Factors Affecting Total Treatment Time in Patients Treated with Orthognathic Surgery Using the Surgery-First Approach: Multivariable Analysis Using 3D CT and Scanned Dental Casts

Abstract

The aim of this study was to analyze factors affecting treatment times in patients treated with the surgery-first approach (SFA) for orthognathic surgery. Fifty skeletal class III patients who had undergone SFA bimaxillary orthognathic surgery were enrolled. Retrospective chart reviews and analysis of 3D CT and digitally scanned casts were conducted to assess the total treatment time. Statistical analysis was then performed with multiple study variables. Longer treatment times were required for patients with severe maxillary or mandibular teeth crowding (p = 0.009), a preoperative anterior open bite (p = 0.021), and those undergoing orthodontic extractions (p < 0.001). Longer treatment times were also observed when setting surgical occlusion in the postoperative anterior open bite (p = 0.007) and in patients with postoperative dental midline deviation (p < 0.001) and transverse maxillary deficiencies (p = 0.035). Treatment times were shorter when a class I molar key was formed in the surgical occlusion setup (p = 0.002) and in bilateral anterior and posterior occlusion with a minimum of four contact points (p < 0.001). The number of contact points, the number of extracted teeth, and postoperative midline deviation were identified as significant predictors. These results suggest that proper patient selection is important when considering SFA and that surgeons can reduce total treatment time with an appropriate surgical occlusion setup.

Skeletal and Dental Outcomes after Facial Allotransplantation: The Cleveland Clinic Experience and Systematic Review of the Literature

“…59 Stable posterior occlusion, a minimum of three contact points, 62,63 no previous extractions, coordination of the maxillary and mandibular midlines, and presence of a limited crossbite (not more than one buccal cusp width of the maxillary molars) are essential prerequisites to achieve a stable occlusion and therefore skeletal bone healing in the ideally positioned maxilla and mandible. 60,64 In our third patient, multiple previous extractions, including molars, and only two contact points created a considerably unstable preoperative occlusion. Similar problems could have coexisted in other donors and this might explain, in part, the high percentage of malocclusion after transplantation.…”

Surgery-as-soon-as-Feasible: A Challenge to One Major Premise of the Surgery-First Approach

“…The use of skeletal orthodontic anchorage is acknowledged to be effective in controlling movements of individual teeth, or groups of teeth-or in fact entire arches in certain surgical and non-surgical situations [1,5]. Three-dimensional imaging, planning and treatment technology will continue to be developed to the advantage of all those involved in all types of orthognathic treatment [2,18]. By all accounts, in skilled hands, Surgery-first has been shown to be an effective way in which various dentofacial problems can be managed [4].…”

“…The so-called Surgery-first approach (usually involving sophisticated three-dimensional digital planning and the use of skeletal screws and plates as orthodontic anchors for necessary tooth movements) has been promoted to reduce "exceptionallylong presurgical orthodontic treatment durations of two years or more" [1]. It is also promoted on the basis that the so-called Rapid Acceleratory Phenomenon (the RAP) effect) following bone trauma or surgery allows the teeth to move through bone more quickly-in the end, leading to much-reduced total active treatment durations [1,2]. It has been pointed out however that, despite the use of skeletal orthodontic anchorage, presenting dentoalveolar compensations may not always be completely reduced [3].…”

Surgery-First Approach in Orthognathic surgery: Literature review

“…(Delgani, Fazeli & Sattarzadeh, 2017) Both studies considered a group of patients with different characteristics of malocclusion. Kim, J.-Y., et al (2020), established factors that affect treatment time in 50 class III patients, using three-dimensional computed tomography and scanned dental models of all patients. We selected 22 men and 28 women with a mean age of 22 years.…”

“…Several other comparative studies of cephalometric measurements have concluded that the instability factors in SFA are a very pronounced overjet, very deep curve of Spee, and a very severe negative overjet. (Kim et al, 2020;Ko et al, 2011;Jeong et al, 2017)…”