Banca de QUALIFICAÇÃO: KERLISON PAULINO DE OLIVEIRA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : KERLISON PAULINO DE OLIVEIRA
DATE: 17/11/2026
TIME: 14:00
LOCAL: NATAL
TITLE:

In Vitro Mechanical Evaluation Comparing 2.0-mm System Miniplates Used in
Short Mandibular Osteotomy in Orthognathic Surgery

KEY WORDS:

orthognathic surgery; fracture fixation, internal; osteotomie

PAGES: 16
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUBÁREA: Cirurgia Buco-Maxilo-Facial
SUMMARY:

Dentofacial deformities represent a significant group of skeletal abnormalities
that affect not only facial aesthetics but also patients’ masticatory, speech, and
respiratory functions. Orthognathic surgery, particularly sagittal split ramus osteotomy
(SSRO), has for decades been one of the main procedures used to correct these
discrepancies, allowing efficient and predictable skeletal realignment associated with
long-term functional and aesthetic stability [1,2].
Traditionally, SSRO is performed using the conventional technique originally
described by Obwegeser and Dal Pont, with subsequent modifications introduced by
Hunsuck and Epker. These approaches involve broad surgical access and extension of
the osteotomy cuts toward the mandibular body, aiming to optimize overlap between the
bone segments and provide a larger bone contact area for stable internal fixation [3,4].
Although this approach has high success rates, it is associated with several well-
documented complications, including unfavorable fractures involving the condylar or
inferior border regions, inferior alveolar nerve paresthesia, hematoma, excessive edema,
and prolonged recovery periods [5].
Over the past decades, the concept of minimally invasive (MI) surgery has
gained increasing acceptance across different fields of medicine and, more recently, in
orthognathic surgery. According to Hunter (1999), the concept of MI surgery involves
performing surgical procedures with less tissue trauma, reduced morbidity, shorter
operative time, and, consequently, an improved postoperative patient experience [6].
Studies have demonstrated that less invasive techniques may significantly reduce
edema, trismus, and pain, while also decreasing the risk of paresthesia and bone-related
complications when compared with traditional approaches [7,8].
Minimally invasive orthognathic surgery (MIOS) has emerged as an evolution of
the conventional technique, prioritizing osteotomy cuts restricted to the mandibular
ramus, avoiding their extension into the mandibular body, reducing exposure of the
inferior alveolar nerve, and decreasing the risk of fractures involving the inferior
mandibular border [7,9]. The technique described by Posnick (2016) and further refined
by Cordier et al. (2020) involves shorter osteotomy lines and limited surgical access,
with reduced detachment of the temporalis muscle and less manipulation of the
surrounding soft tissues [9,10]. Recent evidence suggests that the adoption of MIOS
may not only reduce intraoperative and postoperative complications but also provide
faster recovery and less postoperative discomfort for patients [8,10].
Furthermore, the integration of technological resources such as piezoelectric
devices, three-dimensional virtual surgical planning, surgical navigation, and

instruments specifically designed for MIOS has further enhanced the potential benefits
of this approach, allowing more precise osteotomies, reduced tissue trauma, and greater
predictability of surgical outcomes [11–13]. However, despite these apparent clinical
advantages, an important question remains unresolved: the biomechanical resistance of
fixation systems used in minimally invasive sagittal osteotomy, particularly when
compared with the conventional technique.
Previous biomechanical studies, including investigations conducted by this
research group [14,15], have demonstrated that specific plate and screw configurations
used in conventional SSRO play a decisive role in the primary stability of the bone
segments following mandibular advancement. However, these studies were performed
exclusively using the conventional technique and therefore did not address the particular
characteristics of MIOS, which involves shorter osteotomy cuts and, consequently, a
smaller bone contact area. This raises relevant concerns regarding biomechanical
stability, particularly in cases involving greater mandibular advancements (≥10 mm).
Additionally, recent studies have indicated that the absence of a vertical
osteotomy cut in the mandibular body, which is characteristic of MIOS, substantially
reduces the occurrence of unfavorable fractures and postoperative bone defects,
complications frequently associated with the conventional technique, particularly in
brachyfacial patients and in cases requiring large skeletal movements [9,10,16].
Nevertheless, there remains a lack of quantitative studies objectively evaluating the
resistance provided by different plate configurations—such as MIOS-specific plates and
conventional straight plates—as well as the influence of monocortical and bicortical
locking screws within this specific context.
Therefore, this research project is justified by the need to generate
biomechanical evidence that may guide clinical decision-making regarding the most
appropriate fixation devices for minimally invasive sagittal osteotomy. In vitro
mechanical testing will allow an objective comparison of the resistance provided by
different combinations of plates and screws while taking into account the anatomical
and functional characteristics of MIOS. The findings are expected not only to provide
biomechanical validation for the application of this technique but also to contribute to
its establishment as a safe, effective, and less morbid alternative to conventional
orthognathic surgery.

COMMITTEE MEMBERS:
Presidente - 2379951 - ADRIANO ROCHA GERMANO
Externo à Instituição - PAULO MARIA SANTOS RABELO JUNIOR - UFMA
Externo à Instituição - JOSE THIERS CARNEIRO JUNIOR - UFPA