Integration of Cranial Base and Face in Growing Subject

Facial Asymmetry Detected with 3D Methods in Orthodontics: A Systematic Review

Background:

Historically, the development of two-dimensional (2D) imaging techniquesforerun that of three-dimensional (3D) ones. Some 2D methods are still considered valid and effective to diagnose facial asymmetry but 3D techniques may provide more precise and accurate measurements.

Objective:

The aim of this work is to analyze the accuracy and reliability of the imaging techniques available for the diagnosis of facial asymmetry in orthodontics and find the most reliable.

Methods:

A search strategy was implemented using PubMed (National Library of Medicine, NCBI).

Results:

A total of 3201 papers were identified in electronic searches. 90 articles, available in full text, were included in the qualitative synthesis consisting of 8 reviews on the diagnosis of facial asymmetry, 22 in vivo and in vitro studies on 2D methods and 60 in vivo and in vitro studies on 3D methods to quantify the asymmetry.

Conclusion:

2D techniques include X-ray techniques such as posterior-anterior cephalogram, which still represents the first level exam in the diagnosis of facial asymmetry. 3D techniques represent the second level exam in the diagnosis of facial asymmetry. The most current used techniques are CBCT, stereophotogrammetry, laser scanning, 3D optical sensors and contact digitization. The comparison between bilateral parameters (linear distances, angles, areas, volumes and contours) and the calculation of an asymmetry index represent the best choices for clinicians who use CBCT. The creation of a color-coded distance map seems to represent the most accurate, reliable and validated methods for clinicians who use stereophotogrammetry, laser scanning and 3D optical sensors.

2D vs. 3D Radiological Methods for Dental Age Determination around 18 Years: A Systematic Review

The age of a living human being can be determined by applying a number of different methods; the most diffused are skeletal and dental methods, both principally based on X-rays examinations. This systematic review assesses the current evidence regarding the accuracy and reliability of Cone Beam Computed Tomography (CBCT) vs. Orthopantomography (OPG) in age determination. A computerized systematic literature search of studies published up to January 2020 was conducted without language restrictions in order to identify articles comparing CBCT vs. OPG in dental anatomy evaluation, articles evaluating the accuracy of dental methods for age estimation, both with CT and OPG exams, and articles comparing CBCT vs. OPG in terms of radiation dose. CBCT was found to be more accurate compared to OPG in dental anatomy evaluation. When analyzing young adults, an estimation error of two years is considered forensically acceptable. The radiation dose of a CBCT exam is higher compared to an OPG exam. However, the difference is not as marked with small Fields Of View (FOV) and low-resolution protocols. Final conclusion was that a small FOV CBCT centered on the mandibular angle of a young patient is an accurate and safe method for dental age estimation around the age of 18.