# Modified Endoscopic-Assisted Approach for Removal of
## 3 Discussion  
Tooth development occurs during the 6 th-week of intrauterine development and results from the interaction between the oral epithelium and the underlying mesenchymal tissue [6]. Therefore, ectopic eruption of teeth rarely occurs in regions outside the oral cavity, such as the nasal septum, coronoid process, condyle, and maxillary sinus because abnormal interaction of tissues during tooth development is challenging. There is a higher prevalence of ectopic tooth eruption among third molars and canines since these teeth take longer to erupt [6]. The ectopic teeth in the maxillary sinus may induce headache, nasal obstruction, fever, and secondary infection [7]. Although the cause is not clear, misplaced teeth may induce ROS production, which can lead to abnormal neutrophil recruitment [8]. Ectopic erupted maxillary third molars often have pathological findings and require surgical removal. However, they are technically difficult to remove, and intramuscular sinus removal can often be accompanied by complications. In the past, CLP was the preferred surgical technique to remove ectopic teeth in the maxillary sinus due to the ease of access for visualization, which can reduce the sensitivity of the technique. However, there are several drawbacks to this procedure. Many postoperative complications after CLP have been reported, such as postoperative maxillary cysts (POMC) and a high incidence of recurrence of sinus symptoms. POMC is known to be a late complication that occurs decades after radical maxillary sinus surgery. This is most likely caused by a decrease in the sinus volume after an inferior nasoantrostomy. During CLP, the sinus mucosal lining is completely removed and replaced by nonfunctional mucosa which adversely affects sinus physiology. In addition, a high incidence rate of CLP-related complications has been reported such as postoperative facial edema which is impacted by intraoperative bleeding, oroantral fistula, recurrent sinusitis, numbness or paresthesia of infraorbital nerve distribution, and sclerotic changes in the remaining maxillary sinus wall [9; 10]. Therefore, there has been a shift towards endoscopic management of ectopic teeth in the maxillary sinus, such as FESS, because this approach is less invasive, and carries a reduced risk of injury to the tooth root and the infraorbital nerve and has been associated with rapid sinus function recovery [5]. Enlargement of the middle nasal means with complete removal of diseased tissues could open the drainage pathway of the sinus to restore function and health while preserving the inner respiratory mucosa and remaining SM. However, when this conventional endoscopic technique was used, overly aggressive removal of physiologic structures of the nasal cavity and incomplete odontogenic sinus pathology removal have been inevitable, leading to an elevated risk of sinus complications [5]. Versatile applications for the MESS technique have been reported in recent literature, such as the intraoral reduction of blow-out orbital fractures [11] and the treatment of mucous retention cysts or maxillary sinusitis [12]. The main advantage of this renovated procedure is that the physiological functions of the paranasal sinus (PNS) are maintained while avoiding formation of POMC or sinus scar tissues. The rationale behind this technique is that osteomeatal unit enlargement is performed to improve drainage and ventilation of PNS into the nasal cavity without performing inferior anntrostomy, as in CLP, and preserving the middle nasal meatus. Therefore, MESS accomplishes maximal  
Figure 3: Intraoperative endoscopic images. A maxillary third molar embedded in the sinus mucosa was identified (**A**). After using a curette to expose the tooth (**B**), the tooth was luxated (**C**) and successfully removed with an elevator (**D**). preservation of the sinus anatomy by integrating advantages of traditional CLP and endoscopic sinus surgery.