Antrum

Objectives: The goal of this study was to assess the impact of left atrial scarring (LAS) on the outcome of patients undergoing pulmonary vein antrum isolation (PVAI) for atrial fibrillation (AF).

antrum

Background: Laparoscopic sleeve gastrectomy (LSG) has increased in popularity in recent years as a definitive bariatric procedure. Despite its growing popularity worldwide, the surgical technique is not well standardized. There is a lack of evidence on the matter of the antrum size and its relation to gastric emptying and weight-loss outcomes. The aim of the study is to evaluate the influence of antrum size over gastric emptying and weight-loss outcomes.

Methods: Twenty-five patients were prospectively randomized according to the distance between the first firing and the pylorus: AR group (antrum resection-2 cm from the pylorus) and AP group (antrum preservation-5 cm from the pylorus). Gastric emptying (%GE) was evaluated by a gastric emptying scintigraphy before surgery, 2 months and 1 year after LSG. Antrum volume was measured using a MultiSlice CT Scan performed 2 months and 1 year after surgery. The percent of excess weight loss (%EWL) was calculated after 1 year follow-up.

Conclusions: After LSG there is a global tendency to an accelerated gastric emptying, although only significant in the antrum preservation group; however, no differences were observed regarding the %EWL between groups after 1 year follow-up.

The mastoid antrum (plural: mastoid antra) (also known as tympanic antrum or Valsalva antrum) is an air space (up to 1 cm in size) lying posterior to the middle ear and connected to it by a short passageway, the aditus ad antrum.

The pyloric antrum is the lower or distal portion above the duodenum. The opening between the stomach and the small intestine is the pylorus, and the very powerful sphincter, which regulates the passage of chyme into the duodenum, is called the pyloric sphincter.

Figure 1 illustrates the anatomical position of the sinuses. The maxillary sinus is a large pyramidal chamber within the maxillary bone and is lined with respiratory (pseudo-stratified ciliated) epithelium (also known as the Schneiderian membrane). Its function is uncertain but it has been suggested that it moistens inspired air, lightens the skull and possibly provides vocal resonance. The terms maxillary sinus and antrum of Highmore are frequently abbreviated simply to sinus and antrum and are used synonymously, although maxillary sinus is the preferred terminology in anatomical circles.

Increasing pneumatisation with age concomitant with any alveolar ridge resorption due to loss of teeth may result in there being little bone between the dental alveolus and the floor/base of the maxillary antrum.1

Surgery involving the maxillary antrum may be indicated for implant surgery, operative complications or pathology. This article (book chapter) will concentrate solely on the latter indications as implant surgery is covered in a book in the British Dental Association's clinical guide series: A clinical guide to implants in dentistry.2

Several studies have highlighted the proximity of the maxillary tooth roots to the floor of the maxillary sinus. In 1925 Von Bondsdorff3 studied 84 human skulls and found that second molar roots have the most intimate relationship with the floor of the maxillary antrum, followed by the first molar, third molar, second premolar, first premolar and the canine.

It has been suggested that many maxillary posterior teeth extractions result in an immediate micro-communication between the mouth and the maxillary antrum, but that most of these OACs are subclinical and therefore remain undetected by patient and clinician, healing spontaneously of their own accord without operative intervention.1

b) Coronal CT section through the orofacial region illustrating an opaque left maxillary sinus indicating mucosal thickening or a lesion. c) Axial CT section through the lower maxilla showing left maxillary antral sinus congestion with mucosal thickening. d) Occipitomental view (20 degrees) illustrating bilateral clear maxillary antrum. e) CBCT showing a large cystic lesion of the left maxillary sinus presenting as opacity on DPT

The displacement of tooth fragments, root canal medicaments or surgical instruments into the antrum is usually avoidable, especially if correct extraction techniques are applied. Avoiding the blind placement of forceps and elevators is imperative, and seeking to grasp small pieces of upper roots with forceps can cause an 'orange pip' effect in which the root is forced upwards from the inadequate grip of the forceps beaks. Roots tend to be more commonly displaced than teeth, especially the palatal roots of maxillary molars (Fig. 11a). Fractured roots may also be displaced into the space between the epithelial lining and the antral bone. It is therefore important to establish a correct diagnosis when displacement is suspected. There are several reports of displacement of implants into the maxillary antrum (Fig. 11b), some of which have resulted in litigation.

Acute sinusitis is characterised by a moderate to severe constant pain over the antrum/cheek area, which may be mistaken for dental pain. Other features include pyrexia, tenderness, especially when the head is moved (going down stairs or leaning forward), mucopurulent discharge from the nose, facial swelling and oedema of the cheek and teeth, which are tender to percussion if they are adjacent to the sinus. Unless the tooth is the primary cause of the sinusitis, however, electric pulp testing usually reveals a positive (vital) response.

Carcinoma: Figure 16 shows a carcinoma of left maxillary antrum, discovered in a patient who was complaining of mobile and painful maxillary teeth/roots. Other features of any fast-growing, space-occupying lesion of the maxillary antrum may include orbital floor displacement, diplopia, nasal obstruction or discharge, palatal swelling, cheek numbness and/or pain. Radiographically, the irregular loss of defined borders and outline should always give cause for concern. Sinister symptoms, particularly spontaneous neuropathy, must not be overlooked and urgent referral (maximum 2-week wait) should be secured.23

There are two different antra that exist in or near the stomach, for example. The first is the antrum cardiacum. This is the dilation, or enlarging, that happens low in the esophagus, close to where it flows into the stomach.

The mastoid antrum can be found in the temporal bone near the middle ear. This air-filled antrum is next to mastoid air cells. It also communicates with the middle ear. The mastoid cells are thought to affect the function of the inner and middle ear.

There are a number of different medical conditions that can affect antra within the body. Almost all of these conditions will be specific to one particular type of antrum, and not the others. These conditions include: 041b061a72