Facial Mobility after Maxilla-Mandibular Advancement in Patients with Severe Obstructive Sleep Apnea Syndrome: A Three-Dimensional Study

The Effect of Orthognathic Surgery on Soft-Tissue Facial Asymmetry: A Longitudinal Three-Dimensional Analysis

In modern orthognathic surgery, the functional results cannot disregard a good aesthetic outcome. In this study, a stereophotogrammetric longitudinal analysis of the symmetry of facial thirds was performed in 18 patients affected by Class III skeletal malocclusion, with clinical asymmetry, treated with a bimaxillary osteotomy. Their 3-dimensional facial images were acquired in the preoperative phase and 6, 12, and 24 months after surgery, and compared to those obtained in a control group of 23 subjects with Class I skeletal occlusion, without clinical asymmetry and no history of traumas or alterations at the maxillo-facial area. Images of the hemi-faces of the subjects were divided into thirds (upper, middle, lower), mirrored and superimposed to their contralateral ones; soft-tissue facial symmetry was obtained as the root mean square distance between the hemi-faces in the three thirds.In patients, no significant differences in facial symmetry (root mean square distance) were found among the study time points (analysis of variance, P > 0.05); the lower facial third was more asymmetric than the upper one (Tukey honestly significant difference P < 0.05). Patients were significantly more asymmetric than the control subjects (Student t, P < 0.05). In conclusion, patients with Class III malocclusion exhibited a higher level of facial asymmetry than control subjects; their asymmetry did not change significantly in the different phases of the surgical and orthodontic treatment and throughout a 24-month follow-up. In skeletal Class III patients, bimaxillary osteotomy did not modify the level of asymmetry in any facial third.

Maxillomandibular Advancement for the Treatment of Obstructive Sleep Apnea in Patients With Normal or Class I Malocclusion

BACKGROUND

Maxillomandibular advancement is an effective surgical option for obstructive sleep apnea (OSA) that achieves enlargement of the upper airway by physically expanding the facial skeleton. The authors sought to determine whether an advancement of 10 mm predicts surgical success and if any correlation existed between the magnitude of mandibular/maxillary advancement and improvement in polysomnography metrics using aggregated individual patient data from multiple studies.

METHODS

A search of the PubMed database was performed to identify relevant articles that included preoperative and postoperative polysomnography data and measurements of the advancement of both the maxillary and mandibular portions of the face in patients with normal or class I malocclusion. Each patient was stratified into "Success" or "Failure" groups based on criteria defining a "Success" as a 50% preoperative to post-operative decrease in AHI or RDI and a post-operative AHI or RDI <20.

RESULTS

A review of the PubMed database yielded 162 articles. Review of these resulted in 9 manuscripts and a total of 109 patients who met the inclusion criteria. There was no statistically significant difference in the amount of anterior advancement of either the mandible (P = 0.96) or the maxilla (P = 0.23) between the "Success" or "Failure" groups.

CONCLUSIONS

While there is a paucity of individual data available, the current data does not support an ideal amount of maxillary or mandibular advancement that is required to obtain a surgical success in the treatment of OSA. Until a multicenter, prospective, randomized trial is performed, surgical planning should be tailored to patient-specific anatomy to achieve the desired result.

Juvenile Facial Growth and Mimicry: A Preliminary 3D Study

Studies focused on facial development during childhood have been conducted by means of 3D technology to provide modifications of anthropometric parameters. Facial mobility was also considered. This study proposed a 3D approach to facial growth changes. Facial surface data of 6 subjects were acquired in T1 (age 7-14 years) and after 7 years (T2), in rest position, and during voluntary movements, by a 3D laser scanner. Linear and angular measurements on rest position scans at T1 and T2 were compared. Each mimic scan was superimposed with the corresponding rest scan. Displacement of significant anthropometric points was measured for each facial gesture and at T1 and T2 statistically compared. Vertical measurements were those most influenced by aging. Some measurements of central facial area were consistent over time. The pattern of soft tissues displacement for each expression was consistent in T1 and T2. These results may be helpful for missing children identification.

Assessing Normal Smiling Function Through 3D-3D Surfaces Registration: An Innovative Method for the Assessment of Facial Mimicry

Smiling has a great importance, both from a functional and an aesthetic point of view. The introduction of modern 3D acquisition and elaboration methods may provide additional help in the evaluation of facial mimicry. This study aims at proposing an innovative method to assess facial and labial movements in different types of smiles. Twenty healthy subjects (10 males, 10 females, mean age 27.5 years, SD 4.5 years), were recorded through a stereophotogrammetric system in neutral position and in three types of smiles: Mona-Lisa smile, canine smile, full-denture smile. All the 3D smiling models were superimposed on the corresponding neutral one and point-to-point root mean square (RMS) differences were computed. Labial surface areas in rest position and during each smile were calculated as well, together with the percentage modification in different types of smile. RMS values (facial and labial models), labial surface areas and percentage modifications were compared through ANCOVA tests to verify possible statistically significant differences according to sex and type of smile (p < 0.05). Intercanthal labial width was considered a covariate. RMS values progressively increased from Mona-Lisa to full-denture smile; statistically significant differences were found among all types of smiles, both for facial and labial models (p < 0.05), while no statistically significant sex and sex × smile interactions were found (p > 0.05). Labial surface and percentage of modification showed statistically significant differences according to both sex and type of smile (p < 0.05). The study provides a novel contribution to the field of sexual dimorphism in smiling. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .