Measurement of Thickness at the Inferior Border of the Mandible Using Computed Tomography Images: A Retrospective Study including 300 Japanese Cases.

Vascularised fibular free flaps are integral to reconstructive surgery for head and neck tumours. We investigated the morphological characteristics of the mandible to improve the incidence of plate-related complications after surgery. Using standard radiological software, thickness measurements of the inferior or posterior margin of the mandible were obtained from computed tomography images of 300 patients at seven sites: (1) mandibular symphysis, (2) midpoint between the mandibular symphysis and mental foramen, (3) mental foramen, (4) midpoint between the mental foramen and antegonial notch, (5) antegonial notch, (6) mandibular angular apex (gonion), and (7) neck lateral border of the dentate cartilage. Relationships between age, sex, height, weight, the number of remaining teeth in the mandible, and the thickness of each mandible were also investigated. Measurement point 1 had the largest median mandibular thickness (11.2 mm), and measurement point 6 had the smallest (5.4 mm). Females had thinner measurements than males at all points, with significant differences at points 1, 2, 3, 4, and 7 (p < 0.001). Age and number of remaining teeth in the mandible did not correlate with mandibular thickness; however, height and weight correlated at all points except point 6. Thickness measurements obtained at the sites provide a practical reference for mandibular reconstruction. Choosing the fixation method based on the measured thickness of the mandible at each site allows for sound plating.

Peri-operative hemostatic management of tooth extraction in patients with hemophilia A, with and without inhibitors, receiving emicizumab prophylaxis.

INTRODUCTION: Emicizumab treatment may allow patients with hemophilia A without (PwHA) and with inhibitors (PwHA-I) to undergo some minor surgeries, such as tooth extraction, without peri-operative factor infusions. However, criteria for determining the necessity of factor infusions before minor surgeries are unknown. AIM: We report the peri-operative hemostatic management and outcomes of emicizumab-treated PwHA and PwHA-I cases who underwent tooth extractions using our institutional protocol. METHODS: We retrospectively evaluated PwHA and PwHA-I who underwent tooth extraction with emicizumab prophylaxis at our institution. Local bleeding risk was assessed based on the method, number, and site of tooth extraction. Hemostasis was monitored peri-operatively by rotational thromboelastometry (ROTEM). Hemostatic agents and a mouth splint were used. RESULTS: Twenty-nine extractions (17 interventions) were performed in eight PwHA and two PwHA-I. Based on ROTEM, pre-operative factor infusions were used in ten PwHA and four PwHA-I interventions. Among nine low local bleeding risk interventions, three (33.3%) each received no infusions, one dose of factor infusion pre-operatively, and pre- and post-operative factor infusions. All eight high local bleeding risk interventions involved planned factor infusions. Absorbable hemostats were used in all extractions. A mouth splint was used in 21/25 (84.0%) PwHA and in 4/4 (100%) PwHA-I extractions. No post-extraction bleeding or thrombotic events occurred. CONCLUSIONS: Use of a systemic hemostatic treatment plan according to the local bleeding risk, peri-operative coagulation status assessment using ROTEM, filling the extraction socket with hemostats, and use of a mouth splint can achieve effective and safe hemostatic management in emicizumab-treated PwHA and PwHA-I.