Skeletal Class III malocclusion with a reverse smile

Abstract

A case report by Jang et al (Jang W, Shin C, Hwang S, Kim KH, Jackson T, Nguyen T, et al. Nonsurgical treatment of an adult with a skeletal Class III malocclusion combined with a functional anterior shift, severely overclosed vertical dimension, and a reverse smile. Am J Orthod Dentofacial Orthop 2020;157:561-70) in the April issue reported the treatment of a 17-year-old female patient with a chief concern of crossbite and crowding. It is of great insight to the clinician for treating skeletal Class III malocclusion in adult patients with combined factors of skeletal, dental, and functional origin by applying sequential vertical and sagittal control for camouflage treatment based on precise diagnosis and treatment planning. Figure 4 showed the intraoral photographs, lateral cephalogram, and superimposition, indicating the anterior interference and functional shift of the mandible. For recording centric relation and centric occlusion discrepancy, it is advisable to take bite registration followed by articulation for further evaluation, but lateral cephalogram in an open mouth cannot be used to evaluate the discrepancy in occlusion clearly. Why was the lateral cephalogram used for recording centric relation and centric occlusion? In the table reporting the cephalometric summary, incisor mandibular plane angle showed an increase from 72.4° to 75.9°, but it was observed from Figure 9 (the cephalometric superimposition) that the mandibular incisors had retroclined. The table does not seem to agree with Figure 9. In addition, in the table, soft tissue upper lip to E-line (mm) increased from −3.7 mm to −4.0 mm at progress and subsequently reduced to −0.8 mm. Again, this does not seem to agree with Figure 9, which showed upper lip protrusion in the final radiograph. Nonsurgical treatment of an adult with a skeletal Class III malocclusion combined with a functional anterior shift, severely overclosed vertical dimension, and a reverse smileAmerican Journal of Orthodontics and Dentofacial OrthopedicsVol. 157Issue 4PreviewThis case report illustrates the successful nonsurgical treatment of an adult with a skeletal Class III malocclusion exacerbated by a functional anterior shift that resulted in a severe overclosure of the mandible and a reverse smile line. To maximize the soft tissue and smile esthetics while idealizing the occlusion, active clockwise rotation of the mandible was induced along with mandibular molar uprighting and sequential leveling. In the maxilla, full arch distalization was achieved after second molar extraction. Full-Text PDF Authors' responseAmerican Journal of Orthodontics and Dentofacial OrthopedicsVol. 158Issue 4PreviewWe appreciate the interest and the insightful comments on our case report. The patient had a centric occlusion–centric relation discrepancy with the interference of the incisors resulting in a forward shift of the mandible along with the preexisting skeletal Class III relationship. Thus, Class III malocclusion and facial profile can be exaggerated when the lateral cephalogram at centric occlusion (Ceph-CO) is the only record used for diagnosis. As mentioned, clinical evaluation as well as functional wax bite and/or bite registration of centric occlusion (maximum intercuspation) and centric relation (premature contact) position using orthodontic cast with articulators can provide important diagnostic information. Full-Text PDF