Correlation Analysis between Three-Dimensional Changes in Pharyngeal Airway Space and Skeletal Changes in Patients with Skeletal Class II Malocclusion following Orthognathic Surgery

Introduction. Studies on the pharyngeal airway space (PAS) changes using three-dimensional computed tomography (CT) have shed more light on patients with Class III than Class II malocclusion. This paper focuses on analyzing the long-term changes in the PAS and evaluating the postoperative association between these PAS and skeletal changes in patients with skeletal Class II malocclusion who have undergone orthognathic surgery. Methods. The records of 21 patients with skeletal Class II malocclusion who had undergone orthognathic surgery were included. The anatomical modifications in both jaws, changes in volume, sectional area (SA), minimum sectional area (MSA), and anterior-posterior (AP) and transverse (TV) width in the airway at one month before surgery ( T 0 ), and one month ( T 1 ) and one year ( T 2 ) after surgery were analyzed using CT images. The association between the skeletal and airway changes was evaluated between T 0 , T 1 , and T 2 . Results. After surgery, the ANS, A point, and PNS demonstrated significant posterior and superior movement. The B point and the pogonion exhibited substantial anterior and superior movement. The total and inferior oropharyngeal volumes (vol 3, vol 4) notably increased, while the nasopharyngeal volume (vol 1) decreased. The anterior-posterior movement at the ANS and PNS after surgery was significantly associated with the total volume, vol 2, vol 3, SA 1, MSA, and TV width 1, while substantial association with the total volume was found at the pogonion. Conclusion. Thus, an ideal treatment plan can be formulated for patients with skeletal Class II malocclusion by considering the postoperative PAS changes.

Evaluation of Postsurgical Stability And Condylar Morphology In Skeletal Class II Patients With Condylar Resorption Following Orthognathic Surgery

Background: To retrospectively evaluate postsurgical stability and condylar morphology for skeletal class II malocclusion patients with condylar resorption (CR) treated with orthognathic surgery.Methods: Thirty-five patients treated with combined orthodontic and orthognathic surgery between 2014 and 2018 were enrolled in this retrospective study. CT scans were acquired preoperatively (T0), 2–7 days after surgery (T1), and 1 year postoperatively (T2). The amount of mandibular advancement, postsurgical relapse, condylar morphology and joint spaces were analysed respectively. Statistical analysis was performed using R, version 3.4.3 (R Development Core Team 2010).Results: The average mandibular advancement and counter-clockwise rotation were 5.51 mm and -2.82 degrees respectively. The average relapse was 1.08 mm (19.6% of the advancement) and 1.13 degrees. The condylar volume showed a postoperative reduction of 161.86 mm3(13.7% of initial condylar volume). AJS increased after surgery and gradually returned to its original state, while SJS and PJS decreased and remained stable. Surgical advancement of B point was significantly correlated with skeletal relapse. The optimal cut-off values were as follows: MP-FH (40.75°); ramus height (51.125 mm); SJS (1.63 mm); surgical displacement (4.72 mm); CCR (-4.3°); AJSC (1.07 mm).Conclusions: Skeletal class II patients with CR have a high risk of postsurgical condylar resorption, which was most related to nonsurgical risk factors such as gender(female) and condylar angle. Condylar had moved posteriorly to the concentric position after surgery and remained quite stable through the 1-year follow-up. Preoperative skeletal patterns such as lower ramus height and surgical procedures such as larger advancement of the mandible were closely associated with sagittal relapse of the mandible.

Association between Crowding and the Effective Maxillary and Mandibular Length among Orthodontic Patients of Kathmandu, Nepal.

Background: During orthodontic consultation, the most frequent major complaint of the patients is dental crowding, which is caused by a disparity between the arch length and tooth size. Objective: The purpose of this study was to evaluate the association between crowding and the effective maxillary and mandibular length in Nepalese orthodontic patients.Methods: The orthodontic records of 390 people (from January 2018 to December 2020) were randomly selected and classified into three skeletal malocclusions based on the ANB angle (Angle formed by point A and point B at the nasion). Subjects with skeletal malocclusions were subdivided into two groups depending on the degree of crowding in the mandibular arch: Group 1 had crowding of < 3mm, and Group 2 had crowding of >3mm. On pretreatment casts, digital vernier calipers (Digimatic, Precise, India) were used to assess dental arch crowding, whereas, on a pretreatment lateral cephalogram, digital cephalometric analysis (Vistadent OC 1.1, USA) was done to quantify effective maxillary and mandibular length. Inter-group comparisons were assessed using a one-way analysis of variance. The correlation was assessed by Pearson’s correlation coefficient (p≤0.05).Results: There was a statistically significant difference in effective maxillary and mandibular length among skeletal malocclusions (p<0.05). Skeletal Class II malocclusion had the greatest mandibular crowding, while skeletal Class III malocclusion had the least. The effective maxillary and mandibular lengths and dental crowding had a significant but weak inverse correlation, whereas a strong but moderate positive correlation existed between the maxillary and mandibular effective lengths (r=0.674) and also between maxillary and mandibular crowding (r=0.631).Conclusion: Effective maxillary length was highest in skeletal class II malocclusion whereas effective mandibular length was highest in skeletal class III malocclusion. The shorter effective maxillary and mandibular lengths showed a weak association with dental crowding.

Speech Disorders in Dysgnathic Adult Patients in the Field of Severity of Primary Dysfunction

The normative functioning of the stomatognathic system and masticatory apparatus requires specific coordination between several structures such as teeth with good occlusion, tongue without ankyloglossia or thrusting, and well-balanced facial muscles. This study aimed to evaluate the influence of non-normative primary functions such as breathing, swallowing, biting and chewing on the consonant pronunciation outcome in adults affected with facial skeletal deformities. Moreover, the authors would like to promote a new kind of speech therapy-orthognathic speech therapy. A total of 181 adults affected by skeletal class II and III malocclusion were included, along with the relationship between the malocclusion, speech deficiency (20 phonemes tested) and primary function disorders, in the subjects before and after surgical correction. The impact of surgery on pronunciation and primary function improvement and types of Polish phonemes most often misarticulated by Polish adults were also examined. Patients underwent combined treatment and received a full speech pathology examination. The treatment improved speech (p < 0.05), and primary functions (p < 0.05). Palatal, alveolar (p < 0.05), fricatives (p < 0.05), and labiodental consonant pronunciation (p < 0.05) improved. The surgical correction of malocclusion leads to better oral motor control and articulation of Polish consonants in adults.

Comparative Analysis of Dentoskeletal Changes of the Twin Block Appliance and the AdvanSync2 Appliance in Treatment of Skeletal Class-II Malocclusion in Pakistani Population: A Randomized Clinical Trial

Objective This study aimed to compare dentoskeletal changes in skeletal class-II malocclusion with removable twin block appliance and fixed AdvanSync2 appliance. Materials and Methods A prospective randomized clinical trial was conducted over a span of 1 year at AFID at Rawalpindi. Thirty patients with skeletal class-II malocclusion, 16 males (53.3%) and 14 females (46.6%), were randomly selected and divided in two equal groups (15 each) to be treated with either fixed functional appliances (FFAs) or with removable functional appliances (RFAs). Out of 30 patients, 15 between cervical vertebral maturation (CVM) stages of 2 and 3 were treated with RFA (twin block appliances) and remaining 15 between CVM stages of 4 and 5 were treated with FFA (AdvanSync2 appliances). Pretreatment (T1) and posttreatment (T2), angular variable, and linear variable were measured to compare the dentoskeletal effects between the two groups. Statitical Analysis Paired sample t-test was used to assess significant difference between variables at T1 (Pre-treatment) and T2 (Post-treatment) stage for both RFA and FFA group. Comparison among the RFA and FFA group was made using non-parametric Mann-Whitney U Test. IBM SPSS version 25.0 was used for evaluation. Results No significant difference was found in angular variables between the RFA and FFA groups (p > 0.05) with the exception of linear variables. Sella-posterior nasal spine (S-PNS) length significantly increased and Jarabak's ratio significantly decreased for FFA group (p = 0.010 and 0.045, respectively), when compared with RFA group. Conclusion Both the appliances, twin block (RFA) and AdvanSync2 (FFA), are effective for correction of skeletal class-II malocclusion. Both the appliances produced similar effects in the sagittal plane but for better vertical control twin block should be the appliance of choice. AdvanSync2 appliance could be preferred over twin block appliance when dentoalveolar and slight retrusive effect on the maxilla is desired especially for individuals in postpubertal growth spurt.