Malocclusions in relation to facial soft tissue characteristics, facial aesthetics and temporomandibular disorders in the Northern Finland Birth Cohort 1966

• Main Author: Krooks, L. (Laura)
• Other Authors: Pirttiniemi, P. (Pertti), Lähdesmäki, R. (Raija), Raustia, A. (Aune)
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Oulun yliopisto 2018
• Subjects: TMDs; aesthetics; cephalometry; cohort study; epidemiology; malocclusion; occlusion; orthodontics; soft tissue profile; temporomandibular disorders; TMD; epidemiologia; estetiikka; kefalometria; kohorttitutkimus; oikomishoito; pehmytkudosprofiili; purennan poikkeama; purenta; purentaelimistön toimintahäiriöt; Northern Finland
• Online Access: http://urn.fi/urn:isbn:9789526220109

Abstract Epidemiological studies on malocclusions in Finland have so far concentrated on children and adolescents. Regarding the Finnish adult population, there is scarce epidemiological knowledge available on malocclusions even though the number of adults seeking orthodontic treatment has increased during the last decades. Occlusion is an important factor in the function of the masticatory system, and its role in the aetiology of temporomandibular disorders (TMD) is one of the most disputed topics in dentistry. Malocclusions can affect the characteristics of the facial soft tissue profile. The aim of the study was to investigate the prevalence of malocclusions and the role of occlusion in TMD as well as the association of facial characteristics with malocclusions and facial aesthetics. The study population consisted of subjects from the Northern Finland Birth Cohort 1966 (NFBC1966). Data were collected using questionnaires, standardized clinical examination and facial photos. The profile photographs were analysed using linear and angular soft tissue cephalometric measurements. The most common malocclusion in the NFBC1966 subjects was lateral crossbite. This study showed a significant association between asymmetric malocclusions and TMD. TMD signs associated significantly with lateral crossbite, scissors bite, negative overjet, and the length and lateral deviation in slide between retruded contact position and intercuspal position (RCP-ICP). Soft tissue profile characteristics were highly correlated with negative overjet. The ANB-angle was significantly associated with the perception of facial attractiveness. In conclusion, malocclusions were associated with signs and symptoms of TMD in the Finnish adult population. Overjet appeared to affect the facial profile more than overbite. Facial convexity seemed to be a more important determinant of facial aesthetics for orthodontists than for dentists and laypersons. Tiivistelmä Suomalaiset epidemiologiset tutkimukset purennan poikkeamista ovat tähän asti ...