Three-dimensional evaluation using CBCT of the mandibular asymmetry and the compensation mechanism in a growing patient: A case report

Abstract

BackgroundThis case report aims to evaluate the development and the compensation mechanisms of the mandibular asymmetry in a growing male patient using cone beam computed tomography (CBCT). In this case, the menton deviated on the right, a sporadic condition, which may be the consequence of a disorder in the mandibular growth.Case presentationThe young male patient was treated with rapid palatal expander (RPE) and Fränkel functional regulator III (FR-3). The initial CBCT was acquired at the beginning of therapy when the patient was 8 years old, and the final CBCT was developed at the end of the treatment when the patient was 12 years old. The patient's CBCT was performed with the head oriented according to the Natural Head Position (NHP); the NHP is a physiological and reproducible posture defined for morphological analysis. The 3D image of the cranium was oriented in the Dolphin software according to NHP posture, and cephalometric measurements were taken in the software's frontal, laterolateral right and left, posteroanterior, and submentovertex views. The therapy lasted 3.8 years and ended with significant regression of the mandibular asymmetry from moderate grade (4.2 mm) to slight grade (1.3 mm).ConclusionThe literature shows that the left hemi-mandible has grown more than the right side, which affirms that in case of deviation of the menton >4 mm, the bone volume increases on the non-deviated side.

Soft tissue compensation evaluation in patients with facial asymmetry using cone-beam computed tomography combined with 3D facial photographs

“…This compromised muscular coordination may contribute to asymmetry in soft tissue thickness [ 43 ]. Evidence suggested that the early correction of these posterior crossbite through maxillary expansion had the potential to restore two-arch coordination and muscle function, facilitated by the spontaneous adaptive dentoalveolar compensation observed in the lower arch [ 49 ]. The re-centering of the menton point was attributed to this compensatory mechanism, whereby the contralateral hemi-mandibular demonstrated a greater growth rate compared to the deviated side, resulting in an observable improvement in soft-tissue symmetry in the lower face [ 49 , 50 ].…”

Prevalence of Ponticulus Posticus and Migraine in 220 Orthodontic Patients: A Cross-Sectional Study

“…During the CBCT exams, the head of the patient was oriented in a natural head position (NHP). NHP is a morphological analysis used in orthodontics and described in the anthropological literature as a reproducible and physiological head posture in a tridimensional space [ 16 , 17 ]. To obtain the NHP, all the patients looked into their own eyes through a frontal mirror positioned at a distance of 1.5 m. The patients were sitting with the back perpendicular to the floor, and the head was stabilized with ear rods in the external auditory meatus [ 16 , 17 ].…”

“…After acquiring the CBCT data in the Dolphin software, the head was additionally oriented according to the three reference planes on the front, right and left views [ 16 , 17 ]. The cephalometric measurements were correctly performed using the widgets present in the software [ 16 , 17 ].…”

Elastodontic Appliances for the Interception of Malocclusion in Children: A Systematic Narrative Hybrid Review

“…Thanks to their design, the dental-craniofacial and cervical-postural systems, as well as the neuromuscular system, alveoli, TMJs (temporomandibular joint system), soft tissues, salivary glands, and mandibular and maxillary bases, are all reflected in the functional activity of EAs [21,25,42,[49][50][51][52][53][54].…”

“…As a result, the device itself does not control dental movement. This neutral zone in which they are positioned is created by the harmony between the muscles of the lips, tongue, and cheeks [21,25,28,37,42,[49][50][51][52][53][54][55].…”