Antero-posterior mandibular position at different vertical levels for mandibular advancing device design

Abstract

Introduction Mandibular Advancement Devices (MAD) have been reported to be an alternative treatment to CPAP in moderate to severe obstructive sleep apnea (OSA) cases. The design of MAD has a major influence on its success rate on the patient, and design features that have an influence on efficacy, tolerance, and compliance. The aim of this study was to determine the range of mandibular protrusion at different vertical points; 2, 5, 8 and 11 mm in a young adult population. Methods Fifty two students aged 19 to 23 years (mean 21.3 ± 1.7; 29 females and 23 males), with full permanent dentition participated in the study. The absolute range of maximal mandibular protrusion and retrusion was measured (mm) with the use of the George Gauge. Descriptive statistics, ANOVA and paired t-test using SPSS were used. Results Range of mandibular advancement was possible to be determined for the 4 levels of vertical opening with the gauges: 2 mm fork mean mandibular advance 13,10 mm ± 0.604; 5 mm mean 11.98 mm ± 1.075; 8 mm mean 11.20 mm ± 1.369; 11 mm mean 9.87 mm ± 1.886. No significant differences were found between class I, II, and III. Conclusions There is an impact of increased inter-incisal distance of effective mandibular protrusion when constructing a MAD. As vertical dimension increases the mandible rotates posteriorly and places itself in a more retrusive location, and the range of mandibular advancement reduces (0.3 mm for every 1 mm of vertical increase).

Effectiveness of different mandibular advancement device designs in obstructive sleep apnoea therapy: A systematic review of randomised controlled trials with meta‐analysis

“…The present findings on MAD efficacy could be due to a lower vertical increase provided by the MB with a consequent minor post‐rotation of the mandible and a greater range of mandibular advancement. To this regard, despite Pitsis and coworkers 47 concluded that vertical opening does not influence the treatment efficacy, in a recent investigation Mayoral and coworkers 72 showed that as vertical dimension increases, the mandible rotates posteriorly, placing itself in a more retrusive location that decreases the range of mandibular advancement: as such the efficacy of the therapy could be reduced. Another hypothesis that could explain the major efficacy of MB could be attributable to the fact that it does not allow any mandibular movement, the patient is given a fixed position.…”

Force Distribution of a Novel Core-Reinforced Multilayered Mandibular Advancement Device

“…Regarding the design of MADs, most studies focused on the features of mono-bloc versus duo-bloc or custom-made versus prefabricated. There is no definite consensus on which design is the most effective, and a wide variety of vertical dimension of MADs were reported ranging from 1–14 mm [ 27 , 28 ]. The amount of bite opening should be minimized in the aspect of patient tolerance and treatment efficiency.…”

“…The amount of bite opening should be minimized in the aspect of patient tolerance and treatment efficiency. Mayoral et al [ 28 ] evaluated 4 levels of vertical opening from 2 mm to 11 mm and showed that increase of vertical dimension caused retrusive position of the mandible. Similarly, a recent meta-analysis showed that the mono-bloc type showed a greater reduction in apnea/hypopnea index (AHI), and an increase in oxygen saturation compared to the effects of the duo-bloc type [ 29 ].…”

Craniofacial morphology/phenotypes influence on mandibular range of movement in the design of a mandibular advancement device

“…The mandibular position and related structures are influenced by and participate in patency of the pharynx and the complex mechanisms that lead to obstruction of the upper airway [ 16 ]. Mandible opening during sleep causes mandibular posterior rotation [ 27 ] and is associated with a reduced cross-sectional area of the lumen [ 16 ], reduced mechanical efficiency of the pharyngeal dilator muscles [ 24 ] and increased resistance and collapsibility of the upper airway [ 14 , 21 , 28 ]. All of which may contribute to sleep-related breathing abnormalities.…”