What is Digastric Ridge?
Digastric ridge (DR) is a bony elevation present inferiorly in the mastoid cavity at the level of the mastoid process. The DR corresponds externally to the digastric groove at the medial aspect of the mastoid process, from which the posterior belly of digastric muscle originates.
What is temporal bone dissection?
The temporal bone dissection procedure involves harvesting the bone from a human cadaver and storage in formaldehyde. It is mounted securely in a bone holder in the same position as in actual surgery and dissected using a surgical microscope and a micromotor drill.
Where is the digastric groove?
Posterior belly It lies posterior to the parotid gland and the facial nerve. The mastoid notch is a deep groove between the mastoid process and the styloid process. The mastoid notch is also referred to as the digastric groove or the digastric fossa.
What are the parts of the temporal bone?
The temporal bone is divided into several main parts/portions 1-3:
- squamous part (temporal squama)
- petrous part (petrous pyramid)
- tympanic part.
- mastoid part (usually considered a separate part but it is formed by both the squamous and petrous parts)
How do you drill temporal bone?
The primary purpose of temporal bone drilling is to learn temporal bone anatomy….How to drill:
- Drill strokes should be in one direction instead of back and forth. Use long, steady strokes.
- Start the drill before touching the bone.
- The direction of drill strokes should be the same direction that the burr rotates.
How do you palpate digastric?
Palpation. Direct external palpation of posterior digastric is difficult due to the depth of the muscle. The anterior digastric is examined by identifying the lateral margins of the hyoid, and then palpating the inferior surface of the mandible by placing the thumbs on either side of the midline.
Is digastric muscle a muscle of mastication?
The digastric muscle, although usually not included into the group of masticatory muscles, is one of the prominent muscles for opening the mouth because it is the most superficial hyoid muscle attaching to the mandible (Figs.
What is the importance of suprameatal triangle?
Abstract. Since it covers the lateral wall of the mastoid air system, the suprameatal triangle is of importance to otologic surgeons during mastoidectomy. Because of this clinical importance, topographic anatomy of the suprameatal spine and depression was studied on Anatolian skulls.
What is Citelli’s angle?
Citelli’s angle or Sinodural angle is the angle between sigmoid sinus and middle fossa dural plate. It is an important landmark in mastoid surgery. It is acute in primary sclerosis and obtuse in secondary sclerosis
What is sinodural angle?
Sinodural angle is the angle between sigmoid sinus and middle fossa dura plate.It is the landmark for superior petrosal sinus.
How do you skeletonize Citelli’s angle?
Citelli’s angle can be easily skeletonized by placing the burr at the corner between the sigmoid and the tegmen and drilling in a medial to lateral direction. Skeletonizing the sinodural angle bevels the bone and improves access to deeper structures.
What is a cholesteatoma and Citelli’s angle?
Cholesteatomas: Cholesteatomas are radiolucent and can only be diagnosed if they erode bone. An erosion of mastoid antrum is seen as an area of translucency in a sclerotic mastoid. Citelli’s angle or sinodural angle is the angle between the sinus plate and the dural plate.