Development and validation of predictive models for skeletal malocclusion classification using airway and cephalometric landmarks.

OBJECTIVE: This study aimed to develop a deep learning model to predict skeletal malocclusions with an acceptable level of accuracy using airway and cephalometric landmark values obtained from analyzing different CBCT images. BACKGROUND: In orthodontics, multitudinous studies have reported the correlation between orthodontic treatment and changes in the anatomy as well as the functioning of the airway. Typically, the values obtained from various measurements of cephalometric landmarks are used to determine skeletal class based on the interpretation an orthodontist experiences, which sometimes may not be accurate. METHODS: Samples of skeletal anatomical data were retrospectively obtained and recorded in Digital Imaging and Communications in Medicine (DICOM) file format. The DICOM files were used to reconstruct 3D models using 3DSlicer (slicer.org) by thresholding airway regions to build up 3D polygon models of airway regions for each sample. The 3D models were measured for different landmarks that included measurements across the nasopharynx, the oropharynx, and the hypopharynx. Male and female subjects were combined as one data set to develop supervised learning models. These measurements were utilized to build 7 artificial intelligence-based supervised learning models. RESULTS: The supervised learning model with the best accuracy was Random Forest, with a value of 0.74. All the other models were lower in terms of their accuracy. The recall scores for Class I, II, and III malocclusions were 0.71, 0.69, and 0.77, respectively, which represented the total number of actual positive cases predicted correctly, making the sensitivity of the model high. CONCLUSION: In this study, it is observed that the Random Forest model was the most accurate model for predicting the skeletal malocclusion based on various airway and cephalometric landmarks.

Retrospective analysis of the upper airway anatomy and Sella turcica morphology across different skeletal malocclusions: a computerized technique.

OBJECTIVE: This study aimed to investigate the normal volumetric space and variations in the measurements of different landmarks in adults with different skeletal relations of the maxilla and the mandible based on CBCT data. The study also analyses these landmarks to locate any correlations. BACKGROUND: Numerous studies in orthodontics have found a relationship between orthodontic treatment and changes in the anatomy and function of the airway. Severe changes in airway morphology can cause breathing difficulties, lower quality of life, and even result in life-threatening conditions such as obstructive sleep apnoea. Consequently, orthodontic diagnosis and treatment planning require a thorough understanding of the airway space and its function. METHODS: The present retrospective study was conducted using CBCT records of 120 adult patients, containing 40 samples of each skeletal class (20 males and 20 females). The boundaries were defined for the 3 major regions: the nasopharynx, the oropharynx, and the hypopharynx. Various measurements were recorded across these regions, as well as selective cephalometric landmarks. The obtained data was used to calculate average and standard deviation, while regression analysis was used to evaluate correlations and t-test was used to test statistical significance of gender differences. RESULTS: The results demonstrate that skeletal Class III individuals exhibit a reduced airway volume in the nasopharynx compared to other groups, whereas skeletal Class II individuals displayed a diminished airway volume in the hypopharynx. A strong correlation was observed for Sella turcica parameters. There were no significant differences in skeletal parameters across genders. Nasopharynx cavity volume demonstrated significant differences between skeletal Class I-Class III as well as between skeletal Class II-Class III. Hypopharynx cavity volume also demonstrated significant differences between skeletal Class I-Class II and between skeletal Class II-Class III. CONCLUSION: The major findings are the presence of a reduced nasopharyngeal volume in skeletal Class III malocclusions while skeletal Class II individuals displayed a diminished hypopharyngeal volume, making these critical areas to consider during the diagnostic and orthodontic treatment planning stages. This study also revealed a consistent correlation between Sella turcica parameters across various facial skeletal profiles, with skeletal Class II patients exhibiting a distinct pattern and skeletal Class I and Class III demonstrating an average relationship.

Clinicopathological analysis of nasopharyngeal tuberculosis.

BACKGROUND: The aim of this study is to examine the clinical and pathological attributes of nasopharyngeal tuberculosis. METHODS: We conducted a retrospective analysis of the clinicopathologic characteristics of nasopharyngeal tuberculosis in 14 patients. The medical records and imaging data obtained between March 2004 and February 2023 were scrutinized. During the pathological review, we classified the types of granulomatous inflammation and graded the extent of caseation. RESULTS: Results indicate a 100% female predominance, with chief complaints including hearing loss, postnasal drip, and nasal obstruction. Cervical lymphadenopathy occurred in 21.4% of patients. Chest radiograph abnormalities were found in 58.3%, with three showing active pulmonary tuberculosis. Endoscopic examination revealed three types of lesions, and CT/MRI findings correlated with gross lesions. A statistically significant association was found between lesion characteristics (bulging, ulcerative, necrotic) and pathology patterns (sarcoidosis-like, caseation). Bulging masses exhibited sarcoidosis-like patterns, while ulcerative/necrotic lesions were often associated with caseation. All lesions responded well to over six months of anti-tuberculosis medication, leading to favourable outcomes. CONCLUSION: We studied 14 cases of nasopharyngeal tuberculosis, mostly in females, with common ear and nose symptoms. Lesions were typically visible on nasopharyngeal endoscopy, and endoscopically bulging mass-like lesions had pathologically sarcoidosis-like granulomas. All patients had favourable outcomes.

Endoscopic Features of Chronic Rhinosinusitis in Patients with Gastroesophageal Reflux Disease.

Chronic rhinosinusitis (CRS) is a complex inflammatory condition affecting the nasal and paranasal sinus mucosa. Gastroesophageal reflux disease (GERD) has been implicated as a potential exacerbating factor in CRS, but the specific endoscopic features of nasopharyngeal pathology in this context remain poorly understood. Background and Objectives: Chronic rhinosinusitis is a multifactorial disease with various underlying etiologies, including inflammation, anatomical factors, and environmental triggers. While gastroesophageal reflux disease has been suggested as a potential contributor to chronic rhinosinusitis, the specific endoscopic features indicative of nasopharyngeal pathology in CRS patients with GERD symptoms have not been clearly elucidated. Our aim is to identify specific endoscopic features of nasopharyngeal pathology in patients with CRS associated with GERD symptoms and to propose a method for assessing the influence of gastroesophageal reflux disease on the mucosal layer of the nose and nasopharynx. Materials and Methods: We conducted a cross-sectional observational study involving 521 adult patients presenting with symptoms suggestive of CRS. From this cohort, 95 patients with the highest scores on the Reflux Symptom Index (RSI) and Reflux Symptom Score-12 (RSS-12) questionnaires were selected as the main group. Endoscopic examinations were performed to assess the nasal and nasopharyngeal mucosa. Results: Our study revealed significant alterations in the nasopharyngeal mucosa of patients with CRS associated with GERD symptoms. Increased vascularity of the nasopharyngeal mucosa was observed in 91 patients (95.7%), while hypertrophy was noted in 83 patients (87.4%). Mucus was present in the nasopharynx of 77 patients (81.1%), exhibiting varying characteristics of color and consistency. Asymmetric hypertrophy of the oropharyngeal mucosa was noted in 62 patients (65.3%). Conclusions: We propose a method for assessing the influence of gastroesophageal reflux disease on the mucosal layer of the nose and nasopharynx, which may aid in diagnostic and management decisions. Further research is warranted to explore the potential impact of GERD symptoms on the course and severity of CRS exacerbations.

Effects of adenoid hypertrophy on nasopharyngeal airway ventilation: A computational fluid dynamics study.

OBJECTIVES: Adenoid hypertrophy causes impaired nasopharyngeal airways (NA) ventilation. However, it is difficult to evaluate the ventilatory conditions of NA. Therefore, this study aimed to analyze the nasopharyngeal airway resistance (NARES) based on computational fluid dynamics simulations and the nasopharyngeal airway depth (NAD) and adenoid hypertrophy grade measured on cephalometric cone-beam computed tomography images and determine the relationship between NAD and grade and NARES to ultimately assess using cephalometric measurements whether NA has airway obstruction defects. METHODS: Cephalogram images were generated from cone-beam computed tomography data of 102 children (41 boys; mean age: 9.14 ± 1.43 years) who received orthodontic examinations at an orthodontic clinic from September 2012 to March 2023, and NAD and adenoid grade and NARES values were measured based on computational fluid dynamics analyses using a 3D NA model. Nonlinear regression analyses were used to evaluate the relationship between NARES and NAD and correlation coefficients to evaluate the relationship between grade and NARES. RESULTS: NARES was inversely proportional to the cube of NAD (R2 = 0.786, P < 0.001), indicating a significant relationship between these variables. The resistance NARES increased substantially when the distance NAD was less than 5 mm. However, adenoid Grade 4 (75 % hypertrophy) was widely distributed. CONCLUSIONS: These study findings demonstrate that the ventilatory conditions of NA can be determined based on a simple evaluation of cephalogram images. An NAD of less than 5 mm on cephalometric images results in NA obstruction with substantially increased airflow resistance.

3D analysis of upper airway morphology related to obstructive sleep apnea severity.

BACKGROUND: Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder characterized by repetitive collapse of the upper airway during sleep. However, little evidence is available on the differences between the sub-regions of the upper airway morphology and OSA severity. Since orthodontists frequently perform cone beam computed tomography (CBCT) in the neck area, we aimed to investigate the relationship and the differences between upper airway morphology and OSA severity using CBCT. MATERIALS AND METHODS: The medical records, CBCT imaging of 21 OSA patients diagnosed by polysomnography, and the apnea-hypopnea index (AHI) results were included to classify OSA severity as mild, moderate, or severe. The minimum cross-sectional areas (MCA) and volumes of the upper pharyngeal airway boundaries in four sub-regions: nasopharynx, retropalatal, retroglossal, and hypopharynx were measured. Dolphin Imaging software was used for upper airway segmentation. The correlation coefficient (r), one-way ANOVA, and the least significant difference post hoc multiple comparison test were applied to fulfill the objectives. RESULTS: A statistically significant relationship was found between the MCA of the nasopharynx and the AHI (r = -0.473, P < 0.05). Furthermore, a difference was found between mild and moderate and moderate and severe OSA severity in the MCA results of the retroglossal region (P < 0.05). However, no relationship was found between the upper airway volume and OSA severity. CONCLUSIONS: MCA was moderately negatively correlated to AHI only in the nasopharynx subregion. Moderate OSA presented significantly less MCA than mild and severe OSA only in the oropharynx and retroglossal subregions.

Nasopharyngeal Carcinoma Cell Lines: Reliable Alternatives to Primary Nasopharyngeal Cells?

Nasopharyngeal carcinoma (NPC) is a type of cancer that originates from the mucosal lining of the nasopharynx and can invade and spread. Although contemporary chemoradiotherapy effectively manages the disease locally, there are still challenges with locoregional recurrence and distant failure. Therefore, it is crucial to have a deeper understanding of the molecular basis of NPC cell movement in order to develop a more effective treatment and to improve patient survival rates. Cancer cell line models are invaluable in studying health and disease and it is not surprising that they play a critical role in NPC research. Consequently, scientists have established around 80 immortalized human NPC lines that are commonly used as in vitro models. However, over the years, it has been observed that many cell lines are misidentified or contaminated by other cells. This cross-contamination leads to the creation of false cell lines that no longer match the original donor. In this commentary, we discuss the impact of misidentified NPC cell lines on the scientific literature. We found 1159 articles from 2000 to 2023 that used NPC cell lines contaminated with HeLa cells. Alarmingly, the number of publications and citations using these contaminated cell lines continued to increase, even after information about the contamination was officially published. These articles were most commonly published in the fields of oncology, pharmacology, and experimental medicine research. These findings highlight the importance of science policy and support the need for journals to require authentication testing before publication.

Low-grade malt lymphoma of the nasopharynx in young adults: Successful treatment of a rare diagnosis at a rare site by radiotherapy.

INTRODUCTION: Mucosa Associated Lymphoid Tissue (MALT) lymphoma is the third most common subgroup of Non-Hodgkin's lymphoma and is the most common type of primary extranodal lymphoma. They are rarely found in the nasopharyngeal region and their mean age at presentation is the sixth decade of life. MATERIALS AND METHODS: We present the clinical, pathological, treatment and 5-year follow-up data of 5 cases of nasopharyngeal MALT lymphoma treated with definitive radiotherapy at our hospital, between 2009 and 2011. RESULTS: The average age of diagnosis was 27 years which is more than a decade earlier than what has been reported previously. Clinical symptoms included nasal obstruction, tinnitus and hearing loss. All five patients had locoregional disease. They were treated by definitive radiotherapy to a dose between 30 to 40 Gy. At 5 years of follow-up, 4 patients were in complete remission while one had disease relapse. CONCLUSION: The younger age of presentation compared to older reports in this rare subsite was an interesting finding in our study. The authors speculate that rising levels of particulate air pollution may have played a part in the etiology in this younger population. Our series shows that despite the younger age, the disease displays an indolent course and responds well to radiotherapy alone as the primary treatment. Recurrence or disseminated disease is also highly treatable with systemic chemotherapy.

Angioimmunoblastic T-cell lymphoma involving the nasopharynx: An easily misdiagnosed disease with atypical histopathological features.

OBJECTIVES: To explore the clinicopathologic features, treatment, and survival outcomes of angioimmunoblastic T-cell lymphoma (AITL) involving the nasopharynx. METHODS: We retrospectively analyzed 73 cases of AITL. Among them, 64 cases with complete pre-treatment 18F-FDG positron emission tomography/computed tomography (PET/CT) images were integrated into the analysis of clinical characteristics and PET/CT findings of AITL involving the nasopharynx; 14 cases with both biopsies from lymph node and nasopharynx were included in the comparison of pathological characteristics of AITL in the two areas. Forty-six of the 73 patients who received first-line systemic treatment at our institute were included in the treatment efficacy and survival analyses. RESULTS: Nasopharyngeal involvement was seen in 44/64 (68.8%) patients. Histologically, lymph node and nasopharyngeal biopsies in 14 patients both showed small to medium-sized tumor cells, complex inflammatory infiltration, and Reed-Sternberg-like cells or B immunoblasts. However, tumor cells with clear cytoplasm, significant high endothelial venule (HEV) hyperplasia, and perivascular infiltration were observed in 5/14, 3/14, and 2/14 nasopharyngeal biopsies, respectively, but in all fourteen lymph node biopsies (P < 0.05). Immunophenotypic profiles and gene rearrangements were highly concordant. Treatment efficacy and survival were similar between patients with nasopharyngeal involvement and those without (P > 0.05), indicating nasopharyngeal involvement is not a prognostic factor for AITL patients. CONCLUSIONS: Nasopharyngeal involvement is common in AITL but can be easily misdiagnosed because of its atypical pathologic pattern, especially when a lymph node biopsy is unavailable. However, the patient's clinical presentation, PET/CT manifestations, the typical immunophenotype, and gene rearrangements help the diagnosis.

Successful Antiviral Treatment for Chronic Adenoiditis Caused by Herpes Virus in a Pediatric Patient: A Case Report.

BACKGROUND The adenoids are lymphatic tissue located in the nasopharynx and play a role in upper-airway immunity. Inflammation of the adenoids is called adenoiditis, which can cause a variety of symptoms. This is a common condition and is due to acute viral or bacterial infection. Most patients experience mild symptoms of upper-respiratory tract infection with a self-limiting course. CASE REPORT A 5-year-old female patient was brought into the clinic by her parents with concerns regarding hearing and sleep. Clinical assessment was consistent with persistent otitis media with effusion and sleep-disordered breathing. She was scheduled for surgery, including nasendoscopy, adenoidectomy, and bilateral grommet insertion. During surgery, direct visualization of the postnasal space showed complete obstruction by hypertrophic, inflamed adenoids covered in a thick, white film. A biopsy was taken, which detected herpes virus cytopathic effect. A diagnostic workup excluded a neoplastic process and other bacterial or fungal infections. A trial of oral antiviral medication was successful and follow-up nasendoscopy showed resolution of adenoid hypertrophy. CONCLUSIONS Direct visualization of the postnasal space, with a transoral mirror or 120-degree endoscope, prior to adenoidectomy can aid diagnosis. Adenoiditis may be caused by a wide range of organisms, including herpes virus. Active mucopurulent discharge should raise concern for infection by bacteria, fungi, or virus. Previous research on viral infection of the adenoids have been in asymptomatic patients with presumed latent infection and undergoing elective adenoidectomy. To our knowledge, this is the first paper to report on successful treatment with antiviral medication alone.

Oral and middle ear delivery of otitis media standard of care antibiotics, but not biofilm-targeted antibodies, alter chinchilla nasopharyngeal and fecal microbiomes.

Otitis media (OM) is one of the most globally pervasive pediatric conditions. Translocation of nasopharynx-resident opportunistic pathogens like nontypeable Haemophilus influenzae (NTHi) assimilates into polymicrobial middle ear biofilms, which promote OM pathogenesis and substantially diminish antibiotic efficacy. Oral or tympanostomy tube (TT)-delivered antibiotics remain the standard of care (SOC) despite consequences including secondary infection, dysbiosis, and antimicrobial resistance. Monoclonal antibodies (mAb) against two biofilm-associated structural proteins, NTHi-specific type IV pilus PilA (anti-rsPilA) and protective tip-region epitopes of NTHi integration host factor (anti-tip-chimer), were previously shown to disrupt biofilms and restore antibiotic sensitivity in vitro. However, the additional criterion for clinical relevance includes the absence of consequential microbiome alterations. Here, nine chinchilla cohorts (n = 3/cohort) without disease were established to evaluate whether TT delivery of mAbs disrupted nasopharyngeal or fecal microbiomes relative to SOC-OM antibiotics. Cohort treatments included a 7d regimen of oral amoxicillin-clavulanate (AC) or 2d regimen of TT-delivered mAb, AC, Trimethoprim-sulfamethoxazole (TS), ofloxacin, or saline. Fecal and nasopharyngeal lavage (NPL) samples were collected before and several days post treatment (DPT) for 16S sequencing. While antibiotic-treated cohorts displayed beta-diversity shifts (PERMANOVA, P < 0.05) and reductions in alpha diversity (q < 0.20) relative to baseline, mAb antibodies failed to affect diversity, indicating maintenance of a eubiotic state. Taxonomic and longitudinal analyses showed blooms in opportunistic pathogens (ANCOM) and greater magnitudes of compositional change (P < 0.05) following broad-spectrum antibiotic but not mAb treatments. Collectively, results showed broad-spectrum antibiotics induced significant fecal and nasopharyngeal microbiome disruption regardless of delivery route. Excitingly, biofilm-targeting antibodies had little effect on fecal and nasopharyngeal microbiomes.

Radiation-induced nasopharyngeal ulcers after re-irradiation with intensity-modulated radiotherapy in locoregional recurrent nasopharyngeal carcinoma patients: a dose-volume-outcome analysis.

OBJECTIVE: To analyze the interrelation between radiation dose and radiation-induced nasopharyngeal ulcer (RINU) in locoregional recurrent nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). METHODS: Clinical data were collected from 363 patients with locoregional recurrent NPC who received re-irradiated with definitive IMRT from 2009 to 2017. Twenty-nine patients were diagnosed with RINU. Univariate and multivariate analyses were used to re-evaluate the first and second radiotherapy plans and to identify predictive dosimetric factors. RESULTS: All dosimetric parameters were notably associated with the progression to RINU (p < 0.01) using paired samples Wilcoxon signed rank tests. Multivariate analysis showed that EQD2_ [Formula: see text]D80 (dose for 80 percent volume of the unilateral nasopharynx lesion) was an independent prognostic factor for RINU (p = 0.001). The area under the ROC curve for EQD2_ [Formula: see text]D80 was 0.846 (p < 0.001), and the cutoff point of 137.035 Gy could potentially be the dose tolerance of the nasopharyngeal mucosa. CONCLUSIONS: The sum of equivalent dose in 2 Gy fractions (EQD2) in the overlapping volumes between initial and re-irradiated nasopharyngeal mucosal tissue can be effective in predicting the hazard of developing RINU in NPC patients undergoing radical re­irradiation with IMRT and we propose a EQD2_ [Formula: see text]D80 threshold of 137.035 Gy for the nasopharynx.

Extreme acute radiation-induced toxicity in a patient with polymorphous low-grade adenocarcinoma of the nasopharynx and rare variants in DNA repair genes.

BACKGROUND: Polymorphous low-grade adenocarcinoma (PLGA) is an extremely rare finding in the nasopharynx. There are no guidelines for the treatment of PLGA in this localization. Radiotherapy may be administered to treat this malignancy; however, in radiosensitive individuals, it is associated with a risk of severe radiotherapy-induced toxicity. METHODS: We present a case of a 73-year-old woman with locally advanced polymorphous low-grade adenocarcinoma of the nasopharynx who developed a severe adverse acute reaction to radiotherapy leading to treatment discontinuation. Despite intensive treatment, the patient died 40 days after RT initiation. Whole genome sequencing was performed using DNA from peripheral blood mononuclear cells in the search for variants that could explain such extreme toxicity. RESULTS: We identified a combination of pathogenic variants that may have contributed to the patient's reaction to radiation therapy, including predisposing variants in XRCC1, XRCC3, and LIG4. We also identified candidate variants, not previously described in this context, which could be associated with radiation toxicity based on plausible mechanisms. We discuss previous reports of this rare tumor from the literature and known contributors to radiation-induced toxicity. CONCLUSIONS: Genetic causes should be considered in cases of extreme radiosensitivity, especially when is not explained by clinical factors.

A Case of Nasopharyngeal Pleomorphic Lipoma.

We describe the presentation and treatment of the first reported case of a nasopharyngeal pleomorphic lipoma. The mass was successfully treated with a combined endoscopic trans-oral surgical excision approach by using low temperature-controlled plasma technology, resulting in optimal patient outcomes. Laryngoscope, 134:2710-2712, 2024.

[A case report of nasopharyngeal inflammatory myofibroblastoma in infant].

Inflammatory myofibroblastic tumor （IMT） is a rare mesenchymal soft tissue tumor characterized by borderline or low-grade malignancy. It is rare childhood tumor with an average age of onset of 10 years old. It is even rarer in infants and toddlers, and the etiology and pathogenesis of this tumor are still unclear. The clinical presentation of IMT is non-specific and are related to the location of the tumor. When the tumor compresses adjacent organs, it can cause pain and functional impairment. According to the current literature, IMT is most commonly found in the digestive and respiratory systems, but also occasionally occur in the genitourinary system, head and neck, and limbs. At present, there have been no reports of nasopharyngeal IMT involving nasal cavity of infants and toddlers at home and abroad.This article reports a case of a massive inflammatory myofibroblastic tumor involving the nasal cavity and nasopharynx in an infant. Plasma-assisted minimally invasive surgery was performed through multiple surgical approaches and achieved satisfactory therapeutic results. This case report may provide valuable reference for the treatment of similar diseases.

SEPT9, H4C6, and RASSF1A methylation in nasopharyngeal swabs: A reflection of potential minimally invasive biomarkers for early screening of nasopharyngeal cancer.

The potential value of epigenetic DNA methylation in early cancer screening has been demonstrated. Therefore, in this study, we performed QMS-PCR and quantitative reverse transcription PCR on the genes RASSF1A, H4C6, SEPT9, GSTP1, PAX1, SHOX2, and SOX2, which are common in epithelial cancers. We found hypermethylation in RASSF1A, H4C6 and SEPT9. The mRNA expressions of RASSF1A, H4C6 and SEPT9 in tumor group were significantly different from those in the inflammatory group and healthy group (P < .05). Receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of RASSF1A, H4C6 and SEPT9 genes were 0.831, 0.856 and 0.767, respectively. The areas under the AUC curve of SEPT9 + H4C6, SEPT9 + RASSF1A and H4C6 + RASSF1A are 0.946, 0.912 and 0.851, respectively. The diagnostic ability of dual gene combination is better than that of single gene combination, among which SEPT9 and H4C6 combination has the best diagnostic effect. In conclusion, our findings suggest that H4C6, RASSF1A, and SEPT9 methylation occur more frequently in nasopharyngeal carcinoma, and their detection in nasopharyngeal swabs may be a minimally invasive tool for diagnosis of nasopharyngeal carcinoma.

Nasopharyngeal myeloid sarcoma as a manifestation of acute monomyelocytic leukaemia.

This case report describes the case of a man in his seventies presenting with a nasopharyngeal deposit of myeloid sarcoma associated with acute monomyelocytic leukaemia. He presented with right nasal obstruction associated with unilateral pulsatile tinnitus. CT and MRI scans of sinuses identified a moderately restricting mucosal swelling of the right torus tubarius, and a biopsy of the lesion diagnosed a nasal deposit of myeloid sarcoma.

Etiology of narrow maxilla creating orthodontic and prosthetic treatment difficulties.

OBJECTIVE: Narrow maxilla occurring due to various congenital or acquired causes creates major orthodontic problems and complicates prosthetic dental rehabilitation. The etiologic factors are mostly related to upper airway pathologies that restrict breathing and cause negative pressure at the base of the nose and nasopharynx. The upper and lower airway is a whole unit. Regional anomalies or acquired problems affect the entire system. This can lead to developmental issues and permanent disorders in childhood, which will last their real life. This study was planned to investigate the incidence of nasopharyngeal obstruction originating from allergic rhinitis, turbinate hypertrophy, septum deviation, and adenoid vegetation in children scheduled for orthodontic treatment due to maxillary stenosis. PATIENTS AND METHODS: Our study group consists of one hundred children aged 12-16 years who applied to the orthodontist due to dental malalignment and were found to have a narrowing of the maxilla. After the orthodontic evaluation, the patients were referred for an ENT examination to evaluate the etiological factors originating from the upper respiratory tract. In the study group, nasal congestion and allergic rhinitis were first investigated. All symptoms were evaluated and scored. Then, an ENT physical examination was performed in all cases, and nasal cavities, nasopharynx, and oropharynx were assessed with a fiberoptic endoscope. Regarding etiological factors, allergic rhinitis, turbinate hypertrophy, nasal septum deviation, and adenoid vegetation that would prevent breathing were carefully investigated. RESULTS: Firstly, deep palate, narrowed maxillary arch, V-shaped arch, adenoid face type, bilateral posterior crossbite, insufficient lip presence, maxillary incisor protrusion (upper forward thrust), skeletal class 2 division 1 malocclusion, and increased lower face height detected in patients primarily diagnoses were grouped according to their pathologies. Allergic rhinitis was found in 43 cases, turbinate hypertrophy in 30 instances, nasal septum deviation in 18 cases, and adenoid vegetation that prevented respiration in 61 patients. CONCLUSIONS: It is known that increased nasal airway resistance due to allergic rhinitis, septal deviation, turbinate hypertrophy, or adenoid vegetation in the upper respiratory tract may lead to permanent orthodontic disorders in children and adolescents. A multidisciplinary approach, early diagnosis, and treatment should be the first step to prevent this situation. Secondly, it should be planned to correct the anatomical disorders that have occurred with appliances and, if necessary, surgical approaches. Taking precautions before permanent problems arise in childhood is also crucial in prosthetic dentistry.