Three‐dimensional assessment of craniofacial asymmetry in children with transverse maxillary deficiency after rapid maxillary expansion: A prospective study

Abstract

Objective: The aim of this study was to evaluate craniofacial asymmetry in children with transverse maxillary deficiency, with or without functional unilateral posterior crossbite (UPC), before and after rapid maxillary expansion (RME). Setting and sample population: A sample of 51 children with cone beam computed tomography scans obtained before RME (T1) and a year after RME (T2). Material and methods: This prospective study consisted of 2 groups: 25 children with functional UPC (6.77 ± 1.5 years) and 26 children without UPC (7.41 ± 1.31 years). Linear and angular measurements were obtained from zygomatic, maxilla, glenoid fossa and mandible, using original and mirrored 3D overlapped models. All right and left side comparisons in both groups and intergroups asymmetries were compared using MANOVA and t test for independent samples, respectively, statistically significant at P < .05. Results: The UPC group showed no side differences, but mandibular horizontal rotation at T1, and this asymmetry was improved in T2. The non-UPC group showed at baseline significant lateral asymmetry in orbitale, position of palatine foramen, respectively, in average 2.95 mm and 1.16 mm, and 0.49 mm of average asymmetry in condylar height. The glenoid fossa was symmetric in both groups at T1 and T2. Conclusions: Children with transverse maxillary deficiency showed slight morphological asymmetry, located in the mandible position in cases of UPC, and in the orbital and maxillary regions in cases without UPC. One year after RME, patients improved their craniofacial asymmetry, with significant changes in the mandible and correction of the mandibular rotation in patients who presented UPC.

Effects on the Facial Growth of Rapid Palatal Expansion in Growing Patients Affected by Juvenile Idiopathic Arthritis with Monolateral Involvement of the Temporomandibular Joints: A Case-Control Study on Posteroanterior and Lateral Cephalograms

“…The distance of the affected condyle to the axis of symmetry (Cd A-MID), compared with the omologous parameter in non-JIA patients, showed no significant difference. This event is apparently due to similar condylar repositioning and growth following maxillary expansion [35].…”

“…Solving cross bite and premature contact connected to dental crowding promotes asymmetry reduction and avoidance of dental interferences during function that could cause a worsening of joint inflammation and therefore of mandibular asymmetry [24][25][26][28][29][30]35,[50][51][52]. Abnormal contacts between the area of upper and lower deciduous canines (i.e., cross-bite or premature contacts) for example, are the main causes of functional mandibular shift [53].…”

“…This event is probably due to the anatomy of the TMJ i.e., two hinge joints that are connected to each other and respond to the removal of the premature contacts with a complex three-dimensional movement of rotation and translation. The linear movement of the condylar point appears reduced when compared to the Gonion points as the latter are more distant from the rotation fulcrum (i.e., TMJ) and therefore could be subjected to a greater movement [35].…”

“…The positive effects are allegedly partly due to mandible repositioning after premature contact removal and partly due to skeletal growth at the level of the condyle that will hopefully continue during the residual growth period following the restoration of a correct occlusion. Understanding condylar growth response to functional stimulation promoted by mandibular repositioning [35] is worthy of future studies hopefully based on three-dimensional imaging technologies. The growth response of articular cartilages in JIA patients could indeed be impaired because of their rheumatic condition and results may differ between subjects [54,55].…”

“…RME have already been demonstrated to cause an augmentation of SNB angle, which measures the antero-posterior positioning of the mandible in relation to the cranial base (partly due to condylar repositioning inside the glenoid fossa and partly to condylar growth) [32], to reduce nasal resistances, and to improve nasal respiration and facial symmetry [33][34][35]. These positive effects would be also be desirable in the treatment of JIA patients because their most common facial traits, whenever TMJ are affected by this rheumatic condition, are mandibular hypoplasia and facial asymmetry [11,12].…”