Three-dimensional facial changes correlated with sagittal jaw movements in patients with class III skeletal deformities

The Relationship between the Length/Width of the Face and the Length/Width of the Crown of the Permanent Upper Central Incisors

Background: The face, with its attractiveness, is positively connected with self-esteem and interpersonal relationships, and the maxillary central incisors are the most noticeable teeth and crucial for smile aesthetics. The aim of this study is to examine facial and permanent upper central incisors' clinical crown dimensions and their correlations to establish whether there is a relationship between the length/width of the face and the length/width of the clinical crown of the permanent upper central incisors. Methods: This study included 100 subjects (43 males and 57 females) with a mean age of 17.5 ± 3.4 years before orthodontic treatment. Facial length and width were measured using a cephalometer by the same orthodontist and the upper central incisors' clinical crown lengths and widths were measured using a sliding calliper by the same dental student. Data were analysed using SPSS version 29.0, presenting descriptive statistics for age, facial and upper central incisor crown dimensions, and indices. Pearson's correlation coefficient assessed the relationship between facial features and the upper central incisors' crown. The significance level was p ≤ 0.05. Results: Males exhibit a slightly higher mean value of the face length (11.6 ± 0.8 cm) compared to females' face length (11.2 ± 1.1 cm) and a statistically significant (p < 0.05) higher mean value of the face width (11.7 ± 0.8 cm) compared to females (11.1 ± 0.6 cm). The facial index shows no statistically significant gender difference (males: 99.1 ± 8.4; females: 101.2 ± 11.9, p > 0.05). The upper central incisor crown dimensions are without statistically significant differences between gender and tooth side: males have mean value clinical crown lengths of 10.2 ± 1.1 mm (left) and 10.1 mm ± 1.2 (right) while females have 9.9 ± 1.0 mm (left) and 9.8 ± 0.7 mm (right). Clinical crown widths are also comparable (males: left 9.0 ± 0.7, right 8.9 ± 0.6 and females: left 8.8 ± 0.7, right 8.8 ± 0.7), with no statistically significant differences observed. The tooth index shows no statistically significant difference but there is a statistically significant (p < 0.05) correlation between the facial index and tooth index. Conclusions: Knowledge of the presented data is important for diagnosis and treatment planning and may be useful for restorative dentists, orthodontists, prosthodontists, and maxillofacial surgeons to achieve an aesthetic result. Clinically, our study supports the development of more personalized treatment plans.

Stereophotometric facial changes in edentulous older adults after rehabilitation with complete dentures

OBJECTIVES

To evaluate the facial characteristics of edentulous older adults who underwent rehabilitation using complete dentures, and to compare them with dentate individuals.

BACKGROUND

Edentulism rehabilitation with complete dentures aims to restore occlusion and facial aesthetics.

MATERIALS AND METHODS

The study included 102 edentulous participants needing prosthodontic rehabilitation with complete dentures and 30 with a natural dentition (aged >65). The 3D facial scans were performed using an Artec optical scanner. Superficial facial landmarks were identified, and 16 parameters were calculated. Regional analysis with the superimposition of two scans was used to calculate the average distances and percentage of non-matching surfaces in the 11 regions. Paired and independent t-tests (α = .05) were used to test for group differences, as appropriate.

RESULTS

After rehabilitation with complete dentures, facial changes were most noticeable in the perioral region: wider rima oris, longer upper lip, wider upper vermilion, and more protruded profile. The comparison of facial regions without and with dentures showed fuller and curvier cheeks, with no direct influence of dentures. The edentulous faces with dentures appeared shorter and more retruded than those of dentate individuals. A narrower lower vermilion, retruded upper lip, and more flattened facial profile were observed in females with dentures than in their dentate peers.

CONCLUSION

Besides the expected positive influence of rehabilitation with complete dentures on facial appearance in the perioral region, there are some unexpected changes, such as fuller cheeks, but there is still deficiency in vertical facial dimensions and a more flattened facial profile.

Three-dimensional Measurement of the Zygomatic-maxillary Complex in the Class III Malocclusion Patients with Maxillary Retrusion

This study investigated the anatomic features of the zygomatic-maxillary complex in patients with maxillary retrusion without clefts. Individuals were grouped, and craniofacial measurements were performed for 21 individuals with skeletal Class III malocclusion with maxillary retrusion (CIII) and 48 individuals from the control group (CG). We evaluated the predetermined hard-tissue and soft-tissue points of the facial profile in each group. Independent sample t -tests were performed to determine the differences between groups (significance set at P <0.05). Multiple points on the midface, including the most posterior point on the contour of the maxillary alveolar process, lowest point of the zygomaticomaxillary suture, furthest point to the zygomatic self-base plane, superior point in the infraorbital foramen, and lowest point of the inferior margin of the orbit to the coronal plane were smaller in CIII than in CG (all P <0.05). The soft tissue thickness in these regions was significantly increased compared with that in the normal group. In summary, for class III malocclusion patients with maxillary retrusion, the deficiency in the midface gradually decreased going upward, with the deficiency at the maxillary alveolar level being the most serious. To some extent, soft tissues compensate for the deficiencies in the facial skeleton, and standard Le Fort I osteotomy advancement was sufficient to achieve a harmonious appearance.

Comparison of regional soft tissue changes after bimaxillary rotational surgery between class III deformity with overbite and open bite: A 3D imaging analysis

BACKGROUND

This prospective study aimed to compare regional soft tissue changes between patients with class III overbite and open bite deformities treated with bimaxillary surgery involving clockwise and counter-clockwise mandibular setback, respectively.

MATERIAL AND METHODS

Class III deformity adults receiving Le Fort I and bilateral sagittal split osteotomies were grouped according to the incisal occlusion: overbite (n = 30) and open bite (n = 30). Combined cone-beam CT scans and 3D facial photographs preoperative and at least 1-year postoperative were taken to assess the soft tissue changes.

RESULTS

Postoperative changes for the overbite and open bite groups included anterior repositioning of nose (-0.8 ± 1.2 mm and -1.1 ± 1.1 mm, respectively) and cheek (-1.9 ± 1.3 mm and -1.7 ± 2.6 mm, respectively), posterior repositioning of chin (5.2 ± 4.0 mm and 4.9 ± 3.2 mm, respectively), and medial (-1.7 ± 2.0 mm and -1.9 ± 2.1 mm, respectively) and posterior (2.7 ± 1.4 mm and 2.8 ± 2.3 mm, respectively) repositioning of bilateral angles. Posterior (1.2 ± 2.0 mm and 5.1 ± 3.3 mm) and inferior (-1.4 ± 2.2 mm and -2.4 ± 2.7 mm) repositioning of upper lip and lower lip occurred in overbite group. Inferior (-2.3 ± 2.4 mm) and superior (3.7 ± 3.4 mm) repositioning of chin occurred in the overbite and open bite groups, respectively.

CONCLUSIONS

Treatment of class III overbite and open bite deformities with bimaxillary rotational surgery resulted in comparable regional soft tissue changes, except for upper lip, lower lip and chin.

Three-dimensional nasolabial changes after maxillary advancement osteotomy in class III individuals: a systematic review and meta-analysis

Background Class III malocclusions with maxillary retrognathia are commonly treated with single jaw Le Fort I maxillary advancement. The three-dimensional (3D) effects of surgery on the nasolabial region varies among the clinical studies. Quantifying these changes is of great importance for surgical planning and obtaining valid consent. Objectives To investigate the 3D relationship between soft tissue and skeletal changes secondary to Le Fort I maxillary advancement surgery in skeletal class III patients.Search methods Comprehensive search of multiple electronic databases supplemented by a manual and grey literature search were undertaken from inception to 9 June 2020.Selection criteria Studies that evaluated the 3D soft tissue changes of patients before and after maxillary advancement surgery alone.Data collection and analysis Study selection, data extraction and risk of bias assessment were performed independently by two reviewers, with disputes resolved by a third reviewer. A quantitative synthesis of the data was pre-planned for pooling similar outcome measures.Results Four studies were included in the final review and meta-analysis, with a total of 105 patients (mean age 16.7 + 33.9 years). The mean maxillary advancement of the included studies was 5.58 mm (95% CI 5.20-5.96). The sagittal effects of surgery on nose tip projection and prominence were insignificant (P >0.05, two studies); however, subnasal projection (MD 1.7 mm, two studies) and upper lip projection (MD 2.90 mm, four studies) increased significantly in a forward direction after surgery (P <0.05). Le Fort I osteotomy widens the upper philtrum width (MD 0.84 mm, two studies) (P <0.05). Inconsistencies among the included studies were identified; therefore, the results should be interpreted with caution.Conclusions There is weak evidence based on quantitative assessments that Le Fort I maxillary advancement significantly affects the nasolabial soft tissue envelope mainly in a sagittal dimension. These changes are concentrated around the central zone of the nasolabial region. Future prospective studies on maxillary advancement osteotomy with a standardised method of assessment, taking into consideration the confounding factors, are required.

Review of papers published in The British Journal of Oral and Maxillofacial Surgery and The Journal of Orthodontics regarding three-dimensional computerised planning in orthognathic surgery: 2015 - 2019

This review paper summarises articles regarding orthognathic surgical planning and computerised technology, which were published in two leading national journals in both oral and maxillofacial surgery and orthodontics. This article aims to keep readers up to date with the literature published in this rapidly progressing field.