Table 5. Differences in average anterior maxillary bone thickness between those aged above and below 45 years.

Level	Age	Mean (SD) mm	P value
Nasal spine	≤ 45 years	10.96 (2.27)	0.227
	> 45 years	10.35 (1.87)
Mid Incisive canal	≤ 45 years	6.93 (1.61)	<0.001
	> 45 years	5.28 (1.57)
Lower labial alveolus	≤ 45 years	6.43 (1.79)	<0.001
	> 45 years	4.71 (2.05)
Average bone thickness	≤ 45 years	8.13 (1.54)	<0.001
	> 45 years	6.80 (1.38)

* Independent t-test.