Estimation of Maximum Mouth Opening among Healthy Adults in Benin-City, Nigeria


  • Emeka Danielson ODAI, BDS, MSc, FMCDS), Department of Maxillofacial Surgery, University of Benin Teaching Hospital
  • Vincent Ifechukwukwu UGBOKO, B.Ch.D, FMCDS, FWACS


Adult, mouth opening, Nigerians


Objective: Maximum mouth opening is a simple clinical sign for the evaluation of acute conditions such as
orofacial infections and trauma, as well as chronic condition such as disorders of the temporomandibular
joint and tumours. The objective was to estimate maximal mouth opening of healthy adults.
Methods: This study was descriptive cross-sectional study that involve the measurement of mouth opening
from the mesio-incisal angle of the upper central incisor to the mesio-incisal angle of the corresponding lower
incisor. Two measurements were taken and the average recorded as the mouth opening for the subject. The
findings were analysed, using excel statistical software and results presented as simple bar charts.
Results: This study estimated the maximum mouth opening of 1331 individuals, made up of 643 (48.3%)
females and 688 (51.7%) males. The age ranged from 18-75 years and 621 (46.7%) were in their third decade
of life. There was a slight increase in mean maximal mouth opening from 18-20 year old group to 21-30 year
old group. Thereafter it declined gradually over the age groups to age 71 years and above. This trend is similar
in both gender: 18-20 year old group has 50.4mm and 50.7mm for females and males respectively. The
opening peaked in the 21-30 year old group; 50.5mm in females and 50.8mm in males and declined over the
age groups to 47.3mm in females and 47.6mm in males among those aged 71 years and above.
Conclusion: The findings in this present are in keeping with research findings elsewhere with age and gender
as factors that affect the maximum mouth opening of a population.
Keywords: Adult, mouth opening, Nigerians