Facial anatomy
Michael Parker, Charlie James in Fundamentals for Cosmetic Practice, 2022
The maxillae are the bones which form the medial aspect of the cheek (Figure 3.4), positioned between the nasal bone and zygoma. They have three primary functions: Allowing a point of anchor for the upper teeth in the alveolar processForming the floor and lateral wall of the nasal cavityForming part of the medial wall of the orbit The point of fusion of the maxillae is at the midline immediately inferior to the nose at the intermaxillary suture. Aside from structural support, the maxillae contain sinuses which are important in both altering the depth of voice as well as keeping decreasing the weight of the facial bones. The maxilla is also the site of the infra-orbital foramen, which is located just below the infraorbital margin of the orbit, at an average distance of 6–10 mm inferiorly in the midline. The infraorbital foramen is important in the transmission of the infraorbital artery, vein and nerve, and therefore, this region must be respected, especially in the context of dermal filler administration as it is at risk of avascular necrosis, filler embolisation and neuronal damage.
The Dental Cyst
Wilson Harvey, Alan Bennett in Prostaglandins in Bone Resorption, 2020
A good working definition of a cyst has been given by Killey et al.3 an abnormal cavity in hard or soft tissue containing fluid or semifluid, often encapsulated and lined by epithelium. Dental cysts are benign lesions causing bone destruction in the mandible or maxilla which are usually detected on routine radiography or occasionally when they produce swelling. There are three main groups of cyst which occur in the jaws: “odontogenic cysts”, which arise from the epithelium concerned with tooth development, “fissurai cysts”, arising from epithelial inclusions at the closure lines of embryonic processes, and “bone cysts”, which do not have an epithelium or epithelial etiology and also occur elsewhere in the body. The odontogenic cysts are by far the most common type of cyst and are comprised of three main types.
The Classification of Odontogenic Cysts
Roger M. Browne in Investigative Pathology of the Odontogenic Cysts, 2019
Most previous studies have combined the data for radicular and residual cysts and so there is relatively little information on the age and site distribution of these lesions. This is surprising because in a recent study residual cysts were found to comprise some 10% of odontogenic cysts.43 This study found a predominance in the mandibular premolar region, although they can occur in any part of the jaws. Although radicular cysts are more common in the anterior maxilla, the demand to retain teeth in this part of the jaw for aesthetic reasons probably explains the relatively low incidence of residual cysts. There is evidence too that most residual cysts become progressively smaller in size with age43 and even resolve completely.44
Transnasal endoscopic marsupialization of nasopalatine duct cysts: A novel ‘Mickey Mouse’ sign and a septum-sparing surgical technique to reduce paresthesia risk
Published in Acta Oto-Laryngologica Case Reports, 2023
Shravan Gowrishankar, Nora Haloob, Claire Hopkins
Cross-sectional imaging in the form of CT and/or MRI is typically used to further characterize cysts in this area. Differentials of midline cysts include NPDCs, granulomas, central incisor root cysts, and median palatine cysts [7]. Nasolabial cysts usually appear laterally on either side of the midline [8]. NPDCs are usually well-defined oval, round, or heart-shaped cystic lesions close to the midline of the anterior maxilla [9]. In this patient’s case, the appearance of the cyst on the coronal section MRI produced a characteristic shape which can be referred to as the “Mickey Mouse” sign [10] as the cyst expands on either side of the maxillary crest (Figure 1(B)). This is the first such description using this easy-to-remember term and highlights possible alternative radiological appearances of NPDCs.and will help in radiological differentiation between other pathologies at this site presenting in a similar way. For instance, to our knowledge, nasolabial cysts, which usually form in the soft tissues around the upper lip, have not been reported with this sign. Nasolabial cysts usually appear ovoid on either side of the midline and are unilateral [11]. As they are soft tissue cysts [8], a lack of sharp bony structures in this area similar to the maxillary crest should preclude asymmetric expansion of a nasolabial cyst that could result in a bilobed appearance.
Patient-specific pre-operative simulation of the surgically assisted rapid maxillary expansion using finite element method and Latin hypercube sampling: workflow and first clinical results
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
L. Bonitz, A. Volf, S. Hassfeld, A. Pugachev, B. Ludwig, S. Chhatwani, A. Bicsák
The surgically assisted rapid maxillary expansion (SARME) was first described by E. C. Angell in 1860 (Angell 1860). Today, SARME and surgically assisted rapid palatal expansion (SARPE) are common, combined orthodontic and surgical procedures used to correct maxillary transverse deficiency in skeletally mature patients (de Gijt et al. 2017). The procedure consists of two steps. First, the maxilla is weakened by a bilateral osteotomy in the Le-Fort-I plane and pterygomaxillary suture and an opening in the mid-palatal suture is made (midline split). The extent of osteotomy depends on the patient’s age, bone quality, and anatomical conditions including the dental root position and neural structures (Koudstaal et al. 2005; Han et al. 2009; Rana et al. 2013). The state-of-the-art technique involves weakening the maxilla equally on both sides based on the experience of the surgeon. In this way, the extent of osteotomy can vary widely (Al-Ouf et al. 2010; Nada et al. 2012; Seeberger et al. 2015). In the second step, the maxilla is expanded using a distraction device, which is mounted on the palatine bone or the bicuspids of both the maxillary segments (Sander et al. 2006; Adolphs et al. 2014; Ulusoy and Dogan 2018).
Odontoblasts are cold sensory cells in teeth
Published in Temperature, 2023
Pamela Sotelo-Hitschfeld, Laura Bernal, Katharina Zimmermann
In this study, we did not attempt to isolate odontoblasts to assess cold transduction in culture, but we rather obtained a comprehensive picture of the molecular cold transduction mechanism in sensory neurons innervating the teeth [1]. We employed retrograde labeling to identify the neurons in the trigeminal ganglion that innervate the maxillary molar teeth. These neurons in culture are the cell bodies and a surrogate model for their inaccessible sensory nerve terminals inside the tooth pulp. We used a calcium imaging approach and assessed the individual contributions of TRPM8, TRPA1 and TRPC5 to the cold-induced activity. Experiments from double knockouts and TRP channel agonist pharmacology helped us to differentiate the individual contributions of each channel. Remarkably TRPM8 was responsible for the large majority of cold responses in the cultured dental primary sensory neurons, while the agonist riluzole identified TRPC5-mediated cold responses only in very few neurons. Nevertheless, these TRPC5-like cold responses appeared in larger quantity in the retro-labeled sensory neurons from TRPM8/TRPA1 double null mice, and there we found that the cold-induced activity was blocked by the TRPC5 blocker ML204.
Related Knowledge Centers
- Bone
- Mandible
- Mouth
- Zygomatic Process
- Hard Palate
- Maxillary Sinus
- Jaw
- Mouth
- Anterior Nasal Spine
- Mandibular Symphysis
- Process