![]() Some key muscular attachments are outlined in the table below. In addition to this the mastoid process of the temporal bone is a major site of muscle attachment. joint of the jaw) some fibres from muscles of mastication such as the temporalis and masseter muscles attach to the temporal bone. Due to the involvement of the temporal bone in forming the temporomandibular joint (i.e. The temporal bone serves as a point of attachment for many muscles. ![]() The petrous part is pyramidal shaped, and lies at the base of temporal bone. The mastoid air cells can also become infected, known as mastoiditis. They act as a reservoir of air, equalising the pressure within the middle ear in the case of auditory tube dysfunction. ![]() These are hollowed out areas within the temporal bone. It is a site of attachment for many muscles, such as the sternocleidomastoid.Īlso of clinical importance are the mastoid air cells. The first is the mastoid process, an inferior projection of bone, palpable just behind the ear. There are two items of note on the mastoid. It can be split into a mastoid and petrous parts. This portion of the temporal bone is located posteriorly. It acts as an attachment point for muscles and ligaments, such as the stylomandibular ligament of the TMJ. The styloid process located immediately underneath the opening to the auditory meatus. It surrounds the external auditory opening, which leads into the external auditory meatus of the external ear. The tympanic part of the temporal bone lies inferiorly to the squamous, and anteriorly to the petromastoid part. The masseter muscles attaches some fibres to the lateral surface of the zygomatic process. One of the zygomatic processes’ attachments to the temporal bone forms the articular tubercle – the anterior boundary of the mandibular fossa, part of the temporomandibular joint These two structures form the zygomatic arch (palpable as ‘cheek bones’). It projects anteriorly, articulating with the temporal process of the zygomatic bone. The zygomatic process arises from the lower part of the squama temporalis. The bone articulates with the sphenoid bone anteriorly, and parietal bone laterally. The lower part of the squamous bone is the site of origin of the temporalis muscle The outer facing surface of the squamous bone is convex in shape, forming part of the temporal fossa. It is flat and plate-like, located superiorly. SquamousĪlso known as the squama temporalis, this is the largest part of the temporal bone. We shall now examine the constituent parts of the temporal bone in more detail. S2CID 221477454 – via ScienceDirect.Fig 1.1 – The constituent parts of the temporal bone. British Journal of Oral and Maxillofacial Surgery. "Split zygomaticus major muscle sling reconstruction for significant lower lip defects". ![]() "Application of isometric load on a facial muscle – The zygomaticus major". ^ Kim, Kyoung-Eun Oh, Seung Ha Lee, Shi-Uk Chung, Sun G."Double or bifid zygomaticus major muscle: Anatomy, incidence, and clinical correlation". : CS1 maint: location missing publisher ( link) Gray's Anatomy: The Anatomical Basis of Clinical Practice (42th ed.). "Zygomaticus major muscle bony attachment site: a Thiel-embalmed cadaver study". The zygomaticus major muscle may be used in reconstructive surgery to replace lost tissue, such as with injuries to the lips. The average muscle can contract with a force of 200 g. Acting in conjunction with other muslces of facial expression that elevate the lip, it curls the upper lip to produce facial expressions such as smiling, disdain, contempt, or smugnes. It additionally deepens and raises the nasolabial furrow. The zygomaticus major muscle raises the upper lip to bare the upper teeth. It is thought that cheek dimples are caused by bifid zygomaticus major muscle. The zygomaticus major muscle may occur in a bifid form, with two fascicles that are partially or completely separate from each other but adjacent. The muscle receives arterial supply from the superior labial artery. The muscle muscle receives motor innervation from the buccal branch and zygomatic branch of the facial nerve (CN VII). It inserts at the corner of the mouth by blending with the levator anguli oris muscle, the orbicularis oris muscle, and the deeper muscular structures. The zygomaticus major muscle originates from the superior margin of the lateral surface of the temporal process of zygomatic bone, just anterior to the zygomaticotemporal suture. Bifid zygomaticus major muscle is a notable variant, and may cause cheek dimples. It is a muscle of facial expression which draws the angle of the mouth superiorly and posteriorly to allow one to smile. It is innervated by branches of the facial nerve (cranial nerve VII). It arises from either zygomatic arch ( cheekbone) it inserts at the corner of the mouth. The zygomaticus major muscle is a muscle of the face.
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