarily resulting from infections of the lower second and third molars. These cases demonstrate the lethal effects of odontogenic infections [26; 27; 28; 29; 33]. Recently, peri-implantitis has become one of the most frequent late complications of dental implants with the risk of developing serious inflammatory processes. Peri-implantitis is defined as \"a pathological condition affecting the tissues around implants, characterized by inflammation of the peri-implant connective tissue and progressive loss of supporting bone\"; it has an incidence ranging from less than 7% to 37% of implants and can be perpetuated by a bacterial infection that has contaminated the implant surface and by excessive biomechanical forces [3; 4; 5; 35].