 Hello everyone, welcome back to OMFS lecture series. The topic for the lecture is peregromanibular space infection. Peregromanibular space is a part of the masticator space which apart from the peregromanibular space also contains other spaces like submissive quick space, superficial temporal space and deep temporal spaces. All these spaces are well differentiated but they communicate with each other as well as with other spaces like buckle, submandibular and paraferringial spaces. The masticator space is formed by splitting of the investing layer of deep cervical fascia into superficial and deep layers. So the fascia defines its lateral and the medial extant. The masticator space is again divided into mesotric compartment and tergoid compartment. Boundaries of the mesotric compartment are the mesotra muscle laterally and the mandibular ascending ramus medially. The tergoid compartment is bounded by medial tergoid muscle medially and the medial aspect of the mandible lateral area. Tergomandibular space is found to be the most frequently affected anatomical compartment in cases of severe odontogenic infections. The most common etiology of tergomandibular space infection is the pericoronitis of mandibular third molar. Infection can also be produced by a contaminated needle used for an inferior alveolar nerve block or a posterior superior alveolar nerve block injection. Talking about the boundaries of tergomandibular space, laterally the space is bounded by the medial aspect of the ramus of mandible. The lateral surface of the medial tergoid muscle forms the medial limit. Here is the lateral limit, this is the medial limit. Posteriorly the boundary is formed by the deep part of pedodic gland and anteriorly there is the tergomandibular raffia which is formed by the superior constrictor and the buccinator muscle. And the roof of the tergomandibular space is formed by the lateral tergoid. As already mentioned, the infection of tergomandibular space is associated with pericoronitis of third molar. Even the established cases of tergomandibular space infections do not cause much swelling of the face. The clinical hallmark of every masticator space infection is thrismus. If thrismus is not present, then it can be considered that these spaces are uninvolved in the infectious process. Tenderness can be elicited over the area which is swollen and present medial to the anterior border of ramus. Dysphagia is present, dysphagia means difficult swallowing, there is medial displacement of the lateral wall of the pharynx and redness and edema of the area around the third molar. Midline of the pallet is displaced to the unaffected side and also the uvula appears swollen. It is also associated with difficulty in breathing. Surgical access to the various compartments of masticator space is complicated by the containment of the infectious process within the muscle masses. Secher has suggested an intraoral approach to tergomandibular space by placing a vertical incision along the tergomandibular raffae on the medial aspect of the ramus. A sinus forceps is then inserted into the abscess cavity and opened and closed. It is then withdrawn. The pus is evacuated, a rubber drain is introduced and is secured in position with a suture. The oral approach is a less feasible approach in infected patients with thrismus. In such patients, the oral approach can compromise the airway postoperatively because of persistent blood and pus oozing out of the incision. Also there are chances that the drain which is suture will get loosened and the patient can aspirate it. In such cases, an extraoral approach can be taken. An incision is taken in the skin below the angle of the mandible. A sinus forceps is then inserted towards the medial side of the ramus in an upward direction and backward direction. Pus is evacuated, a drain is inserted from an intraoral approach and sutured in position. These diagrams show the pathway of spread of infection from tergomandibular space which is numbered 2 to its neighboring and distant spaces. The addon numbered 1 shows that the infection can spread posteriorly to lateral pharyngeal space and then to retropharyngeal space. This diagram here is the posterior spread of infection. The second path of spread is superiorly along the medial aspect of the ramus to involve the infra temporal fossa. Through this region, the infection can spread to infra temporal fossa. Through the lateral aspect of the ramus, submesicric space can get involved. Infection can spread along the front of the ramus to involve the buccal space. Number 4 is to involve the buccal space. It can also spread anteriorly below the lower border of mandible and also under the superior constrictor muscle to involve the submandibular space. Five is submandibular space. So this is regarding the spread of infection from tergomandibular space to the neighboring spaces as well as distant spaces. Therefore tergomandibular space infection should be diagnosed and managed at an early stage considering its potential communication with other spaces and also associated complications. So that's all for this lecture. Thank you.