Congenital Anomalies of the Thymus

The thymus, a retrosternal lymphoid tissue, develops from the third and fourth pharyngeal pouches like the parathyroid glands at the sixth week of gestational age. The thymus is usually located in the anterior mediastinum, although it can be found anywhere in the thymopharyngeal path. The thymus has a bilobed or quadrilateral shape; however, it can be found in other shapes. Limited information is available about the precise epidemiology of thymic congenital anomalies. Since these anomalies are not symptomatic, it may be more common than the available reports. There are various reports available about the prevalence of thymic diseases and anomalies ranging from 4.45 to 30%. In this chapter we tried to have a review on epidemiology, definition, and management of congenital anomalies of the thymus

Stapes Management in Tympanosclerosis

Background: Stapes management in tympanosclerosis has always been controversial. There are evidences supporting stapes mobilization, but there are concerns regarding refixation and recurrence of conductive hearing loss; therefore, supporting stapedectomy.Methods: In this retrospective study, clinical records, operative notes, and audiologic data of patients with stapes fixation (1994–2011) were analyzed. Audiometric findings are reported according to the recommendations of the Committee on Hearing and Equilibrium 1995 Guidelines for the Evaluation of Results of Treatment of Conductive Hearing Loss.Results: In the present study, 66 patients were enrolled (23 male, 43 female). Stapedectomy and stapes mobilization both had good hearing results (12.1 dB vs. 10.6 dB reduction in ABG) and there was no significant difference. Overall, 63.6% of patients had achieved good results (mobilization: 57.9%, stapedectomy: 71.4%). The difference in success rate between the two groups was not statistically significant.Conclusions: Stapedectomy and mobilization of stapes both seem to be efficacious and safe in the treatment of stapes involvement in tympanosclerosis. The hearing improvement is long lasting in both procedures

Thyroid Cancers: Considerations, Classifications, and Managements

Rapidly increasing trend of thyroid cancer incidence has turned this disease into a global concern. An estimated number of 64,300 new cases of thyroid cancer occurred in men and women in 2016, which represents 3.8% of all new cancer cases of USA (https://seer.cancer.gov/statfacts/html/thyro.html). Thus, there is a high possibility for every physician to encounter a case of thyroid cancer during his/her professional lifetime. In this chapter, we clarified epidemiology, different categories, and new approaches toward diagnosis and management of thyroid cancer

Cochlear Implants: An Excursus into the Technologies and Clinical Applications

Hearing loss causes severe alterations in social function and daily communications. Cochlear device implantation (CDI) is the only beneficiary method for auditory rehabilitation in patients with severe to profound sensorineural hearing loss (SNHL). Regarding a report in 2014, over 300,000 people had received cochlear implants throughout the world since December 2012 among which about 60,000 were adults and 40,000 were children in the United States. In this chapter, we discuss the history, origin, mechanism of action, and type of cochlear implants, as well as method of surgery and complications

Salivary Gland Cancers: A Survey through History, Classifications and Managements

In this chapter, we are going to discuss about salivary glands cancers, their clinical manifestations and categories, pathogenesis, diagnosis and treatment. We will go through details in each part in both clinical and surgical aspects based on recently prominent published studies and research in prestigious journals. After a short review on clinical features, epidemiology, pathogenesis, diagnosis and treatment, we will show staging and tumor node metastasis (TNM) classification of major salivary gland tumors and also basic principles of approach to salivary gland cancers. A little will be explained about basic surgical procedures for removal of cancers and benign tumors

HEAD AND NECK SURGERY Temporomandibular Joint Dislocation Reduction Technique A New External Method vs. the Traditional

Abstract: The traditional intraoral approach for temporomandibular joint dislocations reduction, although effective, has some disadvantages. Here, a new extraoral approach is described. This study was performed to evaluate this new method's success rate. Patients visiting an emergency room were randomly allocated to 2 groups; one group was reduced with the extraoral approach and the other with the intraoral method. Among 29 attempts with the conventional method, 25 were successful (86.2%; 95% confidence interval: 73-100) and among 29 attempts with the external method, 16 were successful (55.2%; 95% confidence interval: 39 -79). This difference was statistically significant. Because of the benefits of the external approach, such as avoiding hand bites and disease transfer, it can be a reasonable choice to reduce a dislocated temporomandibular joint. Key Words: temporomandibular joint, reduction, extraoral approach, TMJ dislocation (Ann Plast Surg 2009;63: 000 -000) T he most common type of temporomandibular joint (TMJ) dislocation is acute episodes of anterior dislocation, although dislocations may occur in any direction with various associated fractures. 1 Dislocations are usually spontaneous and may result from excess mouth opening in case of yawning, laughing, taking a large bite, seizure, or intraoral procedures such as tooth extraction or orotracheal intubation. Treatment depends on patient status and varies from simple reduction to surgical intervention. The latter is usually necessary only for chronic recurrent and chronic persistent dislocations 2 and in acute forms nearly all cases are managed by hand reduction. The traditional intraoral reduction method, although effective, has some disadvantages: it requires a great effort, especially in patients with strong mastication musculatures 1 ; local or systemic analgesics and muscle relaxants or sedatives are necessary occasionally; risks of bite injury regarding hepatitis, AIDS, syphilis, or other transmittable diseases; and patient discomfort regarding the physicians hand in his/her mouth. Therefore, another method using an extraoral approach always has been a concern. 3,4 The external method introduced by Chen et al is supposed to be an easy and effective way to reduce TMJ dislocation, as they stated. 3 Therefore, we performed this study to evaluate the success rate of this new method in comparison to that of the traditional method. METHODS Amir-A'lam General Hospital is a tertiary center for otolaryngology diseases in Iran. Patients referring to the emergency room (ER) were included consecutively in this prospective trail in an 8-month period (January-August 2007). Procedures were performed by second-year otolaryngology residents with a good level of experience in both techniques, who had performed a large number of under-observation reductions before the study. Block randomization was used for allocating patients into 2 different modality groups. ER reception was provided with a list of random blocks of 2. Every patient, before entry to the clinic and visited by ER physicians, was coded to enter to one of the treatment groups. Therefore, both the patients and the reducing physician were not aware of patient allocation. A thorough history was taken regarding demographic information, past history of general ligament laxity, past history of TMJ dislocation, underlying disorders, trauma, prior use of muscle relaxing agents, and time delay between dislocation and reduction. Mandible fractures especially those involving the condylar and subcondylar region were ruled out by physical examination and proper x-rays when needed. To reduce TMJ dislocation, the patient was put in either a sitting or supine position and the operator sat or stood in front of the patient. An attempt was made to reduce the dislocation using the randomly chosen method. The success rate was calculated regarding successful patient treatment for each method on the first try. As the salvage for the unsuccessful cases if the first method failed, the other method was attempted and if that too was not successful, a muscle relaxant (10 mg diazepam) was administered and the TMJ dislocation was reduced. To avoid patient cross over between groups these second reductions were not included in the analysis. Conventional Method The physician, applying bimanual intraoral force on the mandibular molars of the patient in an inferior and then posterior direction, will reduce the dislocated condyle back into the glenoid fossa. New Method 3 The physician places one hand on each of the patient's cheeks. On one side, the thumb is placed just above the anteriorly displaced coronoid process, and the fingers are placed behind the mastoid process to provide a counteracting force. On the other side, the fingers hold the mandible angle and the thumb is placed over the malar eminence. To reduce the dislocated jaw, one side of the mandible angle is pulled anteriorly by the fingers, with the thumb over the malar eminence acting as a fulcrum. While the mandible angle is pulled anteriorly, steady pressure is applied on the coronoid process of the other side, with the fingers behind the mastoid process providing counteracting force. The mandible is rotated by this maneuver and the dislocated TMJ is usually reduced on one side. Once one side of the dislocation is reduced, the other side will usually go back spontaneousl

Recent advances in additive manufacturing of patient-specific devices for dental and maxillofacial rehabilitation

ObjectivesCustomization and the production of patient-specific devices, tailoring the unique anatomy of each patient's jaw and facial structures, are the new frontiers in dentistry and maxillofacial surgery. As a technological advancement, additive manufacturing has been applied to produce customized objects based on 3D computerized models. Therefore, this paper presents advances in additive manufacturing strategies for patient-specific devices in diverse dental specialties.MethodsThis paper overviews current 3D printing techniques to fabricate dental and maxillofacial devices. Then, the most recent literature (2018–2023) available in scientific databases reporting advances in 3D-printed patient-specific devices for dental and maxillofacial applications is critically discussed, focusing on the major outcomes, material-related details, and potential clinical advantages.ResultsThe recent application of 3D-printed customized devices in oral prosthodontics, implantology and maxillofacial surgery, periodontics, orthodontics, and endodontics are presented. Moreover, the potential application of 4D printing as an advanced manufacturing technology and the challenges and future perspectives for additive manufacturing in the dental and maxillofacial area are reported.SignificanceAdditive manufacturing techniques have been designed to benefit several areas of dentistry, and the technologies, materials, and devices continue to be optimized. Image-based and accurately printed patient-specific devices to replace, repair, and regenerate dental and maxillofacial structures hold significant potential to maximize the standard of care in dentistry

Identification of New Alleles and the Determination of Alleles and Genotypes Frequencies at the CYP2D6 Gene in Emiratis

CYP2D6 belongs to the cytochrome P450 superfamily of enzymes and plays an important role in the metabolism of 20–25% of clinically used drugs including antidepressants. It displays inter-individual and inter-ethnic variability in activity ranging from complete absence to excessive activity which causes adverse drug reactions and toxicity or therapy failure even at normal drug doses. This variability is due to genetic polymorphisms which form poor, intermediate, extensive or ultrarapid metaboliser phenotypes. This study aimed to determine CYP2D6 alleles and their frequencies in the United Arab Emirates (UAE) local population. CYP2D6 alleles and genotypes were determined by direct DNA sequencing in 151 Emiratis with the majority being psychiatric patients on antidepressants. Several new alleles have been identified and in total we identified seventeen alleles and 49 genotypes. CYP2D6*1 (wild type) and CYP2D6*2 alleles (extensive metaboliser phenotype) were found with frequencies of 39.1% and 12.2%, respectively. CYP2D6*41 (intermediate metaboliser) occurred in 15.2%. Homozygous CYP2D6*4 allele (poor metaboliser) was found with a frequency of 2% while homozygous and heterozygous CYP2D6*4 occurred with a frequency of 9%. CYP2D6*2xn, caused by gene duplication (ultrarapid metaboliser) had a frequency of 4.3%. CYP2D6 gene duplication/multiduplication occurred in 16% but only 11.2% who carried more than 2 active functional alleles were considered ultrarapid metabolisers. CYP2D6 gene deletion in one copy occurred in 7.5% of the study group. In conclusion, CYP2D6 gene locus is heterogeneous in the UAE national population and no significant differences have been identified between the psychiatric patients and controls