Occlusal plane canting: a treatment alternative using skeletal anchorage

ABSTRACT A canted occlusal plane is the cause of unaesthetic smile, and also represents a challenge, due to the complex orthodontic procedures involved in its treatment. The skeletal anchorage allows successful treatment of this asymmetry in the majority of cases, with less dependency on the patient cooperation and reducing the necessity of orthognatic surgery. Given this condition, this article aims at discussing the main aspects related to the diagnosis of occlusal plane canting, treatment plan, and orthodontic mechanics using skeletal anchorage either by mini-implants or miniplates. In this context, five cases will be reported, showing the main details related to the orthodontic mechanics used to correct the occlusal plane, avoiding side effects and successfully reaching treatment objectives and long-term stability.

RESUMO O plano oclusal inclinado é causa de um sorriso esteticamente desagradável e representa um desafio, devido à complexidade dos procedimentos ortodônticos envolvidos no seu tratamento. A ancoragem esquelética permite a correção da inclinação do plano oclusal, na maior parte dos casos, sem a necessidade de cirurgia ortognática e com menor dependência da colaboração dos pacientes. Com base nisso, o objetivo desse artigo é discutir os principais aspectos relacionados ao diagnóstico, plano de tratamento e mecânica ortodôntica envolvida no tratamento do plano oclusal inclinado com mini-implantes ou miniplacas. Nesse contexto, cinco casos serão apresentados, demonstrando os principais detalhes relacionados à mecânica utilizada na correção do plano oclusal inclinado com a utilização de ancoragem esquelética.

Positional symmetry of porion and external auditory meatus in facial asymmetry / 대한악안면성형재건외과학회지

BACKGROUND: The porion (Po) is used to construct the Frankfort horizontal (FH) plane for cephalometrics, and the external auditory meatus (EAM) is to transfer and mount the dental model with facebow. The classical assumption is that EAM represents Po by the parallel positioning. However, we are sometimes questioning about the possible positional disparity between Po and EAM, when the occlusal cant or facial midline is different from our clinical understandings. The purpose of this study was to evaluate the positional parallelism of Po and EAM in facial asymmetries, and also to investigate their relationship with the maxillary occlusal cant. METHODS: The 67 subjects were classified into three groups. Group I had normal subjects with facial symmetry (1.05 +/- 0.52 mm of average chin deviation) with minimal occlusal cant (<1.5 mm). Asymmetry group II-A had no maxillary occlusal cant (average 0.60 +/- 0.36), while asymmetry group II-B had occlusal cant (average 3.72 +/- 1.47). The distances of bilateral Po, EAM, and mesiobuccal cusp tips of the maxillary first molars (Mx) from the horizontal orbital plane (Orb) and the coronal plane were measured on the three-dimensional computed tomographic images. Their right and left side distance discrepancies were calculated and statistically compared. RESULTS: EAM was located 10.3 mm below and 2.3 mm anterior to Po in group I. The vertical distances from Po to EAM of both sides were significantly different in group II-B (p = 0.001), while other groups were not. Interside discrepancy of the vertical distances from EAM to Mx in group II-B also showed the significant differences, as compared with those from Po to Mx and from Orb to Mx. CONCLUSIONS: The subjects with facial asymmetry and prominent maxillary occlusal cant tend to have the symmetric position of Po but asymmetric EAM. Some caution or other measures will be helpful for them to be used during the clinical procedures.

Correction of Lip Canting Using Bioabsorbables during Orthognathic Surgery / 대한악안면성형재건외과학회지

Lip canting is associated with facial asymmetry, and is one of the most challenging problems in surgical correction of facial deformities. The author corrected lip canting using bioabsorbable devices during orthognathic surgery. Soft tissue suspension procedures were performed on four patients with facial asymmetry. Lip lines improved for all patients. Over an observation period of five years, no complications were noted, nor did any late relapse develop. Furthermore, as time past, the effect of the Endotine suspension procedure increased probably due to induction of fibrosis on surrounding soft tissues.

Validity of Posterior Anterior Cephalometric and 3D-CT for Orbital Canting Analysis

0.05). In 3D-CT, orbital canting was almost paralleled with horizontal reference line. The orbital canting, maxillay canting and mandibular deviation between two groups showed no significant differences except madibular deviation in 3D-CT.CONCLUSION: Common analysis of posterior anterior cephalometric and 3D-CT is not valide method to evaluate orbital canting for facial asymmetry patients with orbital canting.

Change of lip canting after bimaxillary orthognathic surgery

PURPOSE: The purpose of study was to investigate the correlationship between lip canting change and occlusal canting change after bimaxillary orthognathic surgery, and the ratio of lip canting change and occlusal canting change after the surgery. PATIENTS AND METHODS: The subjects for this study was obtained from a group of 25 patients who took bimaxillary orthognathic surgery for occlusal canting correction at the Department of the Oral and Maxillofacial Surgery, Samsung Medical Center in Seoul, Korea between January 2000 and December 2005 and a patient's chart had to contain a resting frontal facial photograph in natural head position and a corresponding PA cephalogram in occlusion on the same day before the surgery and post-op 6 months later. The lip canting change was assessed with the angle each labial commissure and the bipupilary reference line. And, the occlusal caning change in the frontal plane was assessed with the angle between the each maxillary first molar occulasal surface and the bi-frontozygomatic suture reference line. RESULTS: In angular measurement, average occlusal canting change was 3.09degrees and standard deviation was 1.05degrees, average lip canting change was 1.56degrees and standard deviation was 1.05degrees. In linear measurement, average occlusal canting change was 2.41mm and standard deviation was 2.75mm, average lip canting change was 1.18mm and standard deviation was 0.43mm. Lip canting correction ration to occlusal canting correction was 51.5(+/-8.4)percent in angular measurement and 48.8 (+/-9.1)percent in linear measurement. Under Pearson's correlation analysis, Pearson's correlation coefficient was 0.869 in angular measurement and 0.887 in linear measurement (p-value < 0.01). High correlationship was shown between occlusal canting change and lip canting change. CONCLUSION: First, Bimaxillary orthognathic surgery can correct lip canting as well as occlusal canting. Second, The average amount of lip canting correction is 51.5+/-8.4percent, 48.8+/-9.1percent of occlusal canting correction in the study.