Partial pulpotomy in teeth of young patients with reversible pulpitis, either using ProRoot MTA or Dycal, resulted in favourable treatment outcomes for up to 2 years. The incidence of unfavourable outcomes tended to be higher in teeth with pulp exposure areas larger than 5 mm(2) .

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The maximum bite force (MBF) appears to be different when measured at different jaw openings (e.g., Manns et al., 1979; Mackenna and Turker, 1983; Lindauer et al., 1993). However, the change could be related to a change in the bite direction. We have measured the MBF on incisors and its direction in three dimensions for different jaw openings in ten subjects. Surface electromyography (EMG) of anterior temporalis and masseter muscles on both sides was recorded simultaneously. The results showed that: (1) the average %MBF increased as the jaw was opened, reached a plateau between 14 and 28 mm of incisal separation, and then decreased at wider jaw openings; (2) the initial forward bite direction with respect to the mandibular occlusal plane shifted backwards during jaw opening; and (3) the activity of the masseter muscles declined and that of the temporalis muscles was largely unchanged, resulting in an increase of the ratio between the activity in temporalis and masseter muscles (T/M). There was a significant correlation between bite direction and jaw opening (r = 0.51, p < 0.001) and between T/M ratio and jaw opening (r = 0.56, p < 0.001). Based on comparative data, we have calculated sarcomere lengths while the jaw is opened and hypothesize that the average %MBF reaches its maximum when the sarcomeres in the masseter muscle achieve their optimum length. A plateau continues during further jaw opening, until those of temporalis reach their optimum length while those of masseter lengthen beyond their optimum length. The change in bite direction was attributed to either a change in the relation between upper and lower bite points as the jaw was opened or the gradual decline of masseter activity at larger openings.

Food texture affects chewing movement but it is not known if it also affects the chewing-side pattern. This study determined the chewing sides of three test foods with different textures during habitual chewing. Twenty healthy dental students (aged 20-24 years) chewed pieces of pork jerky, fresh asparagus and almonds on two separate sessions (1 week apart). In each session, each subject chewed 30 food specimens, 10 of the same food type, until swallowing while a video camera recorded the displacement of the chin with respect to the other two reference points vertically marked along the facial midline. A slow-speed video playback was used to identify the chewing side of each cycle. The chewing-side pattern (right preference, left preference, no preference) in each individual was determined statistically. The results showed that overall, 11 subjects did not have any side preference whereas six and three subjects preferred to chew on right or left sides respectively. The chewing-side pattern remained unchanged between three food types in about half of the subjects. When the same food was compared between 2 days, the chewing-side pattern of almonds was shown to be most reproducible (18 subjects). Unidentified cycles with little or no lateral displacement, labelled as bilateral, were observed more frequently near the end of the chewing sequence with more occurrences in almonds and jerky than asparagus (P < 0.01). It was suggested that chewing-side preference is not a fixed characteristic. Food texture seemed to influence the side preference and also the occurrence of bilateral cycles.

This study demonstrated that the LG mouthrinse significantly reduced oral malodour. This mouthrinse would be another alternative mouthrinse choice for prevention of malodour, plaque and gingivitis.