Sinan Dehrab

Congenital agenesis of the maxillary lateral incisors presents significant functional and aesthetic challenges, and there is limited evidence regarding the most effective and sustainable treatment strategy. This research project aims to evaluate orthodontic space closure using skeletal anchorage from two temporary palatal implants (the Mesialslider) and to compare this approach with space opening followed by prosthetic replacement. The project investigates treatment efficiency, changes in facial profile, health‑economic outcomes, and the mechanical properties of the palatal implants used for anchorage. The project is designed as a randomized controlled trial in which patients with agenesis of the maxillary lateral incisors receive either active or passive Mesialslider treatment over a six‑month period. Treatment outcomes are assessed using intraoral scanning, 3D facial photography, and patient‑reported measures at multiple time points. Dental and soft‑tissue changes are analyzed through digital superimposition. A comparative health‑economic analysis will evaluate cost‑effectiveness between Mesialslider‑mediated space closure and traditional space opening with subsequent prosthetic rehabilitation. An additional in vitro study will examine the mechanical strength and fracture patterns of the palatal implants by measuring insertion torque and assessing fracture surfaces via electron microscopy. This project addresses a clinically relevant knowledge gap and requires interdisciplinary expertise in orthodontics, oral radiology, clinical genetics, biomechanics, and health economics. The results are expected to strengthen evidence‑based treatment planning, improve cost‑effectiveness, and enhance patient care. The project will also contribute to postgraduate training and teaching within the dental, dental hygiene, and advanced orthodontic programmes by expanding knowledge in craniofacial genetics, evidence‑based management of anterior agenesis, patient‑reported outcome measures, intraoral scanning, 3D imaging, biomechanics, and health‑economic evaluation.

Congenital absence of the maxillary lateral incisors presents both functional and aesthetic challenges, particularly in growing individuals for whom prosthetic replacement may be unsuitable. This research project investigates a minimally invasive alternative for space closure using skeletal anchorage (the Mesialslider), an appliance anchored in the anterior palate that enables controlled mesial movement of molars and premolars without relying on dental anchorage. The study is conducted as a collaboration between Karolinska Institutet and Region Stockholm, with oral surgical guidance provided for the insertion of anchorage screws. The project evaluates the efficiency, predictability, and aesthetic outcomes of this treatment approach by integrating three-dimensional imaging and intraoral scanning to quantify tooth movement, anchorage stability, and changes in soft tissue contours. Collaboration with the units for oral and maxillofacial surgery, radiology, and biomechanics ensures high methodological precision. Expected outcomes include strengthened evidence to support clinical decision-making in managing anterior tooth agenesis, reduced reliance on prosthetic replacements, and improved long-term stability in young patients. The project will also contribute to the development of the dental and dental hygiene curricula—particularly within orthodontics, paediatric dentistry, and prosthodontics—and enhance knowledge of dental materials and biomechanics through collaboration with materials science.

Background: Agenesis of the maxillary lateral incisors is a common craniofacial anomaly. Clinically, two strategies are weighed: orthodontic space closure or space opening followed by prosthetic replacement. Temporary anchorage devices (orthodontic miniscrews) enable controlled tooth movement, yet knowledge gaps remain regarding safety, mechanical robustness, and cost‑effectiveness. Aim: To assess the clinical efficiency, profile/aesthetic outcomes, and cost‑effectiveness of miniscrew‑assisted space closure (Mesialslider) in adolescents with agenesis, and to elucidate miniscrew mechanical properties and the impact of pre‑drilling, bending, and corrosion. Methods: The project comprises (A) in vitro studies measuring insertion and fracture torque in multi‑layer artificial bone, plus corrosion/wear analyses after artificial saliva exposure (metal ion release via AAS). (B) A clinical RCT comparing active versus initially passive Mesialslider (activated at 6 months). Outcomes include intraoral scanning and 3D facial imaging at 0, 3, and 6 months with digital superimposition of tooth movement and soft‑tissue changes, and patient‑reported pain/discomfort. A complementary health‑economic evaluation compares space closure with space opening plus prosthetic rehabilitation. Expected significance: The study aims to define indications for minimally invasive space closure, reduce reliance on prosthetics and long‑term complications, and provide safe, standardized insertion protocols for miniscrews. Findings are expected to strengthen evidence‑based planning, optimize resource use, and support education in orthodontics, paediatric dentistry, prosthodontics, and biomechanics.