Prevalence of temporomandibular disorders diagnosis in patients treated with Herbst appliance: a systematic review and meta-analysis.

BACKGROUND: The Herbst appliance is an excellent therapy for treating class II malocclusions with increased overjet. Its mechanics involve propelling the mandibular bone using two pistons the patient cannot remove. The so-called bite-jumping keeps the mandible in a more anterior position for a variable period, usually at least 6 months. This appliance does not inhibit joint functions and movements, although there are scientific papers in the literature investigating whether this appliance can lead to temporomandibular disorders. This systematic review aims to evaluate whether Herbst's device can cause temporomandibular diseases by assessing the presence of TMD in patients before and after treatment. METHODS: A literature search up to 3 May 2023 was carried out on three online databases: PubMed, Scopus and Web of Science. Only studies that evaluated patients with Helkimo scores and Manual functional analysis were considered, as studies that assessed the difference in TMD before and after Herbst therapy. Review Manager version 5.2.8 (Cochrane Collaboration) was used for the pooled analysis. We measured the odds ratio (OR) between the two groups (pre and post-Herbst). RESULTS: The included papers in this review were 60. Fifty-seven were excluded. In addition, a manual search was performed. After the search phase, four articles were considered in the study, one of which was found through a manual search. The overall effect showed that there was no difference in TMD prevalence between pre-Herbst and post-Herbst therapy (OR 0.74; 95% CI: 0.33-1.68). CONCLUSION: Herbst appliance seems not to lead to an increase in the incidence of TMD in treated patients; on the contrary, it appears to decrease it. Further studies are needed to assess the possible influence of Herbst on TMDs.

Are the Reasons Why Patients Are Referred for an Orthodontic Visit Correct?

Who does refer patients for an orthodontic consultation? Which are the main reasons for the referral? Does the visit of the orthodontic specialist confirm these reasons or reveal undiagnosed problems? Is there the risk that only evident dental problems are addressed, while craniofacial malformations remain underdiagnosed? This cross-sectional epidemiologic study aims to answer these questions, analysing the clinical data collected during the orthodontic visits of 500 Caucasian young patients referred to a public health structure of northern Italy. All patients were visited by the same expert specialist in orthodontics. Clinical data were collected, analysing both dental and skeletal features. The reasons for the referral of the visit were analysed and compared with the specialistic diagnoses. In our sample, dentists, relatives/friends and paediatricians were the major source of the referrals, followed by family doctors and other facial specialists. In most cases, the reasons for the referral were dental irregularities, but approximately 80% of dental irregularities were associated with undiagnosed facial dysmorphism. Skeletal facial anomalies need an early diagnosis to prevent the development of severe facial malformations that would require invasive and expensive treatments. These findings reveal poor diagnostic skills regarding skeletal anomalies in dentists and paediatricians and the need for better specific training.

Does Head Orientation Influence 3D Facial Imaging? A Study on Accuracy and Precision of Stereophotogrammetric Acquisition.

This study investigates the reliability and precision of anthropometric measurements collected from 3D images and acquired under different conditions of head rotation. Various sources of error were examined, and the equivalence between craniofacial data generated from alternative head positions was assessed. 3D captures of a mannequin head were obtained with a stereophotogrammetric system (Face Shape 3D MaxiLine). Image acquisition was performed with no rotations and with various pitch, roll, and yaw angulations. On 3D images, 14 linear distances were measured. Various indices were used to quantify error magnitude, among them the acquisition error, the mean and the maximum intra- and inter-operator measurement error, repeatability and reproducibility error, the standard deviation, and the standard error of errors. Two one-sided tests (TOST) were performed to assess the equivalence between measurements recorded in different head angulations. The maximum intra-operator error was very low (0.336 mm), closely followed by the acquisition error (0.496 mm). The maximum inter-operator error was 0.532 mm, and the highest degree of error was found in reproducibility (0.890 mm). Anthropometric measurements from alternative acquisition conditions resulted in significantly equivalent TOST, with the exception of Zygion (l)-Tragion (l) and Cheek (l)-Tragion (l) distances measured with pitch angulation compared to no rotation position. Face Shape 3D Maxiline has sufficient accuracy for orthodontic and surgical use. Precision was not altered by head orientation, making the acquisition simpler and not constrained to a critical precision as in 2D photographs.