Nasal Floor Slanting and Its Association With Nasofacial Structures

Background and Objectives Nasal floor slanting (NFS) is an incidental radiographic finding of asymmetry in the nasal floor level. Despite its frequent appearance, however, NFS has never been properly defined, neither has its correlation with the asymmetry of the adjacent nasofacial structures been investigated. We evaluated the incidence of NFS in patients with sinonasal symptoms and its correlation with the nasofacial skeletal structures.Subjects and Method We investigated patients who underwent preoperative ostiomeatal unit (OMU) CT and facial photography. We measured the incidence of NFS and its angle in the 265 patient images, and analyzed the relationships between NFS and radiologically detected asymmetries of the adjacent nasofacial skeleton and facial asymmetry visible on a photograph.Results NFS was found in 51% of the study subjects (136/265), who were defined as the slanted group. The mean NFS angle in the slanted group was 7.7° with a standard deviation (SD) of 4.4°, ranging from 2.4° to 22.4°. The slanted group showed a higher incidence of nasal septal deviation, asymmetry in the orbit and maxillary sinus, and a larger maxillary cavity (p<0.001) than the non-slanted group. Asymmetry of the face showed a higher incidence in the slanted group (p<0.01), whereas an external nasal deviation did not show an association with NFS.Conclusion NFS is evident in about 50% of patients complaining of nasal symptoms and is associated with nasofacial skeletal asymmetry as well as asymmetry in the face.

CHANGES IN THE LINEAR DIMENSIONS OF THE LOWER JAW WITH THE ELIMINATION OF FUNCTIONAL LATERAL DISPLACEMENT

Introduction. Facial asymmetries associated with lateral displacement of the jaw arise due to various reasons, namely, the presence of functional lateral displacement of the lower jaw, skeletal asymmetry of the maxillofacial region, and a combination of the above factors. Purpose. Identification of the etiological factor makes it possible to assess the possibility of correcting the position of the lower jaw and improving the relationship of the intra-articular structures of the temporomandibular joint. Materials and methods. Functional lateral displacement of the lower jaw is characterized by an asymmetric tone of the masticatory muscles, a change in the position of the chin, and dysfunction of the temporomandibular joint on the side of the displacement of the lower jaw. The article discusses a clinical case of a patient with pathology of the temporomandibular joint associated with functional displacement of the mandible. Comparison of the data of cone-beam computed tomography of the lower jaw at the site of attachment of the masticatory muscle before and after the elimination of the asymmetry of the maxillofacial region was carried out. Conclusion. An asymmetric change in the displacement of the condyles was obtained according to the data of electronic axiography, an improvement in the ratio of intra-articular structures, the presence of a change when comparing STL models of the lower jaw.

Orthodontic incisor decompensation in orthognathic therapy—success and efficiency in three dimensions

Objectives Sufficient dental decompensation is crucial for treatment success in combined orthodontic-surgical treatment. The study’s objective was to determine the treatment success and efficiency in sagittal, vertical, and transversal decompensation. Methods This longitudinal, observational study enrolled 52 adult patients, who underwent orthodontic-surgical treatment. Incisor inclinations and positions as well as skeletal changes were assessed pre-treatment (T1), pre-surgical (T2), and post-surgical (T3) by lateral cephalograms and CBCT scans. Results Incisor decompensation was insufficient in all three dimensions. Sagittal: treatment efficiency did not differ between class II and III patients. Vertical: patients with open bite demonstrated pre-surgical bite deepening and insufficient surgical reduction of the maxillomandibular plane angle. Transversal: Dental midline deviations were not adapted to the skeletal asymmetry so that menton deviations were not properly corrected. Conclusions Incisor decompensation was not as successful as requested in all three dimensions and the treatment ideal was seldom achieved. Clinical relevance To improve the skeletal outcome, the orthodontist has to treat the patient with the desired surgical movements in mind and should critically evaluate the pre-surgical incisor decompensation before referral to the surgical team.

Treatment of the mandibular shift in an adult woman and the diagnostic value of joint space index: a case report

Background Mandibular deviations are common clinical complaints. The orthodontic or orthognathic treatment of mandibular deviations is tricky because a comprehensive diagnosis, especially a functional one, is difficult to make. A inaccurate diagnosis may lead to a compromised and unstable treatment outcome. Case presentation This article describes the diagnosis and treatment of a woman with a mandibular deviation and facial skeletal asymmetry. By eliminating the disharmony of the arch form with elastics and bite turbos, her esthetic and functional outcomes improved. Cone-beam CT (CBCT) and Joint Space Index (JSI) analyses served as the diagnostic approaches and outcome evaluation methods before and after treatment. Conclusions A condyle position displacement could be an indication of functional deviation. JSI analysis is a quantitative and convenient choice to compare condyle relative positions.

Evaluation of structural skeletal asymmetry of the glenoid fossa in adult patients with unilateral posterior crossbite using surface-to-surface matching on CBCT images

ABSTRACT Objectives To compare, using surface-to-surface (StS) matching, any shape differences between the crossbite and noncrossbite side of the glenoid fossa and articular eminence in adult patients affected by posterior unilateral crossbite (PUXB) and compare them with unaffected controls. Materials and Methods 32 cone beam computed tomography (CBCT) scans of patients (mean age: 23.72 ± 3.74 years) undergoing surgical maxillary expansion were analyzed to obtain three-dimensional models of the left and right glenoid fossae that were superimposed using stable anatomical reference points and then compared using StS matching to evaluate the presence of any shape differences. These findings were compared with those obtained from 16 CBCT scans of unaffected controls (mean age: 23.72 ± 3.73 years). Results A mean difference of &gt;11% was found between the study group and controls when comparing the matching percentages of the two sides of the glenoid fossa and articular eminence at all three levels of tolerance selected for this study. These differences were found to be highly statistically significant (P ≤ .0001). Conclusions According to the shape analysis findings, adult PUXB patients exhibit a higher degree of glenoid fossa and articular eminence shape differences compared to unaffected controls.

Histopathological features of condylar hyperplasia and condylar Osteochondroma: a comparison study

Background Both mandibular condylar hyperplasia and condylar osteochondroma can lead to maxillofacial skeletal asymmetry and malocclusion, although they exhibit different biological behavior. This study attempted to compare the histological features of mandibular condylar hyperplasia and condylar osteochondroma using hematoxylin-and-eosin (H&E) staining, and immunohistochemistry staining of PCNA and EXT1 with quantitative analysis method. Results The H&E staining showed that condylar hyperplasia and condylar osteochondroma could be divided into four histological types and exhibited features of different endochondral ossification stages. There was evidence of a thicker cartilage cap in condylar osteochondroma as compared condylar hyperplasia (P = 0.018). The percentage of bone formation in condylar osteochondroma was larger than was found in condylar hyperplasia (P = 0.04). Immunohistochemical staining showed that PCNA was mainly located in the undifferentiated mesenchymal layer and the hypertrophic cartilage layer, and there were more PCNA positive cells in the condylar osteochondroma (P = 0.007). EXT1 was mainly expressed in the cartilage layer, and there was also a higher positive rate of EXT1 in condylar osteochondroma (P = 0.0366). The thicker cartilage cap, higher bone formation rate and higher PCNA positive rate indicated a higher rate of proliferative activity in condylar osteochondroma. The more significant positive rate of EXT1 in condylar osteochondroma implied differential biological characteristic as compared to condylar hyperplasia. Conclusions These features might be useful in histopathologically distinguishing condylar hyperplasia and osteochondroma.