Investigating the anatomical relationship between the maxillary molars and the sinus floor in a Chinese population using cone-beam computed tomography

Abstract

Background: The anatomical relationship between the root apices of maxillary molars and the maxillary sinus floor (MSF) is important for the treatment of dental implantations and endodontic procedures. In this study, the detailed anatomical relationships between the root apices of maxillary molars and the MSF were studied in a Chinese population using CBCT. Methods: We collected the CBCT data files of patients who visited the stomatology outpatient clinic in Shanghai Fifth People's Hospital, Fudan University from January 1, 2017 to January 1, 2019 and measured the following items: the distance between the molar root apices and the MSF, the thickness of the mucosa and cortical bone of the MSF closest to the root apices, and the angle between the buccal and palatal roots. Results: The shortest distances between the root apices and the MSF were 1.57 ± 3.33 mm (the mesiobuccal root of the left second molar) and 1.61 ± 3.37 mm (the mesiobuccal root of the right second molar). Apical protrusion over the inferior wall of the sinus most often occurred in the mesiobuccal root of left second molar (frequency, 20.5%). The mucosa of the MSF was thinnest at the distobuccal root of the right second molar (1.52 ± 0.85 mm), the cortical bone of the MSF was thinnest at the mesiobuccal root of the right second molar (0.46 ± 0.28 mm), and the angle between the buccal and palatal roots ranged from 12.01°to 124.2°(42.36 ± 24.33°). Conclusions: Among the root apices of the maxillary molars, the mesiobuccal root apex of the left second molar was closest to the MSF, and it had the highest incidence of protrusion into the sinus. The unique anatomical relationship between the maxillary molars and the MSF in this Chinese population is critical for treatment planning for dental implantation or endodontic procedures.

Comparison of panoramic radiography and cone-beam computed tomography for assessing radiographic signs indicating root protrusion into the maxillary sinus

“…Shokri et al 34 reported that palatal root protrusion of maxillary molars was more common, and other studies reported that buccal root protrusion was more frequent. 24,25,33 In this study, buccal protrusion (B3P0, B3P1, B3P2) was more common than palatal root protrusion (B2P3) ( Table 5).…”

“…Many studies have reported that the type 0 relationship was most commonly observed. 20 22 23 25 28 32 Other studies showed that type 0 was most frequently observed in premolars and type 3 in molars. 16 18 19 26 34 Differences in reported sinus-root relationships might be due to ethnicity or methodology.…”

“…Several studies found that the mesiobuccal root of the maxillary second molar had the highest rate of protrusion into the maxillary sinus floor. 18 23 24 25 26 27 28 Other studies reported that the palatal root of the first molar most frequently protruded into the sinus. 19 29 30 31 32 Our results revealed that the type 3 (root protrusion into the sinus) configuration occurred most frequently in the mesiobuccal root of maxillary second molars (48.4%), while type 2 occurred most frequently in the palatal root of maxillary first molars (43.1%).…”

Intrusion of maxillary molar roots into the maxillary sinus in a sample of the Egyptian population using cone beam computed tomography

“…Zhang et al [28] studied the sinus-root relation in the Chinese population on a total of 800 right and left first and second molars using CBCT images without mentioning the employed software. They nearly agreed with the current study in the percenatge of the roots contacting the sinus floor where they reported 21.75% and this study reported 23.4%.…”

“…Many studies were concerned with analyzing the sinus-root relation in different populations including the Chinese [9,28], Iranian [11,26], Brazilian [29,30], Bulgarian [25], and Saudi Arabian [14] populations. The aim of this study is to assess the relationship between the roots of the maxillary molars and MSF in a sample of the Egyptian population-that was not involved in any previous study-using CBCT.…”