The MMLF is a consistent structure through which the sublingual artery enters the mandible [8, 11]. Perforation of the lingual plate by an implant drill poses a high risk of trauma to this vessel especially when the sublingual fossa is very pronounced because this vessel courses closely to the gland and fossa . When this artery is of a significant size, it is possible for 420 mL of blood to escape in 30 min leading to haematoma formation in the sublingual and submandibular spaces and leading to a compromise of the airway, by swelling and pushing of the tongue against the palate [5, 6, 14].
In a review of literature, Kalpidis et al.  concluded that when the haematoma is large and non-restrictive, extra-oral ligation of the feeder vessel should be applied. They did not establish the exact vessel that should be ligated to arrest bleeding. This was due to the differences in study findings on the prevalence of either the submental or the lingual artery as the main source of blood supply to the floor of the mouth. They thus suggested that in every case, the decision to ligate the facial or the lingual artery should be guided by the operator’s judgment.
In the present study, the sublingual artery appeared to originate mainly from the lingual artery (73.5 %) which was similar to the findings of Hofschneider et al.  (70 %, n = 17) and Loukas et al.  (73 %, n = 100). Our results however contradict those of previous studies that found the sublingual artery to originate from the lingual artery in 100 % of the cadavers dissected [2, 8, 9, 15]. The results of these previous studies should however be interpreted with caution because a majority of them examined one to two cadavers.
In a cadaveric study by Bavitz et al. , it was found that the submental artery was the main arterial blood supply to the floor of the mouth (53 %). Consequently, they suggested that the submental artery should be ligated first during extra-oral ligation to control haemorrhage in the floor of the mouth. Conversely, the sublingual artery appeared to originate from the submental artery in less than a quarter (17.6 %) of the cadavers in the present study. Our results are similar to those of Loukas et al.  (27 %).
The sublingual and submental arteries normally anastomose through their muscular mylohyoid branches . Loukas et al.  only identified anastomotic patterns between sublingual and submental arteries in 40 % of the dissected cadavers, with no case where the two terminate as a single sublingual artery. We found three (8.9 %) cases of an anastomotic branch of the submental and lingual artery forming a single sublingual artery just before entering the MMLF.
The distance from the MMLF to the inferior border of the mandible in our study ranged from 11.03 to 19.62 mm (mean = 15.58 mm ± 2.12 SD) with no statistically significant difference between the two genders (U = 46.000, P = 0.454). Oettle et al.  reported a distance ranging from 10.83 to 12.874 mm in a dry mandible study of both black and white South Africans. In their study, cone beam computed tomography (CBCT) was used to scan the mandibles. Their study did not find a statistically significant difference according to sex or race. Soft tissue remnants on the surface of the mandibles in our study could explain the higher morphometric measurements.
A critical buccal bone thickness of 2 mm is recommended to prevent vertical resorption . A minimum bone thickness of 6 mm would be required for successful placement of a standard-sized ±4-mm-diameter implant . In the current study, the bucco-lingual thickness of the mandible at the level of the MMLF ranged from 8.00 to 12.91 mm (mean = 10.89 mm ± 1.24 SD). Thus, all the cadavers in our study had adequate bone thickness needed for implant placement without perforating the lingual cortical plate and traumatizing the sublingual artery.
A notable limitation in our study was a lower number of female cadavers available. Most of these cadavers are unclaimed bodies from mortuaries in Kenya. Generally, there are more male unclaimed bodies than female bodies. The Mann-Whitney U test was therefore used to compare the two genders.