Analysis of facial features and prediction of lip position in skeletal class III malocclusion adult patients undergoing surgical-orthodontic treatment

Evaluation of facial pleasantness in patients with complete and unilateral cleft lip and palate rehabilitated and submitted to orofacial harmonization

OBJECTIVE

The objective of the present prospective case control study was to evaluate the facial pleasantness of patients with complete and unilateral cleft lip and palate at the end of interdisciplinary rehabilitation, submitted to facial fillers based on hyaluronic acid.

METHODS

The study group consisted of 18 individuals with complete unilateral cleft lip and palate, aged between 18 and 40 years (mean age 29 years) of both sexes. The patients presented a concave profile with mild to moderate maxillary deficiency, with completed orthodontic treatment and conducted by means of dentoalveolar compensations without orthognathic surgery. Participants underwent facial filling procedures with hyaluronic acid (HA) in the midface, inserted by a single operator. Standard photographs in frontal norm at rest, right profile at rest, and left profile at rest were obtained from each patient at the following operative times: (T1) pre-filler and (T2) and one-month post-filler. The photographs in T1 and T2 were randomly placed on a page of a virtual album. A 5-point Likert scale was used to assess facial pleasantness. The photographs were evaluated by two groups of evaluators consisting of 18 individuals with cleft lip and palate (CLPG=18) and 18 orthodontists with experience in the treatment of clefts (OG=18). For comparison between phases T1 and T2, and between evaluators with orofacial clefts and orthodontists, the Wilcoxon test was used (p<0,05).

RESULTS

People with cleft lip and palate rated their face as more pleasant after the midface filling procedure. In the perception of the orthodontists, on the other hand, the facial pleasantness remained similar after the facial filling procedure.

CONCLUSIONS

The filling of the middle third of the face in patients with cleft lip and palate treated without orthognathic surgery increased the pleasantness of the face in the opinion of laypeople with cleft lip and palate.

Machine learning-based decision support system for orthognathic diagnosis and treatment planning

BACKGROUND

Dento-maxillofacial deformities are common problems. Orthodontic-orthognathic surgery is the primary treatment but accurate diagnosis and careful surgical planning are essential for optimum outcomes. This study aimed to establish and verify a machine learning-based decision support system for treatment of dento-maxillofacial malformations.

METHODS

Patients (n = 574) with dento-maxillofacial deformities undergoing spiral CT during January 2015 to August 2020 were enrolled to train diagnostic models based on five different machine learning algorithms; the diagnostic performances were compared with expert diagnoses. Accuracy, sensitivity, specificity, and area under the curve (AUC) were calculated. The adaptive artificial bee colony algorithm was employed to formulate the orthognathic surgical plan, and subsequently evaluated by maxillofacial surgeons in a cohort of 50 patients. The objective evaluation included the difference in bone position between the artificial intelligence (AI) generated and actual surgical plans for the patient, along with discrepancies in postoperative cephalometric analysis outcomes.

RESULTS

The binary relevance extreme gradient boosting model performed best, with diagnostic success rates > 90% for six different kinds of dento-maxillofacial deformities; the exception was maxillary overdevelopment (89.27%). AUC was > 0.88 for all diagnostic types. Median score for the surgical plans was 9, and was improved after human-computer interaction. There was no statistically significant difference between the actual and AI- groups.

CONCLUSIONS

Machine learning algorithms are effective for diagnosis and surgical planning of dento-maxillofacial deformities and help improve diagnostic efficiency, especially in lower medical centers.

Effects of different surgical techniques and displacement distances on the soft tissue profile via orthodontic-orthognathic treatment of class II and class III malocclusions

Background

Orthognathic surgery can be carried out using isolated mandibular or maxillary movement and bimaxillary procedures. In cases of moderate skeletal malocclusion, camouflage treatment by premolar extraction is another treatment option. All these surgical procedures can have a different impact on the soft tissue profile.

Methods

The changes in the soft tissue profile of 187 patients (Class II: 53, Class III: 134) were investigated. The treatment approaches were differentiated as follows: Class II: mandible advancement (MnA), bimaxillary surgery (MxS/MnA), upper extraction (UpEX), or Class III: maxillary advancement (MxA), mandible setback (MnS), bimaxillary surgery (MxA/MnS), and lower extraction (LowEX) as well as the extent of skeletal deviation (moderate Wits appraisal: − 7 mm to 7 mm, pronounced: Wits <− 7 mm, > 7 mm, respectively). This resulted in five groups for Class II treatment and seven groups for Class III treatment.

Results

In the Class II patients, a statistically significant difference (p ≤ 0.05) between UpEX and moderate MnA was found for facial profile (N′-Prn-Pog’), soft tissue profile (N′-Sn-Pog’), and mentolabial angle (Pog’-B′-Li). In the Class III patients, a statistically significant differences (p ≤ 0.05) occurred between LowEX and moderate MxA for facial profile (N′-Prn-Pog’), soft tissue profile (N′-Sn-Pog’), upper and lower lip distacne to esthetic line (Ls/Li-E-line), and lower lip length (Sto-Gn’). Only isolated significant differences (p < 0.05) were recognized between the moderate surgical Class II and III treatments as well between the pronounced Class III surgeries. No statistical differences were noticed between moderate and pronounced orthognathic surgery.

Conclusions

When surgery is required, the influence of orthognathic surgical techniques on the profile seems to be less significant. However, it must be carefully considered if orthognathic or camouflage treatment should be done in moderate malocclusions as a moderate mandibular advancement in Class II therapy will straighten the soft tissue profile much more by increasing the facial and soft tissue profile angle and reducing the mentolabial angle than camouflage treatment. In contrast, moderate maxillary advancement in Class III therapy led to a significantly more convex facial and soft tissue profile by decreasing distances of the lips to the E-Line as well as the lower lip length.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13005-021-00264-4.