Changes in soft tissue profile following the treatment using a Herbst appliance: A photographic analysis

Abstract

Background/Aim. Aesthetics is the reason for most of the class II malocclusion patients to opt for orthodontic treatment. In order to regulate retrognathic profile Herbst appliance for anterior movement of the mandible can be a treatment of choice. The aim of this study was to determine the soft tissue profile changes following Herbst appliance therapy on before and after treatment photos, using the computer program. Methods. This investigation was performed on profile photographs of 20 class II patients (12 females and 8 males) aged 18-23 years. Analysis of the changes in soft tissue facial structure relationships evident on the photographs before and after the Herbst appliance therapy was performed using Bentley Micro Station program. The first contour of the soft tissue profile was marked. The following reference lines were subsequently traced: Ricketts aesthetic E line and Juanita line. The area enclosed by these two lines included the nose, upper and lower lip, chin and free space in front of the lips. Using the computer program, the surfaces of the soft tissue structures and free space defined by the reference lines and profile contours were measured. Calculation of the relative proportion of surfaces was done for each photograph. The data obtained were then compared for each patient before and after the treatment. Skeletal and dentoalveolar treatment effects that support soft tissue changes were presented by the profile cephalometric parameters of sagital occlusion (SO) analysis. Results. A reduction in the relative surface of the upper lip in males (p lt 0.01) and females (p lt 0.05) was shown by the pictures. The space occupied by the chin was reduced after the treatment for females only (p lt 0.05). The relative surface of the nasal soft tissues, that was included in the reference space was increased (p lt 0.01) in both genders. The relationship between the soft tissue and empty surface was changed in favor of the empty surface (p lt 0.05) in females. No statistically significant differences were found between the males and the females, before or after the Herbst appliance therapy. The soft tissue changes were the consequence of skeletal and dentoalveolar treatment effects: upper incisors retrusion, lower incisor protrusion and forward movement of the lower jaw. Conclusions. The Herbst appliance therapy caused a significant improvement of the profile appearance. The extent of soft tissue changes that occur on its dentoalveolar and skeletal support is a complex issue.

Uvod/Cilj. Većina mladih sa malokluzijom klase II odlučuje se za ortodontski tretman iz estetskih razloga. Za ispravljanje retrognatog profila može se koristiti aparat za anteriorno pomeranje mandibule - Herbst aparat. Cilj istraživanja bio je da se utvrde promene mekotkivnog profila posle primene Herbst aparata. Metode. Ispitivanje je izvršeno na profilnim fotografijama 20 mladih ljudi (12 ženskog i 8 muškog pola) sa malokluzijom klase II, starosti od 18 do 23 godine. Analizirane su promene odnosa mekotkivnih struktura lica na fotografijama načinjenim pre i posle sprovedene terapije Herbst aparatom. Za tu analizu korišćen je Bently Micro Station program. Digitalizovana je granica kontura mekotkivnog profila i ucrtavane su referentne linije: Ricketts-ova estetska E linija i Juanita linija. Ove linije ograničavaju prostor u kome su smešteni nos, gornja i donja usna i brada, kao i slobodni prostor koji se nalazi ispred konture mekotkivnog profila. Kompjuterski su merene površine mekotkivnih struktura i slobodnog prostora definisane referentnim linijama i konturom profila. Unutar slike izračunati su relativni odnosi površina. Nakon toga dobijeni podaci su poređeni pre i posle terapije za svaku osobu. Skeletni i dentoalveolarni terapijski efekti koji prouzrokuju mekotkivne promene prikazani su analizom sagitalne okluzije (SO) profilnog telerendgena. Rezultati. Sprovedenim merenjima utvrđeno je da je došlo do smanjenja relativne površine gornje usne kako kod dečaka (p lt 0,01), tako i kod devojčica (p lt 0,05). Prostor koji zauzima brada posle terapije značajno se smanjio samo kod devojčica (p lt 0.05). Relativna površina mekotkivnog profila nosa obuhvaćena referentnim prostorom povećana je sa podjednakom statističkom značajnošću od p lt 0,01 kod oba pola. Odnos mekog tkiva i praznog prostora promenio se u korist praznog prostora (p lt 0,05) kod devojčica. Nije bilo statistički značajne razlike između dečaka i devojčica pre i posle sprovedene terapije. Retruzija gornjih i protruzija donjih sekutića, kao i mezijalno pomeranje donje vilice glavni su terapijski efekti koji izazivaju mekotkivne promene donje trećine lica. Zaključak. Terapija Herbst aparatom dovodi do značajnog poboljšanja izgleda profila lica. Prilagodljivost mekog tkiva na promene njegove koštane i dentoalveolarne potpore je kompleksna.