## 2 Materials and Methods  
### Surgical Procedure  
The case report was conducted in accordance with the ethical laws and the World Medical Association Declaration of Helsinki [31], and the Surgical Case Report (SCARE) guidelines [32]. The present clinical study was based on the ethical laws and the World Medical Association Declaration of Helsinki, and the additional requirements of Italian legislation. Moreover, the University of Chieti-Pescara, Italy, classified the present case reporting to be exempt from ethical review as it carries only negligible risk and involves the use of existing data that contains only non-identifiable data about human beings. A 58-year-old man was referred for rehabilitation of the maxillary. His medical history did not reveal any significant systemic diseases, and he was a non-smoker. The subject reported a history of the removal of a cyst on the left maxillary region approximately 1 year previously. The patient needed rehabilitation with 6 implants and a full prosthesis in the maxilla. The clinical examination of the patient revealed an dentulous state in the maxilla. Radiograph assessment with a Cone Beam Computed Tomography (CBCT) (Vatech Ipax 3D PCH-6500, Fort Lee, NJ, USA) excluded any clinically relevant and radiographically evident pathologies such as odontogenic sinusitis, mucosal thickening, allergy, mucus-retaining cysts, oro-antral fistula, partial to complete sinus obliteration, antroliths, mucoceles, or mucopyoceles, but detected a radiopaque lesion in the right sinus (Figure 1). For this reason, the patient was referred to the Department of Innovative Technology in Medicine and Dentistry of the University \"G. d'Annunzio\" of Chieti-Pescara in Italy by his dentist for case evaluation. The lesion was probably an osteoma and involved the nasal wall of the right maxillary sinus. It had a lateral axis of 8 mm long and a mesiodistal width of 5 mm. Its location did not interfere with the open lateral wall but interfered with the implant position. The computerized tomography (CT) also showed an insufficient height of crestal bone, and the patient, therefore, needed sinus lifting. The mucosa appeared healthy. No nasal obstruction, epistaxis, drainage purulent nasal, or fever were reported by the patient. Based on recorded anamnestic data alone, the patient reported good general health, was a non-smoker, was taking no medications affecting bone metabolism or wound healing, and there was an absence of any disease. After discussing the options with the patient, he agreed to maintain the lesion and a sinus augmentation with a bone graft. According to the observation of the nasal location of the osteoma and the clinical absence of an oro-nasal pathology, the surgery procedure was planned under local anesthesia and in a dentist's surgery (Figure 1). Chlorheximide 0.2% dipluconate solution (Curasept(r) S.p.A., Saromo, Italy) was used for rinsing the mouth for 2 min before surgery. Surgical sites were infiltrated with local Articaine(r) (Ubistesion(r) 4%--Espe Dental(r) AG, Seefeld, Germany) with epinephrine 1:200,000. A modified triangular full-thickness flap was lifted to expose the maxilla lateral sinus wall and crest bone. After removing the crestal bone window, the sinus membrane was gently lifted around the osteoma using primarily the sinusuret (Figure 2). The dental implants were 4.1 mm in diameter and 12 mm in length (2P(r), Bone System(r), Milan, Italy). They were positioned according to the surgical system and drilling sequence provided by the manufacturer protocol: rosehead drill, twist drill 2.1 diameter, 3.5 diameter drill, and 4.1 drill with a speed of 800 rpm and a 40 Ncm surgical motor unit (NSK(r), Surgipro(r), Shinagawa, Japan). The final primary stability was assessed by the system's manual racket torquemeter. Part of the osteoma was removed for histological analysis while avoiding perforation or tearing of the schneiderian membrane. As a grafting material, bovine bone xenograft (Re-Bone(r), Ubgen, Padova, Italy) was used.